Effect of Thermal Fogging on Aedes Mosquito Control and Dengue Surveillance in Malaysia

Chen Zhe Tang; Zhen Yun Siew; Isaac Seow; Kenny Voon

doi:10.22452/jtoh.vol1.8

Authors

Chen Zhe Tang School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia. , Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
Zhen Yun Siew School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia. , Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
Isaac Seow School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
Kenny Voon School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.

DOI:

https://doi.org/10.22452/jtoh.vol1.8

Keywords:

Aedes albopictus, Wolbachia, Surveillance, Vector, Fogging, One Health

Abstract

Dengue virus (DENV) is widespread in Malaysia, causing significant morbidity. Regular thermal fogging is conducted to prevent DENV transmission by vectors, primarily Aedes aegypti and Aedes albopictus. This study investigated the presence of DENV in the Aedes population at a tertiary educational institution in Semenyih, Malaysia, and evaluated the effectiveness of fogging. Aedes mosquitoes and larvae were collected weekly and screened for DENV and Wolbachia. Fogging effectiveness was assessed by comparing the mean number of larvae before and after fogging using Mann-Whitney U tests. A total of 3,844 mosquito larvae were collected, with the most identified as A. albopictus, some as Culex spp., and none as A. aegypti. DENV screening yielded no positive results throughout the study, while Wolbachia was prevalent in the Aedes albopictus population, suggesting its effectiveness in limiting DENV circulation. However, fogging did not significantly reduce Aedes larvae numbers, likely due to insecticide resistance. Specific areas with increased human activity and dense vegetation showed relatively high mosquito densities. Interestingly, DENV serotype 2 was detected in pooled samples of common tree shrews (Tupaia glis) for the first time (same study but published elsewhere). This study aims to assess the prevalence of DENV in local Aedes populations and evaluate the efficacy of thermal fogging as a control measure. Additionally, it seeks to explore the potential role of Wolbachia in reducing DENV transmission in the mosquito population and suggest alternative animal reservoirs of DENV, such as tree shrews.

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