Raghavendra Kamaraju, Barik T K, Sharma S K, Das M K, Dua V K, Pandey A, Ojha V P, Tiwari S N, Ghosh S K, Dash A P
National Institute of Malaria Research (ICMR), New Delhi, India.
J Vector Borne Dis. 2014 Sep;51(3):230-4.
BACKGROUND & OBJECTIVES: The major malaria vector, Anopheles culicifacies Giles is reported to contribute ~ 65% of the malaria cases in India. This species developed resistance to DDT and later to HCH, malathion and also to pyrethroids in some states due to their use in the national malaria control programme. In the present study, insecticide susceptibility of this species was monitored in four states of India.
To determine insecticide susceptibility status of the major malaria vector An. culicifacies, adult mosquitoes were collected from different localities of 32 tribal districts in the states of Andhra Pradesh, Odisha, Jharkhand and West Bengal during October/November 2009-10. Mosquitoes were collected from stratified ecotypes comprising a group of districts in West Bengal and individual districts in three other states. Mosquitoes were exposed to papers treated with WHO diagnostic dose: 4% DDT, 5% malathion and 0.05% deltamethrin following the WHO tube method.
RESULTS provided the susceptibility status of An. culicifacies to different insecticides used in the public health programme in 32 districts in four states. An. culicifacies was found resistant to DDT (mortality range 0-36%) in all the 32 districts; to malathion it was resistant in 14 districts, verification required in 10 districts and susceptible in eight districts (mortality range 32.2-100%). It was resistant to deltamethrin in four districts, verification required in 11 districts and susceptible in 17 districts (mortality range 43.3-100%).
INTERPRETATION & CONCLUSION: Development of widespread resistance to insecticides used in public health sprays for vector control including to pyrethroids in An. culicifacies in the surveyed districts is of great concern for the malaria control programme as the major interventions for vector control are heavily reliant on chemical insecticides, mainly synthetic pyrethroids used both for indoor residual spraying and for long-lasting insecticidal nets. Thus, there is a need to periodically monitor and update the susceptibility status of malaria vector(s) to suggest alternative vector control strategies for effective disease management.
据报道，主要疟疾媒介——嗜人按蚊（Anopheles culicifacies Giles）导致了印度约65%的疟疾病例。由于在国家疟疾控制项目中使用了滴滴涕（DDT）、六六六（HCH）、马拉硫磷以及拟除虫菊酯类杀虫剂，该蚊种在印度一些邦对这些杀虫剂产生了抗性。在本研究中，对印度四个邦的该蚊种的杀虫剂敏感性进行了监测。
为确定主要疟疾媒介嗜人按蚊的杀虫剂敏感性状况，于2009 - 2010年10月/11月期间，从安得拉邦、奥里萨邦、贾坎德邦和西孟加拉邦32个部落地区的不同地点采集成年蚊子。蚊子采自分层生态型，包括西孟加拉邦的一组地区以及其他三个邦的单个地区。按照世界卫生组织（WHO）的药管法，将蚊子暴露于用WHO诊断剂量处理过的纸片上：4%滴滴涕、5%马拉硫磷和0.05%溴氰菊酯。
结果显示了嗜人按蚊对四个邦32个地区公共卫生项目中使用的不同杀虫剂的敏感性状况。在所有32个地区，嗜人按蚊对滴滴涕均有抗性（死亡率范围为0 - 36%）；对马拉硫磷，14个地区有抗性，10个地区需进一步验证，8个地区敏感（死亡率范围为32.2 - 100%）。对溴氰菊酯，4个地区有抗性，11个地区需进一步验证，17个地区敏感（死亡率范围为43.3 - 100%）。
在所调查地区，嗜人按蚊对用于病媒控制的公共卫生喷雾杀虫剂（包括拟除虫菊酯类）产生广泛抗性，这对疟疾控制项目极为不利，因为病媒控制的主要干预措施严重依赖化学杀虫剂，主要是用于室内滞留喷洒和长效杀虫蚊帐的合成拟除虫菊酯类。因此，有必要定期监测并更新疟疾媒介的敏感性状况，以提出有效的病媒控制替代策略，实现有效的疾病管理。
