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Mayor A, Ishengoma DS, Proctor JL, Verity R. Sampling for malaria molecular surveillance. Trends Parasitol 2023; 39:954-968. [PMID: 37730525 PMCID: PMC10580323 DOI: 10.1016/j.pt.2023.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/22/2023]
Abstract
Strategic use of Plasmodium falciparum genetic variation has great potential to inform public health actions for malaria control and elimination. Malaria molecular surveillance (MMS) begins with a strategy to identify and collect parasite samples, guided by public-health priorities. In this review we discuss sampling design practices for MMS and point out epidemiological, biological, and statistical factors that need to be considered. We present examples for different use cases, including detecting emergence and spread of rare variants, establishing transmission sources and inferring changes in malaria transmission intensity. This review will potentially guide the collection of samples and data, serve as a starting point for further methodological innovation, and enhance utilization of MMS to support malaria elimination.
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Affiliation(s)
- Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique; Department of Physiologic Sciences, Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique.
| | - Deus S Ishengoma
- National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania; Faculty of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Joshua L Proctor
- Institute for Disease Modeling in Global Health, Bill and Melinda Gates Foundation, Seattle, WA, USA
| | - Robert Verity
- MRC Centre for Global Infectious Disease Analysis, Imperial College, London, UK
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2
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Plowe CV. Malaria chemoprevention and drug resistance: a review of the literature and policy implications. Malar J 2022; 21:104. [PMID: 35331231 PMCID: PMC8943514 DOI: 10.1186/s12936-022-04115-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/03/2022] [Indexed: 01/19/2023] Open
Abstract
Chemoprevention strategies reduce malaria disease and death, but the efficacy of anti-malarial drugs used for chemoprevention is perennially threatened by drug resistance. This review examines the current impact of chemoprevention on the emergence and spread of drug resistant malaria, and the impact of drug resistance on the efficacy of each of the chemoprevention strategies currently recommended by the World Health Organization, namely, intermittent preventive treatment in pregnancy (IPTp); intermittent preventive treatment in infants (IPTi); seasonal malaria chemoprevention (SMC); and mass drug administration (MDA) for the reduction of disease burden in emergency situations. While the use of drugs to prevent malaria often results in increased prevalence of genetic mutations associated with resistance, malaria chemoprevention interventions do not inevitably lead to meaningful increases in resistance, and even high rates of resistance do not necessarily impair chemoprevention efficacy. At the same time, it can reasonably be anticipated that, over time, as drugs are widely used, resistance will generally increase and efficacy will eventually be lost. Decisions about whether, where and when chemoprevention strategies should be deployed or changed will continue to need to be made on the basis of imperfect evidence, but practical considerations such as prevalence patterns of resistance markers can help guide policy recommendations.
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3
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Baker K, Aide P, Bonnington CA, Rassi C, Richardson S, Roca-Feltrer A, Rodrigues M, Sitoe M, Pulido Tarquino IA, Enosse S, McGugan C, de Carvalho EA, Saute F, Mayor Aparicio AG, Candrinho B. Feasibility, acceptability and protective efficacy of seasonal malaria chemoprevention implementation in Nampula province, Mozambique: a hybrid effectiveness-implementation study protocol. (Preprint). JMIR Res Protoc 2022; 11:e36403. [PMID: 36149743 PMCID: PMC9547334 DOI: 10.2196/36403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/27/2022] [Accepted: 07/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background Seasonal malaria chemoprevention (SMC) is a highly effective community-based intervention to prevent malaria infections in areas where the malaria burden is high and transmission occurs mainly during the rainy season. In Africa, so far, SMC has been implemented in the Sahel region. Mozambique contributes 4% of the global malaria cases, and malaria is responsible for one-quarter of all deaths in the country. Based on recommendations in the Malaria Strategic Plan, the Malaria Consortium, in partnership with the National Malaria Control Programme in Mozambique, initiated a phased SMC implementation study in the northern province of Nampula. The first phase of this 2-year implementation study was conducted in 2020-2021 and focused on the feasibility and acceptability of SMC. The second phase will focus on demonstrating impact. This paper describes phase 2 of the implementation study. Objective Specific objectives include the following: (1) to determine the effectiveness of SMC in terms of its reduction in incidence of malaria infection among children aged 3 to 59 months; (2) to determine the chemoprevention efficacy of sulfadoxine-pyrimethamine plus amodiaquine (SP+AQ) when used for SMC in Nampula Province, Mozambique, and the extent to which efficacy is impacted by drug resistance and drug concentrations; (3) to investigate the presence and change in SP+AQ– and piperaquine-resistance markers over time as a result of SMC implementation; and (4) to understand the impact of the SMC implementation model, determining the process and acceptability outcomes for the intervention. Methods This type 2, hybrid, effectiveness-implementation study uses a convergent mixed methods approach. SMC will be implemented in four monthly cycles between December 2021 and March 2022 in four districts of Nampula Province. Phase 2 will include four components: (1) a cluster randomized controlled trial to establish confirmed malaria cases, (2) a prospective cohort to determine the chemoprevention efficacy of the antimalarials used for SMC and whether drug concentrations or resistance influence the duration of protection, (3) a resistance marker study in children aged 3 to 59 months to describe changes in resistance marker prevalence over time, and (4) a process evaluation to determine feasibility and acceptability of SMC. Results Data collection began in mid-January 2022, and data analysis is expected to be completed by October 2022. Conclusions This is the first effectiveness trial of SMC implemented in Mozambique. The findings from this trial will be crucial to policy change and program expansion to other suitable geographies outside of the Sahel. The chemoprevention efficacy cohort study is a unique opportunity to better understand SMC drug efficacy in this new SMC environment. Trial Registration ClinicalTrials.gov NCT05186363; https://clinicaltrials.gov/ct2/show/NCT05186363 International Registered Report Identifier (IRRID) DERR1-10.2196/36403
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Affiliation(s)
- Kevin Baker
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça, Manhica, Mozambique
| | | | | | | | | | | | | | | | - Sonia Enosse
- National Institute of Health, Maputo, Mozambique
| | | | | | - Francisco Saute
- Centro de Investigação em Saúde de Manhiça, Manhica, Mozambique
| | | | - Baltazar Candrinho
- The National Malaria Control Program, Ministry of Health, Maputo, Mozambique
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4
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Roux AT, Maharaj L, Oyegoke O, Akoniyon OP, Adeleke MA, Maharaj R, Okpeku M. Chloroquine and Sulfadoxine-Pyrimethamine Resistance in Sub-Saharan Africa-A Review. Front Genet 2021; 12:668574. [PMID: 34249090 PMCID: PMC8267899 DOI: 10.3389/fgene.2021.668574] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Malaria is a great concern for global health and accounts for a large amount of morbidity and mortality, particularly in Africa, with sub-Saharan Africa carrying the greatest burden of the disease. Malaria control tools such as insecticide-treated bed nets, indoor residual spraying, and antimalarial drugs have been relatively successful in reducing the burden of malaria; however, sub-Saharan African countries encounter great challenges, the greatest being antimalarial drug resistance. Chloroquine (CQ) was the first-line drug in the 20th century until it was replaced by sulfadoxine–pyrimethamine (SP) as a consequence of resistance. The extensive use of these antimalarials intensified the spread of resistance throughout sub-Saharan Africa, thus resulting in a loss of efficacy for the treatment of malaria. SP was replaced by artemisinin-based combination therapy (ACT) after the emergence of resistance toward SP; however, the use of ACTs is now threatened by the emergence of resistant parasites. The decreased selective pressure on CQ and SP allowed for the reintroduction of sensitivity toward those antimalarials in regions of sub-Saharan Africa where they were not the primary drug for treatment. Therefore, the emergence and spread of antimalarial drug resistance should be tracked to prevent further spread of the resistant parasites, and the re-emergence of sensitivity should be monitored to detect the possible reappearance of sensitivity in sub-Saharan Africa.
