Mosquitoes Dengue-Free

Injecting a bacteria into mosquitoes can block them from transmitting the dengue virus and help control the spread of a disease that kills 20,000 annually in more than 100 countries, scientists said.

In two papers published in the journal Nature on Thursday, researchers in Australia showed how female mosquitoes infected with the Wolbachia bacteria passed the bug easily to their offspring, making them all dengue-free.

They said such infected mosquitoes should be released into the wild, so that the spread of dengue to people may be reduced.

“The main feature we saw was their ability to reduce dengue transmission,” said Professor Scott O’Neill, lead author and science faculty dean at Monash University. “It almost completely abolished dengue virus in the body of the mosquito.”

In their experiment, O’Neill and colleagues injected the bacteria into more than 2,500 embryos of so-called Aedes aegypti mosquitoes that can spread dengue fever. After they hatched, they were treated to blood meals laced with the dengue virus, and none picked up the virus.