drinking fountain buttons; no samples taken from gym equipment turned up positive.
Overall, far fewer positive readings were found in office spaces or around computer keyboards, light switches, tabletops, microwaves, fridge handles or student desks.
But after stacking positive samples up against actual COVID cases on campus, the team determined that the probability of getting COVID after exposure to airborne virus particles was roughly 1 per 100 exposures.
The researchers determined the probability of illness from a contaminated surface to be 1 for every 100,000 exposures.
Still, Neitzel stresses that the findings reflect a time and place in which strict surface cleaning protocols were enforced, and when crowds were nonexistent. “Our results,” he cautions, “may not be completely representative of other community settings.”
Nevertheless, the results suggest people should be more concerned about inhalation risks from the coronavirus than the risks from touching surfaces, “at least in an environment where surfaces are cleaned regularly, as was the case with our campus,” Neitzel adds.
Elizabeth Scott, a professor emerita at Simmons University in Boston, says “there has been a growing recognition that COVID-19 is predominantly airborne.”
Yet Scott, who was not part of the study team, cautions that “the relative importance of surface transmission may be higher in homes, dorms [or] where people are living together and repeatedly touching the same surfaces.”
That kind of private space risk, she stresses, was not evaluated by the study. Also, it’s important to note that “other respiratory viruses and other bacterial infections are spread predominantly via contact surfaces,” Scott, former co-director of the Simmons Center for Hygiene and Health in Home and Community adds.
In her view, “we need to continue effective and holistic hygiene practices for hands and surfaces, as well as respiratory and air hygiene, to protect against all the other community-borne infections that were an issue before COVID-19, and will be with us for the future,” Scott concludes.