Htun Myo Win, Mon Nan Cho Nwe, Aye Khin Myo, Hlaing Chan Myae, Kyaw Myat Phone, Handayuni Irene, Trimarsanto Hidayat, Bustos Dorina, Ringwald Pascal, Price Ric N, Auburn Sarah, Thriemer Kamala
Department of Medical Research, Yangon, 11191, Myanmar.
Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, 0810, Australia.
Malar J. 2017 Jul 10;16(1):281. doi: 10.1186/s12936-017-1912-y.
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.
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.
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 0.855-0.876), with low inter-population differentiation (F 0.016-0.026, P < 0.05).
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.
间日疟原虫疟疾仍是缅甸的一项重大公共卫生负担。该国已报告对间日疟原虫的一线治疗药物氯喹产生耐药性，这有可能破坏当地的防控努力。
2014年在妙瓦底以及2012年在丹老，将6岁以上无并发症的间日疟原虫单一感染患者纳入临床疗效研究。研究参与者接受标准剂量的氯喹（3天内25mg/kg），随后每周复查直至第28天。对参与临床研究的患者样本以及2012年在妙瓦底和瑞贡进行的额外横断面调查样本，评估Pvmdr1拷贝数（CN）和微卫星多样性。
共有85名患者纳入氯喹临床研究，其中妙瓦底25名，丹老60名。妙瓦底有1名患者（1.2%）出现早期治疗失败，丹老有2名患者（2.3%）在第28天出现晚期治疗失败。第28天的疗效在妙瓦底为92.0%（95%CI 71.6 - 97.9），在丹老为98.3%（95%CI 88.7 -
