MercoPress. South Atlantic News Agency

Brazil: Mosquito factory hopes to solve dengue crisis

Oxitec's two methods cannot be used simultaneously

A mosquito manufacturing factory in Campinas, in the Brazilian State of São Paulo, is relying on two new complementary technologies to reduce dengue transmission by tackling the Aedes aegypti populations.

The new facility, opened last Thursday, will have the capacity to supply up to 190 million Wolbachia-infected mosquito eggs per week, enough to protect up to 100 million people annually, it was explained. The plant is also manufacturing products from the Aedes do Bem line, capable of reducing Aedes aegypti mosquito populations in urban communities by 95%.

The Oxitec Brazil factory begins operations as a direct response to the World Health Organization (WHO) call to accelerate access to innovative vector control technologies, and marks a crucial moment in the fight against dengue fever not only in Brazil, but around the world.

With dengue cases reaching record levels in Latin America and the Asia Pacific region, the facility was built to meet the growing demand from governments and communities seeking rapid, scalable, and cost-effective protection.

Pending approval from Brazil's health watchdog Anvisa, the facility is ready to begin supplying Wolbachia-carrying mosquitoes to the government, just in time for the start of the mosquito season, without any government funding for construction or management.

Both biological control technologies work by releasing mosquitoes in urban areas. The Wolbachia method is designed for large public health campaigns in extensive areas, through government-led programs, while Aedes do Bem is designed for targeted mosquito suppression interventions that can be implemented by anyone at critical points where reducing biting mosquitoes is a priority.

Wolbachia technology has been proven to reduce dengue transmission by more than 75% in large-scale urban pilot projects. It has been formally recognized by the WHO and adopted by the Brazilian Health Ministry as part of its National Dengue Control Program (PNCD).

“Wolbachia is a bacterium that is naturally present in more than 60% of insects, but not in Aedes aegypti. Australian researchers had the idea of transferring this bacterium to Aedes aegypti to see if it could reduce its viral load. The bacterium reproduces where the virus would reproduce, preventing the virus from replicating. It works more or less like a vaccine. When a female with Wolbachia mates with a male in the environment, all the offspring of that cross will have the Wolbachia bacterium and will not be able to transmit dengue, Zika, or chikungunya,” explained Natalia Verza Ferreira, executive director of Oxitec Brazil.

The difference between Wolbachia and Aedes do Bem is that, in the latter case, male mosquitoes are released into the environment, where they mate with the females that are already there and are responsible for biting and transmitting the disease.

“The offspring of this 'couple' will only be males, and all females will die. It is like a specific female larvicide, because the females die in the larval stage. Aedes do Bem controls the population, reduces the number of females that bite, and consequently reduces the disease,” Verza Ferreira pointed out.

However, the two technologies cannot be used at the same time, because if both are released at the same time, the male Aedes do Bem will mate with the female with Wolbachia, there will be no females, and Wolbachia will not be transferred to the offspring.

“The recommendation of experts is to first suppress the population with the Good Aedes and then immediately use Wolbachia to vaccinate the remaining mosquitoes so that they cannot transmit diseases,” the expert added.

The application protocol consists of using Aedes do Bem during a season, which in Brazil runs from October, when it starts to get hotter and rainier, until May, when it starts to get cold. Two months after the end of this season, it is already recommended to start using Wolbachia.

“The release of Wolbachia takes place between nine and 15 weeks. This period will depend on how efficient the crossbreeding is in passing the bacteria on to offspring. This can happen faster when it is hot and can happen more slowly because when it is not very hot, the mosquito's life cycle is extended,” recommends Verza.

She also noted that both technologies have been made available to the Ministry of Health as public prevention policies.

“Brazil has suffered devastating dengue outbreaks in recent years. The urgency for action has never been greater. With Oxitec's new complex in Campinas, we are equipped to respond immediately to the Ministry of Health's plans to expand Wolbachia, ensuring that the technology can quickly reach communities across the country in a cost-effective manner,” she said.

Anvisa's Fabiano Pimenta said the agency was “very interested in finding a solution so that it can be made available.” (Source: Agencia Brasil)