Assessing the effectiveness, biosafety, and resident’s perception of a micro-encapsulated propoxur paint against Aedes aegypti: a field trial in a dengue-affected community of Sonora, Mexico

Abstract

Mosquito-borne diseases remain a major public health concern in the Region of the Americas. Concerning dengue, Mexico ranked as the third American country with the highest number of cases in 2023, following Brazil and Peru. In this sense, the development and production of safer, eco-friendly, cost-effective, more efficient, and target-specific insecticides have become essential in disease control strategies. This study aimed to assess the effectiveness and safety of indoor micro-encapsulated propoxur paint against Aedes aegypti, estimate residents' exposure via cholinesterase levels, and gauge resident perceptions in the rural village Poblado Miguel Alemán (PMA), Sonora, Mexico. Houses in PMA were organised into four blocks for a field trial, with different treatments on interior walls: 1) full insecticide paint coverage; 2) insecticide paint applied up to 1 meter; 3) full indoor residual spraying; and 4) no treatment (control). Mosquito surveys were conducted before and after interventions. Blood samples from residents were analysed for cholinesterase levels, while perceptions were gathered through a questionnaire. Aedes resting density correlated closely with the paint formulation and coverage. Full-surface insecticide paint showed the greatest reduction. Both paint interventions notably impacted Aedes breeding, with substantial reductions in House Index (20.1% IP, 31.2% IP 1 m) and Container Index (51.8% IP, 61.7% IP 1 m) compared to the control over one year. Post-intervention blood cholinesterase activity remained within acceptable limits. Over 80% of residents expressed satisfaction with the interventions. The use of propoxur paint proves to be a safe, effective, and well-accepted method for decreasing Ae. aegypti populations in urban areas.