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Ouédraogo A, Pouplin JNN, Mukaka M, Kaendiao T, Ruecker A, Millet P, Vallet T, Ruiz F, Sirima SB, Taylor WR. Anti-infectivity efficacy and pharmacokinetics of WHO recommended single low-dose primaquine in children with acute Plasmodium falciparum in Burkina Faso: study protocol. Trials 2024; 25:583. [PMID: 39227956 DOI: 10.1186/s13063-024-08428-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 08/26/2024] [Indexed: 09/05/2024] Open
Abstract
BACKGROUND Primaquine (PQ) has activity against mature P. falciparum gametocytes and proven transmission blocking efficacy (TBE) between humans and mosquitoes. WHO formerly recommended a single transmission blocking dose of 0.75 mg/kg but this was little used. Then in 2012, faced with the emergence of artemisinin-resistant P. falciparum (ARPf) in SE Asia, the WHO recommended a lower dose of 0.25 mg/kg to be added to artemisinin-based combination therapy in falciparum-infected patients in low transmission areas. This dose was considered safe in glucose-6-phosphate dehydrogenase deficiency (G6PDd) and not requiring G6PD testing. Subsequent single low-dose primaquine (SLDPQ) studies have demonstrated safety in different G6PD variants. Dosing remains challenging in children under the age of 5 because of the paucity of PQ pharmacokinetic (PK) data. We plan to assess the anti-infectivity efficacy of SLDPQ using an allometrically scaled, weight-based regimen, with a target dose of 0.25 mg/kg, in children with acute uncomplicated falciparum malaria. METHODS This study is an open label, randomised 1:1, phase IIb study to assess TBE, tolerability, pharmacokinetics and acceptability of artesunate pyronaridine (ASPYR) administered alone or combined with SLDPQ in 56 Burkinabe children aged ≥ 6 months- < 5 years, with uncomplicated P. falciparum and a haemoglobin (Hb) concentration of ≥ 5 g/dL. We will assess TBE, using direct membrane feeding assays (DMFA), and further investigate PQ pharmacokinetics, adverse events, Hb dynamics, G6PD, sickle cells, thalassaemia and cytochrome 2D6 (CYP2D6) status, acceptability of flavoured PQ [CAST-ClinSearch Acceptability Score Test®], and the population's knowledge, attitude and practices on malaria. EXPECTED RESULTS AND DISCUSSION We expect children to accept tablets, confirm the TBE and gametocytocidal effects of SLDPQ and then construct a PK infectivity model (including age, sex, baseline Hb, G6PD and CYP2D6 status) to define the dose response TBE relationship that may lead to fine tuning our SLDPQ regimen. Our study will complement others that have examined factors associated with Hb dynamics and PQ PK. It will provide much needed, high-quality evidence of SLDPQ in sick African children and provide reassurance that SLDPQ should be used as a strategy against emerging ARPf in Africa. TRIAL REGISTRATION ISRCTN16297951. Registered on September 26, 2021.
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Affiliation(s)
- Alphonse Ouédraogo
- Groupe de Recherche Action en Santé (GRAS), 06 BP 10248, Ouagadougou 06, Burkina Faso.
| | | | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Thoopmanee Kaendiao
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
| | - Andrea Ruecker
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Pascal Millet
- ReMeD, 21bis Avenue du Commandant de L'Herminier, Saint-Nazaire, 44 600, France
| | - Thibaut Vallet
- ClinSearch, 110 Avenue Pierre Brossolette, Malakoff, 92240, France
| | - Fabrice Ruiz
- ClinSearch, 110 Avenue Pierre Brossolette, Malakoff, 92240, France
| | - Sodiomon B Sirima
- Groupe de Recherche Action en Santé (GRAS), 06 BP 10248, Ouagadougou 06, Burkina Faso
| | - Walter R Taylor
- Mahidol Oxford Tropical Medicine Research Unit (MORU), 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Gomes F, Ribeiro AC, Sanches GS, Borges HS, Takahashi LAU, Daniel-Ribeiro CT, Tedesco AC, Nascimento JWL, Carvalho LJM. A nanochitosan-D-galactose formulation increases the accumulation of primaquine in the liver. Antimicrob Agents Chemother 2024; 68:e0091523. [PMID: 38517190 PMCID: PMC11064505 DOI: 10.1128/aac.00915-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/25/2024] [Indexed: 03/23/2024] Open
Abstract
Primaquine is the mainstream antimalarial drug to prevent Plasmodium vivax relapses. However, this drug can induce hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency. Nanostructure formulations of primaquine loaded with D-galactose were used as a strategy to target the drug to the liver and decrease the hemolytic risks. Nanoemulsion (NE-Pq) and nanochitosan (NQ-Pq) formulations of primaquine diphosphate containing D-galactose were prepared and characterized by their physicochemistry properties. Pharmacokinetic and biodistribution studies were conducted using Swiss Webster mice. A single dose of 10 mg/kg of each nanoformulation or free primaquine solution was administered by gavage to the animals, which were killed at 0.5, 1, 2, 4, 8, and 24 hours. Blood samples and tissues were collected, processed, and analyzed by high-performance liquid chromatography. The nanoformulation showed sizes around 200 nm (NE-Pq) and 400 nm (NQ-Pq) and physicochemical stability for over 30 days. Free primaquine solution achieved higher primaquine Cmax in the liver than NE-Pq or NQ-Pq at 0.5 hours. However, the half-life and mean residence time (MRT) of primaquine in the liver were three times higher with the NQ-Pq formulation than with free primaquine, and the volume distribution was four times higher. Conversely, primaquine's half-life, MRT, and volume distribution in the plasma were lower for NQ-Pq than for free primaquine. NE-Pq, on the other hand, accumulated more in the lungs but not in the liver. Galactose-coated primaquine nanochitosan formulation showed increased drug targeting to the liver compared to free primaquine and may represent a promising strategy for a more efficient and safer radical cure for vivax malaria.
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Affiliation(s)
- F. Gomes
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - A. C. Ribeiro
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
- Department of Pharmacology (LaFaCE) - ICB, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Minas Gerais, Brazil
| | - G. S. Sanches
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - H. S. Borges
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - L. A. U. Takahashi
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - C. T. Daniel-Ribeiro
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
| | - A. C. Tedesco
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering - Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - J. W. L. Nascimento
- Department of Pharmacology (LaFaCE) - ICB, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Minas Gerais, Brazil
| | - L. J. M. Carvalho
- Laboratory of Malaria Research, Oswaldo Cruz Institute (IOC/Fiocruz), Reference Center for Malaria Research, Diagnosis and Training, Rio de Janeiro, Brazil
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3
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Feitosa LM, Franca RRF, Ferreira MDLG, Aguiar ACC, de Souza GE, Maluf SEC, de Souza JO, Zapata L, Duarte D, Morais I, Nogueira F, Nonato MC, Pinheiro LCS, Guido RVC, Boechat N. Discovery of new piperaquine hybrid analogs linked by triazolopyrimidine and pyrazolopyrimidine scaffolds with antiplasmodial and transmission blocking activities. Eur J Med Chem 2024; 267:116163. [PMID: 38290351 DOI: 10.1016/j.ejmech.2024.116163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 02/01/2024]
Abstract
The World Health Organization (WHO) estimated that there were 247 million malaria cases in 2021 worldwide, representing an increase in 2 million cases compared to 2020. The urgent need for the development of new antimalarials is underscored by specific criteria, including the requirement of new modes of action that avoid cross-drug resistance, the ability to provide single-dose cures, and efficacy against both assexual and sexual blood stages. Motivated by the promising results obtained from our research group with [1,2,4]triazolo[1,5-a]pyrimidine and pyrazolo[1,5-a]pyrimidine derivatives, we selected these molecular scaffolds as the foundation for designing two new series of piperaquine analogs as potential antimalarial candidates. The initial series of hybrids was designed by substituting one quinolinic ring of piperaquine with the 1,2,4-triazolo[1,5-a]pyrimidine or pyrazolo[1,5-a]pyrimidine nucleus. To connect the heterocyclic systems, spacers with 3, 4, or 7 methylene carbons were introduced at the 4 position of the quinoline. In the second series, we used piperazine as a spacer to link the 1,2,4-triazolo[1,5-a]pyrimidine or pyrazolo[1,5-a]pyrimidine group to the quinoline core, effectively merging both pharmacophoric groups via a rigid spacer. Our research efforts yielded promising compounds characterized by low cytotoxicity and selectivity indices exceeding 1570. These compounds displayed potent in vitro inhibitory activity in the low nanomolar range against the erythrocytic form of the parasite, encompassing both susceptible and resistant strains. Notably, these compounds did not show cross-resistance with either chloroquine or established P. falciparum inhibitors. Even though they share a pyrazolo- or triazolo-pyrimidine core, enzymatic inhibition assays revealed that these compounds had minimal inhibitory effects on PfDHODH, indicating a distinct mode of action unrelated to targeting this enzyme. We further assessed the compounds' potential to interfere with gametocyte and ookinete infectivity using mature P. falciparum gametocytes cultured in vitro. Four compounds demonstrated significant gametocyte inhibition ranging from 58 % to 86 %, suggesting potential transmission blocking activity. Finally, we evaluated the druggability of these new compounds using in silico methods, and the results indicated that these analogs had favorable physicochemical and ADME (absorption, distribution, metabolism, and excretion) properties. In summary, our research has successfully identified and characterized new piperaquine analogs based on [1,2,4]triazolo[1,5-a]pyrimidine and pyrazolo[1,5-a]pyrimidine scaffolds and has demonstrated their potential as promising candidates for the development of antimalarial drugs with distinct mechanisms of action, considerable selectivity, and P. falciparum transmission blocking activity.
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Affiliation(s)
- Livia M Feitosa
- Fundacao Oswaldo Cruz, Instituto de Tecnologia em Farmacos, Farmanguinhos - FIOCRUZ, Laboratorio de Sintese de Farmacos. Rua Sizenando Nabuco 100, Manguinhos, 21041-250, Rio de Janeiro, RJ, Brazil; Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Programa de Pós Graduação em Farmacologia e Química Medicinal, Rio de Janeiro, RJ, Brazil
| | - Rodolfo Rodrigo F Franca
- Fundacao Oswaldo Cruz, Instituto de Tecnologia em Farmacos, Farmanguinhos - FIOCRUZ, Laboratorio de Sintese de Farmacos. Rua Sizenando Nabuco 100, Manguinhos, 21041-250, Rio de Janeiro, RJ, Brazil
| | - Maria de Lourdes G Ferreira
- Fundacao Oswaldo Cruz, Instituto de Tecnologia em Farmacos, Farmanguinhos - FIOCRUZ, Laboratorio de Sintese de Farmacos. Rua Sizenando Nabuco 100, Manguinhos, 21041-250, Rio de Janeiro, RJ, Brazil
| | - Anna C C Aguiar
- Universidade de São Paulo, Instituto de Física de São Carlos, Av. João Dagnone, 1.100, Jd. Santa Angelina, São Carlos, SP, Brazil; Universidade Federal de São Paulo, Departamento de Microbiologia, Imunologia e Parasitologia. Rua Botucatu 862, Vila Clementino, 04023-062, São Paulo, SP, Brazil
| | - Guilherme E de Souza
- Universidade de São Paulo, Instituto de Física de São Carlos, Av. João Dagnone, 1.100, Jd. Santa Angelina, São Carlos, SP, Brazil
| | - Sarah El Chamy Maluf
- Universidade de São Paulo, Instituto de Física de São Carlos, Av. João Dagnone, 1.100, Jd. Santa Angelina, São Carlos, SP, Brazil
| | - Juliana O de Souza
- Universidade de São Paulo, Instituto de Física de São Carlos, Av. João Dagnone, 1.100, Jd. Santa Angelina, São Carlos, SP, Brazil
| | - Luana Zapata
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências BioMoleculares, Laboratório de Cristalografia de Proteínas, Avenida do Café s/n Monte Alegre, 14040-903 Ribeirão Preto, SP, Brazil; Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Center for the Research and Advancement of Fragments and Molecular Targets (CRAFT), Avenida do Café s/n Monte Alegre, 14040-903 Ribeirão Preto, SP, Brazil
| | - Denise Duarte
- Universidade NOVA de Lisboa, UNL, Global Health and Tropical Medicine, GHTM, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical, IHMT, Rua da Junqueira 100, 1349-008 Lisboa, Portugal
| | - Ines Morais
- Universidade NOVA de Lisboa, UNL, Global Health and Tropical Medicine, GHTM, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical, IHMT, Rua da Junqueira 100, 1349-008 Lisboa, Portugal
| | - Fatima Nogueira
- Universidade NOVA de Lisboa, UNL, Global Health and Tropical Medicine, GHTM, Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical, IHMT, Rua da Junqueira 100, 1349-008 Lisboa, Portugal.
| | - M Cristina Nonato
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências BioMoleculares, Laboratório de Cristalografia de Proteínas, Avenida do Café s/n Monte Alegre, 14040-903 Ribeirão Preto, SP, Brazil; Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Center for the Research and Advancement of Fragments and Molecular Targets (CRAFT), Avenida do Café s/n Monte Alegre, 14040-903 Ribeirão Preto, SP, Brazil.
| | - Luiz C S Pinheiro
- Fundacao Oswaldo Cruz, Instituto de Tecnologia em Farmacos, Farmanguinhos - FIOCRUZ, Laboratorio de Sintese de Farmacos. Rua Sizenando Nabuco 100, Manguinhos, 21041-250, Rio de Janeiro, RJ, Brazil; Universidade do Estado do Rio de Janeiro, UERJ, Faculdade de Formação de Professores, Departamento de Ciências, Rua Dr. Francisco Portela, 1470, Patronato, 24435-005, São Gonçalo, RJ, Brazil.
| | - Rafael V C Guido
- Universidade de São Paulo, Instituto de Física de São Carlos, Av. João Dagnone, 1.100, Jd. Santa Angelina, São Carlos, SP, Brazil.
| | - Nubia Boechat
- Fundacao Oswaldo Cruz, Instituto de Tecnologia em Farmacos, Farmanguinhos - FIOCRUZ, Laboratorio de Sintese de Farmacos. Rua Sizenando Nabuco 100, Manguinhos, 21041-250, Rio de Janeiro, RJ, Brazil; Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Programa de Pós Graduação em Farmacologia e Química Medicinal, Rio de Janeiro, RJ, Brazil.
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Manjurano A, Lyimo E, Kishamawe C, Omolo J, Mosha J, Donald M, Kazyoba P, Kapiga S, Changalucha J. Prevalence of G6PD deficiency and submicroscopic malaria parasites carriage in malaria hotspot area in Northwest, Tanzania. Malar J 2023; 22:372. [PMID: 38062464 PMCID: PMC10704740 DOI: 10.1186/s12936-023-04801-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND The use of primaquine for mass drug administration (MDA) is being considered as a key strategy for malaria elimination. In addition to being the only drug active against the dormant and relapsing forms of Plasmodium vivax, primaquine is the sole potent drug against mature/infectious Plasmodium falciparum gametocytes. It may prevent onward transmission and help contain the spread of artemisinin resistance. However, higher dose of primaquine is associated with the risk of acute haemolytic anaemia in individuals with a deficiency in glucose-6-phosphate dehydrogenase. In many P. falciparum endemic areas there is paucity of information about the distribution of individuals at risk of primaquine-induced haemolysis at higher dose 45 mg of primaquine. METHODS A retrospective cross-sectional study was carried out using archived samples to establish the prevalence of G6PD deficiency in a malaria hotspot area in Misungwi district, located in Mwanza region, Tanzania. Blood samples collected from individuals recruited between August and November 2010 were genotyped for G6PD deficiency and submicroscopic parasites carriage using polymerase chain reaction. RESULTS A total of 263 individuals aged between 0 and 87 were recruited. The overall prevalence of the X-linked G6PD A- mutation was 83.7% (220/263) wild type, 8% (21/263) heterozygous and 8.4% (22/263) homozygous or hemizygous. Although, assessment of the enzymatic activity to assign the phenotypes according to severity and clinical manifestation as per WHO was not carried out, the overall genotype and allele frequency for the G6PD deficiency was 16.4% and 13. 2%, respectively. There was no statistically significant difference in among the different G6PD genotypes (p > 0.05). Out of 248 samples analysed for submicroscopic parasites carriage, 58.1% (144/248) were P. falciparum positive by PCR. G6PD heterozygous deficiency were associated with carriage of submicroscopic P. falciparum (p = 0.029). CONCLUSIONS This study showed that 16.4% of the population in this part of North-western Tanzania carry the G6PD A- mutation, within the range of 15-32% seen in other parts of Africa. G6PD gene mutation is widespread and heterogeneous across the study area where primaquine would be valuable for malaria control and elimination. The maps and population estimates presented here reflect potential risk of higher dose of primaquine being associated with the risk of acute haemolytic anaemia (AHA) in individuals with a deficiency in glucose-6-phosphate dehydrogenase and call further research on mapping of G6PD deficiency in Tanzania. Therefore, screening and education programmes for G6PD deficiency is warranted in a programme of malaria elimination using a higher primaquine dose.
