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Lynch E, Jensen TO, Assao B, Chihana M, Turuho T, Nyehangane D, Manyok JB, Pasquale H, Khim N, Witkowski B, Coldiron ME. Evaluation of HRP2 and pLDH-based rapid diagnostic tests for malaria and prevalence of pfhrp2/3 deletions in Aweil, South Sudan. Malar J 2022; 21:261. [PMID: 36085071 PMCID: PMC9461093 DOI: 10.1186/s12936-022-04280-w] [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: 05/20/2022] [Accepted: 08/26/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid diagnostic tests (RDT) for malaria are the primary tool for malaria diagnosis in sub-Saharan Africa but the utility of the most commonly used histidine-rich protein 2 (HRP2) antigen-based tests is limited in high transmission settings due to the long duration of positivity after successful malaria treatment. HRP2 tests are also threatened by the emergence of Plasmodium that do not carry pfhrp2 or pfhrp 3 genes. Plasmodium lactate dehydrogenase (pLDH)-based tests are promising alternatives, but less available. This study assessed the performances of HRP2 and pLDH(pan) tests under field conditions. METHODS The study performed a prospective facility-based diagnostic evaluation of two malaria RDTs in Aweil, South Sudan, during the high transmission season. Capillary blood by fingerprick was collected from 800 children under 15 years of age with fever and no signs of severity. SD Bioline HRP2 and CareStart pLDH(pan) RDTs were performed in parallel, thick and thin smears for microscopy were examined, and dried blood was used for PCR testing. RESULTS Using microscopy as the gold standard, the sensitivity of both tests was estimated at > 99%, but the specificity of each was lower: 55.0% for the pLDH test and 61.7% for the HRP2 test. When using PCR as the gold standard, the sensitivity of both tests was lower than the values assessed using microscopy (97.0% for pLDH and 96.5% for HRP2), but the specificity increased (65.1% for pLDH and 72.9% for HRP2). Performance was similar across different production lots, sex, and age. Specificity of both the pLDH and HRP2 tests was significantly lower in children who reported taking a therapeutic course of anti-malarials in the 2 months prior to enrollment. The prevalence of pfhrp2/3 deletions in the study population was 0.6%. CONCLUSIONS The low specificity of the pLDH RDT in this setting confirms previous results and suggests a problem with this specific test. The prevalence of pfhrp2/3 deletions in the study area warrants continued monitoring and underscores the relevance of assessing deletion prevalence nationally. Improved malaria RDTs for high-transmission environments are needed.
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Affiliation(s)
- Emily Lynch
- Epicentre, 14-34 Avenue Jean Jaurès, Paris, France.
| | - Tomas O Jensen
- Médecins Sans Frontières, 14-34 Avenue Jean Jaurès, Paris, France.,Center of Excellence for Health, Immunity, and Infections (CHIP) and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | | | | | | | | | - John B Manyok
- Médecins Sans Frontières - France, Aweil, South Sudan
| | | | - Nimol Khim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
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Nundu SS, Arima H, Simpson SV, Chitama BYA, Munyeku YB, Muyembe JJ, Mita T, Ahuka S, Culleton R, Yamamoto T. Low prevalence of Plasmodium falciparum parasites lacking pfhrp2/3 genes among asymptomatic and symptomatic school-age children in Kinshasa, Democratic Republic of Congo. Malar J 2022; 21:126. [PMID: 35439987 PMCID: PMC9020024 DOI: 10.1186/s12936-022-04153-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 04/06/2022] [Indexed: 11/26/2022] Open
Abstract
Background Loss of efficacy of diagnostic tests may lead to untreated or mistreated malaria cases, compromising case management and control. There is an increasing reliance on rapid diagnostic tests (RDTs) for malaria diagnosis, with the most widely used of these targeting the Plasmodium falciparum histidine-rich protein 2 (PfHRP2). There are numerous reports of the deletion of this gene in P. falciparum parasites in some populations, rendering them undetectable by PfHRP2 RDTs. The aim of this study was to identify P. falciparum parasites lacking the P. falciparum histidine rich protein 2 and 3 genes (pfhrp2/3) isolated from asymptomatic and symptomatic school-age children in Kinshasa, Democratic Republic of Congo. Methods The performance of PfHRP2-based RDTs in comparison to microscopy and PCR was assessed using blood samples collected and spotted on Whatman 903™ filter papers between October and November 2019 from school-age children aged 6–14 years. PCR was then used to identify parasite isolates lacking pfhrp2/3 genes. Results Among asymptomatic malaria carriers (N = 266), 49%, 65%, and 70% were microscopy, PfHRP2_RDT, and pfldh-qPCR positive, respectively. The sensitivity and specificity of RDTs compared to PCR were 80% and 70% while the sensitivity and specificity of RDTs compared to microscopy were 92% and 60%, respectively. Among symptomatic malaria carriers (N = 196), 62%, 67%, and 87% were microscopy, PfHRP2-based RDT, pfldh-qPCR and positive, respectively. The sensitivity and specificity of RDTs compared to PCR were 75% and 88%, whereas the sensitivity and specificity of RDTs compared to microscopy were 93% and 77%, respectively. Of 173 samples with sufficient DNA for PCR amplification of pfhrp2/3, deletions of pfhrp2 and pfhrp3 were identified in 2% and 1%, respectively. Three (4%) of samples harboured deletions of the pfhrp2 gene in asymptomatic parasite carriers and one (1%) isolate lacked the pfhrp3 gene among symptomatic parasite carriers in the RDT positive subgroup. No parasites lacking the pfhrp2/3 genes were found in the RDT negative subgroup. Conclusion Plasmodium falciparum histidine-rich protein 2/3 gene deletions are uncommon in the surveyed population, and do not result in diagnostic failure. The use of rigorous PCR methods to identify pfhrp2/3 gene deletions is encouraged in order to minimize the overestimation of their prevalence. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04153-2.
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Affiliation(s)
- Sabin S Nundu
- Programme for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. .,Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. .,Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo.
| | - Hiroaki Arima
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Shirley V Simpson
- Programme for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Ben-Yeddy Abel Chitama
- Department of Protozoology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Yannick Bazitama Munyeku
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Jean-Jacques Muyembe
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Toshihiro Mita
- Department of Tropical Medicine and Parasitology, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Steve Ahuka
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Richard Culleton
- Department of Protozoology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. .,Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Ehime, Japan.
| | - Taro Yamamoto
- Programme for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
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3
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Sinzinkayo D, Baza D, Gnanguenon V, Koepfli C. The lead-up to epidemic transmission: malaria trends and control interventions in Burundi 2000 to 2019. Malar J 2021; 20:298. [PMID: 34215270 PMCID: PMC8249825 DOI: 10.1186/s12936-021-03830-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/23/2021] [Indexed: 11/10/2022] Open
Abstract
Burundi has experienced an increase in malaria cases since 2000, reaching 843,000 cases per million inhabitants in 2019, a more than twofold increase compared to the early 2000s. Burundi thus contrasts the decreasing number of cases in many other African countries. To evaluate the impact of malaria control on this increase, data on interventions from 2000 to 2019 were compiled. Over this period, the number of health facilities increased threefold, and the number of tests 20-fold. The test positivity rate remained stable at around 50-60% in most years. Artemisinin-based combination therapy was introduced in 2003, initially using artesunate-amodiaquine and changed to artemether-lumefantrine in 2019/2020. Mass distribution campaigns of insecticide-treated bed nets were conducted, and indoor residual spraying and intermittent preventive treatment in pregnancy introduced. Thus, the increase in cases was not the result of faltering control activities. Increased testing was likely a key contributor to higher case numbers. Despite the increase in testing, the test positivity rate remined high, indicating that current case numbers might still underestimate the true burden.
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Affiliation(s)
- Denis Sinzinkayo
- University of Burundi, Bujumbura, Burundi.,National Malaria Control Program, Ministry of Health, Bujumbura, Burundi
| | - Dismas Baza
- World Health Organization, Burundi Country Office, Bujumbura, Burundi
| | - Virgile Gnanguenon
- PMI VectorLink Project, U.S. Agency for International Development, Abt Associates, Bujumbura, Burundi
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4
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Molina-de la Fuente I, Pastor A, Herrador Z, Benito A, Berzosa P. Impact of Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions on malaria control worldwide: a systematic review and meta-analysis. Malar J 2021; 20:276. [PMID: 34158065 PMCID: PMC8220794 DOI: 10.1186/s12936-021-03812-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022] Open
Abstract
Background Deletion of pfhrp2 and/or pfhrp3 genes cause false negatives in malaria rapid diagnostic test (RDT) and threating malaria control strategies. This systematic review aims to assess the main methodological aspects in the study of pfhrp2 and pfhrp3 gene deletions and its global epidemiological status, with special focus on their distribution in Africa; and its possible impact in RDT. Methods The systematic review was conducted by examining the principal issues of study design and methodological workflow of studies addressing pfhrp2 deletion. Meta-analysis was applied to represent reported prevalences of pfhrp2 and pfhrp3 single and double deletion in the World Health Organization (WHO) region. Pooled-prevalence of deletions was calculated using DerSimonnian-Laird random effect model. Then, in-deep analysis focused on Africa was performed to assess possible variables related with these deletions. Finally, the impact of these deletions in RDT results was analysed combining reported information about RDT sensitivity and deletion prevalences. Results 49 articles were included for the systematic review and 37 for the meta-analysis, 13 of them placed in Africa. Study design differs significantly, especially in terms of population sample and information reported, resulting in high heterogeneity between studies that difficulties comparisons and merged conclusions. Reported prevalences vary widely in all the WHO regions, significantly higher deletion were reported in South-Central America, following by Africa and Asia. Pfhrp3 deletion is more prevalent (43% in South-Central America; 3% in Africa; and 1% in Asia) than pfhrp2 deletion (18% in South-Central America; 4% in Africa; and 3% in Asia) worldwide. In Africa, there were not found differences in deletion prevalence by geographical or population origin of samples. The prevalence of deletion among false negatives ranged from 0 to 100% in Africa, but in Asia and South-Central America was only up to 90% and 48%, respectively, showing substantial relation between deletions and false negatives. Conclusion The concerning prevalence of pfhrp2, pfhrp3 and pfhrp2/3 gene deletions, as its possible implications in malaria control, highlights the importance of regular and systematic surveillance of these deletions. This review has also outlined that a standardized methodology could play a key role to ensure comparability between studies to get global conclusions. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03812-0.
