IMPORTANCEClosure of day care centers (DCCs) to contain the COVID-19 pandemic has been associated with negative effects on children's health and well-being. OBJECTIVE To investigate the acceptance of self-sampling methods for continuous SARS-CoV-2 surveillance among asymptomatic children and childcare workers (CCWs) in DCCs. DESIGN, SETTING, AND PARTICIPANTS This nonrandomized pilot study included children and CCWs at 9 DCCs in Wuerzburg, Germany, from May to July 2021. INTERVENTIONS Twice weekly testing for SARS-CoV-2 was conducted by self-sampled mouthrinsing fluid (saliva sampling [SAL], with subsequent pooled polymerase chain reaction test) plus nasal rapid antigen self-test (RAgT) (group 1), SAL only (group 2), or RAgT only (group 3) in children and CCWs. MAIN OUTCOMES AND MEASURES Main outcomes were rates for initial acceptance and successful (Ն60% of scheduled samples) long-term participation. The probability of SARS-CoV-2 introduction into DCCs was modeled as a function of age-adjusted background incidence and DCC size.
RESULTSOf 836 eligible children, 452 (54.1%; 95% CI, 50.7%-57.4%) participated (median [IQR] age: 4 [3-5] years; 213 [47.1%] girls), including 215 (47.6%) in group 1, 172 (38.1%) in group 2, and 65 (14.4%) in group 3. Of 190 CCWs, 139 (73.2%; 95% CI, 66.4%-79.0%) participated (median [IQR] age: 30 [25-46] years; 128 [92.1%] women), including 96 (69.1%) in group 1, 29 (20.9%) in group 2, and 14 (10.1%) in group 3. Overall, SARS-CoV-2 PCR tests on 5306 SAL samples and 2896 RAgTs were performed in children, with 1 asymptomatic child detected by PCR from SAL. Successful long-term participation was highest in group 2 (SAL only; children: 111 of 172 [64.5%]; CCWs: 18 of 29 [62.1%]).Weekly participation rates in children ranged from 54.0% to 83.8% for SAL and from 44.6% to 61.4% for RAgT. Participation rates decreased during the study course (P < .001). The probability of SARS-CoV-2 introduction into a DCC with 50 children was estimated to reach at most 5% for an age-adjusted SARS-CoV-2 incidence below 143.CONCLUSIONS AND RELEVANCE Self-sampling for continuous SARS-CoV-2 testing was well accepted, with SAL being the preferred method. Given the high number of negative tests, thresholds (continued) Key Points Question What is the acceptance and feasibility of different methods of twice weekly SARS-CoV-2 monitoring in asymptomatic children and childcare workers in day care centers? Findings In this nonrandomized controlled trial and feasibility study with 452 children and 139 childcare workers, self-sampled surveillance testing via saliva sampling and/or nasal rapid antigen self-test for SARS-CoV-2 was well accepted and provided a high sense of safety. Meaning These findings suggest that self-sampled continuous testing allowing continued day care for children should be established based on age-adjusted SARS-CoV-2 incidence rates.