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Affiliation(s)
| | - Eric Lyimo
- Mwanza Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Coleman Kishamawe
- Mwanza Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Justin Omolo
- Mabibo Centre, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Jacklin Mosha
- Mwanza Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Miyaye Donald
- Mwanza Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Paul Kazyoba
- Mabibo Centre, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Saidi Kapiga
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - John Changalucha
- Mwanza Centre, National Institute for Medical Research, Mwanza, Tanzania
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
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Onyamboko MA, Olupot-Olupot P, Were W, Namayanja C, Onyas P, Titin H, Baseke J, Muhindo R, Kayembe DK, Ndjowo PO, Basara BB, Okalebo CB, Williams TN, Uyoga S, Taya C, Bamisaiye A, Fanello C, Maitland K, Day NPJ, Taylor WRJ, Mukaka M. Factors affecting haemoglobin dynamics in African children with acute uncomplicated Plasmodium falciparum malaria treated with single low-dose primaquine or placebo. BMC Med 2023; 21:397. [PMID: 37858129 PMCID: PMC10588240 DOI: 10.1186/s12916-023-03105-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/05/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Single low-dose primaquine (SLDPQ) effectively blocks the transmission of Plasmodium falciparum malaria, but anxiety remains regarding its haemolytic potential in patients with glucose-6-phopshate dehydrogenase (G6PD) deficiency. We, therefore, examined the independent effects of several factors on haemoglobin (Hb) dynamics in falciparum-infected children with a particular interest in SLDPQ and G6PD status. METHODS This randomised, double-blind, placebo-controlled, safety trial was conducted in Congolese and Ugandan children aged 6 months-11 years with acute uncomplicated P. falciparum and day (D) 0 Hbs ≥ 6 g/dL who were treated with age-dosed SLDPQ/placebo and weight-dosed artemether lumefantrine (AL) or dihydroartemisinin piperaquine (DHAPP). Genotyping defined G6PD (G6PD c.202T allele), haemoglobin S (HbS), and α-thalassaemia status. Multivariable linear and logistic regression assessed factor independence for continuous Hb parameters and Hb recovery (D42 Hb > D0 Hb), respectively. RESULTS One thousand one hundred thirty-seven children, whose median age was 5 years, were randomised to receive: AL + SLDPQ (n = 286), AL + placebo (286), DHAPP + SLDPQ (283), and DHAPP + placebo (282). By G6PD status, 284 were G6PD deficient (239 hemizygous males, 45 homozygous females), 119 were heterozygous females, 418 and 299 were normal males and females, respectively, and 17 were of unknown status. The mean D0 Hb was 10.6 (SD 1.6) g/dL and was lower in younger children with longer illnesses, lower mid-upper arm circumferences, splenomegaly, and α-thalassaemia trait, who were either G6PDd or heterozygous females. The initial fractional fall in Hb was greater in younger children with higher D0 Hbs and D0 parasitaemias and longer illnesses but less in sickle cell trait. Older G6PDd children with lower starting Hbs and greater factional falls were more likely to achieve Hb recovery, whilst lower D42 Hb concentrations were associated with younger G6PD normal children with lower fractional falls, sickle cell disease, α-thalassaemia silent carrier and trait, and late treatment failures. Ten blood transfusions were given in the first week (5 SLDPQ, 5 placebo). CONCLUSIONS In these falciparum-infected African children, posttreatment Hb changes were unaffected by SLDPQ, and G6PDd patients had favourable posttreatment Hb changes and a higher probability of Hb recovery. These reassuring findings support SLDPQ deployment without G6PD screening in Africa. TRIAL REGISTRATION The trial is registered at ISRCTN 11594437.
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Affiliation(s)
- Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Peter Olupot-Olupot
- Busitema University, P.O. Box 1460, Mbale, Uganda
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Winifred Were
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Cate Namayanja
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Peter Onyas
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Harriet Titin
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Joy Baseke
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Rita Muhindo
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Daddy K Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Pauline O Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Benjamin B Basara
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | | | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College London, London, SW7 2AS, UK
| | - Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Chiraporn Taya
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Adeola Bamisaiye
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Caterina Fanello
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College London, London, SW7 2AS, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Walter R J Taylor
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Taylor WR, Olupot-Olupot P, Onyamboko MA, Peerawaranun P, Weere W, Namayanja C, Onyas P, Titin H, Baseke J, Muhindo R, Kayembe DK, Ndjowo PO, Basara BB, Bongo GS, Okalebo CB, Abongo G, Uyoga S, Williams TN, Taya C, Dhorda M, Tarning J, Dondorp AM, Waithira N, Fanello C, Maitland K, Mukaka M, Day NJP. Safety of age-dosed, single low-dose primaquine in children with glucose-6-phosphate dehydrogenase deficiency who are infected with Plasmodium falciparum in Uganda and the Democratic Republic of the Congo: a randomised, double-blind, placebo-controlled, non-inferiority trial. THE LANCET. INFECTIOUS DISEASES 2023; 23:471-483. [PMID: 36462528 DOI: 10.1016/s1473-3099(22)00658-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND WHO recommends gametocytocidal, single low-dose primaquine for blocking the transmission of Plasmodium falciparum; however, safety concerns have hampered the implementation of this strategy in sub-Saharan Africa. We aimed to investigate the safety of age-dosed, single low-dose primaquine in children from Uganda and the Democratic Republic of the Congo. METHODS We conducted this randomised, double-blind, placebo-controlled, non-inferiority trial at the Mbale Regional Referral Hospital, Mbale, Uganda, and the Kinshasa Mahidol Oxford Research Unit, Kinshasa, Democratic Republic of the Congo. Children aged between 6 months and 11 years with acute uncomplicated P falciparum infection and haemoglobin concentrations of at least 6 g/dL were enrolled. Patients were excluded if they had a comorbid illness requiring inpatient treatment, were taking haemolysing drugs for glucose-6-phosphate dehydrogenase (G6PD) deficiency, were allergic to the study drugs, or were enrolled in another clinical trial. G6PD status was defined by genotyping for the G6PD c.202T allele, the cause of the G6PD-deficient A- variant. Participants were randomly assigned (1:1) to receive single low-dose primaquine combined with either artemether-lumefantrine or dihydroartemisinin-piperaquine, dosed by bodyweight. Randomisation was stratified by age and G6PD status. The primary endpoint was the development of profound (haemoglobin <4 g/dL) or severe (haemoglobin <5 g/dL) anaemia with severity features, within 21 days of treatment. Analysis was by intention to treat. The sample size assumed an incidence of 1·5% in the placebo group and a 3% non-inferiority margin. The trial is registered at ISRCTN, 11594437, and is closed to new participants. FINDINGS Participants were recruited at the Mbale Regional Referral Hospital between Dec 18, 2017, and Oct 7, 2019, and at the Kinshasa Mahidol Oxford Research Unit between July 17, 2017, and Oct 5, 2019. 4620 patients were assessed for eligibility. 3483 participants were excluded, most owing to negative rapid diagnostic test or negative malaria slide (n=2982). 1137 children with a median age of 5 years were enrolled and randomly assigned (286 to the artemether-lumefantrine plus single low-dose primaquine group, 286 to the artemether-lumefantrine plus placebo group, 283 to the dihydroartemisinin-piperaquine plus single low-dose primaquine group, and 282 to the dihydroartemisinin-piperaquine plus placebo group). Genotyping of G6PD identified 239 G6PD-c.202T hemizygous males and 45 G6PD-c.202T homozygous females (defining the G6PD-deficient group), 119 heterozygous females, 418 G6PD-c.202C normal males and 299 G6PD-c.202C normal females (defining the non-G6PD-deficient group), and 17 children of unknown status. 67 patients were lost to follow-up and four patients withdrew during the study-these numbers were similar between groups. No participants developed profound anaemia and three developed severe anaemia: from the G6PD-deficient group, none (0%) of 133 patients who received placebo and one (0·66%) of 151 patients who received primaquine (difference -0·66%, 95% CI -1·96 to 0·63; p=0·35); and from the non-G6PD-deficient group, one (0·23%) of 430 patients who received placebo and one (0·25%) of 407 patients who received primaquine (-0·014%, -0·68 to 0·65; p=0·97). INTERPRETATION Gametocytocidal, age-dosed, single low-dose primaquine was well tolerated in children from Uganda and the Democratic Republic of the Congo who were infected with P falciparum, and the safety profile of this treatment was similar to that of the placebo. These data support the wider implementation of single low-dose primaquine in Africa. FUNDING UK Government Department for International Development, UK Medical Research Council, UK National Institute for Health Research, and the Wellcome Trust Joint Global Health Trials Scheme.
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Affiliation(s)
- Walter R Taylor
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Peter Olupot-Olupot
- Mbale Clinical Research Institute, Mbale, Uganda; Department of Public Health, Busitema University, Mbale, Uganda
| | - Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Pimnara Peerawaranun
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
| | | | | | - Peter Onyas
- Mbale Clinical Research Institute, Mbale, Uganda
| | | | - Joy Baseke
- Department of Public Health, Busitema University, Mbale, Uganda
| | - Rita Muhindo
- Mbale Clinical Research Institute, Mbale, Uganda
| | - Daddy K Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Pauline O Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Benjamin B Basara
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Georgette S Bongo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | | - Grace Abongo
- Mbale Clinical Research Institute, Mbale, Uganda
| | - Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Institute of Global Health Innovation, Imperial College London, London, UK
| | - Chiraporn Taya
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
| | - Mehul Dhorda
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Naomi Waithira
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Caterina Fanello
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Institute of Global Health Innovation, Imperial College London, London, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J P Day
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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A Novel Ex Vivo Drug Assay for Assessing the Transmission-Blocking Activity of Compounds on Field-Isolated Plasmodium falciparum Gametocytes. Antimicrob Agents Chemother 2022; 66:e0100122. [PMID: 36321830 PMCID: PMC9764978 DOI: 10.1128/aac.01001-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The discovery and development of transmission-blocking therapies challenge malaria elimination and necessitate standard and reproducible bioassays to measure the blocking properties of antimalarial drugs and candidate compounds. Most of the current bioassays evaluating the transmission-blocking activity of compounds rely on laboratory-adapted Plasmodium strains. Transmission-blocking data from clinical gametocyte isolates could help select novel transmission-blocking candidates for further development. Using freshly collected Plasmodium falciparum gametocytes from asymptomatic individuals, we first optimized ex vivo culture conditions to improve gametocyte viability and infectiousness by testing several culture parameters. We next pre-exposed ex vivo field-isolated gametocytes to chloroquine, dihydroartemisinin, primaquine, KDU691, GNF179, and oryzalin for 48 h prior to direct membrane feeding. We measured the activity of the drug on the ability of gametocytes to resume the sexual life cycle in Anopheles after drug exposure. Using 57 blood samples collected from Malian volunteers aged 6 to 15 years, we demonstrate that the infectivity of freshly collected field gametocytes can be preserved and improved ex vivo in a culture medium supplemented with 10% horse serum at 4% hematocrit for 48 h. Moreover, our optimized drug assay displays the weak transmission-blocking activity of chloroquine and dihydroartemisinin, while primaquine and oryzalin exhibited a transmission-blocking activity of ~50% at 1 μM. KDU691 and GNF179 both interrupted Plasmodium transmission at 1 μM and 5 nM, respectively. This new approach, if implemented, has the potential to accelerate the screening of compounds with transmission-blocking activity.
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8
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Plasmodium vivax malaria serological exposure markers: Assessing the degree and implications of cross-reactivity with P. knowlesi. Cell Rep Med 2022; 3:100662. [PMID: 35732155 PMCID: PMC9245056 DOI: 10.1016/j.xcrm.2022.100662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/22/2022] [Accepted: 05/26/2022] [Indexed: 11/21/2022]
Abstract
Serological markers are a promising tool for surveillance and targeted interventions for Plasmodium vivax malaria. P. vivax is closely related to the zoonotic parasite P. knowlesi, which also infects humans. P. vivax and P. knowlesi are co-endemic across much of South East Asia, making it important to design serological markers that minimize cross-reactivity in this region. To determine the degree of IgG cross-reactivity against a panel of P. vivax serological markers, we assayed samples from human patients with P. knowlesi malaria. IgG antibody reactivity is high against P. vivax proteins with high sequence identity with their P. knowlesi ortholog. IgG reactivity peaks at 7 days post-P. knowlesi infection and is short-lived, with minimal responses 1 year post-infection. We designed a panel of eight P. vivax proteins with low levels of cross-reactivity with P. knowlesi. This panel can accurately classify recent P. vivax infections while reducing misclassification of recent P. knowlesi infections.
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Mwaiswelo RO, Ngasala B, Msolo D, Kweka E, Mmbando BP, Mårtensson A. A single low dose of primaquine is safe and sufficient to reduce transmission of Plasmodium falciparum gametocytes regardless of cytochrome P450 2D6 enzyme activity in Bagamoyo district, Tanzania. Malar J 2022; 21:84. [PMID: 35279143 PMCID: PMC8917764 DOI: 10.1186/s12936-022-04100-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/23/2022] [Indexed: 11/10/2022] Open
Abstract
Background Primaquine is a pro-drug and its active metabolite is potent against mature Plasmodium falciparum gametocytes. Primaquine is metabolized by a highly polymorphic cytochrome P450 2D6 (CYP2D6) enzyme. Mutations in the gene encoding this enzyme may lead to impaired primaquine activity. This study assessed if 0.25 mg/kg single-dose primaquine is safe and sufficient to reduce transmission of gametocytes in individuals with no, reduced, or increased CYP2D6 enzyme activity. Methods Between June 2019 and January 2020 children aged 1–10 years, attending at Yombo dispensary, Bagamoyo district, with confirmed microcopy-determined uncomplicated P. falciparum malaria were enrolled in the study. The enrolled patients were treated with a standard artemether-lumefantrine regimen plus 0.25 mg/kg single-dose primaquine and followed up for 28 days for clinical and laboratory assessment. Primaquine was administered with the first dose of artemether-lumefantrine. Safety assessment involved direct questioning and recording of the nature and incidence of clinical signs and symptoms, and measurement of haemoglobin (Hb) concentration. Blood samples collected from 100 patients were used for assessment of post-treatment infectiousness on day 7 using mosquito membrane feeding assays. Molecular methods were used to determine CYP2D6 and glucose-6-phosphate dehydrogenase (G6PD) status. The primary outcome was the safety of 0.25 mg/kg single-dose primaquine based on CYP2D6 status. Results In total, 157 children [median age 6.4 (Interquartile range 4.0–8.2) years] were recruited, of whom 21.0% (33/157) and 12.7% (20/157) had reduced CYP2D6 and deficient G6PD activity, respectively. Day 3 mean absolute Hb concentration reduction was 1.50 g/dL [95% confidence interval (CI) 1.10–1.90] and 1.51 g/dL (95% CI 1.31–1.71) in reduced and normal CYP2D6 patients, respectively (t = 0.012, p = 0.990). The day 3 mean absolute Hb concentration reduction in G6PD deficient, G6PD normal and heterozygous female was 1.82 g/dL (95% CI 1.32–2.32), 1.48 g/dL (95% CI 1.30–1.67) and 1.47 g/dL (95% CI 0.76–2.18), respectively (F = 0.838, p = 0.435). Sixteen percent (16/98) of the patients each infected at least one mosquito on day 7, and of these, 10.0% (2/20) and 17.9% (14/78) had reduced and normal CYP2D6 enzyme activity, respectively (x2 = 0.736, p = 0.513). Conclusion Single-dose 0.25 mg/kg primaquine was safe and sufficient for reducing transmission of P. falciparum gametocytes regardless of CYP2D6 or G6PD status. Trial registration Study registration number: NCT03352843. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04100-1.
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10
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Orwa TO, Mbogo RW, Luboobi LS. Optimal control analysis of hepatocytic-erythrocytic dynamics of Plasmodium falciparum malaria. Infect Dis Model 2022; 7:82-108. [PMID: 34977436 PMCID: PMC8686038 DOI: 10.1016/j.idm.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022] Open
Abstract
This paper presents an in-host malaria model subject to anti-malarial drug treatment and malaria vaccine antigens combinations. Pontryagin's Maximum Principle is applied to establish optimal control strategies against infected erythrocytes, infected hepatocytes and malaria parasites. Results from numerical simulation reveal that a combination of pre-erythrocytic vaccine antigen, blood schizontocide and gametocytocide drugs would offer the best strategy to eradicate clinical P. falciparum malaria. Sensitivity analysis, further reveal that the efficacy of blood schizontocides and blood stage vaccines are crucial in the control of clinical malaria infection. Futhermore, we found that an effective blood schizontocide should be used alongside efficacious blood stage vaccine for rapid eradication of infective malaria parasites. The authors hope that the results of this study will help accelerate malaria elimination efforts by combining malaria vaccines and anti-malarial drugs against the deadly P. falciparum malaria.