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Affiliation(s)
- Alexandra T Roux
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Leah Maharaj
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Olukunle Oyegoke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Oluwasegun P Akoniyon
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Matthew Adekunle Adeleke
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
| | - Rajendra Maharaj
- Office of Malaria Research, South African Medical Research Council, Cape Town, South Africa
| | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, South Africa
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5
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Huijben S, Macete E, Mombo-Ngoma G, Ramharter M, Kariuki S, Desai M, Shi YP, Mwangoka G, Massougbodji A, Cot M, Ndam NT, Uberegui E, Gupta H, Cisteró P, Aponte JJ, González R, Menéndez C, Mayor A. Counter-Selection of Antimalarial Resistance Polymorphisms by Intermittent Preventive Treatment in Pregnancy. J Infect Dis 2020; 221:293-303. [PMID: 31677349 DOI: 10.1093/infdis/jiz451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/19/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Innovative approaches are needed to limit antimalarial resistance evolution. Understanding the role of intermittent preventive treatment in pregnancy (IPTp) on the selection for resistance and the impact such selection has on pregnancy outcomes can guide future interventions. METHODS Plasmodium falciparum isolates (n = 914) from 2 randomized clinical trials were screened for pfmdr1 copy number variation and pfcrt, pfmdr1, pfdhfr, and pfdhps resistance markers. The trials were conducted between 2010 and 2013 in Benin, Gabon, Kenya, and Mozambique to establish the efficacy of IPTp-mefloquine (MQ) compared with IPTp-sulphadoxine-pyrimethamine (SP) in human immunodeficiency virus (HIV)-uninfected and to IPTp-placebo in HIV-infected women. RESULTS In HIV-uninfected women, the prevalence of pfcrt mutants, pfdhfr/pfdhps quintuple mutants, and pfmdr1 copy number was similar between women receiving IPT-SP and IPTp-MQ. However, prevalence of pfmdr1 polymorphism 86Y was lower in the IPTp-MQ group than in the IPTp-SP group, and within the IPTp-MQ group it was lower at delivery compared with recruitment. No effect of IPTp-MQ on resistance markers was observed among HIV-infected women. The carriage of resistance markers was not associated with pregnancy outcomes. CONCLUSIONS Selection of wild-type pfmdr1 polymorphism N86 by IPTp-MQ highlights the strong selective pressure IPTp can exert and the opportunity for using negative cross-resistance in drug choice for clinical treatment and IPTp.
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Affiliation(s)
- Silvie Huijben
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Eusebio Macete
- Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Universität Tübingen, und Deutsches Zentrum für Infektionsforschung, Tübingen, Germany.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine and Department of Medicine I, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine and Department of Medicine I, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon Kariuki
- Kenya Medical Research Institute/Centre for Global Health Research, Kisumu, Kenya
| | - Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ya Ping Shi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Achille Massougbodji
- Unité d'Enseignement et de Recherche de Parasitologie Mycologie, Faculté des Sciences de la Santé, Cotonou, Bénin
| | - Michel Cot
- Université de Paris, MERIT, IRD, Paris, France
| | | | | | - Himanshu Gupta
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - John J Aponte
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique
| | - Raquel González
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique
| | - Clara Menéndez
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique
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Zhao L, Pi L, Qin Y, Lu Y, Zeng W, Xiang Z, Qin P, Chen X, Li C, Zhang Y, Wang S, Si Y, Yang G, Rosenthal BM, Huang Y, Yang Z. Widespread resistance mutations to sulfadoxine-pyrimethamine in malaria parasites imported to China from Central and Western Africa. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 12:1-6. [PMID: 31809965 PMCID: PMC6909128 DOI: 10.1016/j.ijpddr.2019.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND Imported cases of infectious disease provide invaluable information about epidemiological conditions abroad, and should guide treatment decisions at home and abroad. Here, we examined cases of malaria imported from Africa to China for mutations eroding the efficacy of sulfadoxine-pyrimethamine (SP), sometimes used as an intermittent preventive treatment during for pregnant women and infants. METHODS A total of 208 blood samples were collected from P. falciparum-infected workers who had returned from Western and Central Africa to Guangxi Province Frequency distribution. Samples were analyzed for the mutations in dhfr and dhps genes by PCR -sequencing. The prevalence of dhfr and dhps polymorphisms was analyzed. Among the isolates, polymorphisms were detected in mutants N51I, C59R, S108N and I164L of Pfdhfr and I431V, S436 A/F, A437G, K540 E/N, A581G and A613T of pfdhps. RESULTS Mutations promoting drug resistance were widespread in this cohort. For pfdhfr and pfdhps, wild types were equally rare among patients returned from Western Africa and Central Africa. A triple-mutant dhfr haplotype was most prevalent (>70%). We report for the first time mutation I164L-dhfr and I431V-dhps in Ghana, and for the first time we found A581G to exceed a clinically-relevant threshold that may counter-indicate current clinical practices. For Pfdhps, the double-mutant IAGKAA was high prevalent haplotype in Ghana, Western Africa. The single-mutant ISGKAA was a majority haplotype in Cameroon. Alarmingly, a "super resistance" quintuple mutant was detected, for the first time, in parasites of West African origin (defined by IAGKAA/IRNI in combination with pfdhps 581G and dhfr I164L). This may limit the efficacy of this drug combination for even intermittent clinical applications. CONCLUSIONS These data are cause for great concern and call for continued surveillance of the efficacy of SP in source and recipient populations, and should be considered when developing treatment policy for imported malaria cases in China and elsewhere.
