How To Dog Could Stop The Global Spread Of Disease

Several years ago, British entomologist Steve Lindsay landed at an American airport and was immediately struck by the furry creatures walking around the baggage claim area.

"Lindsay, who studies malaria at Durham University in the U.K., said," I was astounded to see sniffer dogs, looking for fruits and vegetables.

Recent studies have found that people carrying malaria has a signature scent. "So I thought, 'Well, if a dog could smell fruits and vegetables in luggage, could they smell malaria in a person?' "Lindsay says.

So he set out to create the ultimate disease watchdogs – canines that can smell parasites living inside people.

Then, as people go off international flights, these watchdogs could take a few sniffs at each person's skin and paw at the people who might be carrying a parasite. "The person can be tested and tested for the disease with a blood test," Lindsay explains.

Sound far-fetched? Well, it might not be as far from reality as you would think.

At a scientific conference on Monday, Lindsay presented a preliminary report that states that they can detect a parasite in their blood by sniffing their odor – or more specifically, sniffing a small piece of their sock. The researchers trained the dogs by rewarding them with a snack when they were correctly identified and sat next to a malaria-tainted sock.

Lindsay and his colleagues trained two dogs – Sally the Labrador retriever and Lexi, a golden retriever-Labrador mix. Although the study was small, the results were encouraging. Overall, Sally and Lexi had a success rate of about 70 percent for picking the socks worn by people with malaria; each dog is at least 21 of the 30 samples.

The dogs did better with the socks worn by the people not infected. Each dog is at least 131 of the 145 negative samples, for a success rate of about 90 percent.

Clearly, larger studies are needed, Lindsay says. But the dogs' performance is not enough when you look at how well some commercial tests perform. For example, 60 percent of 90 percent of the time, depending on the particular conditions. 90 percent of the time – which is similar to the dogs' performance.

And Sally and Lexi have room to improve, Lindsay says. "We made it hard for the dogs," he says. "We did not have many samples to train with – just 30 socks worn by people with malaria."

Lindsay hopes that it will be able to work with malaria, especially in places that are trying to eliminate the parasite or have just gotten rid of it.

"At the moment, malaria detection is taking place with a pin-prick, but you can not do that to everyone coming across a border," Lindsay says. "The malarial dogs would be a non-invasive method of picking up the parasite."

But there's still a bit of a work to do before you'll find Sally and Lexi sniffing your legs at customs areas and baggage claims. For starters, the researchers may not know whether or not they can actually differentiate between infections and other pathogens.

Finally, Lindsay and his team have not tested whether or not they can detect different species or strains of malaria in various parts of the world.

Still though, if you think about it, the dogs are doing something remarkable, Lindsay says: They're detecting the presence of a microscopic organism living inside a person's blood – or by simply taking a sniff of a sock.

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