World Mosquito Program’s Wolbachia Mosquitoes Release Project

One of the Top 20 Most Influential Projects of 2024

World Mosquito Program’s Wolbachia Mosquitoes Release Project

One of the Top 20 Most Influential Projects of 2024

For using nature itself to stop the spread of mosquito-borne diseases

Region: Latin America  Sector: Health  UN SDGs: 3, Good Health and Well-being; 9, Industry, Innovation, and Infrastructure

If you’re one of the four billion people in the world who lives in an area that’s at high risk for mosquito-borne diseases, you’d probably be skeptical if someone came into your community and told you they could solve the problem of mosquito-borne illnesses with…mosquitoes.

Bruno Col, communications director of the World Mosquito Program (WMP), is familiar with this response, which is why he and his colleagues have taken a different approach to seeking community buy-in and engaging local partners who will agree to participate in the WMP’s Wolbachia Mosquito Release Project. “It’s counterproductive to say, ‘We’re going to release more mosquitoes in your backyard.’ You have to be in collaboration and high communication with communities,” says Col.

Such communication includes explaining a bit about the science behind the Wolbachia Mosquito Release Project in simple terms. Wolbachia are naturally occurring bacteria found in up to 50 percent of insects, but not in the Aedes aegypti mosquito, which is the species responsible for transmitting most mosquito-borne viruses that affect human communities, including chikungunya, dengue, yellow fever, and Zika. The WMP conducted research to confirm that Wolbachia, when introduced into Aedes aegypti, helps reduce transmission of the viruses carried by the Aedes aegypti. When introduced to the mosquito population at scale, the WMP has recorded significant declines in the incidence of devastating mosquito-borne ailments.

The decrease in disease isn’t just important from a public health perspective; it also yields substantial economic benefits. Mosquito-borne diseases increase healthcare costs, especially for vulnerable families who lack financial resources to seek medical care. At the same time, household income takes a hit due to missed work. By decreasing the incidence of mosquito-borne illnesses, communities are able to experience multiple benefits, all of which contribute to improved health and well-being.

Convincing a community of these benefits is easier with evidence, and the World Mosquito Program has plenty of it. In 2023, the Wolbachia project’s focus was generating data about the efficacy of the Wolbachia intervention in Colombia’s Aburrá Valley and in Niterói, Brazil. The results confirmed that introducing Wolbachia works, especially in preventing dengue outbreaks in large urban populations. In both countries, WMP’s 2023 research affirmed that a stable population of Wolbachia-carrying Aedes aegypti had been established in cities with populations ranging from half a million to more than 3 million people. What’s more, all of the communities in the study experienced statistically significant reductions in the incidence of dengue as a result. 

 

A man, all covered up, releasing mosquitoes

 

Just how significant? “In Colombia, we reduced the incidence of dengue by 92 percent; in Niteroi, Brazil, the same,” Col reports. But he says that just as important as disease reduction is the fact that the introduction of Wolbachia does not produce other harmful outcomes, as is the case with conventional mosquito- and mosquito-borne disease control methods, such as fumigation. The Wolbachia method is “safe, self-sustaining, and environmentally friendly,” according to the World Mosquito Program. It doesn’t involve genetically modifying mosquitoes, and because Wolbachia is a naturally occurring bacteria, it simply gets introduced to the Aedes aegypti population and inhibits that mosquito’s ability to produce viruses.

But to get Wolbachia-bearing mosquitoes into populations that could benefit from them is challenging, says Col. Releasing more mosquitoes into a community that considers them pests can be a hard sell, but it’s made easier because WMP partners with non-governmental organizations (NGOs) and nonprofits, as well as local, community-based groups that already have trusting relationships with residents. These groups, including USAID, join the World Mosquito Program in a community engagement approach that they refer to as a public acceptance model. “We only proceed with mosquito releases after securing widespread support from the community,” Col explains.

And that support isn’t just about allowing the release of Wolbachia-bearing mosquitoes into the community; it also involves residents in leading the release. “When a country is ready to work with us, we usually provide project management teams, communication teams, and so on. It’s a very effective, collaborative way of working,” Col explains. To date, the Wolbachia project in Colombia has attracted more than 13,000 volunteers, 11 partner organizations, and 2,100 supporting groups, companies, and institutions.

 

Image of a group of mosquitoes flying in the air

 

The approach is also empowering, as residents and community leaders become project managers who aren’t just on the receiving end of a solution; they’re driving it forward. “When we have an agreement with a local population, we help the community release mosquitoes,” Col says. This involves either releasing adult mosquitoes that have already been bred with Wolbachia, or placing mosquito eggs in the community. “We have a way to transport eggs – 250 eggs in a little capsule – and we create a box, like a Chinese food take-away box, and we explain to people how to do it: the eggs will grow, become larvae, then pupae, and then adult mosquitoes. The mosquitoes will reproduce themselves and all eggs will have Wolbachia. We create a population of Wolbachia mosquitoes, and the population will then reproduce itself. The mosquito will bite you but you won’t get disease.”

Col emphasizes that the outcomes in Colombia and Brazil are so positive and robust, that it has springboarded World Mosquito Program’s Wolbachia project into a new phase. “We no longer consider ourselves a research program — the research is done, the results are there. What we want now is to scale up.”

WMP is poised to do exactly that. In Brazil, the project achieved a significant milestone in 2023, involving more than one million residents across the country in mosquito release. The acceptance and involvement levels are significant in a country that has the highest number of dengue cases in the world and bears one-tenth of the global dengue burden, with more than 90 percent of its population at risk of infection. Those statistics are staggering, but they represent a challenge World Mosquito Program’s Wolbachia project is ready to tackle. The success of the Wolbachia project in 2023 has led the organization and public and private partners in Brazil to build a factory that will ultimately produce two billion mosquitoes over five years. "It is a great example of how the public and private sectors can effectively come together to solve a complex public health challenge that deeply affects families in Brazil and across the world,” said Kieran Walters, WMP’s director of global functions and strategy.