Cambridge restates role of mosquitoes with Wolbachia against diseases
A study published in The Lancet – Infectious Diseases by researchers at Cambridge University confirms that releasing mosquitoes with Wolbachia bacteria reduces the incidence of diseases such as dengue fever and chikungunya.
“Our results provide further evidence that wMel can considerably reduce the public health burden from different arboviruses within the same community. The establishment of wMel in complex urban communities such as Rio de Janeiro is a major challenge, and understanding why the introgression of wMel into A aegypti populations is faster and more homogeneous in some locations than in others will help to underpin its future success,” the article reads. The study links the release of mosquitoes with a 38 percent shrinkage in the incidence of dengue fever and a ten percent in chikungunya.
The research was conducted in partnership with the World Mosquito Program (WMP/Brazil), an initiative developed in Brazil by research foundation Fiocruz. Between August 29, 2017 and December 27, 2019, 67 million mosquitoes were released in five areas in northern Rio, including the districts of Ilha do Governador, Ilha do Fundão, Complexo da Maré, Ramos, Penha, and Vigário Geral.
Released mosquitoes
According to Fiocruz, the efforts under the Wolbachia mosquito release program in Rio de Janeiro were expanded in August 2017 as a result of the Zika epidemic. The releases covered a total 86.8 km², home to some 890 thousand people.
By December 2019, 29 months after the releases began, Wolbachia showed prevalence between 27 and 60 percent in the mosquito population surveyed. A protective effect for the people was observed even in areas where Wolbachia prevalence was lower (10%). In locations where wMel prevalence was higher than 60 percent, protection reached 76 percent, which is comparable to previously published results (using different methods) on the neighboring municipality of Niterói and Indonesia.
In 2021, the foundation added, data attesting to the protection provided by Wolbachia were released by the WMP/Brazil, showing a reduction of about 70 percent in dengue cases, 60 percent in chikungunya cases, and 40 percent of Zika cases in the areas where the intervention took place.
