Monday, October 10, 2005

Great Balls of Fire

Bird flu is a looming danger, but some diseases are not looming but with us in full measure. Consider malaria. Once endemic in the US, it is still a present danger for 40% of the world's population, mostly its poorest, who live at risk for contracting this life-threatening disease. Ninety percent of the close to 1 million annual deaths from this parasitic disease transmitted are in sub Saharan Africa.

The parasite is immensely clever in finding ways to evade our immune systems and our drugs, many of which are now useless because of developing resistance. So in this pitched battle of life and death, public health science is always looking for yet another way to fight.

Releasing sterile male mosquitoes is one technique that can be used to reduce or eliminate the insect vector. Female mosquites mate just once, so if they mate with a sterile male, they produce no offspring. Since the strategy doesn't rely on insecticides, it is both environmentally safer and biologically more sure than trying to kill mosquito larvae or adults of all genera with chemicals. But how do you identify and sterilize males? Sexing mosquitoes has been one of the major obstacles to using this technique. Enter genetic engineering:
Researchers at Imperial College in London genetically modified male mosquitoes to produce a green fluorescent protein in their gonads, making it easier to identify males from females, which transmit the malaria parasite. They found that the modified male mosquitoes can be identified accurately and quickly at the larval stage using high-speed sorting machines.

Once identified among the laboratory-bred mosquitoes, the males can be sterilized and released into the wild. (Bloomberg)
This work is still in development and it may be several years before it's ready for full-scale application. But it's pretty nifty. Unless you're a mosquito.