MOSQUITOES infected with bacteria that stop them transmitting the dengue virus will be released into the wild next year.

Some 100 million people in the tropics get dengue fever each year, and 40,000 are killed by it. The virus’s range is expanding, and last week France reported its first locally acquired cases.

Scott O’Neill of the University of Queensland in Brisbane, Australia, and colleagues have found a fruit-fly bacterium called Wolbachia that infects Aedes mosquitoes, and makes them less able to carry the dengue virus. It also halves their lifespan – which is crucial, as only elderly insects …