Serologic Surveillance and Phylogenetic Analysis of SARS-CoV-2 Infection Among Hospital Health Care Workers

Abstract

IMPORTANCE It is unclear when, where, and by whom health care workers (HCWs) working in hospitals are infected with SARS-CoV-2. OBJECTIVE To determine how often and in what manner nosocomial SARS-CoV-2 infection occurs in HCW groups with varying exposure to patients with COVID-19. DESIGN, SETTING, AND PARTICIPANTS This cohort study comprised 4 weekly measurements of SARS-CoV-2-specific antibodies and collection of questionnaires from March 23 to June 25, 2020, combined with phylogenetic and epidemiologic transmission analyses at 2 university hospitals in the Netherlands. Included individuals were HCWs working in patient care for those with COVID-19, HCWs working in patient care for those without COVID-19, and HCWs not working in patient care. Data were analyzed from August through December 2020. EXPOSURES Varying work-related exposure to patients infected with SARS-CoV-2. MAIN OUTCOMES AND MEASURESThe cumulative incidence of and time to SARS-CoV-2 infection, defined as the presence of SARS-CoV-2-specific antibodies in blood samples, were measured. RESULTSAmong 801 HCWs, there were 439 HCWs working in patient care for those with COVID-19, 164 HCWs working in patient care for those without COVID-19, and 198 HCWs not working in patient care. There were 580 (72.4%) women, and the median (interquartile range) age was 36 (29-50) years. The incidence of SARS-CoV-2 was increased among HCWs working in patient care for those with COVID-19 (54 HCWs [13.2%; 95% CI, 9.9%-16.4%]) compared with HCWs working in patient care for those without COVID-19 (11 HCWs [6.7%; 95% CI, 2.8%-10.5%]; hazard ratio [HR], 2.25; 95% CI, 1.17-4.30) and HCWs not working in patient care (7 HCWs [3.6%; 95% CI, 0.9%-6.1%]; HR, 3.92; 95% CI, 1.79-8.62). Among HCWs caring for patients with COVID-19, SARS-CoV-2 cumulative incidence was increased among HCWs working on COVID-19 wards (32 of 134 HCWs [25.7%; 95% CI, 17.6%-33.1%]) compared with HCWs working on intensive care units (13 of 186 HCWs [7.1%; 95% CI, 3.3%-10.7%]; HR, 3.64; 95% CI, 1.91-6.94), and HCWs working in emergency departments (7 of 102 HCWs [8.0%; 95% CI, 2.5%-13.1%]; HR, 3.29; 95% CI, 1.52-7.14). Epidemiologic data combined with phylogenetic analyses on COVID-19 wards identified 3 potential HCW-to-HCW transmission clusters.No patient-to-HCW transmission clusters could be identified in transmission analyses. CONCLUSIONS AND RELEVANCEThis study found that HCWs working on COVID-19 wards were at increased risk for nosocomial SARS-CoV-2 infection with an important role for HCW-to-HCW (continued) Key Points Question Which hospital health care workers are at increased risk for SARS-CoV-2 infection, and by whom are they infected? Findings In this cohort study of 801 hospital health care workers (HCWs), the risk of getting infected with SARS-CoV-2 was nearly 4-fold higher among HCWs on COVID-19 wards compared with HCWs not in patient care. Combined phylogenetic and epidemiological analyses found no patient-to-HCW transmission but several occurrences of HCW-to-HCW transmission. Meaning These findin...

SARS-CoV-2 seroprevalence in healthcare workers of a teaching hospital in a highly endemic region in the Netherlands after the first wave: a cross-sectional study

“… 17 The magnitude of regional differences in serostatus are also reflected by a serological study in HCW of the Amsterdam University Medical Centers between March and June, where the highest seroprevalence observed was 13.2% in HCW who were in direct contact with COVID-19 patients, vs 3.6% in HCW without direct patient contact, while the seroprevalence in our total study population was 21.1%. 18 At the beginning of the pandemic, the Southeast region of the Netherlands was considered a COVID-19 hotspot, while community transmission in Amsterdam was still low. Our data suggest most infections arise from the household, while Sikkens et al reported HCW working at COVID-19 wards to be at increased risk of infection, with transmission between HCW as a major contributor.…”

“…Our data suggest most infections arise from the household, while Sikkens et al reported HCW working at COVID-19 wards to be at increased risk of infection, with transmission between HCW as a major contributor. 18 Nevertheless, both studies indicate the potential impact of infection risks due to HCW-HCW interaction. Similar results were found by Steensels et al , 14 using the same study design, where most infections were most likely acquired in the community.…”

A Prospective, Longitudinal Evaluation of SARS-CoV-2 COVID-19 Exposure, Use of Protective Equipment and Social Distancing in a Group of Community Physicians

“…Because of our relatively small number of IgG-positive subjects, we were unable to study specific risks for COVID-19 infections in our study group. A previous study of the acquisition of COVID-19 infection in healthcare workers showed that between March 2020 and June 2020, healthcare workers working in patient care areas were four times more likely to become infected with COVID-19 than those not working in patient care areas [ 44 ].…”

Time since SARS-CoV-2 infection and humoral immune response following BNT162b2 mRNA vaccination

“…In short, follow-up visits were scheduled regularly (March, April, May, June, October 2020, January 2021) and included serological testing, surveys regarding results of nucleic acid amplification testing (NAAT), and presence of COVID-19 related symptoms since the previous visit. For comprehensive details about inclusion and follow-up of this cohort we refer to the original article of the S3 study [9].…”