Can releasing special male mosquitoes stop dengue? A trial in Singapore shows promising results.

Imagine a way to fight dengue fever that doesn't involve spraying chemicals or just telling people to avoid bites. In Singapore, scientists tried something new: they released millions of male mosquitoes infected with a harmless bacteria called Wolbachia. When these males mate with wild female mosquitoes, the eggs don't hatch. Over time, this can shrink the local mosquito population. The trial involved over 720,000 people across 15 neighborhoods. Some areas got the special mosquito releases; others didn't. The results were striking. In the areas with the releases, the number of adult female mosquitoes—the ones that bite and spread dengue—dropped sharply. More importantly, far fewer people got sick. In those areas, only 6% of people tested for dengue-like symptoms actually had the virus, compared to 21% in the areas without the mosquito releases. The protection was strong and lasted. For people exposed to these mosquitoes for 3 to 12 months or more, their odds of getting a confirmed dengue infection were reduced by 71% to 72%. This trial shows that using these 'sterile' male mosquitoes can be a powerful tool to suppress mosquito populations and protect people from dengue.