Patterns of insecticide resistance in Aedes aegypti: meta‐analyses of surveys in Latin America and the Caribbean

Abstract

BACKGROUND: The re-emergence of worldwide concern with arthropod-borne viruses (arboviruses) draws increasing attention to their mosquito vectors, particularly Aedes aegypti, whose control heavily rely on insecticide use. As a consequence, insecticide resistance is frequent, but the general patterns of occurrence, cross-resistance and prevailing mechanisms remain unrecognized in some areas such as the Neotropical region. Thus, we sought here to recognize the general trends and patterns of insecticide resistance in Latin America and the Caribbean. A systematic literature review (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) aimed the data-gathering for the region and meta-analyses to address the stated knowledge gap.RESULTS: A high incidence of insecticide resistance prevails in the mosquito populations of the region. Dichlorodiphenyltrichloroethane (DDT), temephos and deltamethrin were the main insecticides evaluated and the meta-analyses indicate a high frequency of DDT-resistant populations (86.7 ± 0.1%), followed by temephos (75.7 ± 0.1%) and deltamethrin (33.0 ± 0.1%). No evidence of cross-resistance was detected among these three insecticides, and the V1016I knockdown (KDR) site mutation does not explain the patterns of deltamethrin resistance in the region.CONCLUSION: Resistance to DDT, temephos and deltamethrin is serious and widespread, and there is no cross-resistance among them. Altered target site sensitivity is not the main pyrethroid resistance mechanism, which is likely due to a mix of mechanisms. Therefore, the replacement of deltamethrin and particularly temephos in the region by alternative insecticides is an important resistance management recommendation, but should be done with compounds out of the cross-resistance spectrum for these populations and insecticides. Nonetheless, the non-recognition of the prevalent resistance mechanisms in the region makes this suggestion more difficult to apply and invites more broad-scale studies of resistance mechanisms to fill this knowledge gap and improve the resistance management recommendations.

Assessment of the susceptibility status of Aedes aegypti (Diptera: Culicidae) populations to pyriproxyfen and malathion in a national wide monitoring of insecticide resistance in Brazil, 2017-2018.

“…A systematic literature review covering insecticide resistance data in Ae. aegypti eld populations from Latin America indicates that less than half of the countries in this continent have published bioassay data between 2008 and 2018 [7]. In addition, the number of populations representing each national surveillance was generally rather small [7].…”

“…aegypti eld populations from Latin America indicates that less than half of the countries in this continent have published bioassay data between 2008 and 2018 [7]. In addition, the number of populations representing each national surveillance was generally rather small [7]. Susceptibility monitoring to temephos and deltamethrin carried out between 1999 and 2011 by the previous "National Network for Monitoring the Resistance of Ae.…”

“…High frequencies of resistant populations were also observed for temephos and deltamethrin (75.7±0.1% and 33±0.1%, respectively). These patterns can be explained by the chronic and frequent use of these insecticides in the continent [7].…”

Assessment of the Susceptibility Status of Aedes aegypti (Diptera: Culicidae) Populations to Pyriproxyfen and Malathion in a National Wide Monitoring of Insecticide Resistance in Brazil, 2017-2018.

“…In addition to the presential meeting with State representatives, an instructional video was made available on the institutional webpages of the MoH and IOC/Fiocruz [27]. Overall, these aspects contributed for the success of egg collection (96% of the selected cities collected eggs appropriately), from which 94% of the samples were good enough to perform the bioassays.…”

Assessment of the susceptibility status of Aedes aegypti (Diptera: Culicidae) populations to pyriproxyfen and malathion in a nation-wide monitoring of insecticide resistance performed in Brazil from 2017 to 2018.

“…A systematic literature review covering insecticide resistance data in Ae. aegypti eld populations from Latin America indicates that less than half of the countries in this continent have published bioassay data between 2008 and 2018 [7]. In addition, the number of populations representing each national surveillance was generally rather low [7].…”