Your feet: malaria magnets

It’s hard to argue the benefits of smelly feet — especially in a closed space. But, as it turns out, the noxious odour that bacteria and damp lend to feet might be a new weapon to fight malaria.

We’ve long known that parasites manipulate the behaviour of their hosts to help propagate their kind, but not much is known about how the malaria parasite, Plasmodium falciparum affects mosquitoes infected with it.

Research recently published by Renate C. Smallegange with James Logan in the journal PLoS One tested whether there was a change in olfactory attraction for mosquitoes with the malaria pathogen and without. Both infected and uninfected mosquitoes preferred human skin over a neutral landing area, but the study conclusively showed that pathogen-bearing mosquitoes quite eagerly sought out socks that emitted the odour of human feet, while mosquitoes that weren’t infected weren’t attracted to the smell.

Malaria spreads only through the female mosquito — male mosquitoes don’t bite humans or animals, they feed only on plant nectar and are key in the pollination process. By isolating this factor in what attracts to malaria vectors, scientists could now work on preventing the disease, which causes 770 thousand deaths each year. In 2012, the World Health Organisation said India had 24 million reported cases of malaria.

The study highlights a new path for investigation in preventing malaria – scientists and pharmacies could now test why these mosquitoes exhibit differential behavioural responses. Either way, they could isolate the chemicals in human foot odour to develop new attractive compounds that specifically trap or even neutralise the female mosquitoes that carry malaria. The advantage of targeted traps is that fewer mosquitoes would develop resistance to them.

This piece originally appeared in Popular Science India. Reprinted with permission. Chhavi Sachdev (@chhavi) reserves the right to be identified as its author.