Scientists have worked out how much people vary in their attractiveness to mosquitoes carrying malaria — 20 per cent of those at risk receive 80 per cent of infectious bites, they say.
Targeting public health interventions to those most at risk could lead to more effective malaria control, say the researchers.
They warn, however, that more research is needed to identify what makes some people more attractive to mosquitoes than others.
The study published in tomorrow's (24 November) Nature used data from about 5,000 children in 90 communities across Africa. It looked at how many bites the children got and the proportion that developed malaria, a disease that claims more than a million lives every year.
Some people get more bites than others because, chemically, they are more attractive to mosquitoes, says lead author David Smith of the US National Institutes of Health. Other factors such as living near mosquito habitats, being pregnant and living in poor-quality housing also raise the risk of being bitten, he says.
Bart Knols, a mosquito researcher at the Austria-based International Atomic Energy Agency, says the study provides "a clear mathematical explanation for phenomena observed before but never reported in such detail".
Knols adds that a lot of time, energy and money could be saved by "finding people who are most 'dangerous' in terms of disease transmission, and selectively treating them, or protecting them from mosquito bites."
Smith's team suggests that such a targeted approach could be more effective than using broader malaria control measures.
But as Smith points out, more research is needed to identify those most at risk. "There are not very many good methods available at the present time," he told SciDev.Net.
Link to full article in Nature
Reference: Nature 438, 492 (2005)