– People with malaria parasites produce specific scents in the skin. We found that dogs with a sense of smell can be trained to discover these fragrances. This applies to clothing used by infected people, said Steven Lindsay at the Department of Bioscience at Durham University in the UK and the lead researcher behind the study on malaria.
He recently presented his findings at the annual meeting of the American Society for Tropical Medicine and Hygiene.
Not stamped on stockings
Several hundred Gambian pupils participated in the new research. They first went through a general health check, and then tested for parasites against malaria. After that they get a pair of socks that are used overnight. The next day, researchers collected socks and divided them into the status of children infected with malaria. They only collected socks for children who were infected with malaria without any symptoms and stockings of fresh children. Socks were then sent to England. Here they frozen, while the dogs sniffed.
Sneezing testing should have different socks for malaria – saturated and healthy children. They should sniff each pair of socks and freeze if they think they have found dirt from malaria. If they did not smell something, they should go on.
The result of the test showed that dogs were able to identify 70 percent of children with malaria-infected socks and 90 percent of healthy ones.
The parasite of malaria mutates
Researchers say the accuracy of the impact is impressive and that dogs were able to identify socks for children with a lower status of infection than required by the World Health Organization (WHO) tests.
Generally speaking, the diagnosis of malaria is done with the help of blood samples and microscopy. It may take a lot of time and special skills are needed. You can also use quick blood tests, but these are pretty expensive. They have a high level of accuracy.
The researchers were aware that this is the so-called proof of the conceptstudies to show that a dog can diagnose malaria. They further believe that the accuracy of dogs for sniffing can be as good as blood tests. Lindsey justifies this because malaria parasites on children are not always the same as they go through different stages of the disease. The fragrance that creates in human skin then changes.
He points out that tests that are used today can be short, because parasites of malaria mutate. Therefore, parasites may not have the specific proteins needed for clinical trials to show an infection
Moreover, researchers believe that the ability of sweating dogs to detect certain odors associated with malaria can be an inspiration for the development of new and artificial electronic noses that can smell the disease.
Malaria dog at the border
Lindsei believes that sniffing dogs can be helpful when health authorities want to check the villages for malaria carriers that have no visible symptoms. If you are a carrier, you can transfer parasites against malaria to mosquitoes. The only way to prevent the spread today is to test or cure everything in one village.
Researchers therefore believe that peeling dogs will function well at border crossings, to countries where malaria is almost eradicated. Lindsi deals with the eastern African island of Zanzibar, where the elimination of malaria parasites was hampered by the constant flow of immigrants.
Gunnar Hasle is a specialist in infectious diseases and is managing Reiseklinikken in Oslo. He says the preliminary hit is 70 percent too low.
"This means that the method is useless to find out if a person with a fever has malaria, because it is not acceptable to make a mistake of 30 percent.
He also points out 90 percent of those who were healthy, and 10 percent get the wrong message about malaria.
"This is an unacceptably large number if the method is used to smell a large number of healthy people," he says.
Blood test at the clinic, dogs at the borders
Hasle also says that the smell indications are used for hundreds of years. It is possible, among other things, to succeed in diabetes, inhaling the odor of acetone or removing nail polish. Moreover, it is possible to feel the lack of the liver, because the spirit has a fragrant smell.
"They also tried to find dogs to diagnose lung cancer," Hasle said, referring to the 2012 survey. The result was approximately the same as for malaria trial.
He thinks it is completely impossible to use dogs to diagnose the clinics and that it will still be difficult to train enough dogs to satisfy the need
– Every health unit in the tropics should have access to malaria diagnosis. Then it's much easier to get quick tests that you can use after a minimum training than to get trained dogs.
He still believes that I can help in some cases and support the researchers' opinion that they use shooters as malaria patrons.
"Dogs for shooting can be used to massively evaluate immigration to an area that has eradicated malaria," he concluded.