Fiocruz (Oswaldo Cruz Foundation) closed an agreement to expand the use of Wolbachia bacteria against dengue, zika and chikungunya fever, diseases transmitted through the bite of the Aedes aegypti mosquito.
It is a method that is already used in Brazil and in 11 other countries, based on the articulation of several scientific institutions and coordination of the WMP (World Mosquito Program). Introduced in mosquitoes, the Wolbachia bacterium is capable of blocking the transmission of viruses to humans during a bite.
The agreement – signed between Fiocruz and WMP – was announced this Thursday (30th), in Rio de Janeiro. Among the planned measures is the construction of a large biofactory, which will have the capacity to produce up to 100 million mosquitoes per week. The estimated cost is R$ 100 million.
Resources will come from WMP and IBMP (Institute of Molecular Biology of Paraná), which was born from a partnership between Fiocruz and the government of Paraná.
The forecast is that the biofactory will start operating in 2024, but the city that will house it has not yet been chosen.
“It is a definition that is being taken with the Ministry of Health and some local governments. But it is a project designed so that it can be installed quickly in any place without much preparation of the land. Fiocruz has already accumulated a lot of experience with constructions of this type” , said the president of Fiocruz, Mario Moreira.
Another BRL 80 million – BRL 50 million from WMP and BRL 30 million from Fiocruz – will be allocated to immediately begin expanding current production, which will help states and municipalities to control diseases in more critical locations. It will be up to the Ministry of Health to indicate, based on epidemiological data, which are the priority cities.
artificial introduction – According to Fiocruz, Wolbachia is naturally present in about 60% of insects, but not in Aedes aegypti. The method therefore involves an artificial introduction into the mosquito organism.
The researchers involved point out that the initiative does not involve any genetic modification, neither in Aedes aegypti nor in the bacterium. Furthermore, the objective is not to eliminate the mosquito from the environment, just to replace a population capable of transmitting diseases by another incapable.
The Wolbachia method began to be used in Australia and today it is present in three continents: Asia, Oceania and America. Local epidemiological surveys have indicated the success of the initiative. In addition, different scientific studies have already scientifically proven its effectiveness, including a robust clinical study carried out in Yogyakarta, Indonesia. There was a 77% reduction in the incidence of dengue in the neighborhoods where Wolbachia was introduced, compared to other locations in the city.
In Brazil, the application of the method is carried out by the Oswaldo Cruz Foundation (Fiocruz), with the support of the Ministry of Health. Work began in 2015 with the release of mosquitoes in two small areas: in Jurujuba, in the neighborhood of Niterói (RJ), and in Tubiacanga, in Rio de Janeiro. With the good results, the initiative expanded to other locations in both cities and is already used in Campo Grande (MS), Belo Horizonte and Petrolina (PE).
Sustainability – The project has demonstrated sustainability: the female mosquito that has Wolbachia in her organism is capable of transmitting it to all her offspring, even if she mates with males without the bacteria. Also, when only the male has Wolbachia, the fertilized eggs die. In this way, the bacteria is transmitted naturally to new generations of mosquitoes.
The results, however, are not obtained in the short term. “The speed of implementation of the method varies according to the characteristics of each municipality. In general, we were able to have a real impact in reducing dengue cases a few years after the implementation was completed”, explains Luciano Moreira, researcher at Fiocruz and leader of the WMP in Brazil.
For this reason, the population must continue to strive to prevent the accumulation of stagnant water, which serves as a breeding ground for mosquitoes. In the same way, the government must not slacken other preventive measures, including the application of chemical and biological products when recommended, such as fogging and larvicides.