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Yan H, Feng J, Yin JH, Huang F, Kong XL, Lin KM, Zhang T, Feng XY, Zhou SS, Cao JP, Xia ZG. High Frequency Mutations in pfdhfr and pfdhps of Plasmodium falciparum in Response to Sulfadoxine-Pyrimethamine: A Cross-Sectional Survey in Returning Chinese Migrants From Africa. Front Cell Infect Microbiol 2021; 11:673194. [PMID: 34568082 PMCID: PMC8456993 DOI: 10.3389/fcimb.2021.673194] [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: 02/27/2021] [Accepted: 06/14/2021] [Indexed: 11/13/2022] Open
Abstract
Background Sulfadoxine-pyrimethamine (SP) is recommended for intermittent preventive treatment in Africa against Plasmodium falciparum infection. However, increasing SP resistance (SPR) of P. falciparum affects the therapeutic efficacy of SP, and pfdhfr (encoding dihydrofolate reductase) and pfdhps (encoding dihydropteroate synthase) genes are widely used as molecular markers for SPR surveillance. In the present study, we analyzed single nucleotide polymorphisms (SNPs) of pfdhfr and pfdhps in P. falciparum isolated from infected Chinese migrant workers returning from Africa. Methods In total, 159 blood samples from P. falciparum-infected workers who had returned from Africa to Anhui, Shangdong, and Guangxi provinces were successfully detected and analyzed from 2017 to 2019. The SNPs in pfdhfr and pfdhps were analyzed using nested PCR. The genotypes and linkage disequilibrium (LD) were analyzed using Haploview. Results High frequencies of the Asn51Ile (N51I), Cys59Arg(C59R), and Ser108Asn(S108N) mutant alleles were observed, with mutation frequencies of 97.60, 87.43, and 97.01% in pfdhfr, respectively. A triple mutation (IRN) in pfdhfr was the most prevalent haplotype (86.83%). Six point mutations were detected in pfdhps DNA fragment, Ile431Val (I431V), Ser436Ala (S436A), Ala437Gly (A437G), Lys540Glu(K540E), Ala581Gly(A581G), Ala613Ser(A613S). The pfdhps K540E (27.67%) was the most predominant allele, followed by S436A (27.04%), and a single mutant haplotype (SGKAA; 62.66%) was predominant in pfdhps. In total, 5 haplotypes of the pfdhfr gene and 13 haplotypes of the pfdhps gene were identified. A total of 130 isolates with 12 unique haplotypes were found in the pfdhfr-pfdhps combined haplotypes, most of them (n = 85, 65.38%) carried quadruple allele combinations (CIRNI-SGKAA). Conclusion A high prevalence of point mutations in the pfdhfr and pfdhps genes of P. falciparum isolates was detected among Chinese migrant workers returning from Africa. Therefore, continuous in vitro molecular monitoring of Sulfadoxine-Pyrimethemine combined in vivo therapeutic monitoring of artemisinin combination therapy (ACT) efficacy and additional control efforts among migrant workers are urgently needed.