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Affiliation(s)
- Luyi Zhao
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Liang Pi
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Yucheng Qin
- Shanglin County People's Hospital, Shanglin, 530500, Guangxi, PR China
| | - Yuxin Lu
- Shanglin County People's Hospital, Shanglin, 530500, Guangxi, PR China
| | - Weilin Zeng
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Zheng Xiang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Pien Qin
- Shanglin County People's Hospital, Shanglin, 530500, Guangxi, PR China
| | - Xi Chen
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Cuiying Li
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Yanmei Zhang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Siqi Wang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Yu Si
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China
| | - Gongchao Yang
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, 2500, North State Street, USA
| | - Benjamin M Rosenthal
- Animal Parasitic Disease Laboratory, Agricultural Research Service, US Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA
| | - Yaming Huang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China; Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, 530021, Guangxi, PR China
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, 650500, Yunnan, PR China.
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7
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Chauvin P, Menard S, Iriart X, Nsango SE, Tchioffo MT, Abate L, Awono-Ambéné PH, Morlais I, Berry A. Prevalence of Plasmodium falciparum parasites resistant to sulfadoxine/pyrimethamine in pregnant women in Yaoundé, Cameroon: emergence of highly resistant pfdhfr/pfdhps alleles. J Antimicrob Chemother 2015; 70:2566-71. [PMID: 26080363 DOI: 10.1093/jac/dkv160] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/22/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To determine, 6 years after the adoption of intermittent preventive treatment of pregnant women with sulfadoxine/pyrimethamine (IPTp-SP) in Cameroon, (i) the polymorphism and prevalence of Plasmodium falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) gene mutations associated with sulfadoxine/pyrimethamine resistance and (ii) the consequences of sulfadoxine/pyrimethamine use in the selection of pfdhfr/pfdhps alleles. METHODS pfdhfr and pfdhps genes from P. falciparum isolates collected in Yaoundé (Cameroon) from pregnant women with symptomatic malaria before taking IPTp-SP [SP- group (control) (n = 51)] or afterwards [SP+ group (n = 49)] were sequenced. RESULTS The pfdhfr N51I, C59R, S108N triple mutant had a prevalence close to 100% (96/100) and no mutations at codons 50 and 164 were detected in either of the groups. The most frequent pfdhps mutation was A437G with a prevalence of 76.5% (39/51) in the SP- group, which was significantly higher in pregnant women who took sulfadoxine/pyrimethamine [95.9% (47/49)] (P = 0.012). Our study confirmed the presence of the pfdhps K540E mutation in Cameroon, but it remained rare. The prevalence of pfdhps A581G and A613S mutations had increased [5.9% (3/51) and 11.8% (6/51) in the control group, respectively] since the last studies in 2005. Surprisingly, the new pfdhps I431V mutation was detected, at a prevalence of 9.8% (5/51), and was found to be associated with other pfdhfr/pfdhps alleles to form an octuple N51I, C59R, S108N/I431V, S436A, A437G, A581G, A613S mutant. CONCLUSIONS Significant changes were found in pfdhps polymorphism. In particular, we observed several parasites carrying eight mutations in pfdhfr/pfdhps genes, which are very susceptible to having a high level of resistance to sulfadoxine/pyrimethamine.
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Affiliation(s)
- Pamela Chauvin
- Service de Parasitologie-Mycologie, CHU Toulouse, Toulouse, France
| | - Sandie Menard
- Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS UMR5282, Université de Toulouse, Toulouse, France
| | - Xavier Iriart
- Service de Parasitologie-Mycologie, CHU Toulouse, Toulouse, France Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS UMR5282, Université de Toulouse, Toulouse, France
| | - Sandrine E Nsango
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon Laboratoire d'Entomologie Médicale, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Majoline T Tchioffo
- Laboratoire d'Entomologie Médicale, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroon UMR MIVEGEC, IRD, 224-CNR, 5290-UM1-UM2, Institut de Recherche pour le Développement, Montpellier, France
| | - Luc Abate
- UMR MIVEGEC, IRD, 224-CNR, 5290-UM1-UM2, Institut de Recherche pour le Développement, Montpellier, France
| | - Parfait H Awono-Ambéné
- Laboratoire d'Entomologie Médicale, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroon
| | - Isabelle Morlais
- Laboratoire d'Entomologie Médicale, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, Cameroon UMR MIVEGEC, IRD, 224-CNR, 5290-UM1-UM2, Institut de Recherche pour le Développement, Montpellier, France
| | - Antoine Berry
- Service de Parasitologie-Mycologie, CHU Toulouse, Toulouse, France Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS UMR5282, Université de Toulouse, Toulouse, France
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8
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Plasmodium falciparum and Plasmodium vivax genotypes and efficacy of intermittent preventive treatment in Papua New Guinea. Antimicrob Agents Chemother 2014; 58:6958-61. [PMID: 25155586 DOI: 10.1128/aac.03323-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intermittent preventive treatment of infants (IPTi) reduces early childhood malaria-related morbidity. While genotypic drug resistance markers have proven useful in predicting the efficacy of antimalarial drugs in case management, there are few equivalent data relating to their protective efficacy when used as IPTi. The present data from an IPTi trial in Papua New Guinea demonstrate how these markers can predict protective efficacy of IPTi for both Plasmodium falciparum and Plasmodium vivax.
