Shortening Mosquito Lifespan Could Reduce Malaria, Dengue Transmission, Study Says
The bacterium Wolbachia can shorten the lifespan of mosquitoes and thus reduce the likelihood that the insects will transmit diseases such as malaria and dengue, according to a study published Thursday in the journal Science, the AP/Google.com reports. After a mosquito encounters malaria or dengue, the pathogen undergoes a two-week incubation process, after which the mosquito can spread the disease. Therefore, mosquitoes that die earlier are less likely to transmit pathogens. Wolbachia bacteria are common among fruit flies and typically reduce the lifespan of the flies by half (Neergaard, AP/Google.com, 1/2).
For the study, Scott O'Neill of the University of Queensland and colleagues grew Wolbachia bacteria with some mosquito cells to allow the bacteria to adapt to living in mosquito cells. The researchers identified a subgroup of the bacteria that adapts well to mosquito cells and then introduced these bacteria to Aedes aegypti mosquitoes, which spread dengue (Spears, CNS/Windsor Star, 1/2). According to the study's findings, mosquitoes born with Wolbachia lived for 21 days in laboratory conditions, compared to 50 days for normal mosquitoes. Mosquitoes living in labs tend to live longer than mosquitoes in the wild, so the Wolbachia strain could provide "an inexpensive approach" to controlling malaria and dengue, O'Neill said. According to the AP/Google.com, O'Neill and his colleagues next month will begin longer studies in North Queensland mosquito facilities that better mimic natural conditions. The researchers plan to examine whether the bacteria strain persists in a larger mosquito population and determine the impact of exposing the infected mosquitoes to dengue (AP/Google.com, 1/2). Although malaria is spread by a different mosquito species, the same approach could be used to address the disease, according to the researchers. However, research for a new mosquito species could take three to five years, and safety tests and regulatory approval may take longer, Andrew Read of Pennsylvania State University said in an editorial accompanying the study (CNS/Windsor Star, 1/2).
An abstract of the study is available online.
A summary of the accompanying editorial also is available online.
NPR's "Talk of the Nation" on Friday included a discussion about the study. The segment includes comments from Read (Flatow, "Talk of the Nation," NPR, 1/2).
