Smelly socks help fight malaria
The smell of old socks can help fight malaria by attracting mosquitoes to a trap, scientists have discovered.
Traps scented with the odour of human feet attracted four times as many mosquitoes as a human volunteer, said Dr Fredros Okumu, head of a research project at Tanzania's Ifakara Health Institute. Mosquitoes who fly into the trap are then poisoned.
Bed nets and indoor spraying have already substantially reduced the number of fatal malaria cases, but so far scientists have not come up with a good way to help combat mosquitoes outdoors.
Although the global infection rate of malaria is going down, there are still more than 220 million new cases of malaria each year. The UN says almost 800,000 of those people die. Most of them are children in Africa.
"The global goal of eradication of malaria will not be possible without new technologies," said Dr Okumu, who has been ill with the disease himself several times.
Dutch scientist Dr Bart Knols first discovered mosquitoes were attracted to foot odour by standing in a dark room naked and examining where he was bitten, said Dr Okumu. But over the following 15 years, researchers struggled to put the knowledge to use.
He has been working on his project to trap mosquitoes for two years. He mixed eight chemical compounds to find the perfect odour, and then experimented with poisons to find one that could kill up to 95% of mosquitoes.
Now Dr Okumu has been given extra funds by the Bill and Melinda Gates Foundation and Grand Challenges Canada to create an affordable mosquito trap that could be used outside homes.
Dr Okumu said more research was needed to find the right place to put the traps. Too close would attract mosquitoes near the humans and expose them to greater risk of bites, but the devices would be ineffective if too far away.