Abstract
Background: We investigated the contribution of both occupational and community exposure for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among employees of a university-affiliated long-term care facility (LTCF), during the 1 st pandemic wave in Switzerland (March-June 2020).
Methods: We performed a nested analysis of a seroprevalence study among all volunteering LTCF staff to determine community and nosocomial risk factors for SARS-CoV-2 seropositivity using modified Poison regression. We also combined epidemiological and genetic sequencing data from a coronavirus disease 2019 (COVID-19) outbreak investigation in a LTCF ward to infer transmission dynamics and acquisition routes of SARS-CoV-2, and evaluated strain relatedness using a maximum likelihood phylogenetic tree.
Results: Among 285 LTCF employees, 176 participated in the seroprevalence study, of whom 30 (17%) were seropositive for SARS-CoV-2. Most (141/176, 80%) were healthcare workers (HCWs). Risk factors for seropositivity included exposure to a COVID-19 inpatient (adjusted prevalence ratio [aPR] 2.6; 95% CI 0.9-8.1) and community contact with a COVID-19 case (aPR 1.7; 95% CI 0.8-3.5). Among 18 employees included in the outbreak investigation, the outbreak reconstruction suggests 4 likely importation events by HCWs with secondary transmissions to other HCWs and patients.
Conclusions: These two complementary epidemiologic and molecular approaches suggest a substantial contribution of both occupational and community exposures to COVID-19 risk among HCWs in LTCFs. These data may help to better assess the importance of occupational health hazards and related legal implications during the COVID-19 pandemic.
Keywords: COVID-19; Nosocomial outbreaks; Occupational exposure; SARS-CoV-2.
【저자키워드】 COVID-19, SARS-CoV-2, occupational exposure, Nosocomial outbreaks, 【초록키워드】 coronavirus disease, SARS-CoV-2, coronavirus, pandemic, COVID-19 pandemic, nosocomial, Genetic, Infection, risk, risk factor, healthcare worker, Prevalence, Health, outbreak, HCWs, Transmission dynamics, Community, epidemiological, molecular, Switzerland, Care, patients, seropositive, Phylogenetic tree, Analysis, occupational, Contact, complementary, HCW, acute respiratory syndrome, Factor, 95% CI, COVID-19 case, hazard, secondary transmission, help, sequencing data, acquisition, MOST, implication, approach, event, likelihood, performed, investigated, evaluated, adjusted, determine, participated, Poison, 【제목키워드】 SARS-COV-2 infection, risk, Community, Care, occupational,