Malaria manipulates infected mosquitoes, making them more attracted to human skin odours, new research has revealed.
Writing in PLoS One, London School of Hygiene and Tropical Medicine scientist James Logan and his colleagues presented groups of Anopheles mosquitoes, which transmit malaria, with nylon membranes mimicking human skin.
Half the membranes were also impregnated with human skin odourants, the other half were left clean.
Predictably, the mosquitoes were drawn significantly more frequently to the odour-impregnated membranes. That much was known and expected.
But when mosquitoes infected with the falciparum strain of malaria were tested in the same way, the rate at which they landed on and probed the human-odour-laced membranes was over four-fold higher than the control, uninfected insects.
This shows that the parasite is, in some way, manipulating the behaviour of the insect to intensify its attraction to human odourants.
The team speculate that the effect is likely to be mediated at the level of the insect's olfactory (smell) system, perhaps through increasing the levels of receptor molecules that pick up human scents on the mosquito antennae.
Understanding how this is achieved, they argue, might lead to important new avenues of research that can help to reduce the global burden of falciparum malaria, which causes hundreds of millions of infections each year and kills over three quarters of a million people.