SARS-CoV-2 Seroprevalence Among Nursing Home Staff and Residents (COVID-19)

Assessment of the seroprevalence and sero-incidence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) among Nursing Home (NH) residents and staff in Belgium.

In this longitudinal cohort study, 3036, nursing home (NH) residents (1656) and staff (1380), spread over 69 nursing homes throughout Belgium will be repeatedly sampled at a 2-month interval. Seroprevalence and -incidence will be assessed by means of a point-of-care rapid antibody test with additional collection of a Dry Blood Spot sample for quantitative detection of immune markers\*. Sample collection (capillary blood samples) at baseline (day 0, week 0) will start in a staggered way, so all baseline samples among the different nursing homes are collected within the first 21 days after collection of the first sample. Follow-up sample collection will occur with a 2-month interval in week 8, week 16, week 24, week 32 and week 40 after the baseline collection of that specific nursing home. At each timepoint, questionnaires will be taken concerning medical history, clinical outcomes and potential COVID-19 riskfactors. The recruited NHs will be equally spread across the Belgian territory according to geographic and demographic characteristics to guarantee general representativity. Forty-four participants (20 staff, 24 residents) will be randomly included per nursing home. (\* collection of the Dry Blood Spot is part of a sub-study by Ghent University)