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Affiliation(s)
- Titus Okello Orwa
- Institute of Mathematical Sciences, Strathmore University, P.O Box 59 857-00 200, Nairobi, Kenya
| | - Rachel Waema Mbogo
- Institute of Mathematical Sciences, Strathmore University, P.O Box 59 857-00 200, Nairobi, Kenya
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11
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Fernandes VDS, da Rosa R, Zimmermann LA, Rogério KR, Kümmerle AE, Bernardes LSC, Graebin CS. Antiprotozoal agents: How have they changed over a decade? Arch Pharm (Weinheim) 2021; 355:e2100338. [PMID: 34661935 DOI: 10.1002/ardp.202100338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/21/2022]
Abstract
Neglected tropical diseases are a diverse group of communicable diseases that are endemic in low- or low-to-middle-income countries located in tropical and subtropical zones. The number and availability of drugs for treating these diseases are low, the administration route is inconvenient in some cases, and most of them have safety, efficacy, or adverse/toxic reaction issues. The need for developing new drugs to deal with these issues is clear, but one of the most drastic consequences of this negligence is the lack of interest in the research and development of new therapeutic options among major pharmaceutical companies. Positive changes have been achieved over the last few years, although the overall situation remains alarming. After more than one decade since the original work reviewing antiprotozoal agents came to light, now it is time to question ourselves: How has the scenario for the treatment of protozoal diseases such as malaria, leishmaniasis, human African trypanosomiasis, and American trypanosomiasis changed? This review covers the last decade in terms of the drugs currently available for the treatment of these diseases as well as the clinical candidates being currently investigated.
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Affiliation(s)
- Vitória de Souza Fernandes
- Department of Pharmaceutical Sciences, Pharmaceutical and Medicinal Chemistry Laboratory, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Rafael da Rosa
- Department of Organic Chemistry, Medicinal Chemistry and Molecular Diversity Laboratory, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil
| | - Lara A Zimmermann
- Department of Organic Chemistry, Medicinal Chemistry and Molecular Diversity Laboratory, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil
| | - Kamilla R Rogério
- Department of Pharmaceutical Sciences, Pharmaceutical and Medicinal Chemistry Laboratory, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Arthur E Kümmerle
- Department of Pharmaceutical Sciences, Pharmaceutical and Medicinal Chemistry Laboratory, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Lilian S C Bernardes
- Department of Organic Chemistry, Medicinal Chemistry and Molecular Diversity Laboratory, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil
| | - Cedric S Graebin
- Department of Pharmaceutical Sciences, Pharmaceutical and Medicinal Chemistry Laboratory, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
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12
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van Beek SW, Svensson EM, Tiono AB, Okebe J, D'Alessandro U, Gonçalves BP, Bousema T, Drakeley C, Ter Heine R. Model-based assessment of the safety of community interventions with primaquine in sub-Saharan Africa. Parasit Vectors 2021; 14:524. [PMID: 34627346 PMCID: PMC8502297 DOI: 10.1186/s13071-021-05034-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Single low-dose primaquine (SLD-PQ) is recommended in combination with artemisinin-based combination therapy to reduce Plasmodium falciparum transmission in areas threatened by artemisinin resistance or aiming for malaria elimination. SLD-PQ may be beneficial in mass drug administration (MDA) campaigns to prevent malaria transmission but uptake is limited by concerns of hemolysis in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. The aim of this study was to improve the evidence on the safety of MDA with SLD-PQ in a sub-Saharan African setting. METHODS A nonlinear mixed-effects model describing the pharmacokinetics and treatment-induced hemolysis of primaquine was developed using data from an adult (n = 16, G6PD deficient) and pediatric study (n = 38, G6PD normal). The relationship between primaquine pharmacokinetics and hemolysis was modeled using an established erythrocyte lifespan model. The safety of MDA with SLD-PQ was explored through Monte Carlo simulations for SLD-PQ at 0.25 or 0.4 mg/kg using baseline data from a Tanzanian setting with detailed information on hemoglobin concentrations and G6PD status. RESULTS The predicted reduction in hemoglobin levels following SLD-PQ was small and returned to pre-treatment levels after 25 days. G6PD deficiency (African A- variant) was associated with a 2.5-fold (95% CI 1.2-8.2) larger reduction in hemoglobin levels. In the Tanzanian setting where 43% of the population had at least mild anemia (hemoglobin < 11-13 g/dl depending on age and sex) and 2.73% had severe anemia (hemoglobin < 7-8 g/dl depending on age and sex), an additional 3.7% and 6.0% of the population were predicted to develop at least mild anemia and 0.25% and 0.41% to develop severe anemia after 0.25 and 0.4 mg/kg SLD-PQ, respectively. Children < 5 years of age and women ≥ 15 years of age were found to have a higher chance to have low pre-treatment hemoglobin. CONCLUSIONS This study supports the feasibility of MDA with SLD-PQ in a sub-Saharan African setting by predicting small and transient reductions in hemoglobin levels. In a setting where a substantial proportion of the population had low hemoglobin concentrations, our simulations suggest treatment with SLD-PQ would result in small increases in the prevalence of anemia which would most likely be transient.
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Affiliation(s)
- Stijn W van Beek
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Elin M Svensson
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Alfred B Tiono
- National Center for Research and Training on Malaria (CNRFP), Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Faraja , The Gambia
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- London School of Hygiene & Tropical Medicine, London, UK.
| | - Rob Ter Heine
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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13
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Mosha D, Kakolwa MA, Mahende MK, Masanja H, Abdulla S, Drakeley C, Gosling R, Wamoyi J. Safety monitoring experience of single-low dose primaquine co-administered with artemether-lumefantrine among providers and patients in routine healthcare practice: a qualitative study in Eastern Tanzania. Malar J 2021; 20:392. [PMID: 34627236 PMCID: PMC8501629 DOI: 10.1186/s12936-021-03921-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/20/2021] [Indexed: 12/01/2022] Open
Abstract
Background Primaquine is a gametocytocidal drug recommended by the World Health Organization (WHO) in a single-low dose combined with artemisinin-based combination therapy (ACT) for the treatment and prevention of Plasmodium falciparum malaria transmission. Safety monitoring concerns and the lack of a universal validated and approved primaquine pharmacovigilance tool is a challenge for a national rollout in many countries. This study aimed to explore the acceptance, reliability and perceived effectiveness of the primaquine roll out monitoring pharmacovigilance tool (PROMPT). Methods This study was conducted in three dispensaries in the Coastal region of Eastern Tanzania. The study held six in-depth interviews with healthcare providers and six participatory focus group discussions with malaria patients (3) and parents/guardians of sick children (3). Participants were purposively sampled. Thematic analysis was conducted with the aid of NVivo qualitative analysis software. Results The respondents’ general acceptance and perceived effectiveness of the single-low dose primaquine and PROMPT was good. Screening procedure for treatment eligibility and explaining to patients about the possible adverse events was considered very useful for safety reasons. Crushing and dissolving of primaquine tablet to get the appropriate dose, particularly in children, was reported by all providers to be challenging. Transport costs and poor access to the health facility were the main reasons for a patient failing to return to the clinic for a scheduled follow-up visit. Treatment was perceived to be safe by both providers and patients and reported no case of a severe adverse event. Some providers were concerned with the haemoglobin drop observed on day 7. Conclusion Single-low dose primaquine was perceived to be safe and acceptable among providers and patients. PROMPT demonstrated to be a reliable and user-friendly tool among providers. Further validation of the tool by involving the National Malaria Control Programme is pivotal to addressing key challenges and facilitating primaquine adoption in the national policy.
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Affiliation(s)
- Dominic Mosha
- Ifakara Health Institute, Plot 463, Kiko Ave, Mikocheni, P.O Box 78373, Dar es Salaam, Tanzania.
| | - Mwaka A Kakolwa
- Ifakara Health Institute, Plot 463, Kiko Ave, Mikocheni, P.O Box 78373, Dar es Salaam, Tanzania
| | - Muhidin K Mahende
- Ifakara Health Institute, Plot 463, Kiko Ave, Mikocheni, P.O Box 78373, Dar es Salaam, Tanzania
| | - Honorati Masanja
- Ifakara Health Institute, Plot 463, Kiko Ave, Mikocheni, P.O Box 78373, Dar es Salaam, Tanzania
| | - Salim Abdulla
- Ifakara Health Institute, Plot 463, Kiko Ave, Mikocheni, P.O Box 78373, Dar es Salaam, Tanzania
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Roland Gosling
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.,Global Health Group, Malaria Elimination Initiative, University of California, San Francisco, CA, USA
| | - Joyce Wamoyi
- National Institute for Medical Research, Mwanza, Tanzania
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14
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Sepúlveda N, Grignard L, Curry J, Mahey L, Bastiaens GJH, Tiono AB, Okebe J, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Lanke K, Sirima SB, Dicko A, d’Alessandro U, Clark TG, Campino S, Chen I, Eziefula AC, Gosling R, Bousema T, Drakeley C. G6PD Polymorphisms and Hemolysis After Antimalarial Treatment With Low Single-Dose Primaquine: A Pooled Analysis of Six African Clinical Trials. Front Genet 2021; 12:645688. [PMID: 33897764 PMCID: PMC8062977 DOI: 10.3389/fgene.2021.645688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/23/2021] [Indexed: 11/13/2022] Open
Abstract
Primaquine (PQ) is an antimalarial drug with the potential to reduce malaria transmission due to its capacity to clear mature Plasmodium falciparum gametocytes in the human host. However, the large-scale roll-out of PQ has to be counterbalanced by the additional risk of drug-induced hemolysis in individuals suffering from Glucose-6-phospate dehydrogenase (G6PD) deficiency, a genetic condition determined by polymorphisms on the X-linked G6PD gene. Most studies on G6PD deficiency and PQ-associated hemolysis focused on the G6PD A- variant, a combination of the two single nucleotide changes G202A (rs1050828) and A376G (rs1050829), although other polymorphisms may play a role. In this study, we tested the association of 20 G6PD single nucleotide polymorphisms (SNPs) with hemolysis measured seven days after low single dose of PQ given at the dose of 0.1 mg/kg to 0.75 mg/kg in 957 individuals from 6 previously published clinical trials investigating the safety and efficacy of this drug spanning five African countries. After adjusting for inter-study effects, age, gender, baseline hemoglobin level, PQ dose, and parasitemia at screening, our analysis showed putative association signals from the common G6PD mutation, A376G [-log10(p-value) = 2.44] and two less-known SNPs, rs2230037 [-log10(p-value] = 2.60), and rs28470352 [-log10(p-value) = 2.15]; A376G and rs2230037 were in very strong linkage disequilibrium with each other (R 2 = 0.978). However, when the effects of these SNPs were included in the same regression model, the subsequent associations were in the borderline of statistical significance. In conclusion, whilst a role for the A- variant is well established, we did not observe an important additional role for other G6PD polymorphisms in determining post-treatment hemolysis in individuals treated with low single-dose PQ.
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Affiliation(s)
- Nuno Sepúlveda
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- CEAUL – Centro de Estatística e Aplicações da Universidade de Lisboa, Lisbon, Portugal
| | - Lynn Grignard
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | - Guido J. H. Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Alfred B. Tiono
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Department of International Public Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sam A. Coulibaly
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Bronner P. Gonçalves
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Muna Affara
- MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Fajara, Gambia
| | - Alphonse Ouédraogo
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Edith C. Bougouma
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Guillaume S. Sanou
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Sodiomon B. Sirima
- Department of Public Health, Centre National de Recherche et de Formation sur le Paludisme & Institut National de Santé Publique, Ouagadougou, Burkina Faso
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Sciences, Techniques and Technology of Bamako, Bamako, Mali
| | - Umberto d’Alessandro
- MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Fajara, Gambia
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Taane G. Clark
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Susana Campino
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ingrid Chen
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Alice C. Eziefula
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Roly Gosling
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Teun Bousema
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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15
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Bancone G, Chu CS. G6PD Variants and Haemolytic Sensitivity to Primaquine and Other Drugs. Front Pharmacol 2021; 12:638885. [PMID: 33790795 PMCID: PMC8005603 DOI: 10.3389/fphar.2021.638885] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/01/2021] [Indexed: 02/04/2023] Open
Abstract
Restrictions on the cultivation and ingestion of fava beans were first reported as early as the fifth century BC. Not until the late 19th century were clinical descriptions of fava-induced disease reported and soon after characterised as “favism” in the early 20th century. It is now well known that favism as well as drug-induced haemolysis is caused by a deficiency of the glucose-6-phosphate dehydrogenase (G6PD) enzyme, one of the most common enzyme deficiency in humans. Interest about the interaction between G6PD deficiency and therapeutics has increased recently because mass treatment with oxidative 8-aminoquinolines is necessary for malaria elimination. Historically, assessments of haemolytic risk have focused on the clinical outcomes (e.g., haemolysis) associated with either a simplified phenotypic G6PD characterisation (deficient or normal) or an ill-fitting classification of G6PD genetic variants. It is increasingly apparent that detailed knowledge of both aspects is required for a complete understanding of haemolytic risk. While more attention has been devoted recently to better phenotypic characterisation of G6PD activity (including the development of new point-of care tests), the classification of G6PD variants should be revised to be clinically useful in malaria eliminating countries and in populations with prevalent G6PD deficiency. The scope of this work is to summarize available literature on drug-induced haemolysis among individuals with different G6PD variants and to highlight knowledge gaps that could be filled with further clinical and laboratory research.
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Affiliation(s)
- Germana Bancone
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Cindy S Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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16
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Madkhali AM, Al-Mekhlafi HM, Atroosh WM, Ghzwani AH, Zain KA, Abdulhaq AA, Ghailan KY, Anwar AA, Eisa ZM. Increased prevalence of pfdhfr and pfdhps mutations associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates from Jazan Region, Southwestern Saudi Arabia: important implications for malaria treatment policy. Malar J 2020; 19:446. [PMID: 33267841 PMCID: PMC7709338 DOI: 10.1186/s12936-020-03524-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/25/2020] [Indexed: 11/10/2022] Open
Abstract
Background Despite significant progress in eliminating malaria from the Kingdom of Saudi Arabia, the disease is still endemic in the southwestern region of the country. Artesunate plus sulfadoxine–pyrimethamine (AS + SP) has been used in Saudi Arabia since 2007 as a first-line treatment for uncomplicated Plasmodium falciparum malaria. This study aimed to investigate the prevalence of mutations associated with resistance to artemisinin and sulfadoxine–pyrimethamine (SP) resistance in P. falciparum parasites circulating in Jazan region, southwestern Saudi Arabia. Methods A total of 151 P. falciparum isolates were collected between April 2018 and March 2019 from 12 of the governorates in Jazan region. Genomic DNA was extracted from dried blood spots and amplified using nested PCR. Polymorphisms in the propeller domain of the P. falciparum k13 (pfkelch13) gene and point mutations in the P. falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes were identified by sequencing. Results No mutations in the pfkelch13 propeller domain were found in any of the 151 isolates. However, point mutations in the pfdhfr and pfdhps genes were detected in 90.7% (137/151) of the isolates. The pfdhfr double mutations N51I + S108N (i.e. ACICNI haplotype) and triple mutations N51I + C59R + S108N (i.e. ACIRNI haplotype) were detected in 47% and 37.8% of the isolates, respectively. Moreover, the pfdhps single mutation at codon A437G and double mutations A437G + K540E (i.e. SGEAAI haplotype) were observed in 4.6% and 51.7% of the isolates, respectively. Interestingly, 23.8%, 25.1 and 12.6% of the isolates had quintuple, quadruple and triple mutated combined pfdhfr–pfdhps genotypes, respectively. Furthermore, significant associations were found between the prevalence of mutant haplotypes and the age, gender and nationality of the patients (P < 0.05). Conclusion This study revealed a high prevalence of point mutations in the pfdhfr and pfdhps genes of P. falciparum isolates from Jazan region, with quintuple and quadruple mutant pfdhfr–pfdhps genotypes reported for the first time in Saudi Arabia and the Arabian Peninsula. Despite the absence of the pfkelch13 mutation in the isolates examined, the pfdhfr and pfdhps mutations undermine the efficacy of SP partner drug, thereby threatening the main falciparum malaria treatment policy in Saudi Arabia, i.e. the use of AS + SP. Therefore, the continuous molecular and in-vivo monitoring of ACT efficacy in Jazan region is highly recommended.
