This study aims to examine the efficacy of mosquito mat vaporizers on Aedes aegypti and their associated metabolic detoxication mechanisms. For this purpose, Aedes aegypti (Linnaeus) was collected from nine districts in Selangor, Malaysia and tested with mosquito vaporizing mat bioassays. The same populations were also subjected to biochemical assays to investigate activities of detoxifying enzymes, namely non-specific esterase (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO). The efficacy of Ae. aegypti on the active ingredients tested in decreasing order were d-allethrin > dimefluthrin > prallethrin with PBO > prallethrin. The results further indicated significant enhancement mean levels of EST, GST and MFO in pyrethroid-resistant populations. The mortality rate of Ae. aegypti in response to pyrethroid active ingredients was associated with MFO activity, suggesting it is an important detoxification enzyme for the populations tested. In view of the presence of resistance against household insecticide products, pyrethroid efficacy on Ae. aegypti populations needs to be monitored closely to ensure the implementation of an effective vector control program in Malaysia.

Insecticide application is one of the most important control measures for protection from mosquito bites. A descriptive, community-based cross-sectional survey involving 986 respondents was conducted to probe the knowledge, attitudes, and practices regarding household insecticide use in Selangor—the state that recorded the highest number of dengue cases in Malaysia. In this study, we classified the responses as either low (poor) or high (good) based on median cut-off points. Age, gender, ethnicity, and household income were found to be significantly associated factors relative to the respondents’ mosquito knowledge score, whereas no factors were significantly associated with attitudes toward the use of household insecticide. Practices, on the other hand, were associated with age and high attitude scores. Most respondents (71.4%) had good knowledge of mosquitoes. Conversely, 51.1% and 59.2% of respondents scored high on attitudes and practices, respectively, on the use of household insecticides. This study highlights the need to expand health promotion activities through social mobilization to raise awareness about vector-borne disease prevention and promoting positive attitudes and safe practices in the use of household insecticides.

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