Dogs Are Being Trained to Detect Malaria by Sniffing People's Socks

Dogs can find just about anything with their noses, including bombs, drugs, cadavers, bed bugs, and weirdly, whale poop. Now, man’s best friend is being trained to detect malaria in humans by simply sniffing their socks.

Malaria is a mosquito-borne disease that caused roughly 445,000 deaths worldwide in 2016, according to the World Health Organization (WHO). It’s especially prevalent in Africa, but it's not limited to the continent. As of 2016, nearly half of the world’s population was at risk of contracting the disease.

While malaria is curable, initial symptoms may be mild or difficult to recognize. The disease can progress quickly and result in death if it’s not treated within the first 24 hours. Current diagnostic methods are also time-consuming because they require blood samples to be taken and sent off to a laboratory for testing.

In this way, trained dogs could provide a potentially life-saving service. A group of UK-based researchers say two trained dogs—a Labrador-golden retriever named Lexi and a Labrador named Sally—were able to pick up the scent of malaria on the socks of infected children from The Gambia in West Africa. Although their research is still in the early stages, they believe trained dogs could someday be used to help diagnose malaria more quickly and prevent it from spreading across national borders.

“This could provide a non-invasive way of screening for the disease at ports of entry in a similar way to how sniffer dogs are routinely used to detect fruit and vegetables or drugs at airports,” lead researcher Steve Lindsay, a professor at Durham University's Department of Biosciences, said in a statement.

Their findings are being presented October 29 at the American Society of Tropical Medicine and Hygiene Annual Meeting in New Orleans, Louisiana. For their study, researchers collected 175 sock samples, some of which belonged to 30 children whose blood tested positive for the malaria parasite Plasmodium falciparum. The dogs, which are kept at the Medical Detection Dogs charity in Milton Keynes, UK, were able to accurately categorize 70 percent of the malaria-infected samples and 90 percent of the non-infected samples.

Following the completion of the study, a third dog—a springer spaniel named Freya—also underwent malaria-detection training. Dogs have been trained to sniff out certain kinds of cancer and sugar changes in diabetes patients, but this is the first time they’ve been trained to detect a parasite infection. Researchers say artificial odor sensors could someday be developed, but for now, trained dogs could be a new resource in the global fight against malaria.