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Affiliation(s)
- Aymen M Madkhali
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia. .,Medical Research Centre, Jazan University, Jazan, Kingdom of Saudi Arabia.
| | - Hesham M Al-Mekhlafi
- Medical Research Centre, Jazan University, Jazan, Kingdom of Saudi Arabia. .,Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.
| | - Wahib M Atroosh
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.,Department of Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University of Aden, Aden, Yemen
| | | | - Khalid Ammash Zain
- Medical Research Centre, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Ahmed A Abdulhaq
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Khalid Y Ghailan
- Faculty of Public Health and Tropical Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Alkhansa A Anwar
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Zaki M Eisa
- Saudi Centre for Disease Prevention and Control, Ministry of Health, Jazan, Kingdom of Saudi Arabia
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17
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Significant Efficacy of a Single Low Dose of Primaquine Compared to Stand-Alone Artemisinin Combination Therapy in Reducing Gametocyte Carriage in Cambodian Patients with Uncomplicated Multidrug-Resistant Plasmodium falciparum Malaria. Antimicrob Agents Chemother 2020; 64:AAC.02108-19. [PMID: 32179526 PMCID: PMC7269483 DOI: 10.1128/aac.02108-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 03/06/2020] [Indexed: 11/22/2022] Open
Abstract
Since 2012, a single low dose of primaquine (SLDPQ; 0.25 mg/kg of body weight) with artemisinin-based combination therapies has been recommended as the first-line treatment of acute uncomplicated Plasmodium falciparum malaria to interrupt its transmission, especially in low-transmission settings of multidrug resistance, including artemisinin resistance. Policy makers in Cambodia have been reluctant to implement this recommendation due to primaquine safety concerns and a lack of data on its efficacy. Since 2012, a single low dose of primaquine (SLDPQ; 0.25 mg/kg of body weight) with artemisinin-based combination therapies has been recommended as the first-line treatment of acute uncomplicated Plasmodium falciparum malaria to interrupt its transmission, especially in low-transmission settings of multidrug resistance, including artemisinin resistance. Policy makers in Cambodia have been reluctant to implement this recommendation due to primaquine safety concerns and a lack of data on its efficacy. In this randomized controlled trial, 109 Cambodians with acute uncomplicated P. falciparum malaria received dihydroartemisinin-piperaquine (DP) alone or combined with SLDPQ on the first treatment day. The transmission-blocking efficacy of SLDPQ was evaluated on days 0, 1, 2, 3, 7, 14, 21, and 28, and recrudescence by reverse transcriptase PCR (RT-PCR) (gametocyte prevalence) and membrane feeding assays with Anopheles minimus mosquitoes (gametocyte infectivity). Without the influence of recrudescent infections, DP-SLDPQ reduced gametocyte carriage 3-fold compared to that achieved with DP. Of 48 patients tested on day 0, only 3 patients were infectious to mosquitoes (∼6%). Posttreatment, three patients were infectious on day 14 (3.5%, 1/29) and on the 1st and 7th days of recrudescence (8.3%, 1/12 for each); this overall low infectivity precluded our ability to assess its transmission-blocking efficacy. Our study confirms the effective gametocyte clearance of SLDPQ when combined with DP in multidrug-resistant P. falciparum infections and the negative impact of recrudescent infections due to poor DP efficacy. Artesunate-mefloquine (ASMQ) has replaced DP, and ASMQ-SLDPQ has been deployed to treat all patients with symptomatic P. falciparum infections to further support the elimination of multidrug-resistant P. falciparum in Cambodia. (This study has been registered at ClinicalTrials.gov under identifier NCT02434952.)
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18
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Optimal timing of primaquine to reduce Plasmodium falciparum gametocyte carriage when co-administered with artemether-lumefantrine. Malar J 2020; 19:34. [PMID: 31964380 PMCID: PMC6974976 DOI: 10.1186/s12936-020-3121-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/13/2020] [Indexed: 01/13/2023] Open
Abstract
Background Primaquine is an important gametocytocidal drug that is combined with conventional malaria treatment for prevention of Plasmodium falciparum malaria transmission. Primaquine has been administered together on the first or the last day of conventional treatment but the impact of primaquine timing has never been examined. This study aimed to assess safety, efficacy and optimal timing of single full-dose (0.75 mg/kg) primaquine when added to a standard 6-dose regimen of artemether–lumefantrine (AL). Methods In an individual-level randomized controlled trial, enrolled participants who were G6PD normal and had uncomplicated P. falciparum malaria were randomly assigned to receive: AL only; AL and a single 0.75 mg/kg primaquine dose on the first day of AL (day 1); or AL and single 0.75 mg//kg primaquine on the last day of AL (day 3). On days 2, 3, 4, 8, 11 and 15, gametocytes were assessed and quantified by microscope and quantitative nuclear acid sequence based quantification (QT-NASBA). Results Overall, 111 participants aged between 3 and 17 years were randomly allocated to receive AL only (36) or combined with primaquine on day 1 (38), or primaquine on day 3 (37). Day 4 gametocyte prevalence in AL + day 1 primaquine was half the level seen in either AL + day 3 primaquine or AL only arm (11% [4/35] vs 26% [8/31] and 27% [8/30], respectively) albeit not statistically significant. A similar trend of lower gametocyte in the AL + day 1 primaquine verses AL + day 3 primaquine or AL only arm was observed in mean gametocyte density. Mean (sd) haemoglobin level in AL + day 3 primaquine arm recovered from -0.42(1.2) g/dl on day 2 to 0.35 (1.5) g/dl on day 15 of follow up. This was not the case in AL only and AL + day 1 primaquine arms during the same follow-up period, although the difference was not statistically significant (p = 318). No serious adverse events reported in the study. Across arms, 23% (26/111) of participants reported a total of 31 mild adverse events and the difference was not statistically significant (p = 0.477). Conclusion Primaquine administration on the first day of AL is well tolerated and as safe as later administration. Whilst the World Health Organization currently recommends a lower dose of primaquine (0.25 mg/kg), the findings are supportive of early primaquine administration when combined with artemisinin-combination therapy. ClinicalTrials.gov Registration NCT01906788
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19
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Abstract
The scientific community worldwide has realized that malaria elimination will not be possible without development of safe and effective transmission-blocking interventions. Primaquine, the only WHO recommended transmission-blocking drug, is not extensively utilized because of the toxicity issues in G6PD deficient individuals. Therefore, there is an urgent need to develop novel therapeutic interventions that can target malaria parasites and effectively block transmission. But at first, it is imperative to unravel the existing portfolio of transmission-blocking drugs. This review highlights transmission-blocking potential of current antimalarial drugs and drugs that are in various stages of clinical development. The collective analysis of the relationships between the structure and the activity of transmission-blocking drugs is expected to help in the design of new transmission-blocking antimalarials.
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20
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Deng C, Huang B, Wang Q, Wu W, Zheng S, Zhang H, Li D, Feng D, Li G, Xue L, Yang T, Tuo F, Mohadji F, Su XZ, Xu Q, Wu Z, Lin L, Zhou J, Yan H, Bacar A, Said Abdallah K, Kéké RA, Msa Mliva A, Mohamed M, Wang X, Huang S, Oithik F, Li XB, Lu F, Fay MP, Liu XH, Wellems TE, Song J. Large-scale Artemisinin-Piperaquine Mass Drug Administration With or Without Primaquine Dramatically Reduces Malaria in a Highly Endemic Region of Africa. Clin Infect Dis 2019; 67:1670-1676. [PMID: 29846536 DOI: 10.1093/cid/ciy364] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/23/2018] [Indexed: 01/08/2023] Open
Abstract
Background Mass drug administration (MDA), with or without low-dose primaquine (PMQLD), is being considered for malaria elimination programs. The potential of PMQLD to block malaria transmission by mosquitoes must be balanced against liabilities of its use. Methods Artemisinin-piperaquine (AP), with or without PMQLD, was administered in 3 monthly rounds across Anjouan Island, Union of Comoros. Plasmodium falciparum malaria rates, mortality, parasitemias, adverse events, and PfK13 Kelch-propeller gene polymorphisms were evaluated. Results Coverage of 85 to 93% of the Anjouan population was achieved with AP plus PMQLD (AP+PMQLD) in 2 districts (population 97164) and with AP alone in 5 districts (224471). Between the months of April-September in both 2012 and 2013, average monthly malaria hospital rates per 100000 people fell from 310.8 to 2.06 in the AP+PMQLD population (ratio 2.06/310.8 = 0.66%; 95% CI: 0.02%, 3.62%; P = .00007) and from 412.1 to 2.60 in the AP population (ratio 0.63%; 95% CI: 0.11%, 1.93%; P < .00001). Effectiveness of AP+PMQLD was 0.9908 (95% CI: 0.9053, 0.9991), while effectiveness of AP alone was 0.9913 (95% CI: 0.9657, 0.9978). Both regimens were well tolerated, without severe adverse events. Analysis of 52 malaria samples after MDA showed no evidence for selection of PfK13 Kelch-propeller mutations. Conclusions Steep reductions of malaria cases were achieved by 3 monthly rounds of either AP+PMQLD or AP alone, suggesting potential for highly successful MDA without PMQLD in epidemiological settings such as those on Anjouan. A major challenge is to sustain and expand the public health benefits of malaria reductions by MDA.
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Affiliation(s)
| | - Bo Huang
- Institute of Tropical Medicine, People's Republic of China
| | - Qi Wang
- Institute of Tropical Medicine, People's Republic of China.,Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Wanting Wu
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Shaoqin Zheng
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Hongying Zhang
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Di Li
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Danghong Feng
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Guoming Li
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Linlu Xue
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Tao Yang
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Fei Tuo
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Fouad Mohadji
- Ministry of Health Comoros, Moroni, Union of Comoros, Bethesda, Maryland
| | - Xin-Zhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Qin Xu
- Institute of Tropical Medicine, People's Republic of China
| | - Zhibing Wu
- First Affiliated Hospital, People's Republic of China
| | - Li Lin
- First Affiliated Hospital, People's Republic of China
| | - Jiuyao Zhou
- Traditional Chinese Medicine College, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Hong Yan
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Affane Bacar
- National Malaria Control Programme, Moroni, Union of Comoros, People's Republic of China
| | - Kamal Said Abdallah
- National Malaria Control Programme, Moroni, Union of Comoros, People's Republic of China
| | - Rachadi A Kéké
- National Malaria Control Programme, Moroni, Union of Comoros, People's Republic of China
| | - Ahamada Msa Mliva
- Ministry of Health Comoros, Moroni, Union of Comoros, Bethesda, Maryland
| | - Moussa Mohamed
- Ministry of Health Comoros, Moroni, Union of Comoros, Bethesda, Maryland
| | - Xinhua Wang
- Guangzhou Medical University, People's Republic of China
| | - Shiguang Huang
- School of Stomatology, Jinan University, People's Republic of China
| | - Fatihou Oithik
- Ministry of Health Comoros, Moroni, Union of Comoros, Bethesda, Maryland
| | - Xiao-Bo Li
- Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Fangli Lu
- Department of Parasitology, Zhongshan School of Medicine, People's Republic of China.,Key Laboratory of Tropical Disease Control in Ministry of Education, Sun Yat-sen University, Guangdong, People's Republic of China
| | - Michael P Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland
| | - Xiao-Hong Liu
- First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
| | - Thomas E Wellems
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianping Song
- Institute of Tropical Medicine, People's Republic of China.,Science and Technology Park, Guangzhou University of Chinese Medicine, Guangdong, People's Republic of China
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21
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CYP2D6 Polymorphisms and the Safety and Gametocytocidal Activity of Single-Dose Primaquine for Plasmodium falciparum. Antimicrob Agents Chemother 2019; 63:AAC.00538-19. [PMID: 31383656 PMCID: PMC6761544 DOI: 10.1128/aac.00538-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022] Open
Abstract
Single-dose primaquine (PQ) clears mature gametocytes and reduces the transmission of Plasmodium falciparum after artemisinin combination therapy. Genetic variation in CYP2D6, the gene producing the drug-metabolizing enzyme cytochrome P450 2D6 (CYP2D6), influences plasma concentrations of PQ and its metabolites and is associated with PQ treatment failure in Plasmodium vivax malaria. Single-dose primaquine (PQ) clears mature gametocytes and reduces the transmission of Plasmodium falciparum after artemisinin combination therapy. Genetic variation in CYP2D6, the gene producing the drug-metabolizing enzyme cytochrome P450 2D6 (CYP2D6), influences plasma concentrations of PQ and its metabolites and is associated with PQ treatment failure in Plasmodium vivax malaria. Using blood and saliva samples of varying quantity and quality from 8 clinical trials across Africa (n = 1,076), we were able to genotype CYP2D6 for 774 samples (72%). We determined whether genetic variation in CYP2D6 has implications for PQ efficacy in individuals with gametocytes at the time of PQ administration (n = 554) and for safety in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals treated with PQ (n = 110). Individuals with a genetically inferred CYP2D6 poor/intermediate metabolizer status had a higher gametocyte prevalence on day 7 or 10 after PQ than those with an extensive/ultrarapid CYP2D6 metabolizer status (odds ratio [OR] = 1.79 [95% confidence interval {CI}, 1.10, 2.90]; P = 0.018). The mean minimum hemoglobin concentrations during follow-up for G6PD-deficient individuals were 11.8 g/dl for CYP2D6 extensive/ultrarapid metabolizers and 12.1 g/dl for CYP2D6 poor/intermediate metabolizers (P = 0. 803). CYP2D6 genetically inferred metabolizer status was also not associated with anemia following PQ treatment (P = 0.331). We conclude that CYP2D6 poor/intermediate metabolizer status may be associated with prolonged gametocyte carriage after treatment with single-low-dose PQ but not with treatment safety.
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22
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Delves M, Lafuente-Monasterio MJ, Upton L, Ruecker A, Leroy D, Gamo FJ, Sinden R. Fueling Open Innovation for Malaria Transmission-Blocking Drugs: Hundreds of Molecules Targeting Early Parasite Mosquito Stages. Front Microbiol 2019; 10:2134. [PMID: 31572339 PMCID: PMC6753678 DOI: 10.3389/fmicb.2019.02134] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/30/2019] [Indexed: 11/13/2022] Open
Abstract
Background Despite recent successes at controlling malaria, progress has stalled with an estimated 219 million cases and 435,000 deaths in 2017 alone. Combined with emerging resistance to front line antimalarial therapies in Southeast Asia, there is an urgent need for new treatment options and novel approaches to halt the spread of malaria. Plasmodium, the parasite responsible for malaria propagates through mosquito transmission. This imposes an acute bottleneck on the parasite population and transmission-blocking interventions exploiting this vulnerability are recognized as vital for malaria elimination. Methods 13,533 small molecules with known activity against Plasmodium falciparum asexual parasites were screened for additional transmission-blocking activity in an ex vivo Plasmodium berghei ookinete development assay. Active molecules were then counterscreened in dose response against HepG2 cells to determine their activity/cytotoxicity window and selected non-toxic representative molecules were fully profiled in a range of transmission and mosquito infection assays. Furthermore, the entire dataset was compared to other published screens of the same molecules against P. falciparum gametocytes and female gametogenesis. Results 437 molecules inhibited P. berghei ookinete formation with an IC50 < 10 μM. of which 273 showed >10-fold parasite selectivity compared to activity against HepG2 cells. Active molecules grouped into 49 chemical clusters of three or more molecules, with 25 doublets and 94 singletons. Six molecules representing six major chemical scaffolds confirmed their transmission-blocking activity against P. falciparum male and female gametocytes and inhibited P. berghei oocyst formation in the standard membrane feeding assay at 1 μM. When screening data in the P. berghei development ookinete assay was compared to published screens of the same library in assays against P. falciparum gametocytes and female gametogenesis, it was established that each assay identified distinct, but partially overlapping subsets of transmission-blocking molecules. However, selected molecules unique to each assay show transmission-blocking activity in mosquito transmission assays. Conclusion The P. berghei ookinete development assay is an excellent high throughput assay for efficiently identifying antimalarial molecules targeting early mosquito stage parasite development. Currently no high throughput transmission-blocking assay is capable of identifying all transmission-blocking molecules.
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Affiliation(s)
- Michael Delves
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.,Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Leanna Upton
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Andrea Ruecker
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | - Robert Sinden
- Department of Life Sciences, Imperial College London, London, United Kingdom
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23
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Wojnarski M, Lon C, Vanachayangkul P, Gosi P, Sok S, Rachmat A, Harrison D, Berjohn CM, Spring M, Chaoratanakawee S, Ittiverakul M, Buathong N, Chann S, Wongarunkochakorn S, Waltmann A, Kuntawunginn W, Fukuda MM, Burkly H, Heang V, Heng TK, Kong N, Boonchan T, Chum B, Smith P, Vaughn A, Prom S, Lin J, Lek D, Saunders D. Atovaquone-Proguanil in Combination With Artesunate to Treat Multidrug-Resistant P. falciparum Malaria in Cambodia: An Open-Label Randomized Trial. Open Forum Infect Dis 2019; 6:ofz314. [PMID: 31660398 DOI: 10.1093/ofid/ofz314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 06/28/2019] [Indexed: 12/16/2022] Open
Abstract
Background Recent artemisinin-combination therapy failures in Cambodia prompted a search for alternatives. Atovaquone-proguanil (AP), a safe, effective treatment for multidrug-resistant Plasmodium falciparum (P.f.), previously demonstrated additive effects in combination with artesunate (AS). Methods Patients with P.f. or mixed-species infection (n = 205) in Anlong Veng (AV; n = 157) and Kratie (KT; n = 48), Cambodia, were randomized open-label 1:1 to a fixed-dose 3-day AP regimen +/-3 days of co-administered artesunate (ASAP). Single low-dose primaquine (PQ, 15 mg) was given on day 1 to prevent gametocyte-mediated transmission. Results Polymerase chain reaction-adjusted adequate clinical and parasitological response at 42 days was 90% for AP (95% confidence interval [CI], 82%-95%) and 92% for ASAP (95% CI, 83%-96%; P = .73). The median parasite clearance time was 72 hours for ASAP in AV vs 56 hours in KT (P < .001) and was no different than AP alone. At 1 week postprimaquine, 7% of the ASAP group carried microscopic gametocytes vs 29% for AP alone (P = .0001). Nearly all P.f. isolates had C580Y K13 propeller artemisinin resistance mutations (AV 99%; KT 88%). Only 1 of 14 treatment failures carried the cytochrome bc1 (Pfcytb) atovaquone resistance mutation, which was not present at baseline. P.f. isolates remained atovaquone sensitive in vitro but cycloguanil resistant, with a triple P.f. dihydrofolate reductase mutation. Conclusions Atovaquone-proguanil remained marginally effective in Cambodia (≥90%) with minimal Pfcytb mutations observed. Treatment failures in the presence of ex vivo atovaquone sensitivity and adequate plasma levels may be attributable to cycloguanil and/or artemisinin resistance. Artesunate co-administration provided little additional blood-stage efficacy but reduced post-treatment gametocyte carriage in combination with AP beyond single low-dose primaquine.
