Scientists in Tanzania are developing a new trap for malaria-spreading mosquitoes, using the smell of human feet as a lure.
They came up with the idea when they realised lots of mosquitoes were particularly drawn to smelly socks. As an experiment they persuaded volunteers to donate their stinky footwear and then placed them in canvas and wooden boxes hung with insecticide-laced drapes outside peoples homes in Tanzania.
As mosquitoes work through smell rather than sight, they can't tell the difference between the trap and real humans before it is too late. It seems the traps attracted up to four times as many mosquitoes as humans themselves and 74-95% of those mosquitoes that landed were killed.
Malaria is one of the biggest killers in the developing world. Each year, there are almost 250 million new cases of malaria and almost 800,000 people – mostly children under five and pregnant women – die, according to the World Health Organisation. A reduction in the number of mosquitoes would drastically reduce the transmission rate.
Dr Fredros Okumu is leading the two-year project funded by the Bill and Melinda Gates Foundation and Grand Challenges Canada at the Ifakara Health Institute in Tanzania. "In their attempts to get blood from these devices, between 74 to 95 per cent of all of those who landed in them got killed," he said. "We're hoping this will be a worthwhile and significant addition to the malaria control arsenal."
“It’s a bold idea. Who would have thought there was a life-saving technology working in your laundry basket?” said Peter A. Singer, a physician who heads Grand Challenges Canada.
The scientists will now have to establish whether it is the socks themselves that work, or whether a synthetic version of their smell would be enough. Whatever they end up making they hope to simplify it enough to be made and sold by the villagers themselves. It doesn't seem that they are suggesting people actually use their own smelly socks!