Dengue outpaces virus-blocking mosquitoes in Brazil
Brazilian scientist Luciano Moreira tenderly handles a glass box of swarming mosquitoes infected with a bacterium that blocks the transmission of dengue.
These mosquitoes have protected millions in Brazil, but the debilitating disease is spreading faster than the insects can be bred and shipped around the immense country.
Climate change "accelerates the spread of the virus. In the south of the country, which used to be much colder, there was no dengue before, but now there is," Moreira, 59, told AFP.
The world's largest breeding factory for the mosquitoes—nicknamed "wolbitos" after the Wolbachia bacterium they were injected with—is located in the southern city of Curitiba.
Employees drip with sweat in the breeding room, set to an ideal temperature for the Aedes aegypti mosquitoes, which are confined in large, brightly lit cages made of translucent fabric.
The "wolbitos" are fed a pungent combination of warm horse blood and sugar water.
The bio-factory, inaugurated in 2025, can produce up to 100 million eggs per week that are stored in capsules and shipped to their final destinations in urban areas where they will hatch.
Over the next months these "wolbitos"—which also have a reproductive advantage over normal mosquitoes—slowly displace those that transmit dengue, as well as Zika and chikungunya, other mosquito-borne viral diseases.
View of Aedes aegypti mosquitoes infected with a bacteria that prevents them from spreading dengue.
Aedes aegypti mosquitoes infected with Wolbachia bacteria are released by a technician from the Federal District's Health Department in a residential area of Brasilia.
The world's largest breeding factory for the mosquitoes -- nicknamed 'wolbitos' after the Wolbachia bacterium they were injected with -- is located in the southern city of Curitiba.
The bio-factory, inaugurated in 2025, can produce up to 100 million eggs per week, which are stored in capsules and shipped to their final destinations in urban areas where they will hatch.
Brazilian researcher Luciano Moreira, from the World Mosquito Program Brazil, was recognized in 2025 by Nature magazine as one of the world's top 10 scientists, and this year was named one of Time magazine's 100 most influential people.