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Affiliation(s)
- Mariusz Wojnarski
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chanthap Lon
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Panita Gosi
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Somethy Sok
- Department of Health, Ministry of National Defense, Phnom Penh, Cambodia
| | - Agus Rachmat
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | | | | | - Michele Spring
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,Henry M. Jackson Foundation, Bethesda, Maryland
| | - Suwanna Chaoratanakawee
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mali Ittiverakul
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Nillawan Buathong
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Soklyda Chann
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | | | | | - Mark M Fukuda
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Hana Burkly
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Vireak Heang
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Thay Keang Heng
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Nareth Kong
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - Threechada Boonchan
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Bolin Chum
- Naval Medical Research Unit-2, Phnom Penh, Cambodia
| | - Philip Smith
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | | | - Satharath Prom
- Department of Health, Ministry of National Defense, Phnom Penh, Cambodia
| | - Jessica Lin
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina
| | - Dysoley Lek
- National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia
| | - David Saunders
- US Army Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.,US Army Medical Materiel Development Activity, Fort Detrick, Maryland
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24
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Antimalarial Drugs for Malaria Elimination. Methods Mol Biol 2019. [PMID: 31267500 DOI: 10.1007/978-1-4939-9550-9_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The diversity of Anopheles species and the environmental issues posed by the large-scale use of insecticides make it unlikely that malaria elimination will be achieved by fighting mosquitoes only. Malaria elimination necessitates targeting the parasite itself. For this, in the absence of efficient vaccines against the disease, antimalarial drugs remain the primary tool. We present here the limitations of currently available antimalarials and the different implementation strategies of these drugs, which ultimately depends on the epidemiological context of the disease.
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25
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Raman J, Allen E, Workman L, Mabuza A, Swanepoel H, Malatje G, Frean J, Wiesner L, Barnes KI. Safety and tolerability of single low-dose primaquine in a low-intensity transmission area in South Africa: an open-label, randomized controlled trial. Malar J 2019; 18:209. [PMID: 31234865 PMCID: PMC6592007 DOI: 10.1186/s12936-019-2841-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/17/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND To reduce onward falciparum malaria transmission, the World Health Organization recommends adding single low-dose (SLD) primaquine to artemisinin-based combination treatment in low transmission areas. However, uptake of this recommendation has been relatively slow given concerns about whether individual risks justify potential community benefit. This study was undertaken to generate comprehensive local data on the risk-benefit profile of SLD primaquine deployment in a pre-elimination area in South Africa. METHODS This randomized, controlled open-label trial investigated adding a single low primaquine dose on day 3 to standard artemether-lumefantrine treatment for uncomplicated falciparum malaria. Efficacy, safety and tolerability of artemether-lumefantrine and primaquine treatment were assessed on days 3, 7, 14, 28 and 42. Lumefantrine concentrations were assayed from dried blood spot samples collected on day 7. RESULTS Of 217 patients screened, 166 were enrolled with 140 randomized on day 3, 70 to each study arm (primaquine and no primaquine). No gametocytes were detected by either microscopy or PCR in any of the follow-up samples collected after randomization on day 3, precluding assessment of primaquine efficacy. Prevalence of the CYP2D6*4, CYP2D6*10 and CYP2D6*17 mutant alleles was low with allelic frequencies of 0.02, 0.11 and 0.16, respectively; none had the CYP2D6*4/*4 variant associated with null activity. Among 172 RDT-positive patients G6PD-genotyped, 24 (14%) carried the G6PD deficient (A-) variant. Median haemoglobin concentrations were similar between treatment arms throughout follow-up. A third of participants had a haemoglobin drop > 2 g/dL; this was not associated with primaquine treatment but may be associated with G6PD genotype [52.9% (9/17) with A- genotype vs. 31% (36/116) with other genotypes (p = 0.075)]. Day 7 lumefantrine concentrations and the number and nature of adverse events were similar between study arms; only one serious adverse event occurred (renal impairment in the no primaquine arm). The artemether-lumefantrine PCR-corrected adequate clinical and parasitological response rate was 100%, with only one re-infection found among the 128 patients who completed 42-day follow-up. CONCLUSIONS Safety, tolerability, CYP2D6 and G6PD variant data from this study support the deployment of the WHO-recommended SLD primaquine without G6PD testing to advance malaria elimination in South African districts with low-intensity residual transmission. Trial registration Pan African Clinical Trial Registry, PACTR201611001859416. Registered 11 November 2016, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=1859.
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Affiliation(s)
- Jaishree Raman
- Parasitology Reference Laboratory, National Institute for Communicable Diseases, A Division of the National Health Laboratory Services, Johannesburg, South Africa
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
- UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
| | - Elizabeth Allen
- UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lesley Workman
- UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Aaron Mabuza
- UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- Mpumalanga Provincial Malaria Elimination Programme, Mpumalanga, South Africa
| | - Hendrik Swanepoel
- UP Institute for Sustainable Malaria Control and MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
| | - Gillian Malatje
- Mpumalanga Provincial Malaria Elimination Programme, Mpumalanga, South Africa
| | - John Frean
- Parasitology Reference Laboratory, National Institute for Communicable Diseases, A Division of the National Health Laboratory Services, Johannesburg, South Africa
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Karen I Barnes
- UCT/MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa.
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa.
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Abstract
Over the past two decades, malaria-related deaths have reduced substantially, especially in African children. However, the global malaria burden still remains high. The recent emergence of resistance to artemisinin, the backbone of malaria management, could threaten malaria control. Importantly, over the past five years, there has been an upsurge in research in the development of novel antimalarial drugs (and combinations), malaria vaccine and new vector-control strategies that can boost the malaria control programme.
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Affiliation(s)
- Ashok K Pannu
- Assistant Professor, Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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27
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Moyo P, Kunyane P, Selepe MA, Eloff JN, Niemand J, Louw AI, Maharaj VJ, Birkholtz LM. Bioassay-guided isolation and identification of gametocytocidal compounds from Artemisia afra (Asteraceae). Malar J 2019; 18:65. [PMID: 30849984 PMCID: PMC6408838 DOI: 10.1186/s12936-019-2694-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 03/01/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Optimal adoption of the malaria transmission-blocking strategy is currently limited by lack of safe and efficacious drugs. This has sparked the exploration of different sources of drugs in search of transmission-blocking agents. While plant species have been extensively investigated in search of malaria chemotherapeutic agents, comparatively less effort has been channelled towards exploring them in search of transmission-blocking drugs. Artemisia afra (Asteraceae), a prominent feature of South African folk medicine, is used for the treatment of a number of diseases, including malaria. In search of transmission-blocking compounds aimed against Plasmodium parasites, the current study endeavoured to isolate and identify gametocytocidal compounds from A. afra. METHODS A bioassay-guided isolation approach was adopted wherein a combination of solvent-solvent partitioning and gravity column chromatography was used. Collected fractions were continuously screened in vitro for their ability to inhibit the viability of primarily late-stage gametocytes of Plasmodium falciparum (NF54 strain), using a parasite lactate dehydrogenase assay. Chemical structures of isolated compounds were elucidated using UPLC-MS/MS and NMR data analysis. RESULTS Two guaianolide sesquiterpene lactones, 1α,4α-dihydroxybishopsolicepolide and yomogiartemin, were isolated and shown to be active (IC50 < 10 μg/ml; ~ 10 μM) against both gametocytes and intra-erythrocytic asexual P. falciparum parasites. Interestingly, 1α,4α-dihydroxybishopsolicepolide was significantly more potent against late-stage gametocytes than to early-stage gametocytes and intra-erythrocytic asexual P. falciparum parasites. Additionally, both isolated compounds were not overly cytotoxic against HepG2 cells in vitro. CONCLUSION This study provides the first instance of isolated compounds from A. afra against P. falciparum gametocytes as a starting point for further investigations on more plant species in search of transmission-blocking compounds.
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Affiliation(s)
- Phanankosi Moyo
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Phaladi Kunyane
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Mamoalosi A Selepe
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Jacobus N Eloff
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag x04, Onderstepoort, Pretoria, 0110, South Africa
| | - Jandeli Niemand
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Abraham I Louw
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Vinesh J Maharaj
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa
| | - Lyn-Marie Birkholtz
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag x20, Hatfield, 0028, South Africa.
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28
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Grignard L, Mair C, Curry J, Mahey L, Bastiaens GJH, Tiono AB, Okebe J, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Lanke KHW, Sirima SB, d'Alessandro U, Clark TG, Campino S, Bousema T, Drakeley C. Bead-based assays to simultaneously detect multiple human inherited blood disorders associated with malaria. Malar J 2019; 18:14. [PMID: 30665411 PMCID: PMC6341711 DOI: 10.1186/s12936-019-2648-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/12/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Glucose-6-phosphate dehydrogenase deficiency (G6PDd), haemoglobin C (HbC) and S (HbS) are inherited blood disorders (IBD) common in populations in malaria endemic areas. All are associated to some degree with protection against clinical malaria whilst additionally G6PDd is associated with haemolysis following treatment with 8-aminoquinolines. Measuring the prevalence of these inherited blood disorders in affected populations can improve understanding of disease epidemiology. Current methodologies in epidemiological studies commonly rely on individual target amplification and visualization; here a method is presented to simultaneously detect the polymorphisms and that can be expanded to include other single nucleotide polymorphisms (SNPs) of interest. METHODS Human DNA from whole blood samples was amplified in a novel, multiplex PCR reaction and extended with SNP-specific probes in an allele specific primer extension (ASPE) to simultaneously detect four epidemiologically important human markers including G6PD SNPs (G202A and A376G) and common haemoglobin mutations (HbS and HbC). The products were hybridized to magnetic beads and the median fluorescence intensity (MFI) was read on MAGPIX® (Luminex corp.). Genotyping data was compared to phenotypical data generated by flow cytometry and to established genotyping methods. RESULTS Seventy-five samples from Burkina Faso (n = 75/78, 96.2%) and 58 samples from The Gambia (n = 58/61, 95.1%) had a G6PD and a HBB genotype successfully assigned by the bead-based assay. Flow cytometry data available for n = 61 samples further supported the concordance between % G6PD normal/deficient cells and genotype. CONCLUSIONS The bead based assay compares well to alternative measures of genotyping and phenotyping for G6PD. The screening is high throughput, adaptable to inclusion of multiple targets of interest and easily standardized.
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Affiliation(s)
- Lynn Grignard
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
| | - Catherine Mair
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | | | | | - Guide J H Bastiaens
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Sam A Coulibaly
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
| | - Muna Affara
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Edith C Bougouma
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Guillaume S Sanou
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Kjerstin H W Lanke
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Sodiomon B Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Umberto d'Alessandro
- Disease Control & Elimination Theme, Medical Research Council Unit at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Taane G Clark
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Susana Campino
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK
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Trade-off between tolerance and resistance to infections: an experimental approach with malaria parasites in a passerine bird. Oecologia 2018; 188:1001-1010. [PMID: 30377770 DOI: 10.1007/s00442-018-4290-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 10/22/2018] [Indexed: 10/28/2022]
Abstract
Avian malaria parasites are known to have negative effects on their hosts, including consequences for reproductive success and survival. However, the outcome of disease may vary greatly among individuals, due to their particular genetic background, their past history of exposure to infections, or the way they respond to infections at the physiological level. We experimentally reduced parasitemia in naturally infected birds to examine individual-level variation in physiological parameters involved in anti-parasite defense, focusing specifically on disease resistance and tolerance. As a measure of disease resistance, we used circulating levels of IgY, and as a measure of disease tolerance, we estimated haptoglobin concentrations. Our results show individual consistency in the physiological parameters studied during the experiment, that was statistically significant for body condition, and marginally significant for IgY levels, and a trade-off between physiological mechanisms involved in resistance and tolerance that seem to be mediated by parasitemia. The medication experiment with primaquine was successful in reducing parasite intensity, but was not sufficient to clear the infection, and there was a generalized improvement in body condition in all birds maintained in captivity during the experiment. We suggest that the observed changes in the association between resistance and tolerance estimates may be due to the decrease in parasitemia attained through medication, to the improved nutritional status observed during the experiment or to the combined effect of both. Our study adds to the understanding of how wild animals cope with the diseases they are exposed to in their natural environment, and ultimately the consequences of parasitism at the individual level.
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30
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Cluster-randomized trial of monthly malaria prophylaxis versus focused screening and treatment: a study protocol to define malaria elimination strategies in Cambodia. Trials 2018; 19:558. [PMID: 30326952 PMCID: PMC6192281 DOI: 10.1186/s13063-018-2931-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 09/24/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria remains a critical public health problem in Southeast Asia despite intensive containment efforts. The continued spread of multi-drug-resistant Plasmodium falciparum has led to calls for malaria elimination on the Thai-Cambodian border. However, the optimal approach to elimination in difficult-to-reach border populations, such as the Military, remains unclear. METHODS/DESIGN A two-arm, cluster-randomized controlled, open-label pilot study is being conducted in military personnel and their families at focal endemic areas on the Thai-Cambodian border. The primary objective is to compare the effectiveness of monthly malaria prophylaxis (MMP) with dihydroartemisinin-piperaquine and weekly primaquine for 12 weeks compared with focused screening and treating (FSAT) following current Cambodian national treatment guidelines. Eight separate military encampments, making up approximately 1000 military personnel and their families, undergo randomization to the MMP or FSAT intervention for 3 months, with an additional 3 months' follow-up. In addition, each treatment cluster of military personnel and civilians is also randomly assigned to receive either permethrin- or sham (water)-treated clothing in single-blind fashion. The primary endpoint is risk reduction for malaria infection in geographically distinct military encampments based on their treatment strategy. Monthly malaria screening in both arms is done via microscopy, PCR, and rapid diagnostic testing to compare both the accuracy and cost-effectiveness of diagnostic modalities to detect asymptomatic infection. Universal glucose-6-phosphate dehydrogenase (G6PD) deficiency screening is done at entry, comparing the results from a commercially available rapid diagnostic test, the fluorescence spot test, and quantitative testing for accuracy and cost-effectiveness. The comparative safety of the interventions chosen is also being evaluated. DISCUSSION Despite the apparent urgency, the key operational elements of proposed malaria elimination strategies in Southeast Asian mobile and migrant populations, including the Military, have yet to be rigorously tested in a well-controlled clinical study. Here, we present a protocol for the primary evaluation of two treatment paradigms - monthly malaria prophylaxis and focused screening and treatment - to achieve malaria elimination in a Cambodian military population. We will also assess the feasibility and incremental benefit of outdoor-biting vector intervention - permethrin-treated clothing. In the process, we aim to define the cost-effectiveness of the inputs required for success including a responsive information system, skilled human resource and laboratory infrastructure requirements, and quality management. Despite being a relatively low transmission area, the complexities of multi-drug-resistant malaria and the movement of vulnerable populations require an approach that is not only technically sound, but simple enough to be achievable. TRIAL REGISTRATION ClinicalTrials.gov, ID: NCT02653898 . Registered on 13 January 2016.
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31
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Tun KM, Jeeyapant A, Myint AH, Kyaw ZT, Dhorda M, Mukaka M, Cheah PY, Imwong M, Hlaing T, Kyaw TH, Ashley EA, Dondorp A, White NJ, Day NPJ, Smithuis F. Effectiveness and safety of 3 and 5 day courses of artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in an area of emerging artemisinin resistance in Myanmar. Malar J 2018; 17:258. [PMID: 29996844 PMCID: PMC6042398 DOI: 10.1186/s12936-018-2404-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 07/03/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Artemisinin resistance in Plasmodium falciparum has emerged and spread in Southeast Asia. In areas where resistance is established longer courses of artemisinin-based combination therapy have improved cure rates. METHODS The standard 3-day course of artemether-lumefantrine (AL) was compared with an extended 5-day regimen for the treatment of uncomplicated falciparum malaria in Kayin state in South-East Myanmar, an area of emerging artemisinin resistance. Late parasite clearance dynamics were described by microscopy and quantitative ultra-sensitive PCR. Patients were followed up for 42 days. RESULTS Of 154 patients recruited (105 adults and 49 children < 14 years) 78 were randomized to 3 days and 76 to 5 days AL. Mutations in the P. falciparum kelch13 propeller gene (k13) were found in 46% (70/152) of infections, with F446I the most prevalent propeller mutation (29%; 20/70). Both regimens were well-tolerated. Parasite clearance profiles were biphasic with a slower submicroscopic phase which was similar in k13 wild-type and mutant infections. The cure rates were 100% (70/70) and 97% (68/70) in the 3- and 5-day arms respectively. Genotyping of the two recurrences was unsuccessful. CONCLUSION Despite a high prevalence of k13 mutations, the current first-line treatment, AL, was still highly effective in this area of South-East Myanmar. The extended 5 day regimen was very well tolerated, and would be an option to prolong the useful therapeutic life of AL. Trial registration NCT02020330. Registered 24 December 2013, https://clinicaltrials.gov/NCT02020330.
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Affiliation(s)
- Kyaw Myo Tun
- Defence Services Medical Academy, Yangon, Myanmar.
