– People with parasites from malaria produce specific skin scents. We have found that dogs with a sense of smell can learn to detect these scents. It also applies to clothing used by infected people, says Steven Lindsay at the Department of Biological Sciences at Durham University in the United Kingdom and the lead researcher for a new malaria study.
He recently presented his findings at the annual meeting of the American Society for Tropical Medicine and Hygiene.
He did not have socks
The new study involved hundreds of Gambian schoolchildren. First, they performed a general medical examination, then they were tested for malaria parasites. After that they got some socks that should be used overnight. The next day, the researchers collected stockings and divided them into the state of childhood malaria infection. Only socks for malaria-infected children, without symptoms and socks of fresh children, were made up. Socks were then sent to England. They were frozen here while the dogs were training.
The sniffing test was designed to distinguish between legs for saturated and healthy children with malaria. On each pair of socks you should rest and freeze if they think they have found moles from malaria. If they do not smell something that we should pursue.
The result of the test showed that dogs were able to identify 70 percent of socks of malaria-infected children and 90 percent of healthy ones.
The parasite of malaria mutates
Researchers say that the accuracy of the effect is impressive and that dogs can recognize socks for children with a lower infection rate than required by the World Health Organization (WHO) fast tests.
In general, malaria diagnosis is performed using blood samples and microscopy. This can be lengthy and special skills are needed. You can also use fast blood tests, but these are pretty expensive. They have a high degree of precision.
The researchers were aware that this was so called proof of the conceptstudy to prove that a dog can diagnose malaria. They further believe that the accuracy of trackers can be as good as blood tests. Lindsey justifies this because malaria parasites in children are not always the same species as they go through the various stages of the disease. The smell created in the human skin then changes.
He points out that the tests used today are short because they mutate parasites of malaria. Therefore, parasites may not have specific proteins that are needed for clinical tests that indicate an infection
In addition, researchers believe that the ability of sniffing dogs to detect certain malaria-related odors can inspire the development of emerging and artificial electronic noses that can cure diseases.
Dogs to protect malaria at the borders
Lindsey believes that sniffing dogs can be helpful if health authorities want to check villages for malaria carriers that have no visible symptoms. By using a carrier, you can transfer malaria parasites to local mosquitoes. The only way to prevent spread today is to test or cure everyone in the village.
Researchers believe that sniffing dogs should work well at border crossings, to countries where malaria is almost eliminated. Lindsey draws on the eastern coast of Zanzibar, where the elimination of malaria parasite was difficult due to permanent immigration.
Gunnar Hasle is a specialist for infectious diseases and is operated by Reiseklinikken in Oslo. He says that the speed of the previous hit is 70 percent too low.
"This means that the method is useless if we determine whether a person with fever has a malaria, because it is not acceptable that the errors are completed at 30 percent.
It also highlights 90% of those who are healthy and 10% get the wrong message of malaria.
"This is an unacceptably high figure if the method should be used to smell a large number of healthy people," he says.
Blood test at the clinic, dogs at the borders
Hasle also states that the indications for smell have been for several hundred years. Among other things, it is possible to succeed in diabetes, breathing acetone scent or nail polish remover. In addition, the liver smell may be because the spirit has a sweet odor.
"They also tried to diagnose lung cancer," said Hasle, referring to a study in 2012. The result was about the same as in malaria attempts.
He thought that it was completely impossible to use dogs to diagnose the clinic and that it would still be difficult to train enough dogs to meet the needs
– Each tropical health unit must have access to the diagnosis of malaria. Then it's a lot easier to get quick tests that you can use after a minimum training session than just to learn the dogs.
Nevertheless, they believe that they can help in some cases and support the idea of researchers using fragrances as malaria guards.
"Soul dogs can be used to mass migrate immigration into an area that has eradicated malaria," he concluded.