Household insecticide uses and flea infestation in plague-endemic regions of Madagascar.

Insecticide use remains one of the most common strategies worldwide for controlling household pests and disease vectors, despite growing concerns over misuse, health risks, and the emergence of insecticide resistance. To document household insecticide use and flea infestation across a gradient of plague endemicity in Madagascar, we used a multidisciplinary approach. A descriptive household survey and an observational checklist were implemented with 422 respondents and combined with flea infestation assessment based on flea sampling from small mammals and candle traps. Household insecticide use was primarily reported for pest control (92.4%), mainly targeting fleas (70.3%) and was generally applied reactively rather than preventively. Even though males constituted the majority of respondents (85.0%), mothers are reported to play a primary role in insecticide application (41.4%) and in the purchase (48.2%) of chemical products. Overall, good insecticide practices were observed in 51.3% of households, although the difference between good and poor practice categories was not statistically significant (p = 0.83). Comprehensive understanding of household insecticide use is crucial to implement effective integrated pest management, optimize vector control strategies, minimize selective pressures driving resistance, and protect both human health and the environment.