Fiocruz started an important stage of the project Eliminate Dengue: Brazilian Challenge. The stage of field studies, which was successfully performed in Australia, Vietnam and Indonesia, relies on the release of mosquitoes Aedes aegypti with the bacterium Wolbachia. The project has the support of the Oswaldo Cruz Institute (IOC/Fiocruz), the Research Center René Rachou (Fiocruz Minas) and the Program of Scientific Computing (Procc/Fiocruz).The first site to participate is the neighborhood of Tubiacanga, located at Ilha do Governador, in the city of Rio de Janeiro, which has been studied by the project team since 2012.This is the first time a country in the Americas receives the study.
The announcement was made this Wednesday (24/9) on the campus of Fiocruz in Manguinhos. The following persons were present: the Foundation President Paulo Gadelha; the researcher and project leader 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 project partners also attended the meeting.
The nonprofit initiative integrates the international effort of the Program Eliminate Dengue: Our Challenge (Eliminate Dengue: Our Challenge), which deals with a novel approach to reduce the transmission of dengue virus by the mosquito Aedes aegypti in a natural and self-sustaining way. The project suggests the use of a bacterium found naturally in the environment, called Wolbachia. When present in Aedes, it is able to prevent the transmission of dengue by the mosquito.
Luciano Moreira, Fiocruz researcher and project leader in Brazil, is optimistic about the next steps of the project. "We are facing an innovative and safe scientific strategy, which may contribute to the control of dengue and to improving the health of the population", he says. He was in charge of, with researchers from the Monash University in Australia, the scientific discovery of the ability of Wolbachia to reduce transmission of dengue virus by the mosquito.
"After two years of preparatory studies, it is exciting to see the project advancing to this stage in Brazil, where we rely on the scientific leadership of Fiocruz," added Scott O'Neill, the international program coordinator.
Release of mosquitoes
In Tubiacanga, about ten thousand Aedes aegypti mosquitoes with Wolbachia are released weekly by the researchers. The number of mosquitoes is similar to protocols used successfully in Australia, where this type of study has been completed in over four locations. The releases will happen for about three or four months, according to the assessment of the scientists on the ability of mosquitoes with Wolbachia to settle in place. To reduce the disturbance of the population, before the release of mosquitoes with Wolbachia, researchers, together with the Municipal Health Secretary of Rio de Janeiro, performed a step called elimination of breeding. The goal was to reduce the amount of Aedes aegypti by eliminating vector breeding sites confirmed – so, when releasing Aedes aegypti with Wolbachia in the neighborhood, the total number of mosquitoes will not change. "We seek with this measure lessen the discomfort for the residents of Tubiacanga, who have always supported this scientific initiative," adds Luciano.
Initially, the researchers will evaluate the ability of mosquitoes with Wolbachia to settle in the environment and reproduce with mosquitoes that already exist on site. The project proposes a sustainable, long-term approach, because after Aedes aegypti with Wolbachia is settled in the environment, the bacterium is naturally transmitted to succeeding generations of mosquitoes." Thus, the method becomes self-sustaining: the mosquitoes with Wolbachia predominate without the need to release more mosquitoes with bacteria," explains Luciano. Large-scale studies planned for 2016 in other places in Rio de Janeiro can evaluate the effect of this strategy in reducing the incidence of dengue.
Support of the population
As part of the project, since 2012 Fiocruz works in the districts selected for the study, conducting an intense scientific work to map the mosquitoes of the studied neighborhoods: Tubiacanga, Urca and Vila Valqueire, in Rio de Janeiro, and Jurujuba in Niterói. In this process, regular contact with residents, leaders and associations are made. "The data collected were fundamental to plan field studies," explains Luciano. During the mapping, traps to capture and study the mosquitoes in the area were placed in the home of dozens of residents – called the 'hosts' of the project. "We are extremely grateful to those who receive every week our teams in their homes, contributing to a project that seeks a collective benefit", says Luciano.
