Employees work in a laboratory of the British biotechnology company Oxitec, in Campinas, Brazil, on October 1. The British biotechnology venture that applies genetic modification to produce Aedes aegypti mosquitoes, whose female offspring are infertile, effectively reducing mosquito populations. Photo by Isaac Fontana/EPA
The world’s largest factory that produces mosquitoes that can prevent dengue, Zika and chikungunya viruses from reproducing has opened in Curitiba, Brazil, aiming to boost protection in 40 municipalities with high infection rates.
The mosquitos, which are infused with the Wolbachia bacterium, prevents viruses carried by the Aedes aegypti mosquito from reproducing, sharply reducing the insect’s ability to transmit diseases.
The factory, built by the Oswaldo Cruz Foundation in partnership with the World Mosquito Program and supported by Brazil’s Health Ministry, can produce 100 million eggs per week.
The new complex, covering 37,674 square feet, represents an investment of more than $15 million and is expected to benefit about 140 million people.
“Brazil is now leading this technology worldwide. No other country has such a large public production capacity for mosquitoes with Wolbachia,” Health Minister Alexandre Padilha said during the opening ceremony.
The infected mosquitoes are released in urban areas, where they breed with wild populations and pass the bacterium to new generations. Over time, local mosquito populations become naturally “vaccinated,” reducing the circulation of arboviruses such as dengue, Zika and chikungunya.
The Wolbachia method was first tested in Brazil more than a decade ago with support from World Mosquito Program and Fiocruz. Early releases showed an average reduction of up to 69% in dengue cases, according to data from pilot projects in Niterói and Rio de Janeiro.
Fiocruz researchers said adult female mosquitoes are fed with artificial blood meals five to six days after emerging, using human blood supplied by the Australian Red Cross or human volunteers, to sustain egg production and survival.
Studies by the World Mosquito Program indicate that egg survival can remain around 50% after overwintering, although high temperatures and low humidity can significantly reduce hatch rates.
“The results are clear: fewer illnesses, fewer hospitalizations and significant savings for the public health system. For every 19 cents invested in Wolbachia, the country saves about $90 in treatments and medication,” Fiocruz said in a statement.
Since the method was introduced in 2014, Brazil has become a global leader in using of Wolbachia to control mosquito-borne diseases. The country is now part of a network of 14 nations applying the technology, including Mexico, Colombia, Indonesia and Australia.
The World Health Organization recognizes Wolbachia as an effective, safe and low-cost tool that complements vaccination and fumigation campaigns.
The Health Ministry said it plans to expand the network of biofactories to reach new regions, including the Northeast and the Amazon, where high temperatures and rainfall favor mosquito breeding.
It is also advancing the domestic production of a dengue vaccine, developed by the Butantan Institute, which aims to manufacture 60 million doses per year starting in 2026.
The Fiocruz-World Mosquito Program biofactory in Curitiba is a public, government-backed project that uses a natural biological method developed in Australia and adapted by Brazilian scientists to introduce the Wolbachia bacterium into mosquito populations.
In contrast, the new Oxitec facility in Campinas, São Paulo, is a private British biotechnology venture that applies genetic modification to produce Aedes aegypti mosquitoes, whose female offspring are infertile, effectively reducing mosquito populations.
The company also breeds mosquitoes carrying the Wolbachia bacterium as part of its combined control strategy. The projects operate independently and are seen as complementary approaches within Brazil’s national strategy to control dengue and other mosquito-borne diseases.
“This is a public health policy grounded in Brazilian science, with a direct impact on the lives of millions of people,” Padilha said.
