Objective: A 6-month longitudinal surveillance study of asymptomatic healthcare providers (HCP) was carried out at a large urban academic medical center in the United States to assess whether their job occupation with higher exposure risks to SARS-CoV-2 would equate with higher risk of contracting COVID-19 at the beginning of the pandemic before COVID-19 vaccines were available.
Methods: A longitudinal cohort study design was used to collect and analyze immunological and virological monitoring data and self-report survey assessments of personal protective equipment (PPE) availability, adherence to infection control guidelines, and time spent on COVID-19 wards.
Results: Among 289 eligible participants, SARS-CoV-2 exposure risk was high with 48-69% participants working in COVID-19 units and more than 30% of them caring for COVID-19 patients. However, the seroconversion rate was low with only 2.1% of participants developing humoral or cellular immunity against SARS-CoV-2.
Conclusion: Our study findings suggest that, for this HCP cohort working at a large urban academic medical center, a low incidence of SARS-CoV-2 infection could be maintained under conditions of strict infection prevention protocols and reliable PPE availability.
Keywords: SARS-CoV-2; exposure risk; healthcare worker; infection rate; seroconversion rate.