Should healthcare workers with SARS-CoV-2 household exposures work? A Cohort Study

Abstract

Due to high community transmission of the Omicron variant, healthcare workers (HCWs) have been increasingly reporting household exposures to confirmed COVID19 cases. Quebec (Canada) provincial guidelines required to quarantine these HCWs. Facing the risk of staffing shortages, our hospital decided to allow them to work. Objective: To evaluate the risk for HCWs, who were household contacts, to become positive for COVID19 and evaluate the risk of nosocomial COVID19 transmission. Design: Cohort of consecutive HCWs with a history of household exposure to a confirmed case of COVID19 who contacted OHS at CHU Sainte-Justine, Montreal (QC) Canada between December 20, 2021 and January 17, 2022 for a history of household exposure to COVID19. Exposure: Confirmed case of COVID19 in the household Main outcome and measures: The main outcome was a positive RT-PCR for SARS-CoV-2. Outbreaks and nosocomial cases were identified through daily analysis of COVID-19 cases, by sector and part of the usual Infection Prevention and Control surveillance process. Results: Overall, 237 of 475 (50%) HCWs who declared a known household contact with a confirmed COVID19 case remained negative. Of those who became positive, 196 (82.4%) were positive upon initial testing and were quarantined. Only 42 (15%) of 279 HCWs who were allowed to work became positive, a median of 4 days after the initial test. The absence of symptoms at initial evaluation (OR 3.8, 95% CI 2.5,5.7) and having received a third vaccine dose more than 7 days before (OR 1.88, 95% CI 1.3,2.8) were associated with an increased odds of remaining negative. There was no outbreak among HCWs and no nosocomial transmission to patients from a HCW that was allowed to work, while a known household contact. Conclusion and relevance: Measures taken to protect the health care environment from COVID19 must be cautiously balanced with the risk of staffing shortage. Allowing vaccinated asymptomatic HCWs who are known household contacts of confirmed COVID19 cases to work is likely a safe alternative, when staff shortage is anticipated.

Clinical comparison of omicron and delta variants in older COVID-19 patients and the effect of vaccination status

“…Although there are not many studies on this subject, the rate of asymptomatic Omicron infections is estimated to be between 25-54%. In a study conducted on healthcare workers, the rate of asymptomatic patients was found to be 50% in patients infected with the Omicron variant (18).…”