Mosquito parasite may help fight dengue fever
Dengue fever is a terrible viral disease blighting many of the world's tropical regions. Carried by mosquitoes, such as Aedes aegypti, 40% of the world's population is believed to be at risk from the infection. What is more, previous exposure to other strains of the fever does not confer protection. In fact, subsequent infections are significantly worse, and can result in fatal dengue haemorrhagic fever. The lack of a functioning vaccine forced Scott O'Neill and Elizabeth McGraw to look for a more creative form of defence. Knowing that a parasite, Wolbachia pipientis, shortens the lifespan of host insects and could restrict dengue fever transmission by killing the insects before they can pass the infection on, O'Neill and his team successfully infected Ae. aegypti with a strain of the Wolbachia bacterium and shortened the mosquitoes' lifespan. But before insects carrying the bacterium can be released into the environment, the O'Neill and McGraw teams have to convince international governments that mosquitoes carrying the Wolbachia parasite could successfully limit transmission of the virus. McGraw and O'Neill had to find out how the bacterium affects the mosquito's physiology and behaviour and publish their results in the Journal of Experimental Biology on May 1 2009 at http://jeb.biologists.org.