The Oswaldo Cruz Foundation (F.iocruz) began an important stage of the Eliminate Dengue: Brasi Challenge project.

Already carried out successfully in Australia, Vietnam and Indonesia, the field study phase includes the release of mosquitoes Aedes aegypti with the Wolbachia bacterium.

The first place to participate is the neighborhood of Tubiacanga, located on Ilha do Governador, in the city of Rio de Janeiro, and studied by the project team since 2012. This is the first time that a country in the Americas has received the study.

The project has the participation of the Oswaldo Cruz Institute (IOC/Fiocruz), René Rachou Research Center (Fiocruz/Minas) and Scientific Computing Program (PROCC/Fiocruz).

The announcement was made this Wednesday, September 24, on the F campusiocruz, in Manguinhos. The president of the Foundation, Paulo Gadelha; the researcher and leader of the project in Brazil, Luciano Moreira and the director of the Department of Science and Technology (Decit) of the Ministry of Health, Antonio Carlos Campos de Carvalho. Residents of Tubiacanga and scientific partners of the project were present at the meeting.

The non-profit initiative is part of the international effort of the Eliminate Dengue: Our Challenge Program, which studies an innovative approach to reduce mosquito transmission of the dengue virus Aedes aegypti in a natural and self-sustainable way.

The project proposes the use of a bacteria naturally found in the environment, called Wolbachia. When present in Aedes, it is capable of preventing the transmission of dengue fever by mosquitoes.

F researcheriocruz and project leader in Brazil, Luciano Moreira is optimistic about the next steps of the project. We are facing an innovative and safe scientific strategy, which could contribute to the control of dengue and to the improvement of the population's health, he evaluates. He was responsible, with researchers from the University of Monash, in Australia, for the scientific discovery of Wolbachia's capacity to reduce the transmission of the dengue virus by the mosquito.

After two years of preparatory studies, it is exciting to see the project moving forward to this phase in Brazil, where we have the scientific leadership of Fiocruz, added Scott O'Neill, the Program's international coordinator.

release of mosquitoes

In Tubiacanga, around ten thousand mosquitoes Aedes aegypti with Wolbachia will be released weekly by researchers.

The number of mosquitoes is similar to protocols successfully adopted in Australia, where this type of study has already been completed in more than four locations. The releases will take place for approximately three or four months, depending on scientists' assessment of the ability of mosquitoes with Wolbachia to establish themselves at the site.

To reduce the nuisance of the population, before the start of the release of mosquitoes with Wolbachia, the researchers, together with the Municipal Health Department of Rio de Janeiro, carried out a step called suppression of breeding sites.

The objective was to reduce the amount of Aedes aegypti by eliminating confirmed breeding sites for the vector, by releasing Aedes with Wolbachia into the neighborhood, the total number of mosquitoes will not change.

"With this measure, we seek to reduce discomfort for the residents of Tubiacanga, who have always supported this scientific initiative", Luciano reinforces.

Initially, researchers will evaluate the ability of mosquitoes with Wolbachia to establish themselves in the environment and reproduce with mosquitoes that already exist in the area.

"The project proposes a sustainable and long-term approach, as, after establishing Aedes aegypti With Wolbachia in the environment, the bacteria is naturally transmitted to subsequent generations of mosquitoes. Thus, the method becomes self-sustainable: mosquitoes with Wolbachia predominate without us having to constantly release more mosquitoes with the bacteria", explains Luciano.

Large-scale studies scheduled for 2016 in other locations in Rio de Janeiro will be able to evaluate the effect of this strategy in reducing the incidence of dengue.

population support

As part of the project, since 2012 the Fiocruz works in the neighborhoods selected for the study, carrying out intense scientific work to map mosquitoes in the neighborhoods studied: in Tubiacanga, Urca and Vila Valqueire, in Rio de Janeiro, and Jurujuba, in Niterói.

In this process, regular contacts are made with residents, leaders and associations.

"The data collected was fundamental for planning the field studies", explains Luciano.

During the mapping, traps to capture and study the region's mosquitoes were installed in the homes of dozens of residents who are the so-called hosts of the project.

