—The overall prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is 24.4 percent in a cohort of asymptomatic health care workers, according to a study published online Sept. 11 in Thorax.
Adrian Shields, M.B.B.S., Ph.D., from the University of Birmingham College of Medical and Dental Sciences in the United Kingdom, and colleagues conducted a cross-sectional study of 545 asymptomatic health care workers to determine the rates of asymptomatic viral carriage and seroprevalence of SARS-CoV-2 antibodies.
The researchers noted a 2.4 percent point prevalence of SARS-CoV-2 viral carriage and 24.4 percent overall seroprevalence of SARS-CoV-2 antibodies. Seroprevalence was higher among participants who reported prior symptomatic illness compared with those who had remained asymptomatic (37.5 versus 17.1 percent), and they had quantitatively greater antibody responses. The greatest seroprevalence was seen among those working in housekeeping, acute medicine, and general internal medicine (34.5, 33.3, and 30.3 percent, respectively); lower rates were seen for those working in intensive care (14.8 percent). A significantly increased risk for seropositivity was seen in association with Black, Asian, and minority ethnicity (odds ratio, 1.92). Compared with working in other places in the hospital, working in the intensive care unit was associated with a significantly lower rate of seropositivity (odds ratio, 0.28).
“Multiple logistic regression confirmed a significantly lower risk of seropositivity in individuals working in intensive care medicine,” the authors write. “This strongly supports the conclusion that differential risk of SARS-CoV-2 exposure exists within the hospital environment.”