Prospective SARS-CoV-2 cohort study among general practitioners during the second COVID-19 wave in Flanders, Belgium

Primary health care providers (PHCPs), especially general practitioners (GPs) are essential to organise health care efficiently. During the COVID-19 pandemic, they also keep the pressure off hospitals. PHCPs are assumed to be at high risk of a COVID-19 infection, as they are exposed to a large portion of the population (usually with less personal protective equipment than other frontline health care workers(HCWs)). Nevertheless, previous seroprevalence studies focussed on the general population or HCWs in hospital settings, rather than PHCPs. The aim of this study was to determine the seroprevalence of PHCPs after the first and during the second SARS-CoV-2 wave in Flanders (Belgium) and compare it to the seroprevalence in the general population (blood donors). A prospective cohort of PHCPs, mainly GPs (n=698) was screened for IgG antibodies against SARS-CoV-2 at five different time-points (June-December 2020). The dried blood spots they produced were analysed using a Luminex multiplex immunoassay. The seroprevalence of PHCPs remained stable between June and September 2020 (4.6-5.0%), but increased significantly from October to December (8.1-13.4%) 2020. The seroprevalence of PHCPs was not significantly higher than the seroprevalence of the blood donors at the end of December 2020. In conclusion, the sharp increase in seroprevalence during the second COVID-19 wave in Flanders shows that PHCPs were more at risk during the second wave compared to the first one. However, the increase was in line with the general population suggesting that PHCPs mainly got infected in their private settings.