How a dog could stop the global spread of the disease

Several years ago, British entomologist Steve Lindsay landed in an American airport and was immediately struck by all the furry creatures strolling through the baggage claim area.

"I've been stunned to see sniffer dogs looking for fruits and vegetables," said Lindsay, who studies malaria at the University of Durham, UK.

Recent studies have shown that malaria carriers have a characteristic scent. "Then I thought," Well, if a dog can smell the fruits and vegetables in his luggage, can he smell malaria in a person? " "Said Lindsay.

So he decided to create the best guard dogs for diseases – canines that can smell living parasites inside people.

Then, as people jump on international flights, these guard dogs could take a few sniffs on each person's skin and give a paw to those who might be carrying a parasite. "The person can be taken apart and possibly tested for the disease with a blood test," says Lindsay.

This seems exaggerated? Well, that may not be as far from reality as you think.

At a scientific conference held on Monday, Lindsay presented preliminary evidence that dogs can detect whether a person carries the malaria parasite in their blood simply by breathing their odor, or more specifically by breathing a small piece of their sock. The researchers trained the dogs by rewarding them with a snack when they correctly identified and sat next to a sock infected with malaria.

Lindsay and her colleagues trained two dogs – Sally the Labrador Retriever and Lexi, a mix of Golden Retriever and Labrador. Although the study is small, the results have been encouraging. Overall, Sally and Lexi had a success rate of about 70% in choosing socks worn by people with malaria; each dog correctly identified at least 21 of the 30 samples.

Dogs did better with socks worn by uninfected people. Each dog correctly identified at least 131 of the 145 negative samples, a success rate of about 90%.

Obviously, more important studies are needed, says Lindsay. But the performance of dogs is not too poor when we look at the performance of some commercial tests. For example, one study found that rapid diagnostic tests correctly detected malaria in 60-90% of cases, depending on conditions. And the tests correctly identified the negative samples about 90% of the time – which is similar to the performance of the dogs.

And Sally and Lexi have a way to go, says Lindsay. "We made things difficult for dogs," he says. "We did not have a lot of samples to train them – only 30 socks worn by people with malaria."

Lindsay hopes that trained dogs could someday work at entry points to help countries prevent malaria from entering, especially in places that are trying to eliminate the parasite or who have just come off. To get rid of it.

"At the moment, malaria detection relies on taking blood from a person with a pin prick, but you can not do that for anyone crossing a border," Lindsay said. "Dogs with malaria would be a non-invasive method of picking up the parasite."

But there is still a lot of work to do before you find Sally and Lexi sniffing your legs in the customs and baggage claim areas. For starters, researchers do not know if dogs can actually pick up the odor on a person's skin in addition to their socks – and they're able to tell the difference between a malaria infection and an infection caused by another pathogen.

Finally, Lindsay and her team did not check whether or not dogs could detect different species or strains of malaria found in various parts of the world.

However, if you think about it, dogs do something remarkable, says Lindsay: they detect the presence of a microscopic organism living in the blood – or the liver – of a person by simply taking a whiff of # 39; oxygen.

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