The Aedes aegypti mosquito transmits dengue between people
Wolbachia was transferred from the fruit fly to Aedes aegypti mosquitoes by microinjection
When Wolbachia is present in Aedes aegypti it stops dengue viruses from growing
Potential release sites are chosen after mosquito population studies and community engagement
Wolbachia mosquitoes are reared under laboratory conditions ready for release into field trial sites
Wolbachia mosquitoes are released with community support and government approval
We are now developing the method for low-cost, large-scale application across urban areas
Our approach uses natural bacteria called Wolbachia. Wolbachia occur naturally in up to 60% of all insect species, but not the Aedes aegypti mosquito.
We have successfully transferred Wolbachia from other insects into Aedes aegypti mosquitoes and have shown that when Wolbachia is present in the mosquito it reduces the mosquito’s ability to transmit dengue.
Our hope is to seed wild mosquito populations with Wolbachia in areas where dengue is endemic. We do this through controlled releases of Wolbachia mosquitoes that then breed with the wild mosquitoes. Our prediction is that if Wolbachia can establish in the wild mosquito population in a local area then there would be reduced transmission of dengue between people.
We have been conducting trials of our approach in dengue-affected communities since 2011, which have shown we can deploy the method and that it sustains itself. Ongoing small-scale trials in Australia, Vietnam, Indonesia, Brazil and Colombia are helping us refine our methods.
We are now developing the method for low-cost, large-scale application across urban areas. Our first city-wide trial began in 2014 in northern Australia and we hope to undertake further large-scale trials in Indonesia, Vietnam and Brazil in 2015-16.
Over the next few years, we also plan to evaluate the impact of our approach by directly measuring the reduction in dengue during large-scale trials. To determine the most suitable locations for measuring impact, we will first spend 1-2 years monitoring potential sites.
As a sustainable, long-term approach, we believe our Wolbachia method has the potential to greatly reduce the global burden of dengue. Our approach is compatible and complementary with existing dengue control strategies, and it will support future methods such as a dengue vaccine once available.
The Wolbachia method also has potential to be used on other insect transmitted diseases. We have demonstrated that Wolbachia reduce mosquitoes’ ability to transmit other human viruses such as chikungunya and yellow fever as well as parasites that cause malaria.