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Affiliation(s)
- Irene Molina-de la Fuente
- Department of Biomedicine and Biotechnology, School of Pharmacy, University of Alcalá, Alcalá de Henares, Madrid, Spain. .,Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain. .,Public Health and Epidemiology Research Group, School of Medicine, University of Alcalá, 28871, Alcalá de Henares, Madrid, Spain.
| | - Andrea Pastor
- Public Health and Epidemiology Research Group, School of Medicine, University of Alcalá, 28871, Alcalá de Henares, Madrid, Spain
| | - Zaida Herrador
- National Centre of Epidemiology, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
| | - Agustín Benito
- Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
| | - Pedro Berzosa
- Malaria and Neglected Diseases Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, 28029, Madrid, Spain.,Network Biomedical Research on Tropical Diseases (RICET in Spanish), Madrid, Spain
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King M, George AE, Cisteró P, Tarr-Attia CK, Arregui B, Omeonga S, Chen H, Meyer García-Sípido A, Sarukhan A, Bassat Q, Lansana DP, Mayor A. No evidence of false-negative Plasmodium falciparum rapid diagnostic results in Monrovia, Liberia. Malar J 2021; 20:238. [PMID: 34039355 PMCID: PMC8157453 DOI: 10.1186/s12936-021-03774-3] [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: 01/21/2021] [Accepted: 05/16/2021] [Indexed: 11/25/2022] Open
Abstract
Background Malaria diagnosis in many malaria-endemic countries relies mainly on the use of rapid diagnostic tests (RDTs). The majority of commercial RDTs used in Africa detect the Plasmodium falciparum histidine-rich protein 2 (PfHRP2). pfhrp2/3 gene deletions can therefore lead to false-negative RDT results. This study aimed to evaluate the frequency of PCR-confirmed, false-negative P. falciparum RDT results in Monrovia, Liberia. Methods PfHRP2-based RDT (Paracheck Pf®) and microscopy results from 1038 individuals with fever or history of fever (n = 951) and pregnant women at first antenatal care (ANC) visit (n = 87) enrolled in the Saint Joseph’s Catholic Hospital (Monrovia) from March to July 2019 were used to assess the frequency of false-negative RDT results. True–false negatives were confirmed by detecting the presence of P. falciparum DNA by quantitative PCR in samples from individuals with discrepant RDT and microscopy results. Samples that were positive by 18S rRNA qPCR but negative by PfHRP2-RDT were subjected to multiplex qPCR assay for detection of pfhrp2 and pfhrp3. Results One-hundred and eighty-six (19.6%) and 200 (21.0%) of the 951 febrile participants had a P. falciparum-positive result by RDT and microscopy, respectively. Positivity rate increased with age and the reporting of joint pain, chills and shivers, vomiting and weakness, and decreased with the presence of coughs and nausea. The positivity rate at first ANC visit was 5.7% (n = 5) and 8% (n = 7) by RDT and microscopy, respectively. Out of 207 Plasmodium infections detected by microscopy, 22 (11%) were negative by RDT. qPCR confirmed absence of P. falciparum DNA in the 16 RDT-negative but microscopy-positive samples which were available for molecular testing. Among the 14 samples that were positive by qPCR but negative by RDT and microscopy, 3 only amplified pfldh, and among these 3 all were positive for pfhrp2 and pfhrp3. Conclusion There is no qPCR-confirmed evidence of false-negative RDT results due to pfhrp2/pfhrp3 deletions in this study conducted in Monrovia (Liberia). This indicates that these deletions are not expected to affect the performance of PfHRP2-based RDTs for the diagnosis of malaria in Liberia. Nevertheless, active surveillance for the emergence of PfHRP2 deletions is required.
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Affiliation(s)
- Mandella King
- Saint Joseph's Catholic Hospital, Tubman Boulevard, Oldest Congo, Town, PO Box 10512, 1100, Monrovia, Liberia
| | - Alexander E George
- Liberia Medicines & Health Products Regulatory Authority, VP Road, Old Road, Sinkor , PO Box 1994, Monrovia, Liberia
| | - Pau Cisteró
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | - Christine K Tarr-Attia
- Saint Joseph's Catholic Hospital, Tubman Boulevard, Oldest Congo, Town, PO Box 10512, 1100, Monrovia, Liberia
| | - Beatriz Arregui
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | - Senga Omeonga
- Saint Joseph's Catholic Hospital, Tubman Boulevard, Oldest Congo, Town, PO Box 10512, 1100, Monrovia, Liberia
| | - Haily Chen
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | | | - Adelaida Sarukhan
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain
| | - Quique Bassat
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatrics Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Esplugues,, Barcelona, Spain
| | - Dawoh Peter Lansana
- Saint Joseph's Catholic Hospital, Tubman Boulevard, Oldest Congo, Town, PO Box 10512, 1100, Monrovia, Liberia
| | - Alfredo Mayor
- ISGlobal, Barcelona Institute for Global Health, Hospital Clínic - Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique. .,Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.
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Parr JB, Kieto E, Phanzu F, Mansiangi P, Mwandagalirwa K, Mvuama N, Landela A, Atibu J, Efundu SU, Olenga JW, Thwai KL, Morgan CE, Denton M, Poffley A, Juliano JJ, Mungala P, Likwela JL, Sompwe EM, Rogier E, Tshefu AK, N'Siala A, Kalonji A. Analysis of false-negative rapid diagnostic tests for symptomatic malaria in the Democratic Republic of the Congo. Sci Rep 2021; 11:6495. [PMID: 33753817 PMCID: PMC7985209 DOI: 10.1038/s41598-021-85913-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 03/08/2021] [Indexed: 11/29/2022] Open
Abstract
The majority of Plasmodium falciparum malaria diagnoses in Africa are made using rapid diagnostic tests (RDTs) that detect histidine-rich protein 2. Increasing reports of false-negative RDT results due to parasites with deletions of the pfhrp2 and/or pfhrp3 genes (pfhrp2/3) raise concern about existing malaria diagnostic strategies. We previously identified pfhrp2-negative parasites among asymptomatic children in the Democratic Republic of the Congo (DRC), but their impact on diagnosis of symptomatic malaria is unknown. We performed a cross-sectional study of false-negative RDTs in symptomatic subjects in 2017. Parasites were characterized by microscopy; RDT; pfhrp2/3 genotyping and species-specific PCR assays; a bead-based immunoassay for Plasmodium antigens; and/or whole-genome sequencing. Among 3627 symptomatic subjects, 427 (11.8%) had RDT-/microscopy + results. Parasites from eight (0.2%) samples were initially classified as putative pfhrp2/3 deletions by PCR, but antigen testing and whole-genome sequencing confirmed the presence of intact genes. 56.8% of subjects had PCR-confirmed malaria. Non-falciparum co-infection with P. falciparum was common (13.2%). Agreement between PCR and HRP2-based RDTs was satisfactory (Cohen's kappa = 0.66) and superior to microscopy (0.33). Symptomatic malaria due to pfhrp2/3-deleted P. falciparum was not observed. Ongoing HRP2-based RDT use is appropriate for the detection of falciparum malaria in the DRC.
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Affiliation(s)
- Jonathan B Parr
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA.
| | - Eddy Kieto
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Fernandine Phanzu
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Paul Mansiangi
- University of Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | | | - Nono Mvuama
- University of Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | - Ange Landela
- Institut National Pour La Recherche Biomedicale, Kinshasa, Democratic Republic of the Congo
| | - Joseph Atibu
- University of Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | | | - Jean W Olenga
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Kyaw Lay Thwai
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA
| | - Camille E Morgan
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Madeline Denton
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA
| | - Alison Poffley
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, Institute for Global Health and Infectious Diseases, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Pomie Mungala
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Joris L Likwela
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Eric M Sompwe
- Programme National de La Lutte Contre Le Paludisme, Kinshasa, Democratic Republic of Congo
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30033, USA
| | - Antoinette K Tshefu
- University of Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo
| | - Adrien N'Siala
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
| | - Albert Kalonji
- SANRU Asbl (Sante Rurale/Global Fund), Kinshasa, Democratic Republic of the Congo
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Schlabe S, Reiter-Owona I, Nordmann T, Dolscheid-Pommerich R, Tannich E, Hoerauf A, Rockstroh J. Rapid diagnostic test negative Plasmodium falciparum malaria in a traveller returning from Ethiopia. Malar J 2021; 20:145. [PMID: 33712017 PMCID: PMC7952815 DOI: 10.1186/s12936-021-03678-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/01/2021] [Indexed: 12/23/2022] Open
Abstract
Background Plasmodium falciparum strains with mutations/deletions of the genes encoding the histidine-rich proteins 2/3 (pfhrp2/3) have emerged during the last 10 years leading to false-negative results in HRP2-based rapid diagnostic tests (RDTs). This can lead to unrecognized infections in individuals and to setbacks in malaria control in endemic countries where RDTs are the backbone of malaria diagnostics and control. Case description Here the detection of a pfhrp2/3-negative P. falciparum infection acquired in Ethiopia by a 63-year old female traveller is presented. After onset of symptoms during travel, she was first tested negative for malaria, most probably by RDT, at a local hospital in Harar, Ethiopia. Falciparum malaria was finally diagnosed microscopically upon her return to Germany, over 4 weeks after infection. At a parasite density of approximately 5387 parasites/µl, two different high-quality RDTs: Palutop + 4 OPTIMA, NADALRMalaria PF/pan Ag 4 Species, did not respond at their respective P. falciparum test lines. pfhrp2/3 deletion was confirmed by multiplex-PCR. The patient recovered after a complete course of atovaquone and proguanil. According to the travel route, malaria was acquired most likely in the Awash region, Central Ethiopia. This is the first case of imported P. falciparum with confirmed pfhrp2/3 deletion from Ethiopia. Conclusion HRP2-negative P. falciparum strains may not be recognized by the presently available HRP2-based RDTs. When malaria is suspected, confirmation by microscopy and/or qPCR is necessary in order to detect falciparum malaria, which requires immediate treatment. This case of imported P. falciparum, non-reactive to HRP2-based RDT, possibly underlines the necessity for standardized, nationwide investigations in Ethiopia and should alert clinicians from non-endemic countries to the possibility of false-negative RDT results which may increase in returning travellers with potentially life-threatening infections. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03678-2.
