Seroprevalence of SARS-CoV-2 IgG in healthcare workers and other staff at North Bristol NHS Trust: a sociodemographic analysis

Structured summary Background Healthcare workers (HCWs) are at increased risk of infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). There are limited data exploring the relative impact of geographical and socioeconomic factors on risk of SARS-CoV-2 infection among HCWs. Aim To estimate and explore SARS-CoV-2 IgG antibody seroprevalence in HCWs and support staff at a hospital in South West England. Methods We conducted a nested cross-sectional study from May-July 2020. Inverse probability weighted regression was used to estimate seroprevalence of SARS-CoV-2 and associations with demographic and socioeconomic risk factors that were robust to selection into testing. Findings Attendance for testing varied by demographic and socioeconomic factors. The overall rate of SARS-CoV-2 IgG seroprevalence among tested staff was 9.3% (638/6858). The highest seroprevalence was found in wards associated with SARS-CoV-2 outbreaks and among junior staff with patient-facing roles. Black, Asian and Minority Ethnic (BAME) staff had increased odds of SARS-CoV-2 seroprevalence (adjusted OR: 1.99, 95%CI: 1.69, 2.34; p<0.001) relative to White staff, except for those categorised as Medical/Dental. We found a significant association between neighbourhood deprivation and seroprevalence (p<0.01). Seroprevalence ranged from 12% in staff residing in areas with the greatest relative deprivation to 8.4% in the least deprived. Conclusion Transmission between staff groups is evident within the healthcare setting. BAME individuals were at increased risk of infection with SARS-CoV-2. Work role, area of residence, and neighbourhood deprivation all contribute to SARS-CoV-2 infection risk. As hospitals introduce routine staff SARS-CoV-2 testing they should consider differential uptake of testing among staff groups.