Does use of domestic insecticides undermine public health control strategies?

Abstract

Vector-borne diseases (VBD), particularly dengue and malaria, pose a growing threat to human health worldwide. While insecticides remain the cornerstone of vector control programmes, their efficacy is being compromised by increasing insecticide resistance in mosquito populations, leading to control failures that have significant epidemiological and socioeconomic implications. Current research has predominantly examined resistance development in the context of public health interventions and agricultural applications. However, the contribution of domestic insecticide use to resistance evolution in VBD-endemic regions remains inadequately characterised. Evidence indicates that household insecticide utilisation is extensive, with approximately 60% of residents in endemic areas regularly employing domestic insecticidal products for personal protection. This viewpoint highlights how the poorly regulated household insecticide market may significantly contribute to resistance development. Therefore, understanding the impact of domestic insecticide products and usage patterns is urgently needed to preserve the efficacy of vector control campaigns and protect public health outcomes.

Keywords: Household insecticides; Insecticide resistance; Vector control; Vector-borne diseases.

Fig. 1

Drivers of pyrethroid resistance in vector-borne mosquitoes. Schematic representation of the differences between public health programmes and domestic insecticide usage (left side), and the drivers of evolving mosquito resistance to pyrethroids (right side).

Fig. 2

Estimated country-level use of domestic insecticides in Brazil from 2010 to 2019. This figure was created based on ABIPLA (Associação Brasileira das Indústrias de Produtos de Higiene, Limpeza e Saneante) annual reports available at http://abipla.org.br/anuario.

Fig. 3

A case study of resistance to domestic insecticides in Brazilian Ae. aegypti. (a) Susceptibility profiling of Ae. aegypti from Paraíba State, Northeast Brazil, against pyrethroid insecticides using WHO tube assays (contact insecticide) and Peet Grady chamber assays (aerosolized formulation). The red dashed line represents the WHO threshold for effectiveness at 80% mortality. (b) Association between the growing domestic insecticide market over five years and frequency of kdr-resistant alleles in Ae. aegypti from Paraíba State. (c) Association between the kdr-resistant alleles and whether they reflect resistant phenotypes in Ae. aegypti. The case study research approach is outlined in Panel 2.

Fig. 4

Proxies for domestic insecticide use for self-protection in vector-borne diseases endemic countries. (a) Average usage of domestic insecticides across 19 countries over a decade. (b) Country average use of household insecticides from 2010 to 2021. These figures were created based on a literature review, and citations for studies included are provided in Supplementary Table S1.

Fig. 5

Mosquitocidal active ingredients in aerosolized domestic insecticides. Edge weight represent the frequency and co-occurrence of compounds across formulations, respectively. This figure was created based on the chemical composition described by product manufacturers and published studies as detailed in Supplementary Table S3.