Woitsch Birgit, Wernsdorfer Gunther, Prajakwong Somsak, Rojanawatsirivet Chaiporn, Kollaritsch Herwig, Wernsdorfer Walther H
Division of Specific Prophylaxis and Tropical Medicine, Center for Physiology and Pathophysiology, Medical University of Vienna, Vienna, Austria.
Wien Klin Wochenschr. 2004;116 Suppl 4:35-40.
Artesunate was introduced in Thailand in 1995 for the treatment of falciparum malaria in areas of multidrug resistance, where it is used in combination with mefloquine. The studies were conducted between May and August 1999, 2000 and 2001 in the provinces Mae Hong Son and Tak (Mae Sot District) in northwestern Thailand, both on the border to Myanmar. The province of Mae Hong Son is still largely unaffected by multidrug resistance and infections with Plasmodium falciparum are treated with mefloquine alone. In the district of Mae Sot, 350 km southwards, more than 60% of the Plasmodium falciparum isolates were found to be resistant to mefloquine. Between 1999 and 2001, a total of 227 fresh isolates of Plasmodium falciparum were successfully tested for their sensitivity to artemisinin using the WHO standard in vitro microtest. The weighted mean EC5o and EC90 values for 1999-2001 were 9.20 nM and 34.37 nM in Mae Hong Son and 11.18nM and 71.63nM in Mae Sot, respectively. The comparison of the sensitivity to artemisinin between Mae Hong Son and Mae Sot showed no significant difference in 1999, but significant differences in 2000 (p<0.05) and in 2001 (p<0.01). This phenomenon could be a consequence of different drug pressure. Furthermore, the lower sensitivity of Plasmodium falciparum to mefloquine in Mae Sot may play a minor (but amplifying) role, as the activities of artemisinin and mefloquine show a significant correlation.
1995年，青蒿琥酯被引入泰国，用于治疗多药耐药地区的恶性疟，在这些地区它与甲氟喹联合使用。研究于1999年5月至8月、2000年和2001年在泰国西北部与缅甸接壤的夜丰颂府和来兴府（美索县）进行。夜丰颂府在很大程度上仍未受到多药耐药的影响，恶性疟感染仅用甲氟喹治疗。在向南350公里的美索县，发现超过60%的恶性疟原虫分离株对甲氟喹耐药。1999年至2001年期间，共成功检测了227株新鲜的恶性疟原虫分离株对青蒿素的敏感性，采用世界卫生组织标准体外微量试验。1999 - 2001年夜丰颂府的加权平均EC50和EC90值分别为9.20 nM和34.37 nM，美索县分别为11.18 nM和71.63 nM。夜丰颂府和美索县对青蒿素敏感性的比较在1999年无显著差异，但在2000年（p<0.05）和2001年（p<0.01）有显著差异。这种现象可能是不同药物压力的结果。此外，美索县恶性疟原虫对甲氟喹较低的敏感性可能起了较小（但有放大作用）的作用，因为青蒿素和甲氟喹的活性显示出显著相关性。
