WMP's Wolbachia method limits transmission of yellow fever

A new study confirms the World Mosquito Program’s (WMP) Wolbachia method limits transmission of the yellow fever virus in Aedes aegypti mosquitoes, reducing the threat of urban outbreaks of the disease. Following this research, the WMP’s method has now been demonstrated to be effective against four mosquito-borne diseases including dengue, Zika, chikungunya and yellow fever.

Published on Gates Open Research, the study investigating the effect of naturally occurring Wolbachia bacteria on the yellow fever virus is a joint initiative between René Rachou /Fiocruz Institute (Fiocruz Minas), the Ezequiel Dias Foundation (FUNED) and the Federal University of Minas Gerais (UFMG), in Brazil.

While the urban transmission of yellow fever by Aedes aegypti has not been reported in Brazil since 1942, the risk of re-urbanisation of the disease remains, as these mosquitoes are found in most tropical and subtropical cities in the world and have been the main carrier in the past.

Brazil faced major outbreaks of the disease across a number of states from 2016 to 2018, transmitted by wild mosquitoes of the genera Haemagogus and Sabethes. It resulted in more than 1,200 yellow fever cases and 328 deaths in the nine months from July 2017 to April 2018, according to the Ministry of Health.

"The results indicate that if yellow fever is transmitted by the Aedes aegypti, the Wolbachia method can be a complementary strategy to prevent transmission of the virus, along with the vaccination program,”  says Dr Luciano Moreira, lead researcher and head of the WMP project in Brazil.

The World Health Organization lists 13 countries in the Americas to be at highest risk for yellow fever, including Brazil and Colombia, where the WMP works. The yellow fever vaccine remains the most important means to combat the virus, with a single dose providing life-long immunity.

WMP Director Professor Scott O’Neill says the findings mark an important step in improving global health.

“It further demonstrates the potential impact of the WMP’s Wolbachia method as a long-lasting global health intervention to reduce the burden of mosquito-borne diseases such as dengue, Zika, chikungunya and yellow fever.”

Read the research paper, ‘Pluripotency of Wolbachia against Arbovirus: the case of yellow fever' to learn more.