http://www.sciencedaily.com/releases/2011/08/110824131544.htm

The spread of Dengue fever in northern Australia may be controlled
by a bacterium that infects mosquitoes that harbor the virus, Australian and
U.S. researchers report Aug. 25 in two papers published in the journal
Nature.

The researchers released mosquitoes infected with the bacterial parasite
Wolbachia, which suppresses the virus, and now report that the Wolbachia
parasite spreads rapidly through the wild mosquito population.

"The results show we can completely transform local populations in a few
months," Turelli said.

Wolbachia is transmitted by female mosquitoes to their offspring. A pair of
infected mosquitoes produce slightly fewer eggs than an uninfected couple, but
when an infected male mosquito mates with an uninfected female, she produces no
eggs at all. That provides a big reproductive advantage to the spread of
Wolbachia-infected mosquitoes, generation by generation.

"It's natural selection on steroids," Turelli said.

It turns out that Wolbachia also suppresses various other microbes living in the
same mosquito -- including the dengue virus. As these virus-resistant mosquitoes
spread through the wild population, dengue transmission should dry up.