Susceptibility Status of Insecticides used for Mosquito Control in Asia

As part of its international outlook, the Global Mosquito Resistance Management Summit (held online in late March 2022) featured a review of insecticide resistance status in Asia by Dr. Nazni Wasi Ahmad, Research Officer of the Medical Entomology Unit & GLP Laboratory, which is part of the Institute for Medical Research (IMR) in Malaysia.

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While the human population in the region is burdened by dengue, Zika, chikungunya, and malaria; dengue is of particular and growing importance, particularly in Southeast Asia. Wasi shared that there are three key vectors for dengue: Aedes aegypti, Aedes albopictus, and Aedes nubias; and that air travel is considered a primary cause for its spread.

Key issues facing Asian Public Health officials with respect to Dengue are that there are no specific antiviral medications and no vaccines. That leaves community-based, integrated mosquito control programs to control the vector. Research shows that as low as two (2) to three (3) female Aedes aegypti emerging per day is sufficient for a Dengue transmission in a community of 100 people.

“Thermal fogging mortality is around 60% and below, and the ULV spray mortality is below 20.”

Wasi presented a table showing resistance in each country by active ingredient. As was reported by presenters covering other regions, Wasi confirmed that mosquito insecticide resistance is the result of large-scale pesticide use for both vector control and agriculture. She also shared data that showed the tremendous amount of insecticides being used in mosquito control in the WHO (World Health Organization) South-East Asia region –  estimating that the amount of insecticide used to battle malaria is three times higher than what is being used to control dengue.

Wasi reported that no new mosquito adulticide has been approved by the WHO for use in the region for the past 15 years.