Gimnig John E, Vulule John M, Lo Terrence Q, Kamau Luna, Kolczak Margarette S, Phillips-Howard Penelope A, Mathenge Evan M, ter Kuile Feiko O, Nahlen Bernard L, Hightower Allen W, Hawley William A
Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
Am J Trop Med Hyg. 2003 Apr;68(4 Suppl):16-22.
The effect of permethrin-treated bed nets (ITNs) on malaria vectors was studied as part of a large-scale, randomized, controlled trial in western Kenya. Indoor resting densities of fed Anopheles gambiae s.l. and An. funestus in intervention houses were 58.5% (P = 0.010) and 94.5% (P = 0.001) lower, respectively, compared with control houses. The sporozoite infection rate in An. gambiae s.l. was 0.8% in intervention areas compared with 3.4% (P = 0.026) in control areas, while the sporozoite infection rates in An. funestus were not significantly different between the two areas. We estimated the overall transmission of Plasmodium falciparum in intervention areas to be 90% lower than in control areas. Permethrin resistance was not detected during the study period. As measured by densities of An. gambiae s.l., the efficacy of bed nets decreased if one or more residents did not sleep under a net or if bed nets had not been re-treated within six months. These results indicate that ITNs are optimally effective if used every night and if permethrin is reapplied at least biannually.
作为肯尼亚西部一项大规模随机对照试验的一部分，研究了经氯菊酯处理的蚊帐（长效驱虫蚊帐）对疟疾媒介的影响。与对照房屋相比，干预房屋内冈比亚按蚊复合种和嗜人按蚊的室内栖息密度分别降低了58.5%（P = 0.010）和94.5%（P = 0.001）。在干预地区，冈比亚按蚊复合种的子孢子感染率为0.8%，而对照地区为3.4%（P = 0.026），而在两个地区之间，嗜人按蚊的子孢子感染率没有显著差异。我们估计，干预地区恶性疟原虫的总体传播比对照地区低90%。在研究期间未检测到氯菊酯抗性。以冈比亚按蚊复合种的密度衡量，如果有一名或多名居民不在蚊帐下睡觉，或者如果蚊帐在六个月内未重新处理，则蚊帐的效果会降低。这些结果表明，如果每晚使用长效驱虫蚊帐，并且至少每半年重新施用一次氯菊酯，则其效果最佳。