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Affiliation(s)
- Stefan Schlabe
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany. .,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany.
| | - Ingrid Reiter-Owona
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany
| | - Tamara Nordmann
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany.,National Reference Centre for Tropical Pathogens, Bernhard Nocht-Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | | | - Egbert Tannich
- National Reference Centre for Tropical Pathogens, Bernhard Nocht-Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Jürgen Rockstroh
- Department of Internal Medicine I, University Hospital of Bonn, Venusberg Campus 1, Building 26, 53127, Bonn, Germany.,German Centre of Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
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8
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Nsobya SL, Walakira A, Namirembe E, Kiggundu M, Nankabirwa JI, Ruhamyankaka E, Arinaitwe E, Conrad MD, Kamya MR, Dorsey G, Rosenthal PJ. Deletions of pfhrp2 and pfhrp3 genes were uncommon in rapid diagnostic test-negative Plasmodium falciparum isolates from Uganda. Malar J 2021; 20:4. [PMID: 33386076 PMCID: PMC7777526 DOI: 10.1186/s12936-020-03547-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/12/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid diagnostic tests (RDTs) play a key role in malaria case management. The most widely used RDT identifies Plasmodium falciparum based on immunochromatographic recognition of P. falciparum histidine-rich protein 2 (PfHRP2). Deletion of the paralogous pfhrp2 and pfhrp3 genes leads to false-negative PfHRP2-based RDTs, and has been reported in P. falciparum infections from South America and Africa. However, identification of pfhrp2/pfhrp3 deletions has usually been based only on failure to amplify these genes using PCR, without confirmation based on PfHRP2 protein expression, and understanding of the true prevalence of deletions is incomplete. METHODS Deletions of pfhrp2/pfhrp3 in blood samples were investigated from cross-sectional surveys in 2012-13 in three regions of varied malaria transmission intensity in Uganda. Samples with positive Giemsa-stained thick blood smears, but negative PfHRP2-based RDTs were evaluated by PCR amplification of conserved subunit ribosomal DNA for Plasmodium species, PCR amplification of pfhrp2 and pfhrp3 genes to identify deletions, and bead-based immunoassays for expression of PfHRP2. RESULTS Of 3516 samples collected in cross-sectional surveys, 1493 (42.5%) had positive blood smears, of which 96 (6.4%) were RDT-negative. Of these 96 RDT-negative samples, P. falciparum DNA was identified by PCR in 56 (58%) and only non-falciparum plasmodial DNA in 40 (42%). In all 56 P. falciparum-positive samples there was a failure to amplify pfhrp2 or pfhrp3: in 25 (45%) pfhrp2 was not amplified, in 39 (70%) pfhrp3 was not amplified, and in 19 (34%) neither gene was amplified. For the 39 P. falciparum-positive, RDT-negative samples available for analysis of protein expression, PfHRP2 was not identified by immunoassay in only four samples (10.3%); these four samples all had failure to amplify both pfhrp2 and pfhrp3 by PCR. Thus, only four of 96 (4.2%) smear-positive, RDT-negative samples had P. falciparum infections with deletion of pfhrp2 and pfhrp3 confirmed by failure to amplify the genes by PCR and lack of expression of PfHRP2 demonstrated by immunoassay. CONCLUSION False negative RDTs were uncommon. Deletions in pfhrp2 and pfhrp3 explained some of these false negatives, but most false negatives were not due to deletion of the pfhrp2 and pfhrp3 genes.
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Affiliation(s)
- Sam L Nsobya
- Infectious Diseases Research Collaboration, Kampala, Uganda. .,Department of Pathology, College of Health Science, Makerere University Kampala, Kampala, Uganda.
| | | | | | - Moses Kiggundu
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Joaniter I Nankabirwa
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | | | | | - Melissa D Conrad
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, USA
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9
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Plasmodium falciparum is evolving to escape malaria rapid diagnostic tests in Ethiopia. Nat Microbiol 2021; 6:1289-1299. [PMID: 34580442 PMCID: PMC8478644 DOI: 10.1038/s41564-021-00962-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 08/16/2021] [Indexed: 02/07/2023]
Abstract
In Africa, most rapid diagnostic tests (RDTs) for falciparum malaria recognize histidine-rich protein 2 antigen. Plasmodium falciparum parasites lacking histidine-rich protein 2 (pfhrp2) and 3 (pfhrp3) genes escape detection by these RDTs, but it is not known whether these deletions confer sufficient selective advantage to drive rapid population expansion. By studying blood samples from a cohort of 12,572 participants enroled in a prospective, cross-sectional survey along Ethiopia's borders with Eritrea, Sudan and South Sudan using RDTs, PCR, an ultrasensitive bead-based immunoassay for antigen detection and next-generation sequencing, we estimate that histidine-rich protein 2-based RDTs would miss 9.7% (95% confidence interval 8.5-11.1) of P. falciparum malaria cases owing to pfhrp2 deletion. We applied a molecular inversion probe-targeted deep sequencing approach to identify distinct subtelomeric deletion patterns and well-established pfhrp3 deletions and to uncover recent expansion of a singular pfhrp2 deletion in all regions sampled. We propose a model in which pfhrp3 deletions have arisen independently multiple times, followed by strong positive selection for pfhrp2 deletion owing to RDT-based test-and-treatment. Existing diagnostic strategies need to be urgently reconsidered in Ethiopia, and improved surveillance for pfhrp2 deletion is needed throughout the Horn of Africa.
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10
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Bakari C, Jones S, Subramaniam G, Mandara CI, Chiduo MG, Rumisha S, Chacky F, Molteni F, Mandike R, Mkude S, Njau R, Herman C, Nace DP, Mohamed A, Udhayakumar V, Kibet CK, Nyanjom SG, Rogier E, Ishengoma DS. Community-based surveys for Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions in selected regions of mainland Tanzania. Malar J 2020; 19:391. [PMID: 33148255 PMCID: PMC7640459 DOI: 10.1186/s12936-020-03459-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 10/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Histidine-rich protein 2 (HRP2)-based malaria rapid diagnostic tests (RDTs) are effective and widely used for the detection of wild-type Plasmodium falciparum infections. Although recent studies have reported false negative HRP2 RDT results due to pfhrp2 and pfhrp3 gene deletions in different countries, there is a paucity of data on the deletions of these genes in Tanzania. METHODS A community-based cross-sectional survey was conducted between July and November 2017 in four regions: Geita, Kigoma, Mtwara and Ruvuma. All participants had microscopy and RDT performed in the field and provided a blood sample for laboratory multiplex antigen detection (for Plasmodium lactate dehydrogenase, aldolase, and P. falciparum HRP2). Samples showing RDT false negativity or aberrant relationship of HRP2 to pan-Plasmodium antigens were genotyped to detect the presence/absence of pfhrp2/3 genes. RESULTS Of all samples screened by the multiplex antigen assay (n = 7543), 2417 (32.0%) were positive for any Plasmodium antigens while 5126 (68.0%) were negative for all antigens. The vast majority of the antigen positive samples contained HRP2 (2411, 99.8%), but 6 (0.2%) had only pLDH and/or aldolase without HRP2. Overall, 13 samples had an atypical relationship between a pan-Plasmodium antigen and HRP2, but were positive by PCR. An additional 16 samples with negative HRP2 RDT results but P. falciparum positive by microscopy were also chosen for pfhrp2/3 genotyping. The summation of false negative RDT results and laboratory antigen results provided 35 total samples with confirmed P. falciparum DNA for pfhrp2/3 genotyping. Of the 35 samples, 4 (11.4%) failed to consistently amplify positive control genes; pfmsp1 and pfmsp2 and were excluded from the analysis. The pfhrp2 and pfhrp3 genes were successfully amplified in the remaining 31 (88.6%) samples, confirming an absence of deletions in these genes. CONCLUSIONS This study provides evidence that P. falciparum parasites in the study area have no deletions of both pfhrp2 and pfhrp3 genes. Although single gene deletions could have been missed by the multiplex antigen assay, the findings support the continued use of HRP2-based RDTs in Tanzania for routine malaria diagnosis. There is a need for the surveillance to monitor the status of pfhrp2 and/or pfhrp3 deletions in the future.
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Affiliation(s)
- Catherine Bakari
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Sophie Jones
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Williams Consulting, Baltimore, MD, USA
| | - Gireesh Subramaniam
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
- Oak Ridge Institute for Science and Education, Atlanta, GA, USA
| | - Celine I Mandara
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Mercy G Chiduo
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Susan Rumisha
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Frank Chacky
- National Malaria Control Programme (NMCP), Dodoma, Tanzania
| | | | - Renata Mandike
- National Malaria Control Programme (NMCP), Dodoma, Tanzania
| | - Sigsbert Mkude
- National Malaria Control Programme (NMCP), Dodoma, Tanzania
| | - Ritha Njau
- World Health Organization (WHO) Country Office, Dar es Salaam, Tanzania
| | - Camelia Herman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
- CDC Foundation (CDCF), Atlanta, GA, USA
| | - Douglas P Nace
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ally Mohamed
- National Malaria Control Programme (NMCP), Dodoma, Tanzania
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Caleb K Kibet
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Steven G Nyanjom
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania.
