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Htun MW, Mon NCN, Aye KM, Hlaing CM, Kyaw MP, Handayuni I, Trimarsanto H, Bustos D, Ringwald P, Price RN, Auburn S, Thriemer K. Chloroquine efficacy for Plasmodium vivax in Myanmar in populations with high genetic diversity and moderate parasite gene flow. Malar J 2017; 16:281. [PMID: 28693552 PMCID: PMC5504659 DOI: 10.1186/s12936-017-1912-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/26/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Plasmodium vivax malaria remains a major public health burden in Myanmar. Resistance to chloroquine (CQ), the first-line treatment for P. vivax, has been reported in the country and has potential to undermine local control efforts. METHODS Patients over 6 years of age with uncomplicated P. vivax mono-infection were enrolled into clinical efficacy studies in Myawaddy in 2014 and Kawthoung in 2012. Study participants received a standard dose of CQ (25 mg/kg over 3 days) followed by weekly review until day 28. Pvmdr1 copy number (CN) and microsatellite diversity were assessed on samples from the patients enrolled in the clinical study and additional cross-sectional surveys undertaken in Myawaddy and Shwegyin in 2012. RESULTS A total of 85 patients were enrolled in the CQ clinical studies, 25 in Myawaddy and 60 in Kawthoung. One patient in Myawaddy (1.2%) had an early treatment failure and two patients (2.3%) in Kawthoung presented with late treatment failures on day 28. The day 28 efficacy was 92.0% (95% CI 71.6-97.9) in Myawaddy and 98.3% (95% CI 88.7-99.8) in Kawthoung. By day 2, 92.2% (23/25) in Myawaddy and 85.0% (51/60) in Kawthoung were aparasitaemic. Genotyping and pvmdr1 CN assessment was undertaken on 43, 52 and 46 clinical isolates from Myawaddy, Kawthoung and Shwegyin respectively. Pvmdr1 amplification was observed in 3.2% (1/31) of isolates in Myawaddy, 0% (0/49) in Kawthoung and 2.5% (1/40) in Shwegyin. Diversity was high in all sites (H E 0.855-0.876), with low inter-population differentiation (F ST 0.016-0.026, P < 0.05). CONCLUSIONS Treatment failures after chloroquine were observed following chloroquine monotherapy, with pvmdr1 amplification present in both Myawaddy and Shwegyin. The results emphasize the importance of ongoing P. vivax drug resistance surveillance in Myanmar, particularly given the potential connectivity between parasite population at different sites.
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Affiliation(s)
- Myo Win Htun
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Nan Cho Nwe Mon
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Khin Myo Aye
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Chan Myae Hlaing
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Myat Phone Kyaw
- grid.415741.2Department of Medical Research, Yangon, 11191 Myanmar
| | - Irene Handayuni
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
| | - Hidayat Trimarsanto
- 0000 0004 1795 0993grid.418754.bEijkman Institute for Molecular Biology, Jl. Diponegoro 69, Central Jakarta, 10430 Indonesia ,grid.466915.9The Ministry of Research and Technology (RISTEK), Jakarta, Indonesia ,0000 0001 0746 0534grid.432292.cAgency for Assessment and Application of Technology, Jl. MH Thamrin 8, Jakarta, 10340 Indonesia
| | - Dorina Bustos
- 0000 0004 0576 2573grid.415836.dWorld Health Organization, Country Office for Thailand, Ministry of Public Health, Nonthaburi, Thailand
| | - Pascal Ringwald
- 0000000121633745grid.3575.4Global Malaria Programme, World Health Organization, 20 Avenue Appia, 1211 Geneva, 27, Switzerland
| | - Ric N. Price
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia ,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford Old Road Campus, Oxford, UK
| | - Sarah Auburn
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
| | - Kamala Thriemer
- 0000 0000 8523 7955grid.271089.5Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT 0810 Australia
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