Asian Scientist Magazine (Jul. 18, 2022) — It might seem counterintuitive to thin out a crowd by adding more people to it; but when it comes to Singapore’s dengue-carrying mosquito problem, that might be a surprisingly effective solution.
Since 2016, the National Environment Agency (NEA) of Singapore has been investigating how some specialized bug-carrying bugs might complement existing dengue control measures, under a program called Project Wolbachia.
Naturally, the Aedes aegypti mosquitoes being released by the NEA among the country’s high-rise neighborhoods are no ordinary crowd of insects. For one, they’re all male, meaning they don’t bite; for another, they don’t carry the dengue virus; and uniquely, they’ve all been bred to carry a bacterium called Wolbachia inside their bodies.
When these male mosquitoes breed with females out in the field, this bacterium gets passed on to their eggs—and stops them from hatching entirely.
The result in field trials so far, according to Associate Professor Ng Lee-Ching, can be a steep crash in the local A. aegypti population—up to 98 percent in some residential neighbourhoods—and a simultaneous plunge in local dengue fever cases. Ng, group director of the NEA’s Environmental Health Institute, is part of Project Wolbachia.
“Globally, [Project Wolbachia] is the first such study in a high-rise landscape,” said Ng. “As the project expands, the different terrain and locations have given us different data points and lessons which have enabled us to scale up.”
Building on the project’s promising results, in June 2022 the NEA announced it would expand field trials to eight more sites in Singapore. These will cover an additional 1,400 Housing Development Board (HDB) blocks, bringing the total coverage of Project Wolbachia to 31 percent of all such public housing in the country.
But just how do an obscure bacterium and an infamous mosquito—the most common carrier of the dengue virus in urban environments—combine to form a novel tool in an age-old public health battle? Ng explains more about Project Wolbachia in an interview with Asian Scientist Magazine.
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Copyright: Asian Scientist Magazine
