COVID-19 Sero-prevalence Health Care Workers Kinshasa

This is a cohort study, in which the investigators will follow-up 650 health care workers (HCW) and a selection of their households (of COVID positive and COVID negative HCW) at baseline and in three follow-up surveys, with 4 to 6 weeks of time interval. The investigators will select HCW from different wards and different health care structures in 5 communes of Kinshasa. Additionally, in the first survey among HCW, the investigators will test with different diagnostic platform to evaluate the performance of serological tests in the African setting and the effect of malaria infection on the performance of tests. An amendment is added to the protocol, stating an additional 2 surveys in april/June 2021 and October/November 2021 to evaluate impact of second wave and of vaccination campaign.