Co‐occurrence and distribution of East (L1014S) and West (L1014F) African knock‐down resistance in Anopheles gambiae sensu lato population of Tanzania. Issue 3 (6th January 2014)

• Record Type: Journal Article
• Authors: Kabula, Bilali; Kisinza, William; Tungu, Patrick; Ndege, Chacha; Batengana, Benard; Kollo, Douglas; Malima, Robert; Kafuko, Jessica; Mohamed, Mahdi; Magesa, Stephen
• Is Part Of: Tropical medicine & international health. Volume 19:Issue 3(2014:Mar.)
• Page Start: 331
• Page End: 341
• Publication Date: 2014-01-06
• Subjects: Tropical medicine -- Periodicals; Public health -- Periodicals; 616.988
• DOI: 10.1111/tmi.12248
• Languages: English
• ISSNs: 1360-2276

Abstract

<abstract abstract-type="main" id="tmi12248-abs-0001"> <title>Abstract</title> <sec id="tmi12248-sec-0001" sec-type="section"> <title>Objective</title> <p>Insecticide resistance molecular markers can provide sensitive indicators of resistance development in Anopheles vector populations. Assaying these makers is of paramount importance in the resistance monitoring programme. We investigated the presence and distribution of knock‐down resistance (<italic>kdr)</italic> mutations in <italic>Anopheles gambiae s.l</italic>. in Tanzania.</p> </sec> <sec id="tmi12248-sec-0002" sec-type="section"> <title>Methods</title> <p>Indoor‐resting Anopheles mosquitoes were collected from 10 sites and tested for insecticide resistance using the standard WHO protocol. Polymerase chain reaction‐based molecular diagnostics were used to genotype mosquitoes and detect <italic>kdr</italic> mutations.</p> </sec> <sec id="tmi12248-sec-0003" sec-type="section"> <title>Results</title> <p>The <italic>An. gambiae</italic> tested were resistance to lambdacyhalothrin in Muheza, Arumeru and Muleba. Out of 350 <italic>An. gambiae s.l</italic>. genotyped, 35% were <italic>An. gambiae s.s</italic>. and 65% <italic>An. arabiensis</italic>. L1014S and L1014F mutations were detected in both <italic>An. gambiae s.s</italic>. and <italic>An. arabiensis</italic>. L1014S point mutation was found at the allelic frequency of 4–33%, while L1014F was at the allelic frequency 6–41%. The L1014S mutation was much associated with <italic>An. gambiae s.s</italic>. (χ<sup>2</sup> = 23.41; <italic>P </italic><<italic> </italic>0.0001) and L1014F associated with <italic>An. arabiensis</italic> (χ<sup>2</sup> = 11.21; <italic>P </italic>=<italic> </italic>0.0008). The occurrence of the L1014S allele was significantly associated with lambdacyhalothrin resistance mosquitoes (Fisher exact <italic>P </italic><<italic> </italic>0.001).</p> </sec> <sec id="tmi12248-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The observed co‐occurrence of L1014S and L1014F mutations coupled with reports of insecticide resistance in the country suggest that pyrethroid resistance is becoming a widespread phenomenon among our malaria vector populations. The presence of L1014F mutation in this East African mosquito population indicates the spreading of this gene across Africa. The potential operational implications of these findings on malaria control need further exploration.</p> </sec> </abstract>