NAIROBI, Kenya — What do mosquitoes like more than clean, human skin? Stinky socks. Scientists think the musky odor of human feet can be used to attract and kill mosquitoes that carry deadly malaria. The Gates Foundation announced Wednesday that it will help fund one such pungent project in Tanzania.
If they can be cheaply mass-produced, the traps could provide the first practical way of controlling malaria infections outside. The increased use of bed nets and indoor spraying has already helped bring down transmissions inside homes.
Dutch scientist Dr. Bart Knols first discovered mosquitoes were attracted to foot odor by standing in a dark room naked and examining where he was bitten, said Dr. Fredros Okumu, head of the research project at Tanzania’s Ifakara Health Institute. But over the following 15 years, researchers struggled to put the knowledge to use.
Then Okumu discovered that the stinky-feet smell — which he replicates using a careful blend of eight chemicals — attracts mosquitoes to a trap where they can be poisoned. The odor of human feet attracted four times as many mosquitoes as a human volunteer, and the poison can kill up to 95 percent of mosquitoes.
Although the global infection rate of malaria is going down, there are still more than 220 million new cases of malaria each year. The U.N. estimates almost 800,000 of those people die. Most of them are children in Africa.
“This is the first time that we are focusing on controlling mosquitoes outside of homes,” said Okumu, a Kenyan who has been ill with the disease several times.
Some experts worry eradication is unrealistic because of the lack of an effective malaria vaccine and because some patients have developed resistance to the most-effective medicines.
Other scientists are also researching equally novel ideas, including breeding genetically modified mosquitoes to wipe out malaria-spreading insects and creating a fungus that would kill the parasite.
