Researchers in Australia have shown that a bacterium can sterilize and eradicate a disease-carrying mosquito that is responsible for spreading dengue, yellow fever and Zika.
three million men aedes egypti, or yellow fever mosquitoes, were tested at three sites in the state of northern Queensland. They were raised at James Cook University in Cairns and sterilized with a naturally occurring bacteria called Wolbachia.
Researchers say the bacteria appear to have changed part of the reproductive biology of male insects, so that female mosquitoes that mate with them lay eggs that do not hatch.
The flying insects were released over a 20-week period in 2018. The mosquito population subsequently declined by more than 80%. When the scientists returned the following year, they found that there were almost no mosquitoes in one of the test areas.
Nigel Beebe is an associate professor at the University of Queensland and a research scientist at the Commonwealth Scientific and Industrial Research Organization, or CSIRO. He hopes that the sterilization method will eventually be used in developing countries.
“We wanted to show in a developed country that the technology was robust, we could repel mosquitoes on a large scale. Raising mosquitoes on a large scale is not very expensive and it is really just separating the males from the females,” he said .
The Australian team plans to use similar technology to suppress the virus-carrying Asian tiger mosquito that has become established in the Torres Strait in northern Australia.
“At the moment we have to use relatively sophisticated technology to do this. But now we’re trying to make something that is much more robust and can be used in tropical countries and really able to differentiate males from females. Would be relatively cheap to have. Large-scale breeding of mosquitoes is actually quite cheap. So, I think, we will absolutely have application in developing countries,” said Saeed Beebe.
Researchers are looking into ways to use sterile male mosquitoes to stop the spread of malaria elsewhere, but associate professor Beebe has said it was a “complicated” challenge.
More than 40% of people worldwide suffer from mosquito-borne diseases. The Australian team hopes that its “eco-friendly mosquito control” approach will help combat current and future outbreaks of dengue and other debilitating diseases.