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
| | - Atthanee Jeeyapant
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Aung Hpone Myint
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Medical Action Myanmar, Yangon, Myanmar
| | - Zwe Thiha Kyaw
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Medical Action Myanmar, Yangon, Myanmar
| | - Mehul Dhorda
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Worldwide Antimalarial Resistance Network (WWARN), Asia Regional Centre, Bangkok, Thailand
| | - Mavuto Mukaka
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Phaik Yeong Cheah
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mallika Imwong
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thaung Hlaing
- Department of Health, Ministry of Health and Sports, Naypyidaw, Myanmar
| | - Thar Htun Kyaw
- Department of Health, Ministry of Health and Sports, Naypyidaw, Myanmar
| | - Elizabeth A Ashley
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Arjen Dondorp
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Frank Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Medical Action Myanmar, Yangon, Myanmar
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Roth JM, Sawa P, Omweri G, Osoti V, Makio N, Bradley J, Bousema T, Schallig HDFH, Mens PF. Plasmodium falciparum gametocyte dynamics after pyronaridine-artesunate or artemether-lumefantrine treatment. Malar J 2018; 17:223. [PMID: 29866116 PMCID: PMC5987563 DOI: 10.1186/s12936-018-2373-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/29/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Artemisinin-based combinations differ in their impact on gametocyte prevalence and density. This study assessed female and male gametocyte dynamics after treating children with uncomplicated Plasmodium falciparum malaria with either pyronaridine-artesunate (PA) or artemether-lumefantrine (AL). METHODS Kenyan children with uncomplicated Plasmodium falciparum malaria were included and randomly assigned to PA or AL treatment. Filter paper blood samples were collected as a source of RNA for quantitative reverse-transcription PCR (qRT-PCR) and nucleic acid sequence based amplification (QT-NASBA) to detect female gametocytes (targeting Pfs25 mRNA). Male gametocytes were detected by qRT-PCR (targeting PfMGET mRNA). Duration of gametocyte carriage, the female and male gametocyte response and the agreement between qRT-PCR and QT-NASBA were determined. RESULTS The mean duration of female gametocyte carriage was significantly longer for PA (4.9 days) than for AL (3.8 days) as estimated by QT-NASBA (P = 0.036), but this difference was less clear when determined by Pfs25 qRT-PCR (4.5 days for PA and 3.7 for AL, P = 0.166). qRT-PCR based female gametocyte prevalence decreased from 100% (75/75) at baseline to 6.06% (4/66) at day 14 in the AL group and from 97.7% (83/85) to 13.9% (11/79) in the PA group. Male gametocyte prevalence decreased from 41.3% (31/75) at baseline to 19.7% (13/66) at day 14 in the AL group and from 35.3% (30/85) to 22.8% (18/79) in the PA group. There was good agreement between Pfs25 qRT-PCR and QT-NASBA female gametocyte prevalence (0.85, 95% CI 0.82-0.87). CONCLUSIONS This study indicates that female gametocyte clearance may be slightly faster after AL compared to PA. Male gametocytes showed similar post-treatment clearance between study arms. Future studies should further address potential differences between the post-treatment transmission potential after PA compared to AL. Trial registration This study is registered at clinicaltrials.gov under NCT02411994. Registration date: 8 April 2015. https://clinicaltrials.gov/ct2/show/NCT02411994?term=pyronaridine-artesunate&cond=Malaria&cntry=KE&rank=1.
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Affiliation(s)
- Johanna M Roth
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Patrick Sawa
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - George Omweri
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - Victor Osoti
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - Nicodemus Makio
- Human Health Division, International Centre of Insect Physiology and Ecology, Mbita Point, Kenya
| | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Henk D F H Schallig
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Pètra F Mens
- Department of Medical Microbiology, Laboratory for Clinical Parasitology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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Tine RC, Sylla K, Faye BT, Poirot E, Fall FB, Sow D, Wang D, Ndiaye M, Ndiaye JL, Faye B, Greenwood B, Gaye O, Milligan P. Safety and Efficacy of Adding a Single Low Dose of Primaquine to the Treatment of Adult Patients With Plasmodium falciparum Malaria in Senegal, to Reduce Gametocyte Carriage: A Randomized Controlled Trial. Clin Infect Dis 2018; 65:535-543. [PMID: 28605472 PMCID: PMC5848230 DOI: 10.1093/cid/cix355] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/25/2017] [Indexed: 12/30/2022] Open
Abstract
Introduction More information is needed about the safety of low-dose primaquine in populations where G6PD deficiency is common. Methods Adults with Plasmodium falciparum malaria were randomized to receive 1 of 3 artemisinin combination therapies (ACTs) with or without primaquine (0.25 mg/kg). Glucose-6-phosphate dehydrogenase (G6PD) status was determined using a rapid test. Patients were followed for 28 days to record hemoglobin concentration, adverse events, and gametocyte carriage. The primary end point was the change in Hb at day 7. Results In sum, 274 patients were randomized, 139 received an ACT alone, and 135 received an ACT + primaquine. The mean reduction in Hb at day 7 was similar in each group, a difference in the ACT + PQ versus the ACT alone group of −0.04 g/dL (95% confidence interval [CI] −0.23, 0.31), but the effect of primaquine differed according to G6PD status. In G6PD-deficient patients the drop in Hb was 0.63 g/dL (95% CI 0.03, 1.24) greater in those who received primaquine than in those who received an ACT alone. In G6PD-normal patients, the reduction in Hb was 0.22 g/dL (95% CI −0.08, 0.52) less in those who received primaquine (interaction P = .01). One G6PD normal patient who received primaquine developed moderately severe anaemia (Hb < 8 g/dL). Dark urine was more frequent in patients who received primaquine. Primaquine was associated with a 73% (95% CI 24–90) reduction in gametocyte carriage (P = .013). Conclusion Primaquine substantially reduced gametocyte carriage. However, the fall in Hb concentration at day 7 was greater in G6PD-deficient patients who received primaquine than in those who did not and one patient who received primaquine developed moderately severe anemia. Clinical Trial registration PACTR201411000937373 (www.pactr.org)
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Affiliation(s)
- Roger C Tine
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Khadime Sylla
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Babacar T Faye
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Eugenie Poirot
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco
| | - Fatou B Fall
- National Malaria Control Programme, Ministère de la Santé et de l'Action sociale, Dakar, Senegal
| | - Doudou Sow
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Duolao Wang
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Magatte Ndiaye
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Jean Louis Ndiaye
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Babacar Faye
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Oumar Gaye
- Department of Medical Parasitology, Faculty of Medicine, University Cheikh Anta Diop, Dakar, Senegal
| | - Paul Milligan
- Faculty of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Schaber CL, Katta N, Bollinger LB, Mwale M, Mlotha-Mitole R, Trehan I, Raman B, Odom John AR. Breathprinting Reveals Malaria-Associated Biomarkers and Mosquito Attractants. J Infect Dis 2018; 217:1553-1560. [PMID: 29415208 PMCID: PMC6279169 DOI: 10.1093/infdis/jiy072] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/31/2018] [Indexed: 01/19/2023] Open
Abstract
Current evidence suggests that malarial infection could alter metabolites in the breath of patients, a phenomenon that could be exploited to create a breath-based diagnostic test. However, no study has explored this in a clinical setting. To investigate whether natural human malarial infection leads to a characteristic breath profile, we performed a field study in Malawi. Breath volatiles from children with and those without uncomplicated falciparum malaria were analyzed by thermal desorption-gas chromatography/mass spectrometry. Using an unbiased, correlation-based analysis, we found that children with malaria have a distinct shift in overall breath composition. Highly accurate classification of infection status was achieved with a suite of 6 compounds. In addition, we found that infection correlates with significantly higher breath levels of 2 mosquito-attractant terpenes, α-pinene and 3-carene. These findings attest to the viability of breath analysis for malaria diagnosis, identify candidate biomarkers, and identify plausible chemical mediators for increased mosquito attraction to patients infected with malaria parasites.
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Affiliation(s)
- Chad L Schaber
- Department of Pediatrics, St. Louis, Missouri
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri
| | - Nalin Katta
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | | | - Mwawi Mwale
- Lilongwe District Health Office, Malawi Ministry of Health, Blantyre, Malawi
| | - Rachel Mlotha-Mitole
- Department of Pediatrics and Child Health, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Pediatrics, Kamuzu Central Hospital, Lilongwe, Malawi
| | - Indi Trehan
- Department of Pediatrics, St. Louis, Missouri
- Department of Pediatrics and Child Health, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Pediatrics, Kamuzu Central Hospital, Lilongwe, Malawi
| | - Barani Raman
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri
| | - Audrey R Odom John
- Department of Pediatrics, St. Louis, Missouri
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri
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Understanding human genetic factors influencing primaquine safety and efficacy to guide primaquine roll-out in a pre-elimination setting in southern Africa. Malar J 2018; 17:120. [PMID: 29558929 PMCID: PMC5859786 DOI: 10.1186/s12936-018-2271-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/13/2018] [Indexed: 12/27/2022] Open
Abstract
Background Primaquine (PQ) is recommended as an addition to standard malaria treatments in pre-elimination settings due to its pronounced activity against mature Plasmodium falciparum gametocytes, the parasite stage responsible for onward transmission to mosquitoes. However, PQ may trigger haemolysis in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. Additional human genetic factors, including polymorphisms in the human cytochrome P450 2D6 (CYP2D6) complex, may negatively influence the efficacy of PQ. This study assessed the prevalence of G6PD deficiency and two important CYP2D6 variants in representative pre-elimination settings in South Africa, to inform malaria elimination strategies. Methods Volunteers (n = 248) attending six primary health care facilities in a malaria-endemic region of South Africa were enrolled between October and November 2015. G6PD status was determined phenotypically, using a CareStart™ G6PD rapid diagnostic test (RDT), and genotypically for two common African G6PD variants, namely A+ (A376G) and A− (G202A, A542T, G680T & T968C) by PCR, restriction fragment length polymorphisms (RFLP) and DNA sequencing. CYP2D6*4 and CYP2D6*17 variants were determined with PCR and RFLP. Results A prevalence of 13% (33/248) G6PD deficiency was observed in the cohort by G6PD RDT whilst by genotypic assessment, 32% (79/248) were A+ and 3.2% were A−, respectively. Among the male participants, 11% (6/55) were G6PD A− hemizygous; among females 1% (2/193) were G6PD A− homozygous and 16% (32/193) G6PD A− heterozygous. The strength of agreement between phenotyping and genotyping result was fair (Cohens Kappa κ = 0.310). The negative predictive value for the G6PD RDT for detecting hemizygous, homozygous and heterozygous individuals was 0.88 (95% CI 0.85–0.91), compared to the more sensitive genotyping. The CYP2D6*4 allele frequencies for CYP2D6*4 (inferred poor metabolizer phenotype) and CYP2D6*17 (inferred intermediate metabolizer phenotype) were 3.2 and 19.5%, respectively. Conclusions Phenotypic and genotypic analyses both detected low prevalence of G6PD deficiency and the CYP2D6*4 variants. These findings, combined with increasing data confirming safety of single low-dose PQ in individuals with African variants of G6PD deficiency, supports the deployment of single low-dose PQ as a gametocytocidal drug. PQ would pose minimal risks to the study populations and could be a useful elimination strategy in the study area.
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Graves PM, Choi L, Gelband H, Garner P. Primaquine or other 8-aminoquinolines for reducing Plasmodium falciparum transmission. Cochrane Database Syst Rev 2018; 2:CD008152. [PMID: 29393511 PMCID: PMC5815493 DOI: 10.1002/14651858.cd008152.pub5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The 8-aminoquinoline (8AQ) drugs act on Plasmodium falciparum gametocytes, which transmit malaria from infected people to mosquitoes. In 2012, the World Health Organization (WHO) recommended a single dose of 0.25 mg/kg primaquine (PQ) be added to malaria treatment schedules in low-transmission areas or those with artemisinin resistance. This replaced the previous recommendation of 0.75 mg/kg, aiming to reduce haemolysis risk in people with glucose-6-phosphate dehydrogenase deficiency, common in people living in malarious areas. Whether this approach, and at this dose, is effective in reducing transmission is not clear. OBJECTIVES To assess the effects of single dose or short-course PQ (or an alternative 8AQ) alongside treatment for people with P. falciparum malaria. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; and the WHO International Clinical Trials Registry Platform (ICRTP) portal using 'malaria*', 'falciparum', 'primaquine', '8-aminoquinoline', and eight 8AQ drug names as search terms. We checked reference lists of included trials, and contacted researchers and organizations. Date of last search: 21 July 2017. SELECTION CRITERIA Randomized controlled trials (RCTs) or quasi-RCTs in children or adults, adding PQ (or alternative 8AQ) as a single dose or short course alongside treatment for P. falciparum malaria. DATA COLLECTION AND ANALYSIS Two authors screened abstracts, applied inclusion criteria, and extracted data. We sought evidence on transmission (community incidence), infectiousness (people infectious and mosquitoes infected), and potential infectiousness (gametocyte measures assessed by microscopy or polymerase chain reaction [PCR]). We grouped trials into artemisinin and non-artemisinin treatments, and stratified by PQ dose (low, 0.2 to 0.25 mg/kg; moderate, 0.4 to 0.5 mg/kg; high, 0.75 mg/kg). We used GRADE, and absolute effects of infectiousness using trial control groups. MAIN RESULTS We included 24 RCTs and one quasi-RCT, comprising 43 arms. Fourteen trials evaluated artemisinin treatments (23 arms), nine trials evaluated non-artemisinin treatments (13 arms), and two trials included both artemisinin and non-artemisinin arms (three and two arms, respectively). Two trial arms used bulaquine. Seven PQ arms used low dose (six with artemisinin), 11 arms used moderate dose (seven with artemisinin), and the remaining arms used high dose. Fifteen trials tested for G6PD status: 11 excluded participants with G6PD deficiency, one included only those with G6PD deficiency, and three included all, irrespective of status. The remaining 10 trials either did not test or did not report on testing.No cluster trials evaluating community effects on malaria transmission met the inclusion criteria.With artemisinin treatmentLow dose PQInfectiousness (participants infectious to mosquitoes) was reduced (day 3 or 4: RR 0.12, 95% CI 0.02 to 0.88, 3 trials, 105 participants; day 8: RR 0.34, 95% CI 0.07 to 1.58, 4 trials, 243 participants; low certainty evidence). This translates to a reduction in percentage of people infectious on day 3 or 4 from 14% to 2%, and, for day 8, from 4% to 1%; the waning infectiousness in the control group by day 8 making the absolute effect smaller by day 8. For gametocytes detected by PCR, there was little or no effect of PQ at day 3 or 4 (RR 1.02, 95% CI 0.87 to 1.21; 3 trials, 414 participants; moderate certainty evidence); with reduction at day 8 (RR 0.52, 95% CI 0.41 to 0.65; 4 trials, 532 participants; high certainty evidence). Severe haemolysis was infrequent, with or without PQ, in these groups with few G6PD-deficient individuals (RR 0.98, 95% CI 0.69 to 1.39; 4 trials, 752 participants, moderate certainty evidence).Moderate dose PQInfectiousness was reduced (day 3 or 4: RR 0.13, 95% CI 0.02 to 0.94; 3 trials, 109 participants; day 8 RR 0.33, 95% CI 0.07 to 1.57; 4 trials, 246 participants; low certainty evidence). Illustrative risk estimates for moderate dose were the same as low dose. The pattern and level of certainty of evidence with gametocytes detected by PCR was the same as low dose, and severe haemolysis was infrequent in both groups.High dose PQInfectiousness was reduced (day 4: RR 0.2, 95% CI 0.02 to 1.68, 1 trial, 101 participants; day 8: RR 0.18, 95% CI 0.02 to 1.41, 2 trials, 181 participants, low certainty evidence). The effects on gametocyte prevalence showed a similar pattern to moderate and low dose PQ. Trials did not systematically report evidence of haemolysis.With non-artemisinin treatmentTrials with non-artemisinin treatment have been conducted only for moderate and high dose PQ. With high dose, infectiousness appeared markedly reduced on day 5 (RR 0.09, 95% CI 0.01 to 0.62; 30 participants, very low certainty evidence), with similar reductions at day 8. For both moderate dose (two trials with 221 people) and high dose (two trials with 30 people), reduction in gametocytes (detected by microscopy) showed similar patterns as for artemisinin treatments, with little or no effect at day 4 or 5, and larger effects by day 8. No trials with non-artemisinin partner drugs systematically sought evidence of severe haemolysis.Two trials comparing bulaquine with PQ suggest bulaquine may have larger effects on gametocytes by microscopy on day 8 (RR 0.41, 95% CI 0.26 to 0.66; 2 trials, 112 participants). AUTHORS' CONCLUSIONS A single low dose of PQ (0.25 mg/kg) added to artemisinin-based combination therapy for malaria reduces infectiousness of people to mosquitoes at day 3-4 and day 8, and appears as effective as higher doses. The absolute effect is greater at day 3 or 4, and smaller at day 8, in part because of the lower infectiousness in the control group. There was no evidence of increased haemolysis at 0.25 mg/kg, but few G6PD-deficient individuals were included in the trials. The effect on infectiousness precedes the effect of PQ on gametocyte prevalence. We do not know whether single dose PQ could reduce malaria transmission at community level.