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia.
- Harvard T.H Chan School of Public Health, Boston, MA, USA.
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11
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Bosco AB, Anderson K, Gresty K, Prosser C, Smith D, Nankabirwa JI, Nsobya S, Yeka A, Opigo J, Gonahasa S, Namubiru R, Arinaitwe E, Mbaka P, Kissa J, Won S, Lee B, Lim CS, Karamagi C, Cunningham J, Nakayaga JK, Kamya MR, Cheng Q. Molecular surveillance reveals the presence of pfhrp2 and pfhrp3 gene deletions in Plasmodium falciparum parasite populations in Uganda, 2017-2019. Malar J 2020; 19:300. [PMID: 32843041 PMCID: PMC7449024 DOI: 10.1186/s12936-020-03362-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/05/2020] [Indexed: 01/22/2023] Open
Abstract
Background Histidine-rich protein-2 (HRP2)-based rapid diagnostic tests (RDTs) are the only RDTs recommended for malaria diagnosis in Uganda. However, the emergence of Plasmodium falciparum histidine rich protein 2 and 3 (pfhrp2 and pfhrp3) gene deletions threatens their usefulness as malaria diagnostic and surveillance tools. The pfhrp2 and pfhrp3 gene deletions surveillance was conducted in P. falciparum parasite populations in Uganda. Methods Three-hundred (n = 300) P. falciparum isolates collected from cross-sectional malaria surveys in symptomatic individuals in 48 districts of eastern and western Uganda were analysed for the presence of pfhrp2 and pfhrp3 genes. Presence of parasite DNA was confirmed by PCR amplification of the 18s rRNA gene, msp1 and msp2 single copy genes. Presence or absence of deletions was confirmed by amplification of exon1 and exon2 of pfhrp2 and pfhrp3 using gene specific PCR. Results Overall, pfhrp2 and pfhrp3 gene deletions were detected in 29/300 (9.7%, 95% CI 6.6–13.6%) parasite isolates. The pfhrp2 gene was deleted in 10/300 (3.3%, 95% CI 1.6–6.0%) isolates, pfhrp3 in 9/300 (3.0%, 95% CI 1.4–5.6%) while both pfhrp2 and pfhrp3 were deleted in 10/300 (3.3%, 95% CI 1.6–6.0%) parasite isolates. Proportion of pfhrp2/3 deletions was higher in the eastern 14.7% (95% CI 9.7–20.0%) compared to the western region 3.1% (95% CI 0.8–7.7%), p = 0.001. Geographical location was associated with gene deletions aOR 6.25 (2.02–23.55), p = 0.003. Conclusions This is the first large-scale survey reporting the presence of pfhrp2/3 gene deletions in P. falciparum isolates in Uganda. Roll out of RDTs for malaria diagnosis should take into consideration the existence of pfhrp2/3 gene deletions particularly in areas where they were detected. Periodic pfhrp2/3 surveys are recommended to inform future decisions for deployment of alternative RDTs.
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Affiliation(s)
- Agaba B Bosco
- College of Health Sciences, Makerere University, Kampala, Uganda. .,National Malaria Control Division, Kampala, Uganda.
| | - Karen Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Enoggera, Australia
| | - Karryn Gresty
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Enoggera, Australia
| | - Christiane Prosser
- Australian Defence Force Malaria and Infectious Disease Institute, Enoggera, Australia
| | - David Smith
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Enoggera, Australia
| | - Joaniter I Nankabirwa
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Sam Nsobya
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Adoke Yeka
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Jimmy Opigo
- National Malaria Control Division, Kampala, Uganda
| | | | - Rhoda Namubiru
- College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Paul Mbaka
- World Health Organization Country Office, Kampala, Uganda
| | - John Kissa
- National Health Information Division, Ministry of Health, Kampala, Uganda
| | - Sungho Won
- Department of Public Health Sciences, Seoul National University, Seoul, South Korea
| | - Bora Lee
- Department of Public Health Sciences, Seoul National University, Seoul, South Korea
| | - Chae Seung Lim
- Department of Laboratory Medicine, College of Health Sciences, Korea University, Seoul, South Korea
| | - Charles Karamagi
- College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Joan K Nakayaga
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Moses R Kamya
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Qin Cheng
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Enoggera, Australia
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12
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Addai-Mensah O, Dinko B, Noagbe M, Ameke SL, Annani-Akollor ME, Owiredu EW, Mensah K, Tackie R, Togbe E, Agyare-Kwabi C, Gyasi C, Adu-Gyamfi C, Debrah AY. Plasmodium falciparum histidine-rich protein 2 diversity in Ghana. Malar J 2020; 19:256. [PMID: 32678034 PMCID: PMC7364488 DOI: 10.1186/s12936-020-03328-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/07/2020] [Indexed: 11/30/2022] Open
Abstract
Background In the absence of microscopy, Plasmodium falciparum histidine-rich proteins 2 (PfHRP2)-based rapid diagnostic tests (RDTs) are recommended for the diagnosis of falciparum malaria, particularly in endemic regions. However, genetic variability of the pfhrp2 gene threatens the usefulness of the test due to its impact on RDT sensitivity. This study aimed to investigate the diversity of pfhrp2 in malaria cases among children in Ghana. Methods A cross-sectional study was conducted at the Adidome Government Hospital in the Volta Region of Ghana. A total of 50 children with mean age of 6.6 ± 3.5 years and diagnosed falciparum malaria were included. Blood samples were collected for complete blood count, malaria parasite identification and counting using auto analyzer and microscopy, respectively. DNA was isolated from blood-spotted Whatman filters, amplified and sequenced. Nucleotide sequences were translated in silico to corresponding amino acids and the deduced amino acids sequences were analyzed for diversity using Mega X. Results The number of repeats and number of each repeat within PfHRP2 varied between isolates. Twelve rare PfHRP2 repeat types, two of which are previously unreported, were identified in this study. The HRP2 sequence obtained in this study shared high similarities with isolates from Kenya. Using Baker’s regression model, Group B was the highest occurring type (58.0%). Screening of all sequences for epitopes recognized by PfHRP2-specific monoclonal antibodies (mAbs), the predominant motif was AHHAADAHH, which is recognized by the C1-13 mAbs. Conclusion This study reports diversity of P. falciparum HRP2 in samples from Ghanaian children with symptomatic malaria. The findings of this study highlight the existence of extra amino acid repeat types which adds to the PfHRP2 antigenic variability.
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Affiliation(s)
- Otchere Addai-Mensah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana.
| | - Bismarck Dinko
- School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Mark Noagbe
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
| | | | - Max Efui Annani-Akollor
- Department of Molecular Medicine, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Eddie-Williams Owiredu
- Department of Molecular Medicine, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Kofi Mensah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
| | - Richmond Tackie
- School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Eliezer Togbe
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
| | - Comfort Agyare-Kwabi
- School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Charles Gyasi
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
| | - Constance Adu-Gyamfi
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
| | - Alexander Yaw Debrah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, 00233, Ghana
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13
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Berzosa P, González V, Taravillo L, Mayor A, Romay-Barja M, García L, Ncogo P, Riloha M, Benito A. First evidence of the deletion in the pfhrp2 and pfhrp3 genes in Plasmodium falciparum from Equatorial Guinea. Malar J 2020; 19:99. [PMID: 32122352 PMCID: PMC7050119 DOI: 10.1186/s12936-020-03178-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/22/2020] [Indexed: 11/15/2022] Open
Abstract
Background The World Health Organization (WHO) recommends rapid diagnostic tests (RDTs) as a good alternative malaria-diagnosis method in remote parts of sub-Saharan Africa. The majority of commercial RDTs currently available detect the Plasmodium falciparum protein histidine-rich protein 2 (PfHRP2). There have also been recent reports of pfhrp2 gene deletions being found in parasites collected from several African countries. The WHO has concluded that lacking the pfhrp2 gene must be monitored in Africa. The purpose of the study was to analyse why the samples that were positive by PCR were negative by RDTs and, therefore, to determine whether there have been deletions in the pfhrp2 and/or pfhrp3 genes. Methods Malaria NM-PCR was carried out on all the samples collected in the field. A group of 128 samples was positive by PCR but negative by RDT; these samples were classified as RDT false-negatives. PCR was carried out for exon2 of pfhrp2 and pfhrp3 genes to detect the presence or absence of these two genes. Frequencies with 95% confidence intervals (CIs) were used for prevalence estimates. Associations were assessed by the Chi square test or Fisher´s exact test. The level of significance was set at p ≤ 0.05. Statistical analyses were performed using the software package SPSSv.15.0. Results After PCR, 81 samples were identified (4.7%, 95% CI 3.8–5.8) which had deletion in both genes, pfhrp2 and pfhrp3. Overall, however, 11 samples (0.6%, 95% CI 0.36–1.14) had deletion only in pfhrp2 but not in pfhrp3, and 15 (0.9%, 95% CI 0.6–1.5) presented with deletion only in pfhrp3 but not in pfhrp2. Considering the pfhrp2 gene separately, within the total of 1724 samples, 92 (5.3%, 95% CI 4.37–6.5) had evidence of deletion. Conclusion The present study provides the first evidence of deletion in the pfhrp2 and pfhrp3 genes in P. falciparum isolates from Equatorial Guinea. However, larger studies across different regions within the country and across different seasonal profiles are needed to determine the full extent of pfhrp2 and pfhrp3 deletion. It is strongly recommended to implement an active surveillance programme in order to detect any increases in pfhrp2 and pfhrp3 deletion frequencies.
