Assessing the Effects of Cooking Fuels on Anopheles Mosquito Behavior: An Experimental Study in Rural Rwanda

Globally, cleaner cooking fuels are increasingly promoted to reduce household air pollution. However, there is concern that reductions in smoke from biomass fuels could lead to more favorable conditions for mosquitoes and potentially increase vectorborne disease risk. We investigated household entry, host-seeking, household exit, and mortality among Anopheles mosquitoes across three cooking fuel types: wood, charcoal, and liquid petroleum gas (LPG) in six experimental huts in Rwanda. Fifty laboratory-reared Anopheles gambiae mosquitoes were released each night in entry compartments outside each hut, and fuels were burned for 1 hour in the hut verandas. Collectors conducted human landing catch during cooking and for 2 hours afterward, and CDC light traps were used for the rest of the night to measure host-seeking. Differences in each outcome were assessed using generalized linear mixed models with random effects for hut, collector, and day. Cooking with LPG compared with wood and charcoal was associated with substantial increases in household entry and host-seeking. Household exit was not significantly different across fuels, and mortality was lower in LPG-burning huts compared with wood. Although these results are not directly generalizable to field conditions, they indicate a potential for clean fuel adoption to increase exposure to Anopheles mosquitoes compared with traditional biomass fuels. Additional entomological and epidemiological studies are needed to investigate changes in disease vector exposure associated with clean fuel adoption, and evaluate whether enhanced vector control interventions should be promoted in tandem with cleaner cooking fuels.