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Affiliation(s)
- He Yan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Jun Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China.,School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Hai Yin
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Fang Huang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Xiang-Li Kong
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Kang-Ming Lin
- Instit of Parasitic Diseases, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Guangxi, China
| | - Tao Zhang
- Anhu Provincial Center for Disease Control and Prevention, Anhui, China
| | - Xin-Yu Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Shui-Sen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Jian-Ping Cao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China.,School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
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Quan H, Igbasi U, Oyibo W, Omilabu S, Chen SB, Shen HM, Okolie C, Chen JH, Zhou XN. High multiple mutations of Plasmodium falciparum-resistant genotypes to sulphadoxine-pyrimethamine in Lagos, Nigeria. Infect Dis Poverty 2020; 9:91. [PMID: 32653033 PMCID: PMC7353807 DOI: 10.1186/s40249-020-00712-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/01/2020] [Indexed: 11/24/2022] Open
Abstract
Background Plasmodium falciparum-resistance to sulphadoxine-pyrimethamine (SP) has been largely reported among pregnant women. However, the profile of resistance markers to SP dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) in the general population are varied and not frequently monitored. Currently, SP is used as partner drug for artemisinin combination therapy (SP-artesunate) in some sub-Saharan African countries or as a prophylactic drug in intermittent preventive treatment of malaria during pregnancy and infants and in seasonal malaria chemoprevention (SMC). Profiling of P. falciparum-resistant genotypes to SP is dynamic and critical in providing data that would be useful for malaria control programmes. This study assessed the profile of dhfr and dhps genes genotypes among individuals with malaria in Lagos, Nigeria. Methods Molecular markers of SP resistance were identified by nested PCR and sequenced among malaria positive dried blood spots (DBS) that were collected from individuals attending health facilities from January 2013 to February 2014 and during community surveys from October 2010 to September 2011 across different Local Government Areas of Lagos State, Nigeria. Results A total of 242 and 167 samples were sequenced for dhfr and dhps, respectively. Sequence analysis of dhfr showed that 95.5% (231/242), 96.3% (233/242) and 96.7% (234/242) of the samples had N51I, C59R and S108N mutant alleles, respectively. The prevalence of dhps mutation at codons A437G, A613S, S436A, A581G, I431V and K540E were 95.8% (160/167), 41.9% (70/167), 41.3% (69/167), 31.1% (52/167), 25.1% (42/167), and 1.2% (2/167) respectively. The prevalence of triple mutations (CIRNI) in dhfr was 93.8% and 44.3% for the single dhps haplotype mutation (SGKAA). Partial SP-resistance due to quadruple dhfr-dhps haplotype mutations (CIRNI-SGKAA) and octuple haplotype mutations (CIRNI-VAGKGS) with rate of 42.6% and 22.0%, respectively has been reported. Conclusions There was increased prevalence in dhfr triple haplotype mutations when compared with previous reports in the same environment but aligned with high prevalence in other locations in Nigeria and other countries in Africa. Also, high prevalence of dhfr and dhps mutant alleles occurred in the study areas in Lagos, Nigeria five to eight years after the introduction of artemisinin combination therapy underscores the need for continuous monitoring.
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Affiliation(s)
- Hong Quan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, People's Republic of China.,National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention⁃Shenzhen Center for Disease Control and Prevention Joint Laboratory for Imported Tropical Disease Control, Shanghai, 200025, People's Republic of China
| | - Uche Igbasi
- Center for Infectious Diseases Research, Microbiology Department, Nigerian Institute of Medical Research, 6 Edmund Crescent, Yaba, Lagos, Nigeria
| | - Wellington Oyibo
- ANDI Center of Excellence for Malaria Diagnosis, Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Sunday Omilabu
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Shen-Bo Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, People's Republic of China.,National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention⁃Shenzhen Center for Disease Control and Prevention Joint Laboratory for Imported Tropical Disease Control, Shanghai, 200025, People's Republic of China
| | - Hai-Mo Shen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, People's Republic of China.,National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention⁃Shenzhen Center for Disease Control and Prevention Joint Laboratory for Imported Tropical Disease Control, Shanghai, 200025, People's Republic of China
| | - Chukwuma Okolie
- Department of Surveying and Geoinformatics, Faculty of Engineering, University of Lagos, Lagos, Nigeria
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, People's Republic of China. .,National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention⁃Shenzhen Center for Disease Control and Prevention Joint Laboratory for Imported Tropical Disease Control, Shanghai, 200025, People's Republic of China.