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Affiliation(s)
- Pedro Berzosa
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain.
| | - Vicenta González
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain
| | - Laura Taravillo
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clinic-Universitat de Barcelona, Barcelona, Spain
| | - María Romay-Barja
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain
| | - Luz García
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain
| | - Policarpo Ncogo
- Global Health Programme, Malabo, Equatorial Guinea.,Malaria Programme, Ministry of Health and Social Welfare of Equatorial Guinea, Malabo, Equatorial Guinea
| | - Matilde Riloha
- Global Health Programme, Malabo, Equatorial Guinea.,Malaria Programme, Ministry of Health and Social Welfare of Equatorial Guinea, Malabo, Equatorial Guinea
| | - Agustín Benito
- Malaria Laboratory, National Centre of Tropical Medicine, Institute of Health Carlos III, Madrid, Spain
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14
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Kojom LP, Singh V. Prevalence of Plasmodium falciparum field isolates with deletions in histidine-rich protein 2 and 3 genes in context with sub-Saharan Africa and India: a systematic review and meta-analysis. Malar J 2020; 19:46. [PMID: 31992330 PMCID: PMC6986054 DOI: 10.1186/s12936-019-3090-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/25/2019] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND In 2017, nearly 80% of malaria morbidity and mortality occurred in sub-Saharan African (SSA) countries and India. Rapid diagnostic tests (RDTs), especially those targeting histidine-rich protein 2 (PfHRP2) of Plasmodium falciparum, have become an important diagnostic tool in these malaria-endemic areas. However, the chances of RDT-oriented successful treatment are increasingly jeopardized by the appearance of mutants with deletions in pfhrp2 and pfhrp3 genes. This systematic review and meta-analysis determines the prevalence of field P. falciparum isolates with deletion in pfhrp2 and/or pfhrp3 genes and their proportion among false-negative results in the PfHRP2-based RDTs in SSA and India. METHODS Eight electronic databases were used for searching potentially relevant publications for the systematic review analysis, wherein the main methodological aspects of included studies were analysed and some missing links in the included studies were identified. RESULTS A total of 19 studies were included, 16 from SSA and 3 from India. The pooled prevalence of pfhrp2 deletions was 8 and 5% while 16 and 4% for pfhrp3 gene deletions in Africa and India, respectively. The pooled proportion of pfhrp2 gene deletions found among false negative PfHRP2-based RDTs results was about 27.0 and 69.0% in Africa and India, respectively. CONCLUSIONS This review study indicates a relatively high proportion of both pfhrp2/3 genes deletions in P. falciparum isolates and among false-negative malaria cases using PfHRP2-based RDT results in SSA and India. Recently the deletions in pfhrp2/3 genes have also been reported from two African countries (Nigeria and Sudan). This review emphasizes the importance of more extensive studies and standardization of studies addressing the pfhrp2/3 gene deletions in malarious areas.
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Affiliation(s)
- Loick P Kojom
- Cell Biology Laboratory and Malaria Parasite Bank, ICMR-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India
| | - Vineeta Singh
- Cell Biology Laboratory and Malaria Parasite Bank, ICMR-National Institute of Malaria Research, Sector 8, Dwarka, New Delhi, 110077, India.
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15
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Dong Y, Liu S, Deng Y, Xu Y, Chen M, Liu Y, Xue J. Genetic polymorphism of histidine rich protein 2 in Plasmodium falciparum isolates from different infection sources in Yunnan Province, China. Malar J 2019; 18:446. [PMID: 31888663 PMCID: PMC6937805 DOI: 10.1186/s12936-019-3084-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 12/21/2019] [Indexed: 11/22/2022] Open
Abstract
Background Failed diagnoses of some falciparum malaria cases by RDTs are constantly reported in recent years. Plasmodium falciparum histidine-rich protein 2 (pfhpr2) gene deficiency has been found to be the major reason of RDTs failure in many countries. This article analysed the deletion of pfhpr2 gene of falciparum malaria cases isolated in Yunnan Province, China. Methods Blood samples from falciparum malaria cases diagnosed in Yunnan Province were collected. Plasmodium genomic DNA was extracted and the pfhrp2 gene exon2 region was amplified via nested PCR. The haplotype of the DNA sequence, the nucleic acid diversity index (PI) and expected heterozygosity (He) were analyzed. Count PfHRP2 amino acid peptide sequence repeat and its times, and predict the properties of PfHRP2 peptide chain reaction to RDTs testing. Results A total of 306 blood samples were collected, 84.9% (259/306) from which pfhrp2 PCR amplification products (gene exon2) were obtained, while the remaining 47 samples were false amplification. The length of the 250 DNA sequences ranged from 345 - 927 bp, with 151 haplotypes, with PI and He values of 0.169 and 0.983, respectively. The length of the PfHRP2 peptide chain translated from 250 DNA sequences ranged from 115 to 309 aa. All peptide chains had more than an amino acid codon deletion. All 250 PfHRP2 strands ended with a type 12 amino acid repeat, 98.0% (245/250) started with a type 1 repetition and 2.0% (5/250) with a type 2 repetition. The detection rate for type 2 duplicates was 100% (250/250). Prediction of RDT sensitivity of PfHRP2 peptide chains based on type 2 and type 7 repeats showed that 9.60% (24/250), 50.0% (125/250), 13.20% (33/250) and 27.20.5% (68/250) of the 250 peptide chains were very sensitive, sensitive, borderline and non-sensitive, respectively. Conclusion The diversified polymorphism of the pfhrp2 gene deletion from different infection sources in the Yunnan province are extremely complex. The cause of the failure of pfhrp2 exon2 amplification is still to be investigated. The results of this study appeal to Yunnan Province for a timely evaluation of the effectiveness and applicability of RDTs in the diagnosis of malaria.
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Affiliation(s)
- Ying Dong
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China.
| | - Shuping Liu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China.,School of Basic Medical Sciences, Dali University, Dali, 667000, China
| | - Yan Deng
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China
| | - Yanchun Xu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China
| | - Mengni Chen
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China
| | - Yan Liu
- Yunnan Institute of Parasitic Diseases Control, Yunnan Provincial Key Laboratory, Yunnan Centre of Malaria Research, Academician Workstation of Professor Jin Ningyi, Pu'er, 665000, China
| | - Jingpo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China
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16
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Coldiron ME, Assao B, Langendorf C, Sayinzoga-Makombe N, Ciglenecki I, de la Tour R, Piriou E, Yarima Bako M, Mumina A, Guindo O, Page AL, Grais RF. Clinical diagnostic evaluation of HRP2 and pLDH-based rapid diagnostic tests for malaria in an area receiving seasonal malaria chemoprevention in Niger. Malar J 2019; 18:443. [PMID: 31878947 PMCID: PMC6933886 DOI: 10.1186/s12936-019-3079-1] [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: 07/11/2019] [Accepted: 12/17/2019] [Indexed: 11/27/2022] Open
Abstract
Background Rapid diagnostic tests (RDT) for malaria are common, but their performance varies. Tests using histidine-rich protein 2 (HRP2) antigen are most common, and many have high sensitivity. HRP2 tests can remain positive for weeks after treatment, limiting their specificity and usefulness in high-transmission settings. Tests using Plasmodium lactate dehydrogenase (pLDH) have been less widely used but have higher specificity, mostly due to a much shorter time to become negative. Methods A prospective, health centre-based, diagnostic evaluation of two malaria RDTs was performed in rural Niger during the high malaria transmission season (3–28 October, 2017) and during the low transmission season (28 January–31 March, 2018). All children under 5 years of age presenting with fever (axillary temperature > 37.5 °C) or history of fever in the previous 24 h were eligible. Capillary blood was collected by finger prick. The SD Bioline HRP2 (catalog: 05FK50) and the CareStart pLDH(pan) (catalog: RMNM-02571) were performed in parallel, and thick and thin smears were prepared. Microscopy was performed at Epicentre, Maradi, Niger, with external quality control. The target sample size was 279 children with microscopy-confirmed malaria during each transmission season. Results In the high season, the sensitivity of both tests was estimated at > 99%, but the specificity of both tests was lower: 58.0% (95% CI 52.1–63.8) for the pLDH test and 57.4% (95% CI 51.5–63.1) for the HRP2 test. The positive predictive value was 66.3% (95% CI 61.1–71.2) for both tests. In the low season, the sensitivity of both tests dropped: 91.0% (95% CI 85.3–95.0) for the pLDH test and 85.8% (95% CI 79.3–90.9) for the HRP2 test. The positive predictive value remained low for both tests in the low season: 60.5% (95% CI 53.9–66.8) for the pLDH test and 61.9% (55.0–68.4) for the HRP2 test. Performance was similar across different production lots, gender, age of the children, and, during the high season, time since the most recent distribution of seasonal malaria chemoprevention. Conclusions The low specificity of the pLDH RDT in this setting was unexpected and is not easily explained. As the pLDH test continues to be introduced into new settings, the questions raised by this study will need to be addressed.
