Bridges Daniel J, Molyneux Malcolm, Nkhoma Standwell
Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Chichiri, Malawi.
Trop Med Int Health. 2009 Sep;14(9):1093-6. doi: 10.1111/j.1365-3156.2009.02340.x. Epub 2009 Jul 14.
We conducted a prevalence study of mutations in Plasmodium falciparum that are associated with antimalarial drug resistance at a rural site in Karonga near Malawi's northern border with Tanzania. We found a higher prevalence of the key chloroquine resistance-conferring mutation in the pfcrt gene (K76T) at this site in comparison with the prevalence in Blantyre, a city in the south of Malawi, far from an international border (9%vs. 0%; P < 0.0005). In contrast we found a lower prevalence of the quintuple dhfr/dhps mutation, which is highly predictive of SP treatment failure, at the Karonga site compared to Blantyre (76%vs. 88%; P < 0.005). The prevalence of the K76T pfcrt mutation at two Tanzanian sites close to the border with Malawi was recently reported to be over 50%. Our findings suggest a considerable 'leakage' of parasite antimalarial drug resistance across the border between two countries with different national malaria control policies and with different levels of resistance. Neighbouring countries should consider implementing common regional rather than national malaria treatment policies to prevent the spread of antimalarial drug resistance alleles across their borders.
我们在马拉维与坦桑尼亚北部边境附近的卡龙加一个农村地区，开展了一项关于恶性疟原虫中与抗疟药物耐药性相关突变的患病率研究。我们发现，与马拉维南部远离国际边境的城市布兰太尔相比，该地区pfcrt基因中赋予氯喹耐药性的关键突变（K76T）的患病率更高（9%对0%；P<0.0005）。相比之下，我们发现，与布兰太尔相比，卡龙加地区五重dhfr/dhps突变的患病率较低，该突变高度预示着磺胺多辛-乙胺嘧啶治疗失败（76%对88%；P<0.005）。最近有报道称，在靠近马拉维边境的两个坦桑尼亚地区，K76T pfcrt突变的患病率超过50%。我们的研究结果表明，在两个拥有不同国家疟疾控制政策和不同耐药水平的国家之间，疟原虫抗疟药物耐药性存在相当程度的“渗漏”。邻国应考虑实施共同的区域而非国家疟疾治疗政策，以防止抗疟药物耐药等位基因跨境传播。
