Trouble comes in threes. Brazil struggles with deadly dengue fever.
In order to do it they released millions of genetically modified mosquitoes.
Laboratory insects themselves are not able to reproduce.
But if it finds a wild one, they can create healthy offspring.
And it can not transmit the disease to people. This technique is relatively new, and it has already shown successful results.
The scientists hope this easy way will be effective and help thousands of Brazilians.
"In two years we will have tangible results, the number of dengue cases will be reduced. In general, the study is planned to be carried out for ten years, when it will be possible to trace the spread of the virus among humans and insects", said Luciano Moreira, the researcher of the Health Care Fund.