Prospective SARS-CoV-2 cohort study among primary health care providers during the second COVID-19 wave in Flanders, Belgium

Background: Primary health care providers (PHCPs) are assumed to be at high risk of a COVID-19 infection, as they are exposed to patients with usually less personal protective equipment (PPE) than other frontline health care workers (HCWs). Nevertheless, current research efforts focussed on the assessment of COVID-19 seroprevalence rates in the general population or hospital HCWs. Objective: We aimed to determine the seroprevalence in PHCPs during the second SARS-CoV-2 wave in Flanders (Belgium) and compared it to the seroprevalence in the general population. We also assessed risk factors, availability of PPE and attitudes towards the government guidelines over time. Methods: A prospective cohort of PHCPs (n = 698), mainly general practitioners, was asked to complete a questionnaire and self-sample capillary blood by finger-pricking at five distinct points in time (June-December 2020). We analysed the dried blood spots for IgG antibodies using a Luminex multiplex immunoassay. Results: The seroprevalence of PHCPs remained stable between June and September (4.6-5.0%), increased significantly from October to December (8.1-13.4%) and was significantly higher than the seroprevalence of the general population. The majority of PHCPs were concerned about becoming infected, had adequate PPE and showed increasing confidence in government guidelines. Conclusions: The marked increase in seroprevalence during the second COVID-19 wave shows that PHCPs were more at risk during the second wave compared to the first wave in Flanders.This increase was only slightly higher in PHCPs than in the general population suggesting that the occupational health measures implemented provided sufficient protection when managing patients.