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9
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Venkatesan M, Alifrangis M, Roper C, Plowe CV. Monitoring antifolate resistance in intermittent preventive therapy for malaria. Trends Parasitol 2013; 29:497-504. [PMID: 23948432 DOI: 10.1016/j.pt.2013.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/18/2013] [Accepted: 07/19/2013] [Indexed: 10/26/2022]
Abstract
Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps have rendered sulfadoxine-pyrimethamine (SP) ineffective for malaria treatment in most regions of the world. Yet, SP is efficacious as intermittent preventive therapy in pregnant women (IPTp) and infants (IPTi) and as seasonal malaria control in children (SMC). SP-IPTp is being widely implemented in sub-Saharan Africa. SP-IPTi is recommended where the prevalence of SP-resistant malaria parasites is low, whereas SMC is recommended for areas of intense seasonal malaria transmission. The continuing success of these interventions depends largely on the prevalence of Pfdhfr and Pfdhps resistance mutations in the target population. Here we review the relationship between resistance mutations and SP-IPT within target populations in the context of monitoring and informing implementation of this intervention.
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Affiliation(s)
- Meera Venkatesan
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore Street, HSF1-480, Baltimore, MD 21201, USA; WorldWide Antimalarial Resistance Network (WWARN) Molecular Module(*)
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Selection of antimalarial drug resistance after intermittent preventive treatment of infants and children (IPTi/c) in Senegal. C R Biol 2013; 336:295-300. [PMID: 23916206 DOI: 10.1016/j.crvi.2013.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Senegal has since 2003 used sulphadoxine-pyrimethamine (SP) for Intermittent Preventive Treatment (IPT) of malaria in risk groups. However, the large-scale IPT strategy may result in increasing drug resistance. Our study investigated the possible impact of SP-IPT given to infants and children on the prevalence of SP-resistant haplotypes in the Plasmodium falciparum genes Pfdhfr and Pfdhps, comparing sites with and without IPTi/c. P. falciparum positives samples (n=352) were collected from children under 5years of age during two cross-sectional surveys in 2010 and 2011 in three health districts (two on IPTi/c and one without IPTi/c intervention) located in the southern part of Senegal. The prevalence of SP-resistance-related haplotypes in Pfdhfr and Pfdhps was determined by nested PCR followed by sequence-specific oligonucleotide probe (SSOP)-ELISA. The prevalence of the Pfdhfr double mutant haplotypes (CNRN and CICN) was stable between years at<10% in the control group (P=0.69), while it rose significantly in the IPTi/c group from 2% in 2010 to 20% in 2011 (P=0.008). The prevalence of the Pfdhfr triple mutant haplotype (CIRN) increased in both groups, but only significantly in the IPTi/c group from 41% to 65% in 2011 (P=0.005). Conversely, the Pfdhps 437G mutation decreased in both groups from 44.6% to 28.6% (P=0.07) and from 66.7% to 47.5% (P=0.02) between 2010 and 2011 in the control and the IPTi/c groups, respectively. Combined with Pfdhfr, there was a weak trend for decreasing prevalence of quadruple mutants (triple Pfdhfr+Pfdhps 437G) in both groups (P=0.15 and P=0.34). During the two cross-sectional surveys, some significant changes were observed in the SP-resistance-related genes. However, since these changes were observed in the two groups, the IPTi/c strategy does only seem to have limited impact on resistance development and other factors as well. However, continuous monitoring will be needed, due to the up-scaling of the IPTi/c strategy in Senegal according to WHO recommendations.
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Ndiaye M, Tine R, Faye B, Ndiaye JL, Lo AC, Sylla K, Abiola A, Dieng Y, Ndiaye D, Hallett R, Gaye O, Alifrangis M. Selection of antimalarial drug resistance after intermittent preventive treatment of infants and children (IPTi/c) in Senegal. Am J Trop Med Hyg 2013; 88:1124-1129. [PMID: 23589534 PMCID: PMC3752812 DOI: 10.4269/ajtmh.12-0739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Our study investigated the possible impact of SP-IPT given to infants and children on the prevalence of SP-resistant haplotypes in the Plasmodium falciparum genes Pfdhfr and Pfdhps, comparing sites with and without IPTi/c. P. falciparum positive samples (N = 352) collected from children < 5 years were analyzed to determine the prevalence of SP resistance-related haplotypes by nested PCR followed by sequence-specific oligonucleotide probe-enzyme-linked immunosorbent assay. The prevalence of the Pfdhfr triple mutant haplotype (CIRN) increased in both groups, but only significantly in the IPTi/c group from 41% to 65% in 2011 (P = 0.005). Conversely, the Pfdhps 437G mutation decreased in both groups from 44.6% to 28.6% (P = 0.07) and from 66.7% to 47.5% (P = 0.02) between 2010 and 2011 in the control and the IPTi/c groups, respectively. A weak trend for decreasing prevalence of quadruple mutants (triple Pfdhfr + Pfdhps 437G) was noted in both groups (P = 0.15 and P = 0.34). During the two cross-sectional surveys some significant changes were observed in the SP resistance-related genes.
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Affiliation(s)
- Magatte Ndiaye
- *Address correspondence to Magatte Ndiaye, Universite Cheikh Anta Diop, Faculte de Medecine, Service de Parasitologie, 5005 Dakar-Fann Senegal. E-mail:
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Abdul-Ghani R, Farag HF, Allam AF. Sulfadoxine-pyrimethamine resistance in Plasmodium falciparum: a zoomed image at the molecular level within a geographic context. Acta Trop 2013; 125:163-90. [PMID: 23131424 DOI: 10.1016/j.actatropica.2012.10.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/25/2012] [Accepted: 10/26/2012] [Indexed: 10/27/2022]
Abstract
Antimalarial chemotherapy is one of the main pillars in the prevention and control of malaria. Following widespread resistance of Plasmodium falciparum to chloroquine, sulfadoxine-pyrimethamine came to the scene as an alternative to the cheap and well-tolerated chloroquine. However, widespread resistance to sulfadoxine-pyrimethamine has been documented. In vivo efficacy tests are the gold standard for assessing drug resistance and treatment failure. However, they have many disadvantages, such as influence of host immunity and drug pharmacokinetics. In vitro tests of antimalarial drug efficacy also have many technical difficulties. Molecular markers of resistance have emerged as epidemiologic tools to investigate antimalarial drug resistance even before becoming clinically evident. Mutations in P. falciparum dihydrofolate reductase and dihydrofolate synthase have been extensively studied as molecular markers for resistance to pyrimethamine and sulfadoxine, respectively. This review highlights the resistance of P. falciparum at the molecular level presenting both supporting and opposing studies on the utility of molecular markers.