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, National Centre for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, People's Republic of China.,National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention⁃Shenzhen Center for Disease Control and Prevention Joint Laboratory for Imported Tropical Disease Control, Shanghai, 200025, People's Republic of China
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Bob NS, Diop BM, Renaud F, Marrama L, Durand P, Tall A, Ka B, Ekala MT, Bouchier C, Mercereau-Puijalon O, Jambou R. Parasite polymorphism and severe malaria in Dakar (Senegal): a West African urban area. PLoS One 2010; 5:e9817. [PMID: 20352101 PMCID: PMC2843705 DOI: 10.1371/journal.pone.0009817] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 02/01/2010] [Indexed: 11/25/2022] Open
Abstract
Background Transmission of malaria in West African urban areas is low and healthcare facilities are well organized. However, malaria mortality remains high. We conducted a survey in Dakar with the general objective to establish who died from severe malaria (SM) in urban areas (particularly looking at the age-groups) and to compare parasite isolates associated with mild or severe malaria. Methodology/Principal Findings The current study included mild- (MM) and severe malaria (SM) cases, treated in dispensaries (n = 2977) and hospitals (n = 104), We analysed Pfdhfr/Pfcrt-exon2 and nine microsatellite loci in 102 matched cases of SM and MM. Half of the malaria cases recorded at the dispensaries and 87% of SM cases referred to hospitals, occurred in adults, although adults only accounted for 26% of all dispensary consultations. This suggests that, in urban settings, whatever the reason for this adult over-representation, health-workers are forced to take care of increasing numbers of malaria cases among adults. Inappropriate self treatment and mutations in genes associated with drug resistance were found associated with SM in adults. SM was also associated with a specific pool of isolates highly polymorphic and different from those associated with MM. Conclusion In this urban setting, adults currently represent one of the major groups of patients attending dispensaries for malaria treatment. For these patients, despite the low level of transmission, SM was associated with a specific and highly polymorphic pool of parasites which may have been selected by inappropriate treatment.
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Affiliation(s)
| | | | | | | | | | - Adama Tall
- Institut Pasteur de Dakar, Dakar, Senegal
| | | | - Marie Therese Ekala
- Institut Pasteur, Immunologie Moléculaire des Parasites, CNRS URA 2581, Paris, France
| | | | | | - Ronan Jambou
- Institut Pasteur de Dakar, Dakar, Senegal
- * E-mail:
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Molecular correlates of high-level antifolate resistance in Rwandan children with Plasmodium falciparum malaria. Antimicrob Agents Chemother 2009; 54:477-83. [PMID: 19841150 DOI: 10.1128/aac.00498-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifolate drugs have an important role in the treatment of malaria. Polymorphisms in the genes encoding the dihydrofolate reductase and dihydropteroate synthetase enzymes cause resistance to the antifol and sulfa drugs, respectively. Rwanda has the highest levels of antimalarial drug resistance in Africa. We correlated the efficacy of chlorproguanil-dapsone plus artesunate (CPG-DDS+A) and amodiaquine plus sulfadoxine-pyrimethamine (AQ+SP) in children with uncomplicated malaria caused by Plasmodium falciparum parasites with pfdhfr and pfdhps mutations, which are known to confer reduced drug susceptibility, in two areas of Rwanda. In the eastern province, where the cure rates were low, over 75% of isolates had three or more pfdhfr mutations and two or three pfdhps mutations and 11% had the pfdhfr 164-Leu polymorphism. In the western province, where the cure rates were significantly higher (P < 0.001), the prevalence of multiple resistance mutations was lower and the pfdhfr I164L polymorphism was not found. The risk of treatment failure following the administration of AQ+SP more than doubled for each additional pfdhfr resistance mutation (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.01 to 5.55; P = 0.048) and each pfdhps mutation (OR = 2.1; 95% CI = 1.21 to 3.54; P = 0.008). The risk of failure following CPG-DDS+A treatment was 2.2 times higher (95% CI = 1.34 to 3.7) for each additional pfdhfr mutation, whereas there was no association with mutations in the pfdhps gene (P = 0.13). The pfdhfr 164-Leu polymorphism is prevalent in eastern Rwanda. Antimalarial treatments with currently available antifol-sulfa combinations are no longer effective in Rwanda because of high-level resistance.
