Bacteria-infected mosquitoes for dengue

Washington: They still bite, but new research shows lab-grown mosquitoes are fighting dangerous dengue fever that they normally would spread. Dengue infections appear to be dropping fast in communities in Indonesia, Vietnam, Brazil and Australia that are buzzing with the specially bred mosquitoes, a resea-rch team reported.

It’s the first evidence from large-scale field trials that mosquitoes are less likely to spread dengue and similar viruses when they also carry a type of bacteria that’s common in insects and harmless to people.

Rather than using pesticides to wipe out bugs, “this is really about transforming the mosquito,” said Cameron Simmons of the nonprofit World Mosquito Programme that is conducting the research.

The first hint of success came from Australia. Mosquitoes bred to carry Wolbachia bacteria were released in parts of North Queensland starting in 2011, and gradually spread through the local mosquito population. Dengue is transmitted when a mosquito bites someone who is infected, and then bites another person, but somehow Wolbachia blocks that — and local transmission has nearly disappeared in those North Queensland communities.