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Pearce RJ, Ord R, Kaur H, Lupala C, Schellenberg J, Shirima K, Manzi F, Alonso P, Tanner M, Mshinda H, Roper C, Schellenberg D. A community-randomized evaluation of the effect of intermittent preventive treatment in infants on antimalarial drug resistance in southern Tanzania. J Infect Dis 2012; 207:848-59. [PMID: 23225897 DOI: 10.1093/infdis/jis742] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Intermittent preventive treatment in infants (IPTi) is the administration of sulfadoxine-pyrimethamine (SP) at 2, 3, and 9 months of age to prevent malaria. We investigated the influence of IPTi on drug resistance. METHODS Twenty-four areas were randomly assigned to receive or not receive IPTi. Blood collected during representative household surveys at baseline and 15 and 27 months after implementation was tested for SP and resistance markers. RESULTS The frequency of SP in blood was similar in the IPTi and comparison areas at baseline and at 15 months. dhfr and dhps mutations were also similar at baseline and then increased similarly in both arms after 15 months of SP-IPTi. First-line treatment was switched from SP to artemether-lumefantrine before the final survey, when SP positivity fell among infants in comparison areas but increased in IPTi areas. This was accompanied by an increase in dhfr but not dhps mutations in IPTi areas (P = .004 and P = .18, respectively). CONCLUSIONS IPTi did not increase drug pressure or the selection on dhfr and dhps mutants, when SP was the first-line malaria treatment. Introduction of artemether-lumefantrine was followed by an increase in dhfr mutations, consistent with weak selection attributable to SP-IPTi, but not by an increase in dhps mutations, suggesting a fitness cost of this mutation.
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Affiliation(s)
- Richard J Pearce
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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Bardají A, Bassat Q, Alonso PL, Menéndez C. Intermittent preventive treatment of malaria in pregnant women and infants: making best use of the available evidence. Expert Opin Pharmacother 2012; 13:1719-36. [PMID: 22775553 DOI: 10.1517/14656566.2012.703651] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Malaria continues to represent a huge global health burden on the most vulnerable populations. The Intermittent Preventive Treatment (IPT) strategy has been shown to be an efficacious intervention in preventing most of the deleterious effects of malaria in pregnant women and infants. Yet, the effectiveness of the IPT strategy may be impaired by the increasing resistance to sulfadoxine-pyrimethamine (SP), and the scarcity of alternative antimalarial drugs. AREAS COVERED This review examines all the available information on IPT, in an aim to provide the scientific community with a framework to understand the benefits and limitations of this malaria control strategy. It includes the understanding of the historical background of the IPT strategy, the drug's mechanisms of actions, updated information on current available evidence, the implications of drug resistance and choice of alternative drugs, and a comprehensive discussion on the perspectives of IPT for malaria control in pregnant women and infants. EXPERT OPINION IPT in pregnancy and infants is a cost-effective strategy that can contribute significantly to the control of malaria in endemic areas. Monitoring its effectiveness will allow tracking of progress, evaluation of the adequacy of currently used drugs and will highlight the eventual need for new therapies or alternative interventions.
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Affiliation(s)
- Azucena Bardají
- University of Barcelona, Hospital Clínic, Barcelona Centre for International Health Research, Roselló, 132, 08036, Barcelona, Spain.
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Senn N, Rarau P, Stanisic DI, Robinson L, Barnadas C, Manong D, Salib M, Iga J, Tarongka N, Ley S, Rosanas-Urgell A, Aponte JJ, Zimmerman PA, Beeson JG, Schofield L, Siba P, Rogerson SJ, Reeder JC, Mueller I. Intermittent preventive treatment for malaria in Papua New Guinean infants exposed to Plasmodium falciparum and P. vivax: a randomized controlled trial. PLoS Med 2012; 9:e1001195. [PMID: 22479155 PMCID: PMC3313928 DOI: 10.1371/journal.pmed.1001195] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 02/09/2012] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Intermittent preventive treatment in infants (IPTi) has been shown in randomized trials to reduce malaria-related morbidity in African infants living in areas of high Plasmodium falciparum (Pf) transmission. It remains unclear whether IPTi is an appropriate prevention strategy in non-African settings or those co-endemic for P. vivax (Pv). METHODS AND FINDINGS In this study, 1,121 Papua New Guinean infants were enrolled into a three-arm placebo-controlled randomized trial and assigned to sulfadoxine-pyrimethamine (SP) (25 mg/kg and 1.25 mg/kg) plus amodiaquine (AQ) (10 mg/kg, 3 d, n = 374), SP plus artesunate (AS) (4 mg/kg, 3 d, n = 374), or placebo (n = 373), given at 3, 6, 9 and 12 mo. Both participants and study teams were blinded to treatment allocation. The primary end point was protective efficacy (PE) against all episodes of clinical malaria from 3 to 15 mo of age. Analysis was by modified intention to treat. The PE (compared to placebo) against clinical malaria episodes (caused by all species) was 29% (95% CI, 10-43, p ≤ 0.001) in children receiving SP-AQ and 12% (95% CI, -11 to 30, p = 0.12) in those receiving SP-AS. Efficacy was higher against Pf than Pv. In the SP-AQ group, Pf incidence was 35% (95% CI, 9-54, p = 0.012) and Pv incidence was 23% (95% CI, 0-41, p = 0.048) lower than in the placebo group. IPTi with SP-AS protected only against Pf episodes (PE = 31%, 95% CI, 4-51, p = 0.027), not against Pv episodes (PE = 6%, 95% CI, -24 to 26, p = 0.759). Number of observed adverse events/serious adverse events did not differ between treatment arms (p > 0.55). None of the serious adverse events were thought to be treatment-related, and the vomiting rate was low in both treatment groups (1.4%-2.0%). No rebound in malaria morbidity was observed for 6 mo following the intervention. CONCLUSIONS IPTi using a long half-life drug combination is efficacious for the prevention of malaria and anemia in infants living in a region highly endemic for both Pf and Pv.