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Fanello C, Karema C, Ngamije D, Uwimana A, Ndahindwa V, Van Overmeir C, Van Doren W, Curtis J, D’Alessandro U. A randomised trial to assess the efficacy and safety of chlorproguanil/dapsone + artesunate for the treatment of uncomplicated Plasmodium falciparum malaria. Trans R Soc Trop Med Hyg 2008; 102:412-20. [DOI: 10.1016/j.trstmh.2008.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Revised: 01/28/2008] [Accepted: 01/28/2008] [Indexed: 10/22/2022] Open
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Nicastri E, Paglia MG, Severini C, Ghirga P, Bevilacqua N, Narciso P. Plasmodium falciparum multiple infections, disease severity and host characteristics in malaria affected travellers returning from Africa. Travel Med Infect Dis 2008; 6:205-9. [PMID: 18571110 DOI: 10.1016/j.tmaid.2008.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 01/04/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND The pathogenesis of malaria is the result of complex interactions between parasites, host and environment. Several studies have assessed the role of genetic characteristics of Plasmodium falciparum infection in the clinical severity of malaria infection comparing different genotypic determinants in mild and severe cases. The genes encoding the polymorphic merozoite surface proteins 1 (msp-1) and 2 (msp-2) and the dihydrofolate reductase (dhfr) of malaria parasites have been extensively used as markers to investigate the genetic diversity and the population structure of P. falciparum. The aim of this study was to assess the epidemiological, clinical, host- and parasite-related determinant factor of the genetic diversity of P. falciparum infections in travellers returning to Italy. METHODS Between 1998 and 2001, we have retrospectively studied 64 inpatients all returning from African malaria-endemic countries. Designation of severe malaria was determined by using the World Health Organization (WHO) definition. P. falciparum infections detected by species-specific PCR were genotyped at the msp-1 and msp-2 loci and clones were determined. PCR and enzyme-digestion methods were used to screen the mutation occurring at codon 108. RESULTS Multiple P. falciparum genotypes were detected in 32 patients (50%). The number of genotypes was correlated to different host characteristics. No association was found between allelic number of msp-1 or msp-2 and season of travel, absence of antimalarial prophylaxis, length of stay or blood parasitemia. At multiple analysis adjusted for few confounding variables, two variables showed a significant association with multiplicity of P. falciparum genotypes: male gender (p=0.018) and severity of disease (p=0.044). CONCLUSION In our study all but one patients with severe malaria had a infection with a multiplicity of P. falciparum clones. At multivariate analysis the male gender, and the occurrence of severe malaria were significantly more commonly detected in patients affected by imported malaria with multiple clones.
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Affiliation(s)
- Emanuele Nicastri
- Istituto Nazionale per le Malattie Infettive Lazzaro Spallanzani, IRCCS, Rome, Italy.
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Webb ME, Marquet A, Mendel RR, Rébeillé F, Smith AG. Elucidating biosynthetic pathways for vitamins and cofactors. Nat Prod Rep 2007; 24:988-1008. [PMID: 17898894 DOI: 10.1039/b703105j] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The elucidation of the pathways to the water-soluble vitamins and cofactors has provided many biochemical and chemical challenges. This is a reflection both of their complex chemical nature, and the fact that they are often made in small amounts, making detection of the enzyme activities and intermediates difficult. Here we present an orthogonal review of how these challenges have been overcome using a combination of methods, which are often ingenious. We make particular reference to some recent developments in the study of biotin, pantothenate, folate, pyridoxol, cobalamin, thiamine, riboflavin and molybdopterin biosynthesis.
