In a first, Australian researchers have successfully protected an entire city from dengue outbreaks by deploying captive-bred mosquitoes that are unable to spread the deadly virus.
Mosquitoes bred to carry naturally-occurring Wolbachia bacteria, which prevents the transmission of viruses, were let loose over 66 square kilometres of Townsville, Queensland in places where they could naturally breed.
In four years since the mosquitoes were introduced, no new cases of dengue have been reported in the area. “We’re wanting to have a really major impact on disease. For dengue and Zika nothing’s working at the moment for control. There’s evidence of a growing disease burden and there was the big Zika pandemic that stripped through the Americas recently and the rest of the world,” said Scott O’Neill, director of the World Mosquito Program at Monash University in Australia.
“I think we’ve got something here that’s going to have a significant impact and I think this study is the first indication that it’s looking very promising,” O’Neill told ‘The Guardian’.
Researchers are now conducting a randomised controlled trial in Indonesia. In Brazil, mosquitoes have been introduced in Rio de Janeiro, with the hopes of countering Zika virus outbreaks. The land area covered in Rio is twice that of Townsville and the population six times as great, with more than 1.5 million people.
“Rio is one of the hardest places to work in. If we can be successful in Rio we can probably be successful anywhere in the world,” O’Neill said.
In the long run, if Wolbachia does prove safe and effective, scientists may attempt its use against malaria.