In daycare centres, the close contact of children with other children and employees favours the transmission of infections. The majority of children <6 years attend daycare programmes in Germany, but the role of daycare centres in the SARS-CoV-2 pandemic is unclear. We investigated the transmission risk in daycare centres and the spread of SARS-CoV-2 to associated households. 30 daycare groups with at least one recent laboratory-confirmed SARS-CoV-2 case were enrolled in the study (10/2020–06/2021). Close contact persons within daycare and households were examined over a 12-day period (repeated SARS-CoV-2 PCR tests, genetic sequencing of viruses, symptom diary). Households were interviewed to gain comprehensive information on each outbreak. We determined primary cases for all daycare groups. The number of secondary cases varied considerably between daycare groups. The pooled secondary attack rate (SAR) across all 30 daycare centres was 9.6%. The SAR tended to be higher when the Alpha variant was detected (15.9% vs. 5.1% with evidence of wild type). The household SAR was 53.3%. Exposed daycare children were less likely to get infected with SARS-CoV-2 than employees (7.7% vs. 15.5%). Containment measures in daycare programmes are critical to reduce SARS-CoV-2 transmission, especially to avoid spread to associated households.

在日托中心，儿童与其他儿童和员工的密切接触有利于感染的传播。在德国，大多数 6 岁以下的儿童参加日托计划，但日托中心在 SARS-CoV-2 大流行中的作用尚不清楚。我们调查了日托中心的传播风险以及 SARS-CoV-2 向相关家庭的传播。30 个近期至少有 1 例实验室确诊 SARS-CoV-2 病例的日托小组参加了该研究（10/2020–06/2021）。在 12 天内对日托和家庭中的密切接触者进行了检查（重复 SARS-CoV-2 PCR 测试、病毒基因测序、症状日记）。对住户进行了采访，以获取有关每次爆发的全面信息。我们确定了所有日托小组的主要病例。日托组之间的继发病例数量差异很大。所有 30 个日托中心的合并二次发作率 (SAR) 为 9.6%。当检测到 Alpha 变体时，SAR 往往更高（15.9%与有野生型证据的 5.1% 相比）。家庭 SAR 为 53.3%。与员工相比，接触日托的儿童感染 SARS-CoV-2 的可能性更低（7.7%对15.5%）。日托计划中的遏制措施对于减少 SARS-CoV-2 传播至关重要，尤其是避免传播到相关家庭。