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Affiliation(s)
- Patricia M Graves
- James Cook UniversityCollege of Public Health, Medical and Veterinary SciencesPO Box 6811CairnsQueenslandAustralia4870
| | - Leslie Choi
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
| | | | - Paul Garner
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
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Taylor WR, Naw HK, Maitland K, Williams TN, Kapulu M, D'Alessandro U, Berkley JA, Bejon P, Okebe J, Achan J, Amambua AN, Affara M, Nwakanma D, van Geertruyden JP, Mavoko M, Lutumba P, Matangila J, Brasseur P, Piola P, Randremanana R, Lasry E, Fanello C, Onyamboko M, Schramm B, Yah Z, Jones J, Fairhurst RM, Diakite M, Malenga G, Molyneux M, Rwagacondo C, Obonyo C, Gadisa E, Aseffa A, Loolpapit M, Henry MC, Dorsey G, John C, Sirima SB, Barnes KI, Kremsner P, Day NP, White NJ, Mukaka M. Single low-dose primaquine for blocking transmission of Plasmodium falciparum malaria - a proposed model-derived age-based regimen for sub-Saharan Africa. BMC Med 2018; 16:11. [PMID: 29347975 PMCID: PMC5774032 DOI: 10.1186/s12916-017-0990-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 12/12/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND In 2012, the World Health Organization recommended blocking the transmission of Plasmodium falciparum with single low-dose primaquine (SLDPQ, target dose 0.25 mg base/kg body weight), without testing for glucose-6-phosphate dehydrogenase deficiency (G6PDd), when treating patients with uncomplicated falciparum malaria. We sought to develop an age-based SLDPQ regimen that would be suitable for sub-Saharan Africa. METHODS Using data on the anti-infectivity efficacy and tolerability of primaquine (PQ), the epidemiology of anaemia, and the risks of PQ-induced acute haemolytic anaemia (AHA) and clinically significant anaemia (CSA), we prospectively defined therapeutic-dose ranges of 0.15-0.4 mg PQ base/kg for children aged 1-5 years and 0.15-0.5 mg PQ base/kg for individuals aged ≥6 years (therapeutic indices 2.7 and 3.3, respectively). We chose 1.25 mg PQ base for infants aged 6-11 months because they have the highest rate of baseline anaemia and the highest risks of AHA and CSA. We modelled an anthropometric database of 661,979 African individuals aged ≥6 months (549,127 healthy individuals, 28,466 malaria patients and 84,386 individuals with other infections/illnesses) by the Box-Cox transformation power exponential and tested PQ doses of 1-15 mg base, selecting dosing groups based on calculated mg/kg PQ doses. RESULTS From the Box-Cox transformation power exponential model, five age categories were selected: (i) 6-11 months (n = 39,886, 6.03%), (ii) 1-5 years (n = 261,036, 45.46%), (iii) 6-9 years (n = 20,770, 3.14%), (iv) 10-14 years (n = 12,155, 1.84%) and (v) ≥15 years (n = 328,132, 49.57%) to receive 1.25, 2.5, 5, 7.5 and 15 mg PQ base for corresponding median (1st and 99th centiles) mg/kg PQ base of: (i) 0.16 (0.12-0.25), (ii) 0.21 (0.13-0.37), (iii) 0.25 (0.16-0.38), (iv) 0.26 (0.15-0.38) and (v) 0.27 (0.17-0.40). The proportions of individuals predicted to receive optimal therapeutic PQ doses were: 73.2 (29,180/39,886), 93.7 (244,537/261,036), 99.6 (20,690/20,770), 99.4 (12,086/12,155) and 99.8% (327,620/328,132), respectively. CONCLUSIONS We plan to test the safety of this age-based dosing regimen in a large randomised placebo-controlled trial (ISRCTN11594437) of uncomplicated falciparum malaria in G6PDd African children aged 0.5 - 11 years. If the regimen is safe and demonstrates adequate pharmacokinetics, it should be used to support malaria elimination.
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Affiliation(s)
- W Robert Taylor
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Division of Tropical and Humanitarian Medicine, University Hospitals of Geneva, Geneva, Switzerland.
| | - Htee Khu Naw
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
- Wellcome Trust Centre for Clinical Tropical Medicine and Department of Paediatrics, Faculty of Medicine, Imperial College, London, UK
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
- Wellcome Trust Centre for Clinical Tropical Medicine and Department of Paediatrics, Faculty of Medicine, Imperial College, London, UK
| | - Melissa Kapulu
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Umberto D'Alessandro
- MRC Unit, Fajara, Banjul, The Gambia
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - James A Berkley
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Philip Bejon
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | | | | | | | | | | | | | - Muhindo Mavoko
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Pascal Lutumba
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Junior Matangila
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | | | - Patrice Piola
- Institut Pasteur de Madagascar, BP 1274, Antananarivo, Madagascar
| | | | - Estrella Lasry
- Kinshasa Mahidol Oxford Research Unit, Kinshasa, Democratic Republic of Congo
| | - Caterina Fanello
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | - Marie Onyamboko
- Kinshasa Mahidol Oxford Research Unit, Kinshasa, Democratic Republic of Congo
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | | | - Zolia Yah
- National Malaria Control Programme, Monrovia, Sierra Leone
| | - Joel Jones
- National Malaria Control Programme, Monrovia, Sierra Leone
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | | | - Malcolm Molyneux
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | | | | | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | | | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Chandy John
- Department of Pediatrics, Indiana University, Indianapolis, IN, USA
| | - Sodiomon B Sirima
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
- Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Karen I Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Peter Kremsner
- Institute of Tropical Medicine, University of Tubingen, Tubingen, Germany
| | - Nicholas P Day
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Bastiaens GJH, Tiono AB, Okebe J, Pett HE, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Bradley J, Lanke KHW, Niemi M, Sirima SB, d’Alessandro U, Bousema T, Drakeley C. Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials. PLoS One 2018; 13:e0190272. [PMID: 29324864 PMCID: PMC5764271 DOI: 10.1371/journal.pone.0190272] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022] Open
Abstract
Background Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. Methods and findings In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. Conclusions Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the study participants developed moderate or severe anemia; there were no severe adverse events. This indicates that single low-dose PQ is safe in G6PDd African males when used with artemisinin-based combination therapy. Trial registration Clinicaltrials.gov NCT02174900 Clinicaltrials.gov NCT02654730
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Affiliation(s)
- Guido J. H. Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
| | - Alfred B. Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Helmi E. Pett
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sam A. Coulibaly
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner P. Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Muna Affara
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Edith C. Bougouma
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Guillaume S. Sanou
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Kjerstin H. W. Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sodiomon B. Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Umberto d’Alessandro
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
- Department of Disease Control, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Wadi I, Pillai CR, Anvikar AR, Sinha A, Nath M, Valecha N. Methylene blue induced morphological deformations in Plasmodium falciparum gametocytes: implications for transmission-blocking. Malar J 2018; 17:11. [PMID: 29310655 PMCID: PMC5759873 DOI: 10.1186/s12936-017-2153-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/23/2017] [Indexed: 12/24/2022] Open
Abstract
Background Malaria remains a global health problem despite availability of effective tools. For malaria elimination, drugs targeting sexual stages of Plasmodium falciparum need to be incorporated in treatment regimen along with schizonticidal drugs to interrupt transmission. Primaquine is recommended as a transmission blocking drug for its effect on mature gametocytes but is not extensively utilized because of associated safety concerns among glucose-6-phosphate dehydrogenase (G6PD) deficient patients. In present work, methylene blue, which is proposed as an alternative to primaquine is investigated for its gametocytocidal activity amongst Indian field isolates. An effort has been made to establish Indian field isolates of P. falciparum as in vitro model for gametocytocidal drugs screening. Methods Plasmodium falciparum isolates were adapted to in vitro culture and induced to gametocyte production by hypoxanthine and culture was enriched for gametocyte stages using N-acetyl-glucosamine. Gametocytes were incubated with methylene blue for 48 h and stage specific gametocytocidal activity was evaluated by microscopic examination. Results Plasmodium falciparum field isolates RKL-9 and JDP-8 were able to reproducibly produce gametocytes in high yield and were used to screen gametocytocidal drugs. Methylene blue was found to target gametocytes in a concentration dependent manner by either completely eliminating gametocytes or rendering them morphologically deformed with mean IC50 (early stages) as 424.1 nM and mean IC50 (late stages) as 106.4 nM. These morphologically altered gametocytes appeared highly degenerated having shrinkage, distortions and membrane deformations. Conclusions Field isolates that produce gametocytes in high yield in vitro can be identified and used to screen gametocytocidal drugs. These isolates should be used for validation of gametocytocidal hits obtained previously by using lab adapted reference strains. Methylene blue was found to target gametocytes produced from Indian field isolates and is proposed to be used as a gametocytocidal adjunct with artemisinin-based combination therapy. Further exploration of methylene blue in clinical studies amongst Indian population, including G6PD deficient patients, is recommended.
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Affiliation(s)
- Ishan Wadi
- Indian Council of Medical Research-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India. .,Department of Chemistry, University of Delhi, Delhi, 110007, India.
| | - C Radhakrishna Pillai
- Indian Council of Medical Research-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India
| | - Anupkumar R Anvikar
- Indian Council of Medical Research-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India
| | - Abhinav Sinha
- Indian Council of Medical Research-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India
| | - Mahendra Nath
- Department of Chemistry, University of Delhi, Delhi, 110007, India
| | - Neena Valecha
- Indian Council of Medical Research-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India
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40
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Bousema T, Drakeley C. Determinants of Malaria Transmission at the Population Level. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025510. [PMID: 28242786 DOI: 10.1101/cshperspect.a025510] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transmission of malaria from man to mosquito defines the human infectious reservoir of malaria. At the population level this is influenced by a variety of human, parasite, and mosquito vector factors some or all of which may vary depending on the epidemiological setting. Here, we review our current state of knowledge related to human infectiousness to mosquitoes and how current malaria control strategies might be adapted to focus on reducing this. While much progress has been made in malaria control, we argue that an improved understanding of human infectivity will allow more effective use of current control tools and make elimination a more feasible goal.
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Affiliation(s)
- Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands.,Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Chris Drakeley
- Department of Immunology & Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
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41
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Achan J, Mwesigwa J, Edwin CP, D'alessandro U. Malaria medicines to address drug resistance and support malaria elimination efforts. Expert Rev Clin Pharmacol 2017; 11:61-70. [PMID: 28965427 DOI: 10.1080/17512433.2018.1387773] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Antimalarial drugs are essential weapons to fight malaria and have been used effectively since the 17th century. However, P.falciparum resistance has been reported to almost all available antimalarial drugs, including artemisinin derivatives, raising concerns that this could jeopardize malaria elimination. Areas covered: In this article, we present a historical perspective of antimalarial drug resistance, review current evidence of resistance to available antimalarial drugs and discuss possible mitigating strategies to address this challenge. Expert commentary: The historical approach to drug resistance has been to change the national treatment policy to an alternative treatment. However, alternatives to artemisinin-based combination treatment are currently extremely limited. Innovative approaches utilizing available schizonticidal drugs such as triple combination therapies or multiple first line treatments could delay the emergence and spread of drug resistance. Transmission blocking drugs like primaquine may play a key role if given to a substantial proportion of malaria infected persons. Deploying antimalarial medicines in mass drug administration or mass screening and treatment campaigns could also contribute to containment efforts by eliminating resistant parasites in some settings. Ultimately, response to drug resistance should also include further investment in the development of new antimalarial drugs.
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Affiliation(s)
- Jane Achan
- a Disease Control and Elimination Theme , Medical Research Council Unit , Banjul , The Gambia
| | - Julia Mwesigwa
- a Disease Control and Elimination Theme , Medical Research Council Unit , Banjul , The Gambia
| | | | - Umberto D'alessandro
- a Disease Control and Elimination Theme , Medical Research Council Unit , Banjul , The Gambia.,c Department of Disease Control , London School of Hygiene and Tropical Medicine , London , UK
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Stone W, Sawa P, Lanke K, Rijpma S, Oriango R, Nyaurah M, Osodo P, Osoti V, Mahamar A, Diawara H, Woestenenk R, Graumans W, van de Vegte-Bolmer M, Bradley J, Chen I, Brown J, Siciliano G, Alano P, Gosling R, Dicko A, Drakeley C, Bousema T. A Molecular Assay to Quantify Male and Female Plasmodium falciparum Gametocytes: Results From 2 Randomized Controlled Trials Using Primaquine for Gametocyte Clearance. J Infect Dis 2017; 216:457-467. [PMID: 28931236 PMCID: PMC5853855 DOI: 10.1093/infdis/jix237] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Single low-dose primaquine (PQ) reduces Plasmodium falciparum infectivity before it impacts gametocyte density. Here, we examined the effect of PQ on gametocyte sex ratio as a possible explanation for this early sterilizing effect. Methods Quantitative reverse-transcription polymerase chain reaction assays were developed to quantify female gametocytes (targeting Pfs25 messenger RNA [mRNA]) and male gametocytes (targeting Pf3D7_1469900 mRNA) in 2 randomized trials in Kenya and Mali, comparing dihydroartemisinin-piperaquine (DP) alone to DP with PQ. Gametocyte sex ratio was examined in relation to time since treatment and infectivity to mosquitoes. Results In Kenya, the median proportion of male gametocytes was 0.33 at baseline. Seven days after treatment, gametocyte density was significantly reduced in the DP-PQ arm relative to the DP arm (females: 0.05% [interquartile range {IQR}, 0.0–0.7%] of baseline; males: 3.4% [IQR, 0.4%–32.9%] of baseline; P < .001). Twenty-four hours after treatment, gametocyte sex ratio became male-biased and was not significantly different between the DP and DP-PQ groups. In Mali, there was no significant difference in sex ratio between the DP and DP-PQ groups (>0.125 mg/kg) 48 hours after treatment, and gametocyte sex ratio was not associated with mosquito infection rates. Conclusions The early sterilizing effects of PQ may not be explained by the preferential clearance of male gametocytes and may be due to an effect on gametocyte fitness.
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Affiliation(s)
- Will Stone
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Patrick Sawa
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sanna Rijpma
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robin Oriango
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Maureen Nyaurah
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Paul Osodo
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Victor Osoti
- Human Health Division, International Centre for Insect Physiology and Ecology, Mbita Point, Kenya
| | - Almahamoudou Mahamar
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Halimatou Diawara
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Rob Woestenenk
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Ingrid Chen
- Global Health Group, Malaria Elimination Initiative
| | - Joelle Brown
- Department of Epidemiology and Biostatistics, University of California, San Francisco
| | - Giulia Siciliano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Roly Gosling
- Global Health Group, Malaria Elimination Initiative.,Department of Epidemiology and Biostatistics, University of California, San Francisco
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Mali
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, United Kingdom
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43
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Uthman OA, Graves PM, Saunders R, Gelband H, Richardson M, Garner P. Safety of primaquine given to people with G6PD deficiency: systematic review of prospective studies. Malar J 2017; 16:346. [PMID: 28830424 PMCID: PMC5568268 DOI: 10.1186/s12936-017-1989-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/09/2017] [Indexed: 12/15/2022] Open
Abstract
Background Haemolysis risk with single dose or short course primaquine was evaluated in glucose-6-phosphate dehydrogenase (G6PD) deficient people. Methods Major electronic databases (to August 2016) were searched for single or short course 8-aminoquinolines (8-AQ) in (1) randomized comparisons against placebo in G6PD deficient people; and (2) observational comparisons in G6PD deficient compared to replete people. Two authors independently assessed eligibility, risk-of-bias, and extracted data. Results Five randomized controlled trials and four controlled observational cohorts were included. In G6PD deficient individuals, high-dose (0.75 mg/kg) PQ resulted in lower average haemoglobin levels at 7 days (mean difference [MD] −1.45 g/dl, 95% CI −2.17 to −0.74, 2 trials) and larger percentage fall from baseline to day 7 (MD −10.31%, 95% CI −17.69 to −2.92, 3 trials) compared to placebo. In G6PD deficient compared to replete people, average haemoglobin was lower at 7 days (MD −1.19 g/dl, 95% CI −1.94 to −0.44, 2 trials) and haemoglobin change from baseline to day 7 was greater (MD −9.10%, 95% CI −12.55 to −5.65, 5 trials). One small trial evaluated mid-range PQ dose (0.4–0.5 mg/kg) in G6PD deficient people, with no difference detected in average haemoglobin at day 7 compared to placebo. In one cohort comparing G6PD deficient and replete people there was a greater fall with G6PD deficiency (MD −4.99%, 95% CI −9.96 to −0.02). For low-dose PQ (0.1–0.25 mg/kg) in G6PD deficient people, haemoglobin change from baseline was similar to the placebo group (MD 1.72%, 95% CI −1.89 to 5.34, 2 trials). Comparing low dose PQ in G6PD deficient with replete people, the average haemoglobin was lower in the G6PD deficient group at 7 days (−0.57 g (95% CI −0.97 to −0.17, 1 trial)); although change from baseline was similar (MD −1.45%, 95% CI −5.69 to 2.78, 3 trials). Conclusions Falls in average haemoglobin are less marked with the 0.1 to 0.25 mg/kg PQ than with the 0.75 mg/kg dose, and severe haemolytic events are not common. However, data were limited and the evidence GRADE was low or very low certainty. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1989-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Olalekan A Uthman
- Centre for Evidence Synthesis in Global Health, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK. .,Warwick Centre for Applied Health Research and Delivery (WCAHRD), Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
| | - Patricia M Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Australia
| | - Rachel Saunders
- Centre for Evidence Synthesis in Global Health, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Hellen Gelband
- Cochrane Infectious Disease Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Marty Richardson
- Centre for Evidence Synthesis in Global Health, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Paul Garner
- Centre for Evidence Synthesis in Global Health, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
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Tadesse FG, Lanke K, Nebie I, Schildkraut JA, Gonçalves BP, Tiono AB, Sauerwein R, Drakeley C, Bousema T, Rijpma SR. Molecular Markers for Sensitive Detection of Plasmodium falciparum Asexual Stage Parasites and their Application in a Malaria Clinical Trial. Am J Trop Med Hyg 2017; 97:188-198. [PMID: 28719294 PMCID: PMC5508903 DOI: 10.4269/ajtmh.16-0893] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum parasite life stages respond differently to antimalarial drugs. Sensitive stage-specific molecular assays may help to examine parasite dynamics at microscopically detectable and submicroscopic parasite densities in epidemiological and clinical studies. In this study, we compared the performance of skeleton-binding protein 1 (SBP1), ring-infected erythrocyte surface antigen, Hyp8, ring-exported protein 1 (REX1), and PHISTb mRNA for detecting ring-stage trophozoite-specific transcripts using quantitative reverse transcriptase polymerase chain reaction. Markers were tested on tightly synchronized in vitro parasites and clinical trial samples alongside established markers of parasite density (18S DNA and rRNA) and gametocyte density (Pfs25 mRNA). SBP1 was the most sensitive marker but showed low-level expression in mature gametocytes. Novel markers REX1 and PHISTb showed lower sensitivity but higher specificity for ring-stage trophozoites. Using in vivo clinical trial samples from gametocyte-negative patients, we observed evidence of persisting trophozoite transcripts for at least 14 days postinitiation of treatment. It is currently not clear if these transcripts represent viable parasites that may have implications for clinical treatment outcome or transmission potential.
