More than 10,000 mosquitoes infected with bacteria that suppress dengue fever have been released by scientists at the Rio de Janeiro-based Fiocruz research institute to let them multiply and breed in order to reduce cases of the disease.
The mosquitoes released are infused with intercellular bacteria Wolbachia, which is found in 60% of insects, and it cannot be transmitted to humans.
The Brazilian researchers intend to release the same number of mosquitoes each month for four months, with the first release in Tubiacanga, in the north of Rio de Janeiro.
It is expected that the bacteria Wolbachia will be passed through generations of mosquitoes and eventually wipe out the insects’ ability to spread dengue.
The project was started in 2012, and similar action has already been taken place in Australia, Vietnam and Indonesia.
Wolbachia acts like a vaccine for the mosquito which carries dengue Aedes aegypti, and prevents the dengue virus from multiplying in its body by suppressing reproduction.
According to reports, if a contaminated male fertilises the eggs of a female without the bacteria, these eggs do not transformed into larvae, while if the male and female are contaminated or if only a female has the bacteria, all future generations of mosquito will carry the good bacteria.
In 2008, Australia’s University of Monash initiated the research on Wolbachia.
According to some scientists’ estimation, around 390 million people get dengue each year.
During the period 2009-2014, Brazil reported around 3.2 million dengue cases, resulting in about 800 deaths.