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Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India
Author(s) -
Dinesh Diwakar S.,
Hassan Faizan,
Kumar Vijay,
Kesari Shreekant,
Topno Roshan K.,
Yadav Rajpal S.
Publication year - 2021
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/tmi.13576
Subject(s) - bendiocarb , propoxur , visceral leishmaniasis , indoor residual spraying , permethrin , deltamethrin , malathion , toxicology , pyrethroid , biology , veterinary medicine , cyhalothrin , cypermethrin , leishmaniasis , medicine , malaria , pesticide , immunology , plasmodium falciparum , ecology , artemisinin
Objectives 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. Methods 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. Results 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. Conclusion 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.