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Affiliation(s)
| | | | | | | | - Iza Ciglenecki
- Médecins Sans Frontières, 70 rue de Lausanne, Geneva, Switzerland
| | | | - Erwan Piriou
- Médecins Sans Frontières, Naritaweg 10, Amsterdam, The Netherlands
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17
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van Lenthe M, van der Meulen R, Lassovski M, Ouabo A, Bakula E, Badio C, Cibenda D, Okell L, Piriou E, Grignard L, Lanke K, Rao B, Bousema T, Roper C. Markers of sulfadoxine-pyrimethamine resistance in Eastern Democratic Republic of Congo; implications for malaria chemoprevention. Malar J 2019; 18:430. [PMID: 31852480 PMCID: PMC6921399 DOI: 10.1186/s12936-019-3057-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/07/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sulfadoxine-pyrimethamine (SP) is a cornerstone of malaria chemoprophylaxis and is considered for programmes in the Democratic Republic of Congo (DRC). However, SP efficacy is threatened by drug resistance, that is conferred by mutations in the dhfr and dhps genes. The World Health Organization has specified that intermittent preventive treatment for infants (IPTi) with SP should be implemented only if the prevalence of the dhps K540E mutation is under 50%. There are limited current data on the prevalence of resistance-conferring mutations available from Eastern DRC. The current study aimed to address this knowledge gap. METHODS Dried blood-spot samples were collected from clinically suspected malaria patients [outpatient department (OPD)] and pregnant women attending antenatal care (ANC) in four sites in North and South Kivu, DRC. Quantitative PCR (qPCR) was performed on samples from individuals with positive and with negative rapid diagnostic test (RDT) results. Dhps K450E and A581G and dhfr I164L were assessed by nested PCR followed by allele-specific primer extension and detection by multiplex bead-based assays. RESULTS Across populations, Plasmodium falciparum parasite prevalence was 47.9% (1160/2421) by RDT and 71.7 (1763/2421) by qPCR. Median parasite density measured by qPCR in RDT-negative qPCR-positive samples was very low with a median of 2.3 parasites/µL (IQR 0.5-25.2). Resistance genotyping was successfully performed in RDT-positive samples and RDT-negative/qPCR-positive samples with success rates of 86.2% (937/1086) and 55.5% (361/651), respectively. The presence of dhps K540E was high across sites (50.3-87.9%), with strong evidence for differences between sites (p < 0.001). Dhps A581G mutants were less prevalent (12.7-47.2%). The dhfr I164L mutation was found in one sample. CONCLUSIONS The prevalence of the SP resistance marker dhps K540E exceeds 50% in all four study sites in North and South Kivu, DRC. K540E mutations regularly co-occurred with mutations in dhps A581G but not with the dhfr I164L mutation. The current results do not support implementation of IPTi with SP in the study area.
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Affiliation(s)
| | - Renske van der Meulen
- Médecins Sans Frontières (MSF), Amsterdam, The Netherlands.,Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | | | | | | | - Deogratias Cibenda
- Programme National de Lutte contre le Paludisme (PNLP) South Kivu, Bukavu, Democratic Republic of Congo
| | | | - Erwan Piriou
- Médecins Sans Frontières (MSF), Amsterdam, The Netherlands
| | - Lynn Grignard
- London School of Hygiene and Tropical Medicine, London, UK
| | - Kjerstin Lanke
- Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Teun Bousema
- Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Cally Roper
- London School of Hygiene and Tropical Medicine, London, UK
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18
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Herman C, Huber CS, Jones S, Steinhardt L, Plucinski MM, Lemoine JF, Chang M, Barnwell JW, Udhayakumar V, Rogier E. Multiplex malaria antigen detection by bead-based assay and molecular confirmation by PCR shows no evidence of Pfhrp2 and Pfhrp3 deletion in Haiti. Malar J 2019; 18:380. [PMID: 31775743 PMCID: PMC6882344 DOI: 10.1186/s12936-019-3010-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 11/16/2019] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The Plasmodium falciparum parasite is the only human malaria that produces the histidine-rich protein 2 and 3 (HRP2/3) antigens. Currently, HRP2/3 are widely used in malaria rapid diagnostic tests (RDTs), but several global reports have recently emerged showing genetic deletion of one or both of these antigens in parasites. Deletion of these antigens could pose a major concern for P. falciparum diagnosis in Haiti which currently uses RDTs based solely on the detection of the HRP2/3 antigens. METHODS From September 2012 through February 2014, dried blood spots (DBS) were collected in Haiti from 9317 febrile patients presenting to 17 health facilities in 5 departments throughout the country as part of a bed net intervention study. All DBS from RDT positive persons and a random sampling of DBS from RDT negative persons were assayed for P. falciparum DNA by nested and PET-PCR (n = 2695 total). All PCR positive samples (n = 331) and a subset of PCR negative samples (n = 95) were assayed for three malaria antigens by a multiplex bead assay: pan-Plasmodium aldolase (pAldo), pan-Plasmodium lactate dehydrogenase (pLDH), and HRP2/3. Any samples positive for P. falciparum DNA, but negative for HRP2/3 antigens were tested by nested PCR for Pfhrp2 and Pfhrp3 gene deletions. RESULTS Of 2695 DBS tested for Plasmodium DNA, 345 (12.8%) were originally found to be positive for P. falciparum DNA; 331 of these had DBS available for antigen detection. Of these, 266 (80.4%) were positive for pAldo, 221 (66.8%) positive for pLDH, and 324 (97.9%) were positive for HRP2/3 antigens. Seven samples (2.1%) positive for P. falciparum DNA were not positive for any of the three antigens by the bead assay, and were investigated for potential Pfhrp2/3 gene deletion by PCR. These samples either successfully amplified Pfhrp2/3 genes or were at an estimated parasite density too low for sufficient DNA to perform successful genotyping. CONCLUSIONS Malaria positive samples in multiple Haitian sites were found to contain the HRP2/3 antigens, and no evidence was found of Pfhrp2/3 deletions. Malaria RDTs based on the detection of the HRP2/3 antigens remain a reliable P. falciparum diagnostic tool as Haiti works towards malaria elimination.
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Affiliation(s)
- Camelia Herman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.,CDC Foundation (CDCF), Atlanta, GA, USA
| | - Curtis S Huber
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Sophie Jones
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Atlanta Research and Education Foundation (AREF), Atlanta, GA, USA
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Mateusz M Plucinski
- U.S. President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jean F Lemoine
- Programme National de Contrôle de la Malaria/MSPP, Port-au-Prince, Haiti
| | - Michelle Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - John W Barnwell
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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19
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Agaba BB, Yeka A, Nsobya S, Arinaitwe E, Nankabirwa J, Opigo J, Mbaka P, Lim CS, Kalyango JN, Karamagi C, Kamya MR. Systematic review of the status of pfhrp2 and pfhrp3 gene deletion, approaches and methods used for its estimation and reporting in Plasmodium falciparum populations in Africa: review of published studies 2010-2019. Malar J 2019; 18:355. [PMID: 31694718 PMCID: PMC6836395 DOI: 10.1186/s12936-019-2987-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/24/2019] [Indexed: 12/13/2022] Open
Abstract
Background Malaria rapid diagnostic tests based on histidine-rich protein-2 have played a vital role in improving malaria case management and surveillance particularly in Africa, where Plasmodium falciparum is predominant. However, their usefulness has been threatened by the emergence of gene deletion on P. falciparum histidine rich protein 2 (pfhrp2) and P. falciparum histidine rich protein 3 (pfhrp3). Use of standard and recommended methods is key for accurate investigation, confirmation and reporting of pfhrp2 and pfhrp3 gene deletion. Methods A systematic review was conducted to assess the status, methods and approaches that have been used for investigation, confirmation and reporting of pfhrp2 and pfhrp3 gene deletion in Africa. An online search was done using PubMed and MEDLINE Google Scholar for all articles published in English on pfhrp2/3 gene deletion in Africa. Relevant articles that met the inclusion criteria were summarized and assessed based on the protocol recommended by the World Health Organization for confirmation and reporting of pfhrp2/3 gene deletion. Results The search identified a total of 18 articles out of which 14 (77.7%) fulfilled the criteria for inclusion and were retained for review. The articles were distributed across 12 countries where the pfhrp2 and pfhrp3 gene deletion studies were conducted and reported. The level of pfhrp2/3 gene deletion across selected studies in Africa ranged from the highest 62% to the lowest 0.4%. There was wide variation in methods and approaches including study designs, size and sampling and whether both pfhrp2 and pfhrp3 double deletions or pfhrp2 single deletion were investigated, with a wide variation in laboratory methods. Conclusion Based on the review, there is evidence of the presence of pfhrp2/3 gene-deleted P. falciparum parasites in Africa. The approaches and methods used for investigation, confirmation and reporting of pfhrp2/3 deleted parasites have varied between studies and across countries. Countries that are considering plans to investigate, confirm and report pfhrp2/3 deletion should use recommended standard and harmonized methods to prevent unnecessary recommendations for costly switch of RDTs in Africa.
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Affiliation(s)
- Bosco B Agaba
- School of Medicine, College of Health Sciences Makerere University, Kampala, Uganda. .,Clinical Epidemiology Unit, Makerere University Kampala, Kampala, Uganda. .,National Malaria Control Programme, Kampala, Uganda.