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Affiliation(s)
- Nicolas Senn
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Department of Medicine, University of Melbourne, Melbourne Australia
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Patricia Rarau
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Danielle I. Stanisic
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
| | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
| | - Céline Barnadas
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
| | - Doris Manong
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Mary Salib
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Jonah Iga
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Nandao Tarongka
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Serej Ley
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | | | - John J. Aponte
- Barcelona Centre for International Health Research (CRESIB), Barcelona, Spain
| | - Peter A. Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - James G. Beeson
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Burnet Institute, Melbourne, Australia
| | - Louis Schofield
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | | | | | - Ivo Mueller
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Barcelona Centre for International Health Research (CRESIB), Barcelona, Spain
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Schellenberg JRMA, Maokola W, Shirima K, Manzi F, Mrisho M, Mushi A, Alonso P, Mshinda H, Tanner M, Schellenberg DM. Cluster-randomized study of intermittent preventive treatment for malaria in infants (IPTi) in southern Tanzania: evaluation of impact on survival. Malar J 2011; 10:387. [PMID: 22208409 PMCID: PMC3261134 DOI: 10.1186/1475-2875-10-387] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 12/30/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intermittent Preventive Treatment for malaria control in infants (IPTi) consists of the administration of a treatment dose of an anti-malarial drug, usually sulphadoxine-pyrimethamine, at scheduled intervals, regardless of the presence of Plasmodium falciparum infection. A pooled analysis of individually randomized trials reported that IPTi reduced clinical episodes by 30%. This study evaluated the effect of IPTi on child survival in the context of a five-district implementation project in southern Tanzania. [ TRIAL REGISTRATION clinicaltrials.gov NCT00152204]. METHODS After baseline household and health facility surveys in 2004, five districts comprising 24 divisions were randomly assigned either to receive IPTi (n = 12) or not (n = 12). Implementation started in March 2005, led by routine health services with support from the research team. In 2007, a large household survey was undertaken to assess the impact of IPTi on survival in infants aged two-11 months through birth history interviews with all women aged 13-49 years. The analysis is based on an "intention-to-treat" ecological design, with survival outcomes analysed according to the cluster in which the mothers lived. RESULTS Survival in infants aged two-11 months was comparable in IPTi and comparison areas at baseline. In intervention areas in 2007, 48% of children aged 12-23 months had documented evidence of receiving three doses of IPTi, compared to 2% in comparison areas (P < 0.0001). Over the three years of the study there was a marked improvement in survival in both groups. Between 2001-4 and 2005-7, mortality rates in two-11 month olds fell from 34.1 to 23.6 per 1,000 person-years in intervention areas and from 32.3 to 20.7 in comparison areas. In 2007, divisions implementing IPTi had a 14% (95% CI -12%, 49%) higher mortality rate in two-11 month olds in comparison with non-implementing divisions (P = 0.31). CONCLUSION The lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management. This study raises important questions for programme evaluation design.
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Fernando SD, Rodrigo C, Rajapakse S. Chemoprophylaxis in malaria: drugs, evidence of efficacy and costs. ASIAN PAC J TROP MED 2011; 4:330-6. [PMID: 21771482 DOI: 10.1016/s1995-7645(11)60098-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/27/2010] [Accepted: 02/15/2011] [Indexed: 11/18/2022] Open
Abstract
This review concentrates on different aspects of malaria chemoprophylaxis, namely drug combinations, resistance, impact of malaria prevention in pregnancy and cost effectiveness. A MEDLINE search was performed for all articles with the key word 'Malaria' in the title field and 'Prophylaxis' in any field. The search was restricted to articles published in English within the last decade (1999-2009). Data sources included review articles published in core clinical journals, cohort studies, interventional studies, case control studies and cross sectional analyses. The mechanism of action, trial evidence of efficacy, side effects and geographical distribution of resistance is discussed for each prophylactic drug regimen. Impact of prophylaxis in pregnancy and the cost considerations are discussed under two separate sub topics.
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Fortes F, Dimbu R, Figueiredo P, Neto Z, do Rosário VE, Lopes D. Evaluation of prevalence's of pfdhfr and pfdhps mutations in Angola. Malar J 2011; 10:22. [PMID: 21288345 PMCID: PMC3039635 DOI: 10.1186/1475-2875-10-22] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 02/02/2011] [Indexed: 11/14/2022] Open
Abstract
Background Malaria is the major cause of morbidity and mortality in Angola. The most vulnerable groups to Plasmodium falciparum infection are pregnant women and children under five years of age. The use of an intermittent preventive treatment (IPT) with sulphadoxine/pyrimethamine (SP) in pregnant women was introduced in Angola in 2006 by the National Malaria Control Programme, and currently this strategy has been considered to be used for children malaria control. Considering the previous wide use of SP combination in Angola, together to the reported cases of SP treatment failure it is crucial the evaluation of the prevalence of five mutations in pfdhfr and pfdhps genes associated to P. falciparum resistance to SP before the introduction of S/P IPT in children. Methods The study was conducted in five provinces, with different transmission intensities: Huambo, Cabinda, Uíge, Kwanza Norte, and Malanje. The detection of the mutations in pfdhfr and pfdhps genes was carried out in 452 P. falciparum blood samples by PCR RFLP. Results For pfdhfr gene, 90,3% of the samples carried the mutation 51I, with 7.5% of mixed infections; 51% carried wild type allele 59C, with 29.2% mixed infections and; 99.1% of isolates harboured the mutant allele 108N. Concerning, pfdhps gene, 83,1% were mutant type 437G with 11% mixed infections , while 87% of the studied isolates were wild type for codon 540. Discussion This is the first representative epidemiological study of the whole Angola country on the prevalence of the genotypes associated with SP chemoresistance. A high frequency of individual mutations in both genes (51I and 108N in pfdhfr, and 437G in pfdhps) was found, besides a low prevalence of the quintuple mutation. Conclusion The data showed that the implementation IPT using SP in children needs to be reviewed.
