The first Wolbitos, the Aedes aegypti mosquitoes containing the Wolbachia bacteria, have begun being released in five neighborhoods of the city of Joinville. The routes have been previously defined and will include, in this first part of the project, 17 neighborhoods, taking into account technical criteria such as number of outbreaks and of confirmed cases. About 3.6 million Wolbitos will be released every week, to protect a population of about 360,000 inhabitants.

Each vehicle is loaded with the number of tubes equivalent to the release points. In the car, two agents carry out this work against endemic diseases. An app displays the places where the mosquitoes must be released. When the car drives by the location and the tube is opened, between 200 and 250 mosquitoes are released. The app immediately shows that that release point has been contemplated. The car drives at up to 20 km/h.

“There will be 20 weeks of release and 70 routes in Joinville. We’ll initially release about 3.6 million mosquitoes every week. It’s important that the population knows that the cars which are marked as Local Government vehicles will be driving by and that our collaborators will be releasing these tubes. This will probably last until January 2025”, says Diogo Chalegre, leader of Institutional and Governmental relations of WMP Brazil. According to Chalegre, monitoring starts on the first month of release. “The Joinville local government will be collecting eggs in field and these eggs will be then sent to a laboratory, where the mosquitoes are identified and forwarded to Belo Horizonte. That’s where we run diagnostic tests to detect whether Wolbachia is establishing itself in the field or not”, he explains.

The Wolbachia Method is another strategy in the fight against diseases such as dengue fever, zika and chikungunya. “It’s a complementary method, from medium to long term. We hope that in a year or two we can see the impact of the project on the transmission of these diseases”, he states. From 50 to 60% of the insects already contain the Wolbachia bacteria, a natural occurrence in the environment. The Aedes aegypti mosquito does not naturally contain these bacteria, so researchers inserted them in the mosquitoes and realized the bacteria stopped viruses from replicating - viruses such as the one that causes dengue.

“Wolbachia is absolutely natural, there’s no danger for the human population. It’s safe and hasn’t been genetically modified in any way. So, the population has nothing to worry about, but people do need to continue doing their best. They have to keep on taking care of their yards and following preventive measures”, highlights Chalegre.

The Wolbitos are produced in the biofactory in the neighborhood of Nova Brasília, at a plant prepared for this work. The Aedes aegypti eggs come from Rio de Janeiro and hatch in Joinville. The mosquitoes are then prepared until they’re ready to be released. The Wolbachia Method is being implemented in Joinville in a joint action with the Local Goverment of Joinville, Fiocruz, World Mosquito Program (WMP), the Government of Santa Catarina, and the Ministry of Health.

The Wolbachia Method

The Wolbachia Method consists in releasing Aedes aegypti with Wolbacchia so they mate with local Aedes aegypti and therefore gradually establish a new population of these mosquitoes, all carrying Wolbachia. Over time, the percentage of mosquitoes carrying Wolbachia increases, until it remains stable without the need for new releases. This effect makes this method self-sustainable, an intervention that is accessible in the long term. There is no genetic modification involved in the Wolbachia Method of the WMP, neither in the mosquito nor in the Wolbachia.

Source: Fiocruz News Agency (AFN).