Brazilian scientists figured out a way to curb dengue transmission: letting bacteria-infected mosquitoes run free. And their strategy has already shown promising results.
Photo: Bing AI
Armed with the microscopic bacterium Wolbachia pipientis, modified mosquitoes released in three cities in Columbia have led to a dramatic fall in the incidence of dengue: up to a 97 percent decrease, reported Nature.
Context: Dengue, a viral fever, is transmitted by mosquitoes of the Aedes species. While approximately 80 percent of the infections are asymptomatic, others experience flu-like symptoms: high fever, headache, and excruciating joint and body pain that has earned it the nickname “breakbone fever.”
Dengue is unlikely to become a serious problem for the United States, but the condition can be deadly in tropical countries like Brazil and Columbia. This is where the “mosquito factories” come in.
The World Mosquito Program has collaborated with several countries to curb the incidence of dengue with these modified mosquitoes — and their effectiveness has been promising.
Wolbachia is a bacteria found in about half of all insects, but not in the Aedes mosquito. The bacteria can have a “virus-blocking” effect — reducing the transmission of human viruses like dengue, Zika, chikungunya, and yellow fever.
Scientists began injecting Wolbachia into the eggs of Aedes mosquitoes in 2011, and the bacterium spread into their offspring naturally — making for a cost-effective approach.
Scientists breed mosquitoes and inject the eggs — using microscopic needles — with the Wolbachia bacterium. The larvae then grow infected.
Photo: World Mosquito Program
The World Mosquito Program is currently leading this Wolbachia effort in 14 countries: Brazil, Columbia, Mexico, Honduras, El Salvador, Indonesia, Laos, Sri Lanka, Vietnam, Australia, Fiji, Kiribati, New Caledonia, and Vanuatu.
Challenges ahead: The WMP plans to build a factory in Brazil that produces 5 billion bacteria-infected mosquitoes per year. However, they still require strategies that function for different geographical conditions.
What the officials hope is for their multi-million dollar bet on mosquito control to pay off — at least in the short term.