"We are extremely grateful to these people who welcome our teams into their homes every week, contributing to a project that seeks collective benefit", says Luciano.

"As we approached the beginning of field studies, relationship actions with the residents of Tubiacanga were intensified so that they were properly informed of all activities", he adds.

Residents' associations, in addition to other local institutions, support the project, which carries out regular home visits to present the initiative and resolve doubts. Meetings and lectures between residents and researchers are also promoted.

Customer service is provided via telephone and email.

Safe and natural method

Naturally present in around 60% of insects in the world (including several species of mosquitoes, such as mosquitoes), there is no evidence of any risk from Wolbachia to human health or the environment.

These mosquitoes commonly bite people without negative effects. As it is an intracellular bacterium, which does not infect humans or domestic animals, Wolbachia can only be transmitted from mother to child, during the reproduction process of mosquitoes, and not during an Aedes bite on a human being, for example.

Furthermore, for five years, team members from the Eliminate Dengue program in Australia voluntarily fed a colony of mosquitoes with Wolbachia using their own arms. This resulted in hundreds of thousands of mosquito bites without reactions to the bacteria being detected.

official approvals

The field tests in Brazil were approved by the National Health Surveillance Agency (ANVISA), by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA), by the Ministry of Agriculture, Livestock and Supply (Mapa) and by the National Commission on Ethics in Research (CONEP) after rigorous assessment of safety for health and the environment.

Funders and partners

The Eliminate Dengue: Brazil Challenge project is part of the international non-profit effort of the Eliminate Dengue: Our Challenge Program.

In Brazil, the project is financed by Fiocruz, Ministry of Health (Secretariat of Health Surveillance SVS and Department of Science and Technology of the Secretariat of Science, Technology and Strategic Inputs DECIT/SCTIE), Ministry of Science, Technology and Innovation and CNPq.

The Municipal Health Department of Niterói and the Municipal Health Department of Rio de Janeiro act as local partners in implementing the project.

The international funding comes from funds from Monash University, obtained by the Foundation for the National Institutes of Health (FNIH, United States) through the Vector-Based Transmission of Control program: Discovery Research - VCTR) of the Bill & Melinda Gates Foundation's Grand Challenges in Global Health Initiatives.

The project also has direct resources from the Bill & Melinda Gates Foundation, and a counterpart from Fiocruz in structure, human resources and equipment.

"The Health Surveillance Secretariat of the Ministry of Health has been supporting the 'Eliminate Dengue: Brazil Challenge' project so that we can have new technologies and strategies capable of improving the prevention and control of dengue. The first release of mosquitoes with Wolbachia is another important step that the project takes and we will closely monitor all results", highlights the Secretary of Health Surveillance at the Ministry of Health, Jarbas Barbosa.

"Brazil's participation shows that national innovation can bring concrete benefits to the control of dengue in Brazil and around the world. Partnerships like this, which bring research closer to SUS priorities, have support from the Ministry of Health", says Carlos Gadelha , Secretary of Science, Technology and Strategic Inputs (SCTIE) of the Ministry.

For the President of theiocruz, Paulo Gadelha, the proposal puts the country on the frontier of knowledge about the disease. The research is relevant for associating technological innovation with a central problem in Brazilian health and the ability to involve the population in the execution of the project, adding three dimensions that are very important in the work of Fiocroz", he opines.

The project in the world

Since 2011, the Eliminate Dengue Program: Our Challenge has been testing the method in different countries, operating in different phases in each of them.

In Australia, mosquitoes that received Wolbachia in the laboratory have been systematically released in some locations in the northeast of the country. In these locations, the presence of mosquitoes with Wolbachia became predominant after ten weeks of mosquito release.

In the following years, new Australian locations began field trials.

In addition to Australia, Vietnam and Indonesia also carry out studies of this type.

The Eliminate Dengue: Our Challenge program is a non-profit initiative with the aim of offering a sustainable and low-cost alternative to health authorities in areas affected by dengue, without any financial burden for the population.

More information on www.fiocruz.br/eliminaradengue.