Australian researchers say for the first time an entire city has been protected from viral disease dengue.

Captive-bred mosquitoes with a naturally occurring bacteria were released in the city of Townsville, where they mated with local mosquitoes.

By spreading the bacteria Wolbachia, which hinders dengue transmission, the city has been dengue-free since 2014.

Researchers from Monash University also believe their work could stop mosquito-borne diseases Zika and malaria.

“Nothing we’ve got is slowing these diseases down – they are getting worse,” said Scott O’Neill, director of the World Mosquito Program, quoted by the Guardian.

“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.”

“At a cost of around A$15 (£8.50) per person, the Townsville trial demonstrates the approach can be rolled out quickly, efficiently and cost effectively to help provide communities ongoing protection from mosquito-borne diseases,” Professor O’Neill said.

The programme is currently working in 11 countries and aims to deploy the Wolbachia mosquitoes in larger and poorer parts around the world with a target of reducing the cost to just US$1 (75p) per person.