Rio releases new mosquitoes used to fight dengue fever
On Tuesday (Abr. 2), the municipality of Rio de Janeiro started a new release of wolbitos—Aedes aegypti mosquitoes infected with the Wolbachia bacteria. The microorganisms are used to combat arboviruses such as dengue, Zika, and chikungunya, as they prevent the viruses that cause these diseases from developing inside their main carrier, the Aedes aegypti.
The idea is to make releases in at least three neighborhoods in the city over 20 weeks to expand the population of these mosquitoes.
After being released into the environment, females contaminated with Wolbachia mate with mosquitoes without the bacteria. The offspring of these crosses are born with the bacteria, thus without the ability to transmit the diseases. If all goes well, over time the wolbito population will increase, reducing the population of arbovirus carriers and eliminating the need for further releases.
“We’re going to have these releases until the end of August, and we hope to first establish this mosquito population in these three areas. Maybe next year we’ll be able to observe a reduction in the transmission of cases of these diseases,” said Diogo Chalegre, head of Institutional Relations for the World Mosquito Program (WMP) in Brazil.
The so-called Wolbachia method was first implemented in Niterói in 2014, where releases have been conducted across all the neighborhoods. Next was the city of Rio, which has already had wolbites released in 29 neighborhoods, in addition to municipalities outside the state of Rio: Campo Grande, Belo Horizonte, and Petrolina.
“What we can say is that there has been an average reduction of 38 percent in dengue cases in the 29 neighborhoods in Rio where we have worked so far,” Chalegre noted.
WMP spearheads strategies involving Wolbachia in Brazil, in partnership with the Oswaldo Cruz Foundation, and funding from the Ministry of Health. Currently, according to Chalegre, 40 million Wolbachia eggs are produced every month. Around 3.2 million people live in the areas where these mosquitoes have been released.
A new biofactory began to be built in Curitiba, in Paraná state, in March this year, to increase production capacity to 400 million eggs per month in 2025. After this expansion, releases to new locations are expected to surge, benefiting up to 70 million people over the next ten years.
