Division of Vector Biology and Control, ICMR-Rajendra Memorial Research Institute of Medical Sciences, Patna, India.
Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland.
Trop Med Int Health. 2021 Jul;26(7):823-828. doi: 10.1111/tmi.13576. Epub 2021 Apr 15.
Indoor residual spraying (IRS) with insecticides is the main vector control intervention for the elimination of visceral leishmaniasis in India. After a change in IRS policy in 2015 due to widespread resistance of Phlebotomus argentipes to DDT, IRS with DDT was replaced with alpha-cypermethrin IRS in 2016. The objective of the present study was to evaluate the susceptibility of P. argentipes to DDT and its alternatives, namely malathion and pirimiphos-methyl (organophosphates); alpha-cypermethrin, deltamethrin, lambda-cyhalothrin and permethrin (pyrethroids), and bendiocarb and propoxur (carbamates), in support of visceral leishmaniasis elimination in India.
Phlebotomus argentipes sandflies were collected from the visceral-leishmaniasis endemic states of Bihar, Jharkhand and West Bengal. In the WHO tube tests, the phenotypic susceptibility of F1, 2-day old, non-blood fed females were determined against filter papers impregnated with DDT 4%, malathion 5%, pirimiphos-methyl 0.25%, alpha-cypermethrin 0.05%, deltamethrin 0.05%, lambda-cyhalothrin 0.05%, permethrin 0.75%, bendiocarb 0.1% and propoxur 0.1%, which were sourced from Universiti Sains Malaysia. The knockdown of sandflies after 1-h exposure and mortality at 24 h after the 1-h exposure period were scored.
Mean mortality of P. argentipes 24 h after exposure in tube tests was 22.6% for DDT and ≥ 98% for other insecticide-impregnated papers tested.
Phlebotomus argentipes continues to be highly resistant to DDT with no reversal of resistance after DDT's withdrawal from IRS. P. argentipes was fully susceptible to pyrethroid, organophosphate and carbamate insecticides tested. Regular monitoring is warranted for insecticide resistance management in sandfly vectors.
室内滞留喷洒（IRS）用杀虫剂是消除印度内脏利什曼病的主要病媒控制干预措施。由于 2015 年采采蝇对滴滴涕的广泛耐药性，IRS 政策发生变化，2016 年用 alpha-氯氰菊酯 IRS 取代滴滴涕 IRS。本研究的目的是评估采采蝇对滴滴涕及其替代品（马拉硫磷和吡虫·辛硫磷）、alpha-氯氰菊酯、氯菊酯、高效氯氟氰菊酯和氯氰菊酯（拟除虫菊酯）以及苯醚菊酯和残杀威（氨基甲酸酯）的敏感性，以支持印度消除内脏利什曼病。
从印度内脏利什曼病流行的比哈尔邦、恰尔康得邦和西孟加拉邦收集采采蝇。在世界卫生组织管测试中，用马来西亚理科大学提供的浸渍有滴滴涕 4%、马拉硫磷 5%、吡虫·辛硫磷 0.25%、alpha-氯氰菊酯 0.05%、氯菊酯 0.05%、高效氯氟氰菊酯 0.05%、氯氰菊酯 0.75%、苯醚菊酯 0.1%和残杀威 0.1%的滤纸，对 1 龄、2 日龄、未吸血的雌性进行表型敏感性测定。记录 1 小时接触后苍蝇的击倒情况和 1 小时接触期后 24 小时的死亡率。
管测试中 24 小时后，采采蝇死亡率为滴滴涕 22.6%，其他杀虫剂浸渍滤纸死亡率均≥98%。
采采蝇对滴滴涕的耐药性仍然很高，停用滴滴涕后没有出现耐药性逆转。采采蝇对测试的拟除虫菊酯、有机磷和氨基甲酸酯杀虫剂完全敏感。需要定期监测，以进行沙蝇媒介的杀虫剂耐药性管理。
