Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia.
Department of Disease Control, School of Hygiene and Tropical Medicine, London, London, UK.
Parasit Vectors. 2019 Mar 19;12(1):124. doi: 10.1186/s13071-019-3392-0.
Outdoor, early-biting, zoophagic behaviours by Anopheles farauti (s.s.) can compromise the effectiveness of bed nets for malaria control. In the Western Pacific region, pigs and dogs represent significant alternative blood sources for mosquitoes. Treating these animals with endectocides may impact mosquito survival and complement control measures. This hypothesis was explored using membrane feeding assays (MFAs), direct feeds on treated pigs, pharmacokinetic analyses and a transmission model.
Ivermectin was 375-fold more mosquitocidal than moxidectin (24 h LC= 17.8 ng/ml vs 6.7 µg/ml) in MFAs, and reduced mosquito fecundity by > 50% at ≥ 5 ng/ml. Treatment of pigs with subcutaneous doses of 0.6 mg/kg ivermectin caused 100% mosquito mortality 8 days after administration. Lethal effects persisted for up to 15 days after administration (75% death within 10 days).
The application of these empirical data to a unique malaria transmission model that used a three-host system (humans, pigs and dogs) predicts that the application of ivermectin will cause a significant reduction in the entomological inoculation rate (EIR = 100 to 0.35). However, this is contingent on local malaria vectors sourcing a significant proportion of their blood meals from pigs. This provides significant insights on the benefits of deploying endectocides alongside long-lasting insecticide-treated nets (LLINs) to address residual malaria transmission.
按蚊（s.s.）的户外、早叮咬、嗜动物行为可能会降低蚊帐在疟疾控制方面的效果。在西太平洋地区，猪和狗是蚊子的重要替代血液来源。用驱虫药治疗这些动物可能会影响蚊子的生存并补充控制措施。本研究通过膜饲养分析（MFA）、对处理过的猪进行直接喂养、药代动力学分析和传播模型来探索这一假设。
在 MFA 中，伊维菌素比莫昔克丁的杀蚊效果强 375 倍（24 小时 LC=17.8ng/ml 对 6.7µg/ml），并且在 ≥5ng/ml 时可使蚊子的繁殖力降低超过 50%。给猪皮下注射 0.6mg/kg 的伊维菌素，可导致 8 天后蚊子 100%死亡。在给药后 15 天内仍存在致死作用（10 天内死亡 75%）。
将这些经验数据应用于一个独特的疟疾传播模型（使用三宿主系统（人类、猪和狗）），预测伊维菌素的应用将导致昆虫接种率（EIR=100 至 0.35）显著降低。然而，这取决于当地的疟疾传播媒介是否从猪身上获取大量血液。这为在长效杀虫剂处理蚊帐（LLINs）旁边部署驱虫剂来解决残留疟疾传播提供了重要的见解。
