08/21/2020

A New Study Suggests a Possible Disease Vector: Germy Dust

Since the pandemic’s beginning, scientists have argued over how respiratory viruses can spread

For the past few years, up until the pandemic hit, Bill Ristenpart, a chemical engineer at UC Davis (and next-level coffee geek), had been bringing a team of researchers and crates of expensive instruments across the country each summer to New York City and into the lab of Nicole Bouvier. An infectious disease physician and researcher at Mount Sinai Hospital, Bouvier studies respiratory viruses, influenza A in particular. Ristenpart’s specialty is fluid dynamics. In the case of flu, that means measuring how physical properties like temperature, humidity, and wind speed change the flight of the respiratory bloblets that fly out of human and rodent noses and mouths. Together, with dozens of guinea pigs and nearly $2 million from the National Institutes of Health, they hoped to figure out a century-old mystery: Why is there a flu season?

That, they still don’t know. Instead, their work has turned up compelling evidence that some respiratory viruses, at least in lab animals, don’t always travel through liquid droplets, the way scientists have long assumed. Infected guinea pigs don’t just breathe or sneeze out bits of influenza. They can actually launch infectious particles into the air from their fur, paws, and cages.

Remember “fomites,” those germ deposits on surfaces that led to so much hand-washing and hand-wringing over face-touching during the early days of the pandemic? Well, sometimes, rather than settling on large objects like tables and cell phones, germs stick to the surfaces of solids that are so tiny you can’t even see them, like microscopic fibers, dead skin cells, and dust. Those minuscule solids can later get kicked up into the air. When they do, Bouvier and Ristenpart call them “aerosolized fomites.” And according to their research, these germy particles can make other animals sick. In fact, in their latest study, aerosolized fomites appeared to be the primary way their guinea pigs passed around the flu.

Please select this link to read the complete article from WIRED.