Bacteria, Man’s New Ally Against Mosquito

January 2nd, 2009

The research, described in Friday’s issue of Science, illustrates a new strategy of biological warfare against this species of mosquitoes that transmits viruses that cause dengue fever and chikungunya, among other infections.

…….Biological War->

The scientists at the University of Queensland, Brisbane, have shown that mosquitoes infected with Wolbachia live an average of only 27 days in contrast to the average longevity of 61 days for those not infected with the bacteria.

Female mosquitoes infected with the bacteria transmit it to their offspring. “This may allow a small seed population of infected mosquitoes to grow into large numbers over time,” Scott ’Neill, the research team leader, told The Telegraph.

The shortened lives of the infected mosquitoes reduce their opportunity to spread disease-causing viruses. Most viruses transmitted by mosquitoes require about two weeks to incubate inside the insects before they are ready to be spread through bites. Mosquitoes whose life spans have been slashed by half won’t have enough time to spread the infection.

The vertical transmission of Wolbachia from female mosquitoes to offspring will be the key to successful spread of the infected mosquitoes, ’Neill said.

Experiments by ’Neill and his colleagues showed that 99 per cent of larvae from a group of infected females carried the infection.

But the experiments were done in closed environments and scientists are yet to develop an effective mechanism to introduce such infected mosquitoes in the wild.

“Modelling studies suggest that if we can infect about 0.4 per cent of mosquitoes, the infected population will establish itself,” ’Neill said.

Sources: The Telegraph (Kolkata, India)