Can a dog smell disease?

Malaria: Dogs can sniff out the disease

Nothing escapes this nose: dogs have up to 300 million olfactory cells - around 60 times more than humans. Scientists have now found out that the four-legged friends can sniff out malaria in addition to other diseases and that this can already be done on a worn item of clothing

Dogs are already being used in various areas to search for special objects with their noses - for example drugs or tobacco. But even if diseases such as diabetes or cancer are detected, the animals can help with their fine sensory organs.

Now British scientists at the University of Durham have found out in a study that appropriately trained dogs are also able to recognize the smell of malaria. If left untreated, the disease can lead to death - the infectious disease is particularly widespread in Africa, Asia and Latin America.

The research team led by Professor Steve Lindsay presented the results of its investigations at the annual congress of the American Society of Tropical Medicine and Hygiene.

Socks served as a training object

In their experiment, the researchers successfully trained the dogs to sniff out malaria in humans. Worn socks served as test objects. The four-legged friends were able to tell whether a person was infected just by the smell of the garment they were wearing - even before they even developed symptoms of a malaria infection.

For their experiment, the researchers used the socks worn by five to fourteen year old children from Gambia. The scientists put a sock behind several test plates - sometimes from healthy, sometimes from infected malaria patients.

When trained accordingly, the dogs sit in front of the socks of the sick. Hit rate: 70 percent. When determining uninfected children, the rate was 90 percent.

Professor Steven Lindsay, lead researcher on the study, suspects that the dogs' success rate might actually have been even higher if all children had been affected by the same type of malaria.

As the malaria infection progresses, the parasite goes through several stages of development. And Lindsay's speculations suggest that the smell the parasite creates on human skin changes when it reaches a certain stage of maturity.

Professor James Logan, Head of Disease Control at the London School of Hygiene & Tropical Medicine, said: "Our results show that the use of sniffer dogs could become a quick and easy way to diagnose malaria in people who don't have symptoms show, but are still highly contagious. "

Perhaps the fine dog noses could be used at border crossings and airports in the future to find infected travelers before they introduce the pathogen into a country. To do this, however, the sniffer dogs would also have to be trained to recognize malaria-infected people not only by the smell of their socks, but also directly by their body odor.

Video: Sally malaria tracking dog during training

Further research is planned

Next, the scientists are planning a follow-up study to work with clothing samples from people from different parts of Africa. The researchers want to test whether parasites from other parts of the continent have differentiated smells.

Lindsay and his team hope that this will provide information about the framework in which the animal diagnosticians can be used sensibly and how the hit rate can be increased.

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