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Affiliation(s)
- Filomeno Fortes
- Programa Nacional de Controlo da Malária/Ministério da Saúde de Angola, Luanda, Angola
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Prevalence of molecular markers of Plasmodium falciparum resistance to sulfadoxine-pyrimethamine during the intermittent preventive treatment in infants coupled with the expanded program immunization in Senegal. Parasitol Res 2011; 109:133-8. [PMID: 21207062 DOI: 10.1007/s00436-010-2236-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
Abstract
Several studies have shown the efficacy of the intermittent preventive treatment (IPT) using sulfadoxine-pyrimethamine (SP) coupled with the expanded program of immunization (EPI) in infants. However, its adoption as a strategy is conditioned by the long-term efficacy of SP. The impact of IPT-SP coupled with the EPI on the prevalence of markers of resistance to SP was evaluated during this study conducted in Southern Senegal. Three cross-sectional surveys in two health districts (IPT+) were conducted prior to the implementation, 1 year, and 2 years after. A third district located between the two districts served as a test zone (IPT-). PCR tests were carried out from filter papers collected in children under five for the two first measures and from positive rapid diagnostic tests in the same population for the third measure. Mutations in codons 51, 59, and 108 of the DHFR gene and in codons 437 and 540 of the DHPS were analyzed. The results showed that the prevalence of DHFR triple mutation was more frequent after 2 years in IPT+ areas. Regarding quadruple mutation, DHFR (51, 59, and 108) and DHPS (437), no difference was noted between the two areas. The quintuple mutation was not observed after 2 years of implementation in both areas. However, an individual analysis showed significant differences in the individual mutation points 51, 59, 108, and 437. This study reveals that despite an increase in the prevalence of individual mutations, the IPT-SP coupled with the EPI has no major impact on DHFR and DHPS combined mutations.
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Menendez C, Serra-Casas E, Scahill MD, Sanz S, Nhabomba A, Bardaji A, Sigauque B, Cistero P, Mandomando I, Dobano C, Alonso PL, Mayor A. HIV and Placental Infection Modulate the Appearance of Drug-Resistant Plasmodium falciparum in Pregnant Women who Receive Intermittent Preventive Treatment. Clin Infect Dis 2011; 52:41-8. [DOI: 10.1093/cid/ciq049] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Protective efficacy of intermittent preventive treatment of malaria in infants (IPTi) using sulfadoxine-pyrimethamine and parasite resistance. PLoS One 2010; 5:e12618. [PMID: 20838642 PMCID: PMC2935388 DOI: 10.1371/journal.pone.0012618] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 08/06/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intermittent Preventive Treatment of malaria in infants using sulfadoxine-pyrimethamine (SP-IPTi) is recommended by WHO for implementation in settings where resistance to SP is not high. Here we examine the relationship between the protective efficacy of SP-IPTi and measures of SP resistance. METHODS AND RESULTS We analysed the relationship between protective efficacy reported in the 7 SP-IPTi trials and contemporaneous data from 6 in vivo efficacy studies using SP and 7 molecular studies reporting frequency of dhfr triple and dhps double mutations within 50 km of the trial sites. We found a borderline significant association between frequency of the dhfr triple mutation and protective efficacy to 12 months of age of SP-IPTi. This association is significantly biased due to differences between studies, namely number of doses of SP given and follow up times. However, fitting a simple probabilistic model to determine the relationship between the frequency of the dhfr triple, dhps double and dhfr/dhps quintuple mutations associated with resistance to SP and protective efficacy, we found a significant inverse relationship between the dhfr triple mutation frequency alone and the dhfr/dhps quintuple mutations and efficacy at 35 days post the 9 month dose and up to 12 months of age respectively. CONCLUSIONS A significant relationship was found between the frequency of the dhfr triple mutation and SP-IPTi protective efficacy at 35 days post the 9 month dose. An association between the protective efficacy to 12 months of age and dhfr triple and dhfr/dhps quintuple mutations was found but should be viewed with caution due to bias. It was not possible to define a more definite relationship based on the data available from these trials.
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Dicko A, Sagara I, Djimdé AA, Touré SO, Traore M, Dama S, Diallo AI, Barry A, Dicko M, Coulibaly OM, Rogier C, de Sousa A, Doumbo OK. Molecular markers of resistance to sulphadoxine-pyrimethamine one year after implementation of intermittent preventive treatment of malaria in infants in Mali. Malar J 2010; 9:9. [PMID: 20064223 PMCID: PMC2820043 DOI: 10.1186/1475-2875-9-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 01/10/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intermittent preventive treatment in infants (IPTi) with sulphadoxine-pyrimethamine (SP) given during routine vaccinations is efficacious in preventing malaria disease and shows no interaction with the vaccines. However, there is a fear that IPTi may result in a rapid increase of parasite resistance to SP. METHODS To evaluate the impact of IPTi on SP-resistance point mutations, the 22 health sub-districts in the district of Kolokani, Mali, were randomized in a 1:1 ratio and starting in December 2006, IPTi with SP was implemented in 11 health sub-districts (intervention zone), while the other 11 health sub-districts served as the control (non-intervention zone). Blood smears and blood dots on filter paper were obtained from children aged 0-5 years, randomly selected in each of heath sub-districts during two cross-sectional surveys. The first survey was conducted in May 2007 before the start of the transmission season to collect baseline prevalence of the molecular markers of resistance to SP and the second in December 2007 after the end of the transmission season and one year after implementation of IPTi. A total of 427 and 923 randomly selected blood samples from the first and second surveys respectively were analysed by PCR for dhfr and dhps mutations. RESULTS Each of the three dhfr mutations at codons 51, 59 and 108 was present in 35% and 57% of the samples during the two surveys with no significant differences between the two zones. Dhps mutations at codons 437 and 540 were present respectively in about 20% and 1% of the children during the two surveys in both zones at similar proportion. The prevalence of quadruple mutants (triple dhfr-mutants + dhps-437G) associated with in-vivo resistance to SP in Mali after one year implementation of IPTi was also similar between the two zones (11.6% versus 11.2%, p = 0.90) and to those obtained at baseline survey (10.3% versus 8.1%). CONCLUSION This study shows no increase in the frequency of molecular markers of SP resistance in areas where IPTi with SP was implemented for one year.
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Affiliation(s)
- Alassane Dicko
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine Pharmacy and Dentistry, University of Bamako, PO Box 1805 Bamako, Mali.
