Insecticide susceptibility of <i>Phlebotomus argentipes</i> sandflies, vectors of visceral leishmaniasis in India

Objectives Indoor residual spraying (IRS) with insecticides is the main vector control intervention for elimination of visceral leishmaniasis in India. After a change IRS policy 2015 due to widespread resistance Phlebotomus argentipes DDT, DDT was replaced alpha-cypermethrin 2016. The objective present study evaluate susceptibility P. and its alternatives, namely malathion pirimiphos-methyl (organophosphates); alpha-cypermethrin, deltamethrin, lambda-cyhalothrin permethrin (pyrethroids), bendiocarb propoxur (carbamates), support Methods sandflies were collected from visceral-leishmaniasis endemic states Bihar, Jharkhand West Bengal. In WHO tube tests, phenotypic F1, 2-day old, non-blood fed females determined against filter papers impregnated 4%, 5%, 0.25%, 0.05%, deltamethrin 0.75%, 0.1% 0.1%, which sourced Universiti Sains Malaysia. knockdown after 1-h exposure mortality at 24 h period scored. Results Mean tests 22.6% ≥ 98% other insecticide-impregnated tested. Conclusion continues be highly resistant no reversal DDT's withdrawal IRS. fully susceptible pyrethroid, organophosphate carbamate Regular monitoring warranted insecticide management sandfly vectors.