In a Colombian laboratory, jars teeming with larvae in stagnant water and thick clouds of mosquitoes are not just scenes from a nightmare but essential components of a crucial project combating the spread of dengue fever.
For nearly a decade, the World Mosquito Program (WMP) has been at the forefront, replacing local populations of Aedes aegypti mosquitoes with biologically modified insects to curb the virus that has claimed over 4,500 lives in Latin America and the Caribbean this year alone.
Rather than resorting to harmful insecticides, biologist Nelson Grisales emphasizes the innovative approach: “This technology is designed to use a living bacterium within the mosquitoes themselves, aiming to sustain life.”
Supported by American philanthropist Bill Gates, the project has yielded promising results, with dengue cases plummeting by 95 percent in Colombia’s northwestern Antioquia department, according to health authorities.
Despite its success, the initiative has not been immune to conspiracy theories. Grisales laments, “There are viral rumors that the mosquitoes we release carry mind-control chips from Bill Gates, can induce homosexuality, or transmit more potent diseases.”
Contrary to these claims, the WMP introduces mosquitoes infected with Wolbachia, a common bacterium found in various insect species, to encourage its spread among Aedes aegypti in the wild.
Wolbachia operates twofold: bolstering the mosquito’s immune system to reduce dengue susceptibility and hindering virus replication within the insect, thereby lowering transmission rates to humans.
“This is not genetic modification,” clarifies biologist Beatriz Giraldo. “The bacterium enters the mosquito cell, effecting biological changes.”
As global temperatures rise, facilitating the spread of dengue, the urgency of such initiatives becomes more pronounced. Dengue fever, notorious for its severe joint pain, is colloquially known as “breakbone fever” and can escalate to hemorrhagic fever or fatal outcomes.
The WMP strategy involves transporting Wolbachia-infected mosquitoes in jars to heavily impacted areas in Colombia, where they are released to breed with and eventually supplant local mosquito populations.
Originating from discoveries in Australia, where trials began in 2011, the project has expanded to Indonesia, Brazil, and is set to launch in El Salvador.
Grisales underscores the program’s alignment with the escalating dengue crisis: “As dengue problems grow, our program accelerates.”
While currently operating as a private initiative under local authorization, Grisales hopes it will evolve into public policy. In Cali, where Wolbachia mosquitoes were introduced in 2019, resident Albency Orozco recalls initial skepticism giving way to acceptance following comprehensive monitoring and community engagement.