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Affiliation(s)
- Fitsum G Tadesse
- Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.,Medical Biotechnology Unit, Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Issa Nebie
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou,Burkina Faso
| | - Jodie A Schildkraut
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alfred B Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou,Burkina Faso
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Sanna R Rijpma
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
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45
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Arroyo-Arroyo M, Arango E, Carmona-Fonseca J, Aristizabal B, Yanow S, Maestre A. Efficacy of Different Primaquine Regimens to Control Plasmodium falciparum Gametocytemia in Colombia. Am J Trop Med Hyg 2017; 97:712-718. [PMID: 28749756 DOI: 10.4269/ajtmh.16-0974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Treatment against Plasmodium falciparum malaria includes blood schizonticides to clear asexual parasites responsible for disease. The addition of gametocytocidal drugs can eliminate infectious sexual stages with potential for transmission and the World Health Organization recommends a single dose (SD) of primaquine (PQ) to this end. The efficacy of PQ at 0.75 mg/kg to suppress gametocytemia when administered in single or fractionated doses was evaluated. A clinical controlled study with an open-label design was executed; three groups of 20 subjects were studied sequentially. All subjects were treated with the standard dose of artemether-lumefantrine plus the total dose of 0.75 mg/kg of PQ administered (without previous G6PD testing) in three different ways: Group "0.75d-3" received 0.75 mg/kg on day 3; Group "0.50d-1 + 0.25d-3" received 0.50 mg/kg on day 1 and 0.25 mg/kg on day 3; Group "0.25d-1,2,3" received 0.25 mg/kg on days 1, 2, and 3. Subjects were evaluated on days 1, 4, and 7 by thick smear microscopy and quantitative polymerase chain reaction to determine the carriage of immature and mature gametocytes. There were no adverse events. The three schemes caused a marked reduction (75-85%) in prevalence of gametocytes on day 4 compared with day 1, but only the group that received 0.75 mg/kg on day 3 maintained the reduced gametocyte burden until day 7. None of the three treatments were able to clear gametocyte carriage on days 4 or 7, but the group that received the SD had the lowest prevalence of gametocytes (15%). Further studies are needed to establish a PQ regimen with complete efficacy against gametocytes.
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Affiliation(s)
- Maria Arroyo-Arroyo
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
| | - Eliana Arango
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
| | - Jaime Carmona-Fonseca
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
| | - Beatriz Aristizabal
- Laboratorio de Biología Molecular, Hospital Pablo Tobon Uribe, Medellin, Colombia
| | - Stephanie Yanow
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Amanda Maestre
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
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Effects of liver-stage clearance by Primaquine on gametocyte carriage of Plasmodium vivax and P. falciparum. PLoS Negl Trop Dis 2017; 11:e0005753. [PMID: 28732068 PMCID: PMC5540608 DOI: 10.1371/journal.pntd.0005753] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/02/2017] [Accepted: 06/27/2017] [Indexed: 01/08/2023] Open
Abstract
Background Primaquine (PQ) is the only currently licensed antimalarial that prevents Plasmodium vivax (Pv) relapses. It also clears mature P. falciparum (Pf) gametocytes, thereby reducing post-treatment transmission. Randomized PQ treatment in a treatment-to-reinfection cohort in Papua New Guinean children permitted the study of Pv and Pf gametocyte carriage after radical cure and to investigate the contribution of Pv relapses. Methods Children received radical cure with Chloroquine, Artemether-Lumefantrine plus either PQ or placebo. Blood samples were subsequently collected in 2-to 4-weekly intervals over 8 months. Gametocytes were detected by quantitative reverse transcription-PCR targeting pvs25 and pfs25. Results PQ treatment reduced the incidence of Pv gametocytes by 73%, which was comparable to the effect of PQ on incidence of blood-stage infections. 92% of Pv and 79% of Pf gametocyte-positive infections were asymptomatic. Pv and to a lesser extent Pf gametocyte positivity and density were associated with high blood-stage parasite densities. Multivariate analysis revealed that the odds of gametocytes were significantly reduced in mixed-species infections compared to single-species infections for both species (ORPv = 0.39 [95% CI 0.25–0.62], ORPf = 0.33 [95% CI 0.18–0.60], p<0.001). No difference between the PQ and placebo treatment arms was observed in density of Pv gametocytes or in the proportion of Pv infections that carried gametocytes. First infections after blood-stage and placebo treatment, likely caused by a relapsing hypnozoite, were equally likely to carry gametocytes than first infections after PQ treatment, likely caused by an infective mosquito bite. Conclusion Pv relapses and new infections are associated with similar levels of gametocytaemia. Relapses thus contribute considerably to the Pv reservoir highlighting the importance of effective anti-hypnozoite treatment for efficient control of Pv. Trial registration ClinicalTrials.gov NCT02143934 Plasmodium vivax (Pv) mainly affects Asia, Central and South America as well as Ethiopia. In Papua New Guinea (PNG) Pv prevalence is among the highest worldwide. The biggest challenge for the control of Pv infections is the formation of dormant liver stages, which have the ability to relapse and cause disease even after successful clearance of asexual stages in the blood circulation. Primaquine is the only licensed drug that is able to prevent Pv relapses. A randomized treatment-to-reinfection cohort in Papua New Guinean children permitted permitted the study of Pv and P. falciparum gametocyte carriage after radical cure with Primaquine and to investigate the contribution of Pv relapses to transmission. We found that most gametocyte carriers in this study were detected in asymptomatic infections and that relapses and new infections are associated with similar Pv gametocyte production. These are strong arguments emphasizing the importance of sensitive detection and early treatment of asymptomatic and submicroscopic Plasmodium spp. infections and of anti-hypnozoite treatment for an effective control of Pv.
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Single dose primaquine to reduce gametocyte carriage and Plasmodium falciparum transmission in Cambodia: An open-label randomized trial. PLoS One 2017; 12:e0168702. [PMID: 28591198 PMCID: PMC5462369 DOI: 10.1371/journal.pone.0168702] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 11/26/2016] [Indexed: 12/19/2022] Open
Abstract
Background Single low dose primaquine (SLD PQ, 0.25mg/kg) is recommended in combination with artemisinin-based combination therapy (ACT) as a gametocytocide to prevent Plasmodium falciparum transmission in areas threatened by artemisinin resistance. To date, no randomized controlled trials have measured primaquine’s effect on infectiousness to Anopheline mosquitoes in Southeast Asia. Methods Cambodian adults with uncomplicated falciparum malaria were randomized to receive a single 45mg dose of primaquine (equivalent to three SLD PQ) or no primaquine after the third dose of dihydroartemisin-piperaquine (DHP) therapy. A membrane-feeding assay measured infectiousness to Anopheles dirus on days 0, 3, 7, and 14 of blood-stage therapy. Gametocytemia was evaluated by microscopy and reverse-transcriptase PCR. Results Prior to trial halt for poor DHP treatment efficacy, 101 participants were randomized and 50 received primaquine. Overall microscopic gametocyte prevalence was low (9%), but gametocytemic subjects given primaquine were gametocyte-free by day 14, and significantly less likely to harbor gametocytes by day 7 compared to those treated with DHP-alone, who remained gametocytemic for a median of two weeks. Only one infectious subject was randomized to the primaquine group, precluding assessment of transmission-blocking efficacy. However, he showed a two-fold reduction in oocyst density of infected mosquitoes less than 24 hours after primaquine dosing. In the DHP-alone group, four subjects remained infectious through day 14, infecting roughly the same number of mosquitoes pre and post-treatment. Overall, microscopic gametocytemia was an excellent predictor of infectiousness, and performed better than submicroscopic gametocytemia post-treatment, with none of 474 mosquitoes infected post-treatment arising from submicroscopic gametocytes. Conclusions In a setting of established ACT resistance, a single dose of 45mg primaquine added to DHP rapidly and significantly reduced gametocytemia, while DHP-alone failed to reduce gametocytemia and prevent malaria transmission to mosquitoes. Continued efforts to make single dose primaquine widely available are needed to help achieve malaria elimination.
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Age, Weight, and CYP2D6 Genotype Are Major Determinants of Primaquine Pharmacokinetics in African Children. Antimicrob Agents Chemother 2017; 61:AAC.02590-16. [PMID: 28289025 PMCID: PMC5404566 DOI: 10.1128/aac.02590-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/06/2017] [Indexed: 12/22/2022] Open
Abstract
Low-dose primaquine is recommended to prevent Plasmodium falciparum malaria transmission in areas threatened by artemisinin resistance and areas aiming for malaria elimination. Community treatment campaigns with artemisinin-based combination therapy in combination with the gametocytocidal primaquine dose target all age groups, but no studies thus far have assessed the pharmacokinetics of this gametocytocidal drug in African children. We recruited 40 children participating in a primaquine efficacy trial in Burkina Faso to study primaquine pharmacokinetics. These children received artemether-lumefantrine and either a 0.25- or a 0.40-mg/kg primaquine dose. Seven blood samples were collected from each participant for primaquine and carboxy-primaquine plasma levels determinations: one sample was collected before primaquine administration and six after primaquine administration according to partially overlapping sampling schedules. Physiological population pharmacokinetic modeling was used to assess the impact of weight, age, and CYP2D6 genotype on primaquine and carboxy-primaquine pharmacokinetics. Despite linear weight normalized dosing, the areas under the plasma concentration-time curves and the peak concentrations for both primaquine and carboxy-primaquine increased with age and body weight. Children who were CYP2D6 poor metabolizers had higher levels of the parent compound, indicating a lower primaquine CYP2D6-mediated metabolism. Our data indicate that primaquine and carboxy-primaquine pharmacokinetics are influenced by age, weight, and CYP2D6 genotype and suggest that dosing strategies may have to be reconsidered to maximize the transmission-blocking properties of primaquine. (This study has been registered at ClinicalTrials.gov under registration no. NCT01935882.)
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Hayes DJ, Banda CG, Chipasula-Teleka A, Terlouw DJ. Modelling the therapeutic dose range of single low dose primaquine to reduce malaria transmission through age-based dosing. BMC Infect Dis 2017; 17:254. [PMID: 28390397 PMCID: PMC5385020 DOI: 10.1186/s12879-017-2378-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Low-dose primaquine is a key candidate for use in malaria transmission reduction and elimination campaigns such as mass drug administration (MDA). Uncertainty about the therapeutic dose range (TDR) required for general and paediatric populations challenge the implementation of the World Health Organisation's recommendation to add 0.25 mg/kg to current standard antimalarial treatment in such settings. Modelling work shows that for low-dose primaquine to have an impact, high efficacy and extensive population coverage are needed. In practice, age-based dose regimens, often used in MDA, could lead to safety concerns and a different effectiveness profile. We aimed to define TDRs for primaquine and to assess dosing accuracy of age-based dose regimens. METHODS Optimised regional age-based dosing regimens for low-dose primaquine were developed in steps. First, we identified potential TDR options based on suggested published efficacy and safety thresholds (i.e. 0.1-0.4, 0.125-0.375, 0.15-0.35 mg/kg). We then used our previously defined weight-for-age growth references and age-based dose optimisation tool to model predicted regimen accuracies for Africa, Asia and Latin America based on low-dose primaquine tablets (3.75 mg and 7.5 mg) currently under development by Sanofi while employing the identified dose range options and pre-specified regimen characteristics. RESULTS Dose regimens employing TDRs of 0.1-0.4 and 0.125-0.375 mg/kg had the highest average predicted dose accuracies in all regions with the widest dose range of 0.1-0.4 mg/kg resulting in ≥99% dose accuracy in all three regions. The narrower 0.15-0.35 mg/kg range was on average predicted to correctly dose 91.4% of the population in Africa, 93.2% in Asia and 92.6% in Latin America. This range would prescribe ≥20% of 3-year-olds doses below 0.15 mg/kg and ≥20% of 11-year-olds doses above 0.35 mg/kg. Widening the TDR from 0.15-0.35 to 0.1-0.4 mg/kg increased the dose accuracy by ≥20% in Africa, ≥15% in Asia and ≥10% in Latin America. CONCLUSION Optimised age-based dose regimens derived from wider TDRs are predicted to attain the dose accuracies required for effective MDA in malaria transmission reduction and elimination settings. We highlight the need for a clearly defined TDR and for safety and efficacy trials to focus on doses compatible with age-based dosing often employed in such settings.
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Affiliation(s)
- Daniel Joseph Hayes
- Department of Clinical Sciences, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Clifford George Banda
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri Blantyre 3, Malawi
| | - Alexandra Chipasula-Teleka
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri Blantyre 3, Malawi.
| | - Dianne Janette Terlouw
- Department of Clinical Sciences, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK. .,Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri Blantyre 3, Malawi.
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Howes RE, Chan ER, Rakotomanga TA, Schulte S, Gibson J, Zikursh M, Franchard T, Ramiranirina B, Ratsimbasoa A, Zimmerman PA. Prevalence and genetic variants of G6PD deficiency among two Malagasy populations living in Plasmodium vivax-endemic areas. Malar J 2017; 16:139. [PMID: 28376871 PMCID: PMC5381087 DOI: 10.1186/s12936-017-1771-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/08/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The prevalence and variants of G6PD deficiency in the Plasmodium vivax-endemic zones of Madagascar remain unknown. The admixed African-Austronesian origins of the Malagasy population make it probable that a heterogeneous mix of genetic variants with a spectrum of clinical severity will be circulating. This would have implications for the widespread use of P. vivax radical cure therapy. Two study populations in the P. vivax-endemic western foothills region of Madagascar were selected for G6PD screening. Both the qualitative fluorescent spot test and G6PD genotyping were used to screen all participants. RESULTS A total of 365 unrelated male volunteers from the Tsiroanomandidy, Mandoto, and Miandrivazo districts of Madagascar were screened and 12.9% were found to be phenotypically G6PD deficient. Full gene sequencing of 95 samples identified 16 single nucleotide polymorphisms, which were integrated into a genotyping assay. Genotyping (n = 291) found one individual diagnosed with the severe G6PD Mediterranean C563T mutation, while the remaining G6PD deficient samples had mutations of African origin, G6PD A- and G6PD A. CONCLUSIONS Deployment of P. vivax radical cure in Madagascar must be considerate of the risks presented by the observed prevalence of G6PDd prevalence. The potential morbidity associated with cumulative episodes of P. vivax clinical relapses requires a strategy for increasing access to safe radical cure. The observed dominance of African G6PDd haplotypes is surprising given the known mixed African-Austronesian origins of the Malagasy population; more widespread surveying of G6PDd epidemiology across the island would be required to characterize the distribution of G6PD haplotypes across Madagascar.
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Affiliation(s)
- Rosalind E Howes
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA. .,Nuffield Department of Medicine, Oxford Big Data Institute, University of Oxford, Oxford, UK.
| | - Ernest R Chan
- Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Tovonahary Angelo Rakotomanga
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,Faculty of Science, University of Antananarivo, Antananarivo, Madagascar
| | - Seth Schulte
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - John Gibson
- Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Melinda Zikursh
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Thierry Franchard
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,Faculty of Science, University of Antananarivo, Antananarivo, Madagascar
| | - Brune Ramiranirina
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar
| | - Arsène Ratsimbasoa
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,University of Antananarivo, Antananarivo, Madagascar
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA.
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