You Can Catch COVID Here Even If It's Not Crowded, Study Finds
Research shows it's more likely you'll get infected if the space has the wrong kind of ventilation.
We've come a long way from the earliest days of the pandemic, when doorknobs, elevator buttons, and delivery packages were thought to be teeming with the virus. Now that scientists have a better understanding that coronavirus is mostly spread from person to person through aerosol droplets, it's become somewhat easier to safely navigate daily life and avoid specific situations. But a new study says there's one place that's always dangerous, even if it's not filled with people. It turns out you can catch COVID in enclosed spaces with air conditioning, even if they're not overly crowded.
The new research, which was published in the journal JAMA Internal Medicine, focused on a group in China that traveled in two buses to a Buddhist worship event held outdoors in the early days of the pandemic before face masks had become widely used. Results showed that one patient infected with COVID was able to pass the virus along to as many as 24 other passengers on one of the poorly ventilated vehicles, despite how far apart they were seated—even spreading COVID to those in the very front and back rows. No coronavirus cases were found on the other bus.
A key takeaway from the study lies in the fact that both buses were found to be using air conditioning that recycled air through the coach's interior. "The investigations suggest that, in closed environments with air recirculation, SARS-CoV-2 is a highly transmissible pathogen," the study's authors wrote. "Our finding of potential airborne transmission has important public health significance."
The findings also reveal that only patients seated near points of exterior air ventilation, including doors or windows that could be opened, were not infected. "[The study] adds strong epidemiological evidence that the virus is transmitted through the air, because if it were not, we would only see cases close to the index patient—but we see it spread throughout the bus," Linsey Marr, PhD, a professor of civil and environmental engineering at Virginia Tech and a leading expert on airborne viruses, told The New York Times.
Previous studies have also shed light on the notion that ventilation systems in enclosed spaces can quickly spread COVID. A Centers for Disease Control and Prevention (CDC) study of an outbreak from a restaurant in Guangzhou, China, found that one infected person seated near an air conditioner was able to infect others seated throughout the space, thanks to airborne virus particles that were carried around the space via the recycled air from the A/C unit.
Marr also notes that the new study gives her cause for concern for the upcoming winter months, when people will be more likely to congregate indoors. That's why she's urging Americans to "avoid crowded indoor spaces where people are not wearing masks and the ventilation is poor." And if you're trying to keep COVID at bay, be sure to avoid this one type of mask because This Face Covering Is Actually Worse Than No Mask at All, Study Finds.