Differential occupational risks to healthcare workers from SARS-CoV-2: A prospective observational study

Abstract

Background Personal protective equipment (PPE) and social distancing are key measures designed to mitigate the risk of occupational SARS-CoV-2 infection in hospitals. Why healthcare workers nevertheless remain at increased risk is uncertain. Methods We conducted voluntary Covid-19 testing programmes for symptomatic and asymptomatic staff at a large UK teaching hospital using nasopharyngeal PCR testing and immunoassays for IgG antibodies. A positive result by either modality was used as a composite outcome. Risk factors for Covid-19 were investigated using multivariable logistic regression. Results 1083/9809(11.0%) staff had evidence of Covid-19 at some time and provided data on potential risk-factors. Staff with a confirmed household contact were at greatest risk (adjusted odds ratio [aOR] 4.63 [95%CI 3.30-6.50]). Higher rates of Covid-19 were seen in staff working in Covid-19-facing areas (21.2% vs. 8.2% elsewhere) (aOR 2.49 [2.00-3.12]). Controlling for Covid-19-facing status, risks were heterogenous across the hospital, with higher rates in acute medicine (1.50 [1.05-2.15]) and sporadic outbreaks in areas with few or no Covid-19 patients. Covid-19 intensive care unit (ICU) staff were relatively protected (0.46 [0.29-0.72]). Positive results were more likely in Black (1.61 [1.20-2.16]) and Asian (1.58 [1.34-1.86]) staff, independent of role or working location, and in porters and cleaners (1.93 [1.25-2.97]). Contact tracing around asymptomatic staff did not lead to enhanced case identification. 24% of staff/patients remained PCR-positive at ≥6 weeks post-diagnosis. Conclusions Increased Covid-19 risk was seen in acute medicine, among Black and Asian staff, and porters and cleaners. A bundle of PPE-related interventions protected staff in high-risk ICU areas.

High prevalence of SARS-CoV-2 antibodies in care homes affected by COVID-19: Prospective cohort study, England

“…The RT-PCR Ct values were consistent with non-live virus in all residents and staff members who were RT-PCR positive on nasal swab at follow-up. The prolonged nasal swab RT-PCR positivity in a proportion of residents and staff is consistent with a recent large healthcare worker study where up to a quarter were still RT-PCR positive up to six weeks later, highlighting yet another limitation of our understanding of the kinetics of viral replication and immune responses COVID-19 [19,20]. This well-characterised cohort will be followed with routine care home screening, [21] providing key insights into the potential for reinfection in seropositive individuals.…”

SARS-CoV-2 exposure, symptoms and seroprevalence in healthcare workers in Sweden

“…This large serological investigation reports symptoms associated with SARS-CoV-2 infection, which may aid in healthcare personnel screening guidance and in the recommendations of selfisolation. The results furthermore support an occupational risk of SARS-CoV-2 transmission to HCW, exceeding the risk presented in recent studies [8][9][10][11][12][13][14] . Among the enrolled 2149 HCW, one in five were seropositive, suggesting prior or still ongoing infection with SARS-CoV-2.…”

“…Reports now highlight the risk of occupational transmission of SARS-CoV-2 as well [25][26][27][28][29][30][31] , and contamination of SARS-CoV-2 RNA has been demonstrated to be widespread across hospital environmental surfaces 32 and air samples from both ICU and general wards 33 . Emerging serological investigations, however, document relatively low seroprevalences among HCW, ranging from 1.6% in Germany 12 and 3.8% in Wuhan 8 , the epicenter of the COVID-19 pandemic in China, to 7.6 and 11% in the severely affected countries Belgium 10 and UK 11 , which are all significantly lower than the seroprevalence found in this cohort of HCW.…”

“…This raises concerns about the safety of front-line HCW and the risk of healthcare system collapse as well as transmission from healthcare settings to the community. Little is, however, known about the occupational risk of HCW to SARS-CoV-2 infection, but the few emerging studies report relatively low seroprevalences, ranging from 1.6% to 11.0% [8][9][10][11][12][13][14] .…”

Preventing disease after exposure to COVID-19 using hydroxychloroquine: A summary of a protocol for exploratory re-analysis of age and time-nuanced effects

“…Differences between exposure risk related to type of in hospital-assignment and household risk among UK HCW and likely use of PPE has been suggested to account for differences in rates of COVID-19 in a UK study. 8 The study also included observational data relating to use of zinc and Vitamin C. There was a higher incidence of symptoms when Vitamin C was used, both without (20.8% vs 11.2%, p=0.014) and with (14.3 vs. 10.6%, p=0.33) HCQ. For zinc there was a similar relationship in the HCQ group, but not in the placebo group.…”