A new, easier method for detecting Covid in kids is in development.
It works like a breathalyzer used to perform field sobriety tests — no nasal swab necessary. Just blow out and this version will look for signs of SARS-CoV-2, the virus that causes Covid. The emerging technology may change how kids are screened at school.
It is science rooted in another infectious disease. At Children’s Hospital of Philadelphia, Chief of Infectious Diseases, Dr Audrey John had already identified specific biomarkers — actual smells in the breath — linked to malaria.
“There’s two places that these VOC’s or smells can come from,” she said. “They can come from the bug itself, the bacteria or the parasite that is causing the infection. Or they can come from the body’s response. In our malaria work, we think some of the volatiles are being made by the parasite and making it out of the lungs.”
That’s not the case in Covid.
“When you get infected, then your body’s immune response is dramatic, and it changes the metabolism, the kinds of things your body is making,” John said. “And then we can see that in your breath.”
The tool they currently use is a mass spectrometer. But the hope is to refine the technology to the size of a breathalyzer used to detect alcohol in field sobriety tests.
“We have the child blow into the bag, collect the air onto something we can shoot onto a machine, and the machine gives us a readout of everything present,” John said.
They collected breath samples from both infected and non-infected children. In kids with Covid, they identified six specific elevated biomarkers. Dogs helped sniff them out in the lab.
“The dogs had already shown us that they could sniff out the difference between children with and without COVID,” John said. “They just do it in their noses.”
In her study, John found the six biomarkers could predict infection with 91% sensitivity and 75% specificity.
“Just using six of the things that are different we get a very high sensitivity that is we’re really quite easily able to detect the children that are infected,” John said. “Our specificity is not as great as current tests. So, what we see is that some of the kids that we think are positive a couple of them turn out not to be positive.”
PCR tests have more overall accuracy but ultimately, John hopes to see the technology deployed in schools and at home. No lab needed.
“I think there will be a real need for a while to be able to tell when your kid has a runny nose and cough, is it something boring or is this a reason everybody needs to stay home for a week?” John said.
Right now the researchers are testing the breathalyzer in other respiratory viruses that have emerged this summer, including RSV. They hope to secure more funding to bring their technology to the masses.