"As we approach the beginning of the field studies, the actions of relationship with the residents of Tubiacanga were intensified so that they were fully informed of all activities," he adds. The neighborhood associations, and other local institutions, support the project, which involves regular home visits to introduce the initiative and clarify doubts. Lectures and meetings between residents and researchers are also promoted. The care of the population is conducted by telephone and email.
Safe and natural method
Naturally present in about 60% of the insects in the world (including several species of mosquitoes, like stilt), there is no evidence of any risk of Wolbachia to human health or the environment. These mosquitoes usually bite people without negative effects. As it is an intracellular bacterium that does not infect humans and domestic animals, Wolbachia can only be transmitted from mother to child, in the mosquito breeding process and not during the bite of Aedes in a human being, for example. Besides, for five years, members of the program team Eliminate Dengue, in Australia, fed a colony of mosquitoes with Wolbachia using their own arms voluntarily. This resulted in hundreds of thousands of mosquito bites without reactions to the bacterium.
Official approvals
The field tests in Brazil were approved by the National Sanitary Surveillance Agency (ANVISA), the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA), the Ministry of Agriculture, Livestock and Supply (MAPA) and the National Commission of Ethics in Research (Conep) after a rigorous assessment on safety for health and the environment.
Funders and partners
The project Eliminate Dengue: Brazilian Challenge integrates the nonprofit international effort of the Program Eliminate Dengue: Our Challenge.In Brazil, the project is funded by Fiocruz, Ministry of Health (Department of Health Surveillance (SVS) and Department of Science and Technology of the Secretary of Science, Technology and Strategic Inputs (DECIT/SCTIE)), the Ministry of Science, Technology and Innovation and CNPq. The Municipal Secretary of Health of Niterói and the Municipal Health Secretary of Rio de Janeiro act as local partners in project implementation.
The international funding comes from the Monash University, which obtains funds from the Foundation for the National Institutes of Health (FNIH, United States) through the Vector-based Control of Transmission: Discovery Research (VCTR) of the Grand Challenges in Global Health Initiatives of the Bill & Melinda Gates Foundation. The project also includes direct funding from the Bill & Melinda Gates Foundation and, in return, Fiocruz provides infrastructure, human resources and equipment.
"The Surveillance Department of the Ministry of Health has been supporting the Project Eliminate Dengue: Brazilian Challenge so we can have new technologies and strategies to improve prevention and control of dengue. The first release of mosquitoes with Wolbachia is another important step of the project and we will closely monitor all the results", said the Secretary of Health Surveillance of the Ministry of Health, Jarbas Barbosa. "The participation of Brazil shows that domestic innovation can bring tangible benefits for the control of dengue in Brazil and worldwide. Partnerships such as this, approaching the research of priorities of the NHS, have the support of the Ministry of Health", said Carlos Gadelha, Secretary of Science, Technology and Strategic Inputs (SCTIE) of the Ministry.
To the President of Fiocruz, Paulo Gadelha, the proposal puts the country on the border of knowledge about the disease. "The research is relevant in associating technological innovation with a central problem in the Brazilian health and the ability to involve the population in the project, adding three dimensions that are very important in the work of Fiocruz," said he.
The project in the world
Since 2011, the Program Eliminate Dengue: Our Challenge has been testing the method in different countries, acting in different phases in each one of them. In Australia, mosquitoes into which Wolbachia was inserted in the laboratory have been released in a systematic way, in some locations in the Northeast. At these locations the presence of mosquitoes with Wolbachia became predominant after ten weeks of release of mosquitoes. In the following years, new Australian localities began field testing. Apart from Australia, Vietnam and Indonesia also conduct such studies. The program Eliminate Dengue, Our Challenge is a nonprofit initiative with the goal of providing a sustainable and low-cost alternative solution to health authorities of the areas affected by dengue, without any financial burden to the public.
Source: Cristiane Albuquerque and Vinicius Ferreira - CCS/Fiocruz