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Affiliation(s)
- Michael E Webb
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
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Chanda P, Hawela M, Kango M, Sipilanyambe N. Assessment of the therapeutic efficacy of a paediatric formulation of artemether-lumefantrine (Coartesiane) for the treatment of uncomplicated Plasmodium falciparum in children in Zambia. Malar J 2006; 5:75. [PMID: 16938133 PMCID: PMC1574335 DOI: 10.1186/1475-2875-5-75] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Accepted: 08/28/2006] [Indexed: 11/22/2022] Open
Abstract
Background Sentinel site surveillance of antimalarials by in-vivo therapeutic efficacy studies in Zambia is one of the key activities ear-marked for monitoring and evaluation. The studies are conducted annually in order to provide timely and reliable information on the status of the recommended regimens for malaria case management. The findings of the therapeutic efficacy of an artemisinin-based combination therapy of pediatric artemether-lumefantrine (Coartesiane®) are reported. Method The design is a simple, one-arm, prospective evaluation of the clinical and parasitological response to directly observed treatment for uncomplicated malaria. The study was conducted in sentinel sites using the WHO standardized protocol for the assessment of therapeutic efficacy of antimalarial drugs (WHO 2000) in children under five years of age, weighing less than 10 Kg. The study was conducted at two clinics, one in Chongwe (Lusaka Province) and Chipata (Eastern Province). The 28-day follow-up period was used coupled with PCR genotyping for MSP1 and MSP2 in order to differentiate recrudescence from re-infections for parasites that appeared after Day 14. Results 91/111 children enrolled in the study, were successfully followed up. Artemether-lumefantrine (Coartesiane®) was found to produce significant gametocyte reduction. The Adequate Clinical and Parasitological Response (ACPR) was found to be 100% (95% CI 96.0;100). Conclusion Coartesiane® was effective in treating uncomplicated malaria in Zambian children weighing less than 10 kg, an age group normally excluded from taking the tablet formulation of artemether-lumefantrine (Coartem®).
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Affiliation(s)
| | - Moonga Hawela
- National Malaria Control Centre, P.O. Box 32509, Lusaka, Zambia
| | - Mabvuto Kango
- National Malaria Control Centre, P.O. Box 32509, Lusaka, Zambia
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Happi CT, Gbotosho GO, Folarin OA, Akinboye DO, Yusuf BO, Ebong OO, Sowunmi A, Kyle DE, Milhous W, Wirth DF, Oduola AMJ. Polymorphisms in Plasmodium falciparum dhfr and dhps genes and age related in vivo sulfadoxine-pyrimethamine resistance in malaria-infected patients from Nigeria. Acta Trop 2005; 95:183-93. [PMID: 16023986 DOI: 10.1016/j.actatropica.2005.06.015] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Revised: 06/04/2005] [Accepted: 06/06/2005] [Indexed: 11/26/2022]
Abstract
Mutations in Plasmodium falciparum dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes have been used as means to predict treatment failure to sulfadoxine-pyrimethamine (SP) and for monitoring/surveillance of resistance to the drug in many areas where malaria is endemic. However, patients responses to treatment are significantly dependent on factors like host immunity profile of treated patients. In order to investigate the relationship between molecular markers of SP resistance, host immunity and clinical outcome, the association between pre-treatment dhfr and dhps genotypes, age and treatment outcomes was evaluated in 109 children treated with SP for acute uncomplicated malaria in Ibadan, Nigeria. Seventy-three percent of the children were cured with the drug, while 27% failed treatment after 28 days of follow-up. All children infected with parasites harboring less than two dhfr/dhps mutations were cured with SP. The dhfr triple (Asn-108/Ile-51/Arg-59) mutants or the dhps double mutants (Gly-437/Glu-540) were independently associated with SP treatment failure in children aged less than 5 years, but not in older children. The dhfr and dhps quintuple mutant (dhfr triple mutant+dhps double mutant) was the genotype most strongly associated with SP treatment failure (OR=24.72, 95%CI=8.24-74.15) in both younger and older children.
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Affiliation(s)
- C T Happi
- Malaria Research Laboratories, Postgraduate Institute for Medical Research and Training (PIMRAT), College of Medicine, University of Ibadan, Ibadan, Nigeria.
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