Thanks to a Labrador named Sally, a Labrador-Golden mix named Lexi, and a Springer Spaniel named Freya, how the world manages disease prevention might soon change. It’s no secret a dog’s nose is powerful, and scent detection dogs are already trained to detect everything from fruits and vegetables to low blood sugar in humans. Sally, Lexi, and Freya won’t tell you when someone is smuggling illegal ivory, but they’ve been trained to help with a worldwide health issue. They’re proving dogs may be instrumental in stopping the spread of malaria and in treating those who show no symptoms.
Medical Detection Dogs is a nonprofit organization in Milton Keynes, England dedicated to training dogs to help people. They train medical alert dogs that save lives, and malaria detection is the latest of their exciting projects. The group presented their findings on using dogs as a noninvasive way to detect malaria at the American Society of Tropical Medicine and Hygiene Annual Meeting in New Orleans. Their research is still in the early stages, but they’re hopeful dogs like Sally, Lexi, and Freya will soon be able to do a lot of good.
The goal of training dogs to detect malaria is to limit the spread of disease across borders and to ensure those affected receive treatment as soon as possible. According to the Centers for Disease Control and Prevention, malaria is spread through mosquitoes. Without treatment, it can be fatal. An estimated 445,000 people died of malaria in 2016, and with many people not experiencing symptoms right away, it can be difficult to diagnose.
The standard malaria test involves a finger prick and a blood sample, but testing thousands of people is a problem of logistics. The question is, how can someone find an infected person in a large group of healthy people before they spread the disease to others? With more research and training, dogs may be the answer.
When a person is about to experience a seizure, there’s a biological shift in their body that results in an almost indistinguishable scent. The same happens when someone experiences a sudden change in their blood sugar level or if they’re in an early stage of cancer. Sometimes it’s the person’s skin that smells differently, and it can also be their breath or urine. Human noses can’t detect these subtle shifts in scent, but lucky for us, dogs can.
According to researchers from ETH Zurich and Pennsylvania State University, malaria pathogens change body odor to attract mosquitoes. When a person is infected, they emit a scent that draws in more mosquitoes. When a mosquito bites them, that tiny bug carries the disease to the next person they bite. This makes the scent of malaria part of the problem, but Medical Detection Dogs has found a way to make it part of the solution. If mosquitoes can identify a person infected with malaria, why can’t dogs?
Sally, Lexi, and Freya were trained using socks worn by both healthy and malaria-stricken children living in the Upper River Region of The Gambia in West Africa. Out of the 175 total sock samples, 30 of them belonged to children already diagnosed with malaria. The socks were then sent to Medical Detection Dogs where their star sniffers got to work.
In this early stage of research and training, the team of malaria detection dogs correctly identified 70 percent of the malaria-infected samples. They also correctly categorized 90 percent of the samples without malaria. Their success is encouraging news as health officials around the world struggle to stop malaria from spreading. The use of scent detection dogs allows for a noninvasive and transportable means of testing large groups of people for infection. Once a person is identified as possibly having the disease, they would then be tested with a finger prick and blood sample. If the results are positive for malaria, they will receive necessary treatments to halt symptoms and stop the disease from being contagious.
Sally, Lexi, and Freya have impressed researchers so far, but their work isn’t over. Future studies will determine if the dogs can directly detect malaria in the odor of infected people even in crowded and chaotic areas like airports and shipping ports.
Featured image via Facebook/Medical Detection Dogs