Six municipalities are expected to receive the first releases of Aedes aegypti mosquitoes infected with the wolbachia bacteria in July: Uberlândia in Minas Gerais; Londrina and Foz do Iguaçu, in Paraná; Presidente Prudente, in São Paulo, Joinville, in Santa Catarina; and Natal, capital of Rio Grande do Norte. Next year, the strategy will be adopted in another 22 municipalities in Minas Gerais. According to the Ministry of Health, Brazil is the first country to incorporate technology as a public policy to reduce dengue cases in the medium and long term.
The so-called Wolbachia method consists of inserting the bacteria into mosquito eggs in the laboratory and creating Aedes aegypti that carry the microorganism. Once infected, they are not capable of carrying the viruses that cause dengue, zika, chikungunya or yellow fever and, when they reproduce, mosquitoes pass the bacteria to others, meaning that fewer insects can transmit diseases to humans.
Before the mosquitoes are released, there is a community engagement stage because, initially, the community has the perception that the number of mosquitoes has increased in the region. “Furthermore, where the mosquito is released, insecticide cannot be applied, because the method is based on population change, replacing mosquitoes that have wolbachia with those that do not”, explains the Secretary of Health and Environmental Surveillance at the Ministry of Health, Ethel Maciel.
According to Ethel, there are a series of criteria that need to be observed for the municipality to receive this strategy, mainly the little variation in temperature during the day, because this harms the mosquito’s adaptation to wolbachia.
According to the secretary, the strategy has proven to be quite effective. An example is the city of Niterói, in the state of Rio, the first to receive the project in the research stage, in 2014, which saw a reduction of 69.4% in dengue cases, 56.3% in chikungunya cases and 37% us with zika. “There, the number of cases is much lower than in neighboring municipalities, showing that in the medium and long term the strategy can be very important”, said the secretary, in an interview this Tuesday (30).
Other cities in the country that are using the Wolbachia Method are Rio de Janeiro, Campo Grande and Petrolina, in Pernambuco. In addition to Brazil, Indonesia and three other countries participate in the research in partnership with the World Mosquito Program.
Yesterday (29), the Ministry of Health and the government of Minas Gerais inaugurated the Wolbachia Biofactory in Belo Horizonte. The unit, managed by the Oswaldo Cruz Foundation (Fiocruz), will allow Brazil to expand its production capacity for one of the main technologies in the fight against dengue and other arboviruses.
