The ambitious goal: to build one mosquito factory modified in Brazil to protect the country from dengue disease (and others). The project was baptized Operation Wolbachia
and was created by the World Mosquito Program (Wmp), a non-profit organization whose goal is to combat mosquito-borne diseases (Zika, Chikungunya, Yellow Fever, and of course Dengue).

The bacterium Wolbachia

Wolbachia the name of a bacterium that severely limits the ability of Aedes aegypti mosquitoes to transmit the virus what causes dengue: the bacterium and the virus in fact they cannot coexist in the same host organism. When the modified mosquitoes are released into Aedes aegypti infested areas, they slowly spread the bacteria to the wild mosquito population. The Brazilian project plans to release modified mosquitoes in urban areas of Brazil over the next 10 years.

Studies on modified mosquitoes

The largest study on the new technology conducted in Indonesia showed that the technology could reduce the incidence of dengue by 77%. In Brazil, where the modified mosquitoes have been tested in five cities so far, the results have been more modest. In Niteri, the intervention involved a 69% decrease of dengue cases. In Rio de Janeiro the Reduction was 38%. However, it should be specified that these latest studies are not considered as reliable as the Indonesian one by epidemiologists for various reasons (including the use of different methods). Instead, more consistent data are awaited from a large randomized controlled trial underway in Belo Horizonte, which aims to compare the occurrence of dengue fever in areas where mosquitoes modified with the Wolbachia bacterium are released with that in other areas not affected by the experiments.

A production of 5 billion mosquitoes per year

It has not yet been decided where in Brazil the mosquito factory will be built, but the plant is expected to become operational 2024 and produces up to five billion mosquitoes a year. Insects could be spread in the environment with drones, but also more easily with cars or bicycles. This will be the world’s largest plant producing Wolbachia-infected mosquitoes, says Scott O’Neill, a microbiologist at Monash University in Melbourne, Australia, and director of the WMP. And it will allow us to cover more people in a short period of time than any other country. In fact, Brazil has one of the highest dengue infection rates in the world over two million cases were reported in 2022. The WMP scientists themselves emphasize that the Wolbachia plan is not an alternative to other public health intervention strategies such as vaccines, disinfestation and bed nets, but is a complementary weapon to combat dengue, Zika and chikungunya.