| | - Adoke Yeka
- School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Sam Nsobya
- School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | | | - Joaniter Nankabirwa
- School of Medicine, College of Health Sciences Makerere University, Kampala, Uganda.,Clinical Epidemiology Unit, Makerere University Kampala, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Jimmy Opigo
- National Malaria Control Programme, Kampala, Uganda
| | - Paul Mbaka
- World Health Organization Country Office, Kampala, Uganda
| | - Chae Seung Lim
- Department of Laboratory Medicine, College of Health Sciences, Korea University, Seoul, South Korea
| | - Joan N Kalyango
- Clinical Epidemiology Unit, Makerere University Kampala, Kampala, Uganda
| | - Charles Karamagi
- Clinical Epidemiology Unit, Makerere University Kampala, Kampala, Uganda
| | - Moses R Kamya
- School of Medicine, College of Health Sciences Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
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20
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Fagbamigbe AF. On the discriminatory and predictive accuracy of the RDT against the microscopy in the diagnosis of malaria among under-five children in Nigeria. Malar J 2019; 18:46. [PMID: 30791912 PMCID: PMC6385408 DOI: 10.1186/s12936-019-2678-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 02/14/2019] [Indexed: 12/21/2022] Open
Abstract
Background Accurate identification of malaria cases is crucial to the management of cases and the eventual success of malaria eradication agenda. This study is designed to evaluate the discriminatory and predictive accuracy of malaria rapid diagnostic tests (RDTs) in Nigeria. Methods The data obtained during the 2015 Nigeria Malaria Indicator Survey was used to quantify the discriminatory accuracy of the RDT against the microscopy through the analysis of its sensitivity, specificity, positive (LR+) and negative (LR−) likelihood ratio. The positive (PPV) and negative (NPV) predictive values, area under the receiver operating characteristic curve, and diagnostic odds ratio were used to assess the predictive accuracy of the RDTs using expert microscopy as a gold standard at p = 0.05. The McNemar paired test and the Kappa statistics were used to assess the level of agreement between the diagnostic tests. Results There was a significant but not an excellent agreement between the results of the RDT and microscopy tests (p < 0.001). The overall sensitivity of the RDT was 87.6% (85.9–89.2%), specificity was 75.8% (74.4–77.1%), while the diagnostic accuracy stood at 79.0% (77.9–80.0%). The LR+, LR−, PPV and NPV were 3.6 (3.4–3.8) and 0.16 (0.14–0.19), 57.5% (56.1–58.9%) and 94.2% (93.5–94.9%), respectively. The sensitivity of RDT increased as the age of the children increased, from 85.7% among those aged 0–6 months to 86.1% in 7–23 month olds to 88.1% among those aged 24–59 months, but the reverse was the specificity. For children with severe anaemia, the sensitivity of the RDT was nearly 100% compared with a specificity of 39%. While the sensitivity and the PPV reduced with children’s level of anaemia, the higher the severity of anaemia, the lower the NPV, specificity, the diagnostic accuracy of the RDT. The odds of RDT being sensitive was about 50% [adjusted Odds Ratio (aOR) = 0.52 (95% CI 0.30–0.90)] lower among children aged 7–23 months compared with those aged 24–59 months while the odds of RDT being sensitive was 2 times [aOR = 2.15 (95% CI 1.67–2.77)] higher among those 7–23 months than among those aged 24–59 months. Conclusions Although there was a significant agreement in the outcomes of RDT and microscopy tests, the discriminatory accuracy of RDT was weak. Also, the predictive accuracy, especially the PPV of the RDTS, were very low. These measures of accuracies differed across the age of the children, level of anaemia, recent experience of malaria and other characteristics. Without an accurate, efficient and reliable diagnosis of malaria, the goal of eliminating malaria and reduction of malaria-related deaths to zero by 2020 will only remain elusive. Electronic supplementary material The online version of this article (10.1186/s12936-019-2678-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Adeniyi Francis Fagbamigbe
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria. .,Centre for AIDS Research, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA. .,Division of Health Sciences, Populations, Evidence and Technologies Group, Warwick Medical School, University of Warwick, Coventry, UK.
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21
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Plasmodium falciparum histidine-rich protein (PfHRP2 and 3) diversity in Western and Coastal Kenya. Sci Rep 2019; 9:1709. [PMID: 30737461 PMCID: PMC6368535 DOI: 10.1038/s41598-018-38175-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/21/2018] [Indexed: 01/24/2023] Open
Abstract
Plasmodium falciparum histidine-rich proteins 2 (PfHRP2) based RDTs are advocated in falciparum malaria-endemic regions, particularly when quality microscopy is not available. However, diversity and any deletion in the pfhrp2 and pfhrp3 genes can affect the performance of PfHRP2-based RDTs. A total of 400 samples collected from uncomplicated malaria cases from Kenya were investigated for the amino acid repeat profiles in exon 2 of pfhrp2 and pfhrp3 genes. In addition, PfHRP2 levels were measured in 96 individuals with uncomplicated malaria. We observed a unique distribution pattern of amino acid repeats both in the PfHRP2 and PfHRP3. 228 PfHRP2 and 124 PfHRP3 different amino acid sequences were identified. Of this, 214 (94%) PfHRP2 and 81 (65%) PfHRP3 amino acid sequences occurred only once. Thirty-nine new PfHRP2 and 20 new PfHRP3 amino acid repeat types were identified. PfHRP2 levels were not correlated with parasitemia or the number of PfHRP2 repeat types. This study shows the variability of PfHRP2, PfHRP3 and PfHRP2 concentration among uncomplicated malaria cases. These findings will be useful to understand the performance of PfHRP2-based RDTs in Kenya.
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22
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McCreesh P, Mumbengegwi D, Roberts K, Tambo M, Smith J, Whittemore B, Kelly G, Moe C, Murphy M, Chisenga M, Greenhouse B, Ntuku H, Kleinschmidt I, Sturrock H, Uusiku P, Gosling R, Bennett A, Hsiang MS. Subpatent malaria in a low transmission African setting: a cross-sectional study using rapid diagnostic testing (RDT) and loop-mediated isothermal amplification (LAMP) from Zambezi region, Namibia. Malar J 2018; 17:480. [PMID: 30567537 PMCID: PMC6299963 DOI: 10.1186/s12936-018-2626-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/11/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Subpatent malaria infections, or low-density infections below the detection threshold of microscopy or standard rapid diagnostic testing (RDT), can perpetuate persistent transmission and, therefore, may be a barrier for countries like Namibia that are pursuing malaria elimination. This potential burden in Namibia has not been well characterized. METHODS Using a two-stage cluster sampling, cross-sectional design, subjects of all age were enrolled during the end of the 2015 malaria transmission season in Zambezi region, located in northeast Namibia. Malaria RDTs were performed with subsequent gold standard testing by loop-mediated isothermal amplification (LAMP) using dried blood spots. Infection prevalence was measured and the diagnostic accuracy of RDT calculated. Relationships between recent fever, demographics, epidemiological factors, and infection were assessed. RESULTS Prevalence of Plasmodium falciparum malaria infection was low: 0.8% (16/1919) by RDT and 2.2% (43/1919) by LAMP. All but one LAMP-positive infection was RDT-negative. Using LAMP as gold standard, the sensitivity and specificity of RDT were 2.3% and 99.2%, respectively. Compared to LAMP-negative infections, a higher portion LAMP-positive infections were associated with fever (45.2% vs. 30.4%, p = 0.04), though 55% of infections were not associated with fever. Agricultural occupations and cattle herding were significantly associated with LAMP-detectable infection (Adjusted ORs 5.02, 95% CI 1.77-14.23, and 11.82, 95% CI 1.06-131.81, respectively), while gender, travel, bed net use, and indoor residual spray coverage were not. CONCLUSIONS This study presents results from the first large-scale malaria cross-sectional survey from Namibia using molecular testing to characterize subpatent infections. Findings suggest that fever history and standard RDTs are not useful to address this burden. Achievement of malaria elimination may require active case detection using more sensitive point-of-care diagnostics or presumptive treatment and targeted to high-risk groups.
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Affiliation(s)
- Patrick McCreesh
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Davis Mumbengegwi
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Kathryn Roberts
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Munyaradzi Tambo
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Jennifer Smith
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Brooke Whittemore
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gerard Kelly
- Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Caitlin Moe
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Max Murphy
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, UCSF, San Francisco, CA, USA
| | - Mukosha Chisenga
- Multidisciplinary Research Center, University of Namibia, Windhoek, Namibia
| | - Bryan Greenhouse
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, UCSF, San Francisco, CA, USA
| | - Henry Ntuku
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Immo Kleinschmidt
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Wits Research Institute for Malaria, University of Witwatersrands, Johannesburg, South Africa
| | - Hugh Sturrock
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Petrina Uusiku
- National Vectorborne Disease Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Roland Gosling
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco (UCSF), San Francisco, CA, USA. .,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Pediatrics, UCSF Benioff Children's Hospital, San Francisco, CA, USA.
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Pati P, Dhangadamajhi G, Bal M, Ranjit M. High proportions of pfhrp2 gene deletion and performance of HRP2-based rapid diagnostic test in Plasmodium falciparum field isolates of Odisha. Malar J 2018; 17:394. [PMID: 30373573 PMCID: PMC6206925 DOI: 10.1186/s12936-018-2502-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 10/03/2018] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND With the documentation of cases of falciparum malaria negative by rapid diagnostic tests (RDT), though at low frequency from natural isolates in a small pocket of Odisha, it became absolutely necessary to investigate the status of HRP-2 based RDT throughout the state and in different seasons of the year. METHODS Suspected individuals were screened for malaria infection by microscopy and RDT in 25/30 districts of Odisha, India. Discrepancies in results were confirmed by PCR. False negative RDT samples for Plasmodium falciparum mono-infection were evaluated for detection of HRP2 antigen in ELISA and genotyped for pfhrp2, pfhrp3 and their flanking genes. Multiplicity of infection was ascertained based on msp1 and msp2 genotyping and parasitaemia level was determined by microscopy. RESULTS Of the total 1058 patients suspected for malaria, 384 were microscopically confirmed for P. falciparum mono-infection and RDT failure was observed in 58 samples at varying proportion in different regions of the state. The failure in detection was due to undetectable level of HRP-2. Although most of these samples were screened during rainy season (45/345), significantly high proportion (9/17) of RDT negative samples were obtained during the summer compared to rainy season (P = 0.0002; OR = 7.5). PCR genotyping of pfhrp2 and pfhrp3 in RDT negative samples showed 38/58 (65.5) samples to be pfhrp2 negative and 24/58 (41.4) to be pfhrp3 negative including dual negative in 17/58 (29.3). Most of the RDT negative samples (39/58) were with single genotype infection and high proportions of pfhrp2 deletion (7/9) was observed in summer. No difference in parasitaemia level was observed between RDT positive and RDT negative patients. CONCLUSION High prevalence of parasites with pfhrp2 deletion including dual deletions (pfhrp2 and pfhrp3) is a serious cause of concern, as these patients could not be given a correct diagnosis and treatment. Therefore, HRP2-based RDT for diagnosing P. falciparum infection in Odisha is non-reliable and must be performed in addition to or replaced by other appropriate diagnostic tools for clinical management of the disease.
