Armpit sweat, Covid19 and dogs

The Covid19 pandemic has a huge impact on our daily lives. At the beginning of the pandemic, I was still doing research at UC San Diego. The whole lab – in fact multiple labs (Knight lab, Dorrestein lab and Gilbert lab) – completely shifted research focus to studying the virus and the pandemic. The lockdown in San Diego came one or two weeks after the lockdown in Europe. As a result, the number of cases was not that high – still it was steadily growing. With a whole team, we started taking samples in hospitals, from patients, floors, surfaces, etc., to see where and how the virus was spreading. The lab started doing qPCR tests to identify the culprits. Upon today, the Knight lab is conducting >1000 qPCR tests per day (!). One problem with the qPCR test is that viral RNA is highly unstable, and rapidly deteriorates on the swab, if not stored on liquid nitrogen. That is why there are many false-negative results. In April, I eventually took one of the few transatlantic flights back to Europe, as we were instructed by the government to come back. Everyone in Belgium was in lockdown, and I had never seen the airport so empty.

Back in Belgium, I got in touch with a detection dog training facility, with whom I met before and discussed about stress sweat. They wanted to find out if detection dogs could be trained to sniff out Covid19 infection. A wild, yet intriguing idea. Apparently another dog training company was busy with this and had some preliminary results. The idea is that SARS-CoV-2 virus has a reaction on the human immune system, which can be smelled in armpit sweat. For my research I knew that every infection, be it from a virus, bacterium or fungus, can cause unique VOC release from human cells. So the idea was quite plausible. And sweat would be a safe route, as the virus appeared not to transmit through the skin. So there was little or no chance that people handling sweat samples would get infected as well.

So we started to have conversations with hospitals & doctors, and started writing grant application. I have to say, it was not easy to convince people of this idea. Three grant applications were almost immediately rejected. But in my quest, I met other people that started to believe in the idea, most of which having a veterinary background. We started a Belgian task force on Covid19 detection dogs and found common ground with the federal police, Belgian army and fire brigade, all of which having drugs or explosives detection dogs. When the second wave hit Belgium, we suddenly obtained momentum and the government supported our group in training the detection dogs. We started collecting samples from hospitals all over the country. Now we have ethical approvals and collections set up with over 25 (!) hospitals and elderly homes (setting up the administration for one hospital is already quite a tremendous work, let alone for 25). The media attention definitely helped in convincing people, politicians, doctors and board members to support the idea. Now, we are training 6 detection dogs, and we see that they can clearly distinguish positive from negative samples; although we need a couple more weeks to fully train the dogs. Also the dog training company has 2 detection dogs that can fully distinguish positive from negative samples.

I strongly believe in the concept as a cost-efficient, fast and reliable screening method. We can deploy the dogs in airports, sports centers, elderly homes, events, etc. More news on these dogs will follow. I am sure there is a great future for these detection dogs. When I started my research on armpits more than 12y ago, I would have never believed that armpit sweat would help in fighting a worldwide pandemic, but here we are!