Interestingly, Wolbachia has shown that it reduces the ability of insects to become infected with viruses which would correspondingly reduce transmission of viruses by biting insects to and between people. The bacteria is not usually present in the Aedes aegypti mosquito, the primary species responsible for transmitting viruses such as dengue, chikungunya and Zika, so scientists have been looking for ways to use Wolbachia to control the spread of these diseases.
One approach is to infect male and female Aedes aegypti mosquitoes with Wolbachia and release them into an area where these viruses are present over a number of weeks. These mosquitoes will then breed with the wild mosquito population, passing the bacteria from generation to generation. Over time, the percentage of mosquitoes carrying Wolbachia will reach high enough levels to preclude the need for further releases. This will result in greater protection for communities from mosquito-borne diseases such as dengue and chikungunya without posing a risk to natural ecosystems.
Experiments in northern Australia have shown that after releasing approximately 10 mosquitoes per house per week for 10 weeks, more than 80 percent of the wild mosquitoes in the area had Wolbachia. And they still had it when they tested them two months after they had stopped releasing mosquitoes. Because Wolbachia passes so well through successive generations, repeat releases were not required; Wolbachia should spread on its own.
Currently, however, there is a lack of evidence demonstrating reduction of dengue virus transmission in places where Wolbachia releases were done. The current challenge, therefore, is to convert a promising strategy into a proven public health intervention through rigorous assessment of its epidemiological impact.
Source: World Mosquito Program