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Affiliation(s)
- Pallabi Pati
- Molecular Epidemiology Laboratory, ICMR-Regional Medical Research Centre, Bhubaneswar, 751023, India
| | | | - Madhusmita Bal
- Immunology Laboratory, ICMR-Regional Medical Research Centre, Bhubaneswar, 751023, India
| | - Manoranjan Ranjit
- Molecular Epidemiology Laboratory, ICMR-Regional Medical Research Centre, Bhubaneswar, 751023, India.
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Fontecha G, Mejía RE, Banegas E, Ade MP, Mendoza L, Ortiz B, Sabillón I, Alvarado G, Matamoros G, Pinto A. Deletions of pfhrp2 and pfhrp3 genes of Plasmodium falciparum from Honduras, Guatemala and Nicaragua. Malar J 2018; 17:320. [PMID: 30170596 PMCID: PMC6119307 DOI: 10.1186/s12936-018-2470-7] [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: 07/11/2018] [Accepted: 08/27/2018] [Indexed: 01/02/2023] Open
Abstract
Background Malaria remains a public health problem in some countries of Central America. Rapid diagnostic tests (RDTs) are one of the most useful tools to assist in the diagnosis of malaria in remote areas. Since its introduction, a wide variety of RDTs have been developed for the detection of different parasite antigens. PfHRP2 is the most targeted antigen for the detection of Plasmodium falciparum infections. Genetic mutations and gene deletions are important factors influencing or affecting the performance of rapid diagnostic tests. Methods In order to demonstrate the presence or absence of the pfhrp2 and pfhrp3 genes and their flanking regions, a total of 128 blood samples from patients with P. falciparum infection from three Central American countries were analysed through nested or semi-nested PCR approaches. Results In total, 25.8 and 91.4% of the isolates lacked the region located between exon 1 and exon 2 of pfhrp2 and pfhrp3 genes, respectively. Parasites from the three countries showed deletions of one or both genes. The highest proportion of pfhrp2 deletions was found in Nicaragua while the isolates from Guatemala revealed the lowest number of pfhrp2 deletions. Parasites collected from Honduras showed the highest proportion of phfrp3 absence (96.2%). Twenty-one percent of isolates were double negative mutants for the exon 1–2 segment of both genes, and 6.3% of isolates lacked the full-length coding region of both genes. Conclusions This study provides molecular evidence of the existence of P. falciparum isolates lacking the pfhrp2 and pfhrp3 genes, and their flanking regions, in Honduras, Guatemala and Nicaragua. This finding could hinder progress in the control and elimination of malaria in Central America. Continuous evaluation of RDTs and molecular surveillance would be recommended.
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Affiliation(s)
- Gustavo Fontecha
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras.
| | - Rosa E Mejía
- Panamerican Health Organization, Tegucigalpa, Honduras
| | - Engels Banegas
- National Department of Surveillance, Ministry of Health, Tegucigalpa, Honduras
| | | | - Lisandro Mendoza
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
| | - Bryan Ortiz
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
| | - Isaac Sabillón
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
| | - Gerardo Alvarado
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
| | - Gabriela Matamoros
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
| | - Alejandra Pinto
- Microbiology Research Institute, Universidad Nacional Autonoma de Honduras, Tegucigalpa, Honduras
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25
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Markwalter CF, Mudenda L, Leelawong M, Kimmel DW, Nourani A, Mbambara S, Thuma PE, Wright DW. Evidence for histidine-rich protein 2 immune complex formation in symptomatic patients in Southern Zambia. Malar J 2018; 17:256. [PMID: 29986725 PMCID: PMC6038308 DOI: 10.1186/s12936-018-2400-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/26/2018] [Indexed: 11/20/2022] Open
Abstract
Background Rapid diagnostic tests based on histidine-rich protein 2 (HRP2) detection are the primary tools used to detect Plasmodium falciparum malaria infections. Recent conflicting reports call into question whether α-HRP2 antibodies are present in human host circulation and if resulting immune complexes could interfere with HRP2 detection on malaria RDTs. This study sought to determine the prevalence of immune-complexed HRP2 in a low-transmission region of Southern Zambia. Methods An ELISA was used to quantify HRP2 in patient sample DBS extracts before and after heat-based immune complex dissociation. A pull-down assay reliant on proteins A, G, and L was developed and applied for IgG and IgM capture and subsequent immunoprecipitation of any HRP2 present in immune complexed form. A total of 104 patient samples were evaluated using both methods. Results Immune-complexed HRP2 was detectable in 17% (18/104) of all samples evaluated and 70% (16/23) of HRP2-positive samples. A majority of the patients with samples containing immune-complexed HRP2 had P. falciparum infections (11/18) and were also positive for free HRP2 (16/18). For 72% (13/18) of patients with immune-complexed HRP2, less than 10% of the total HRP2 present was in immune-complexed form. For the remaining samples, a large proportion (≥ 20%) of total HRP2 was complexed with α-HRP2 antibodies. Conclusions Endogenous α-HRP2 antibodies form immune complexes with HRP2 in the symptomatic patient population of a low-transmission area in rural Southern Zambia. For the majority of patients, the percentage of HRP2 in immune complexes is low and does not affect HRP2-based malaria diagnosis. However, for some patients, a significant portion of the total HRP2 was in immune-complexed form. Future studies investigating the prevalence and proportion of immune-complexed HRP2 in asymptomatic individuals with low HRP2 levels will be required to assess whether α-HRP2 antibodies affect HRP2 detection for this portion of the transmission reservoir. Electronic supplementary material The online version of this article (10.1186/s12936-018-2400-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Lwiindi Mudenda
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA.,Rusangu University, Monze, Zambia
| | - Mindy Leelawong
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Danielle W Kimmel
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | - Armin Nourani
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA
| | | | | | - David W Wright
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37235, USA.
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Parr JB, Anderson O, Juliano JJ, Meshnick SR. Streamlined, PCR-based testing for pfhrp2- and pfhrp3-negative Plasmodium falciparum. Malar J 2018; 17:137. [PMID: 29609602 PMCID: PMC5879555 DOI: 10.1186/s12936-018-2287-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/21/2018] [Indexed: 11/22/2022] Open
Abstract
Background Rapid diagnostic tests (RDTs) that detect histidine-rich protein 2 (PfHRP2) are used throughout Africa for the diagnosis of Plasmodium falciparum malaria. However, recent reports indicate that parasites lacking the pfhrp2 and/or histidine-rich protein 3 (pfhrp3) genes, which produce antigens detected by these RDTs, are common in select regions of South America, Asia, and Africa. Proving the absence of a gene is challenging, and multiple PCR assays targeting these genes have been described. A detailed characterization and comparison of published assays is needed to facilitate robust and streamlined testing approaches. Results Among six pfhrp2 and pfhrp3 PCR assays tested, the lower limit of detection ranged from 0.01 pg/µL to 0.1 ng/µL of P. falciparum 3D7 strain DNA, or approximately 0.4–4000 parasite genomes/µL. By lowering the elongation temperature to 60 °C, a tenfold improvement in the limit of detection and/or darker bands for all exon 1 targets and for the first-round reaction of a single exon 2 target was achieved. Additionally, assays targeting exon 1 of either gene yielded spurious amplification of the paralogous gene. Using these data, an optimized testing algorithm for the detection of pfhrp2- and pfhrp3-negative P. falciparum is proposed. Conclusions Surveillance of pfhrp2- and pfhrp3-negative P. falciparum requires careful laboratory workflows. PCR-based testing methods coupled with microscopy and/or antigen testing serve as useful tools to support policy development. Standardized approaches to the detection of pfhrp2- and pfhrp3-negative P. falciparum should inform efforts to define the impact of these parasites. Electronic supplementary material The online version of this article (10.1186/s12936-018-2287-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA.
| | - Olivia Anderson
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr, Chapel Hill, NC, 27599, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr, Chapel Hill, NC, 27599, USA.,Curriculum in Genetics and Microbiology, University of North Carolina, 321 South Columbia Street, Chapel Hill, NC, 27599, USA
| | - Steven R Meshnick
- Division of Infectious Diseases, Department of Medicine, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC, 27599, USA.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, 135 Dauer Dr, Chapel Hill, NC, 27599, USA
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Amir A, Cheong FW, De Silva JR, Lau YL. Diagnostic tools in childhood malaria. Parasit Vectors 2018; 11:53. [PMID: 29361963 PMCID: PMC5781272 DOI: 10.1186/s13071-018-2617-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/02/2018] [Indexed: 01/05/2023] Open
Abstract
Every year, millions of people are burdened with malaria. An estimated 429,000 casualties were reported in 2015, with the majority made up of children under five years old. Early and accurate diagnosis of malaria is of paramount importance to ensure appropriate administration of treatment. This minimizes the risk of parasite resistance development, reduces drug wastage and unnecessary adverse reaction to antimalarial drugs. Malaria diagnostic tools have expanded beyond the conventional microscopic examination of Giemsa-stained blood films. Contemporary and innovative techniques have emerged, mainly the rapid diagnostic tests (RDT) and other molecular diagnostic methods such as PCR, qPCR and loop-mediated isothermal amplification (LAMP). Even microscopic diagnosis has gone through a paradigm shift with the development of new techniques such as the quantitative buffy coat (QBC) method and the Partec rapid malaria test. This review explores the different diagnostic tools available for childhood malaria, each with their characteristic strengths and limitations. These tools play an important role in making an accurate malaria diagnosis to ensure that the use of anti-malaria are rationalized and that presumptive diagnosis would only be a thing of the past.
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Affiliation(s)
- Amirah Amir
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Fei-Wen Cheong
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Jeremy R De Silva
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia.
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Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo. Malar J 2017; 16:456. [PMID: 29121931 PMCID: PMC5680818 DOI: 10.1186/s12936-017-2110-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/06/2017] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented. RESULTS Overall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6-15. While the majority of households own bed nets, bed net usage is less than 50%. CONCLUSIONS The study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.
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