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Aponte JJ, Schellenberg D, Egan A, Breckenridge A, Carneiro I, Critchley J, Danquah I, Dodoo A, Kobbe R, Lell B, May J, Premji Z, Sanz S, Sevene E, Soulaymani-Becheikh R, Winstanley P, Adjei S, Anemana S, Chandramohan D, Issifou S, Mockenhaupt F, Owusu-Agyei S, Greenwood B, Grobusch MP, Kremsner PG, Macete E, Mshinda H, Newman RD, Slutsker L, Tanner M, Alonso P, Menendez C. Efficacy and safety of intermittent preventive treatment with sulfadoxine-pyrimethamine for malaria in African infants: a pooled analysis of six randomised, placebo-controlled trials. Lancet 2009; 374:1533-42. [PMID: 19765816 DOI: 10.1016/s0140-6736(09)61258-7] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Intermittent preventive treatment (IPT) is a promising strategy for malaria control in infants. We undertook a pooled analysis of the safety and efficacy of IPT in infants (IPTi) with sulfadoxine-pyrimethamine in Africa. METHODS We pooled data from six double-blind, randomised, placebo-controlled trials (undertaken one each in Tanzania, Mozambique, and Gabon, and three in Ghana) that assessed the efficacy of IPTi with sulfadoxine-pyrimethamine. In all trials, IPTi or placebo was given to infants at the time of routine vaccinations delivered by WHO's Expanded Program on Immunization. Data from the trials for incidence of clinical malaria, risk of anaemia (packed-cell volume <25% or haemoglobin <80 g/L), and incidence of hospital admissions and adverse events in infants up to 12 months of age were reanalysed by use of standard outcome definitions and time periods. Analysis was by modified intention to treat, including all infants who received at least one dose of IPTi or placebo. FINDINGS The six trials provided data for 7930 infants (IPTi, n=3958; placebo, n=3972). IPTi had a protective efficacy of 30.3% (95% CI 19.8-39.4, p<0.0001) against clinical malaria, 21.3% (8.2-32.5, p=0.002) against the risk of anaemia, 38.1% (12.5-56.2, p=0.007) against hospital admissions associated with malaria parasitaemia, and 22.9% (10.0-34.0, p=0.001) against all-cause hospital admissions. There were 56 deaths in the IPTi group compared with 53 in the placebo group (rate ratio 1.05, 95% CI 0.72-1.54, p=0.79). One death, judged as possibly related to IPTi because it occurred 19 days after a treatment dose, was subsequently attributed to probable sepsis. Four of 676 non-fatal hospital admissions in the IPTi group were deemed related to study treatment compared with five of 860 in the placebo group. None of three serious dermatological adverse events in the IPTi group were judged related to study treatment compared with one of 13 in the placebo group. INTERPRETATION IPTi with sulfadoxine-pyrimethamine was safe and efficacious across a range of malaria transmission settings, suggesting that this intervention is a useful contribution to malaria control. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- John J Aponte
- Barcelona Centre for International Health Research, Hospital Clinic, University of Barcelona, Barcelona, Spain
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Gosling RD, Carneiro I, Chandramohan D. Intermittent preventive treatment of malaria in infants: how does it work and where will it work? Trop Med Int Health 2009; 14:1003-10. [PMID: 19558374 DOI: 10.1111/j.1365-3156.2009.02303.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We discuss the potential public health impact of IPTi by estimating the cases of malaria, anaemia and hospital admissions likely to be averted in different transmission settings; and we review the mechanism of action, choice of drugs regimens, and the effect on immunity of IPTi. IPTi using an efficacious drug is likely to substantially reduce cases of clinical malaria in moderate to high transmission settings. However, geographical heterogeneity in malaria transmission could hamper rolling out IPTi as a national policy.
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Affiliation(s)
- R D Gosling
- London School of Hygiene & Tropical Medicine, London, UK.
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Beck HP, Blake D, Dardé ML, Felger I, Pedraza-Díaz S, Regidor-Cerrillo J, Gómez-Bautista M, Ortega-Mora LM, Putignani L, Shiels B, Tait A, Weir W. Molecular approaches to diversity of populations of apicomplexan parasites. Int J Parasitol 2009; 39:175-89. [PMID: 18983997 DOI: 10.1016/j.ijpara.2008.10.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 10/14/2008] [Accepted: 10/14/2008] [Indexed: 11/30/2022]
Affiliation(s)
- Hans-Peter Beck
- Swiss Tropical Institute, Socinstrasse 57, CH 4002 Basel, Switzerland.
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Figueiredo P, Benchimol C, Lopes D, Bernardino L, do Rosário VE, Varandas L, Nogueira F. Prevalence of pfmdr1, pfcrt, pfdhfr and pfdhps mutations associated with drug resistance, in Luanda, Angola. Malar J 2008; 7:236. [PMID: 19014684 PMCID: PMC2613152 DOI: 10.1186/1475-2875-7-236] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 11/17/2008] [Indexed: 11/13/2022] Open
Abstract
Background Malaria is the infectious disease causing the highest morbidity and mortality in Angola and due to widespread chloroquine (CQ) resistance, the country has recently changed its first-line treatment recommendations for uncomplicated malaria, from CQ to artemisinin combination therapies (ACT) in adults, and sulphadoxine/pyrimethamine (S/P) in pregnant women. Loss of SP sensitivity is, however, progressing rapidly in Africa and, in this study, were investigated a number of molecular markers associated to CQ and S/P. Methods Blood samples were collected from 245 children with uncomplicated malaria, admitted at the Pediatric Hospital Dr. David Bernardino (HPDB), Angola, and the occurrence of mutations in Plasmodium falciparum was investigated in the pfmdr1 (N86Y) and pfcrt (K76T) genes, associated with CQ resistance, as well as in pfdhfr (C59R) and pfdhps (K540E), conferring SP resistance. Results The frequencies of pfmdr1 mutations in codon 86 were 28.6% N, 61.3% Y and 10.1% mixed infections (NY). The frequency of pfcrt mutations in codon 76 were 93.9% K, 5.7% T and 0.4% mixed infections (KT). For pfdhfr the results were in codon 59, 60.6% C, 20.6% R and 18.8% mixed infections (CR). Concerning pfdhps, 6.3% of the isolates were bearers of the mutation 540E and 5.4% mixed infections (K540E). Conclusion The results of this epidemiologic study showed high presence of CQ resistance markers while for SP a much lower prevalence was detected for the markers under study.
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Affiliation(s)
- Paula Figueiredo
- UEI Malária/Centro de Malária e Doenças Tropicais/IHMT/Universidade Nova de Lisboa, Lisbon, Portugal.
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