BACKGROUND The role of children and staff in SARS-CoV-2 transmission outside and within households is still not fully understood when large numbers are in regular, frequent contact in schools. METHODS We used the self-controlled case-series method during the alpha- and delta-dominant periods to explore the incidence of infection in periods around a household member infection, relative to periods without household infection, in a cohort of primary and secondary English schoolchildren and staff from November 2020 to July 2021. RESULTS We found the relative incidence of infection in students and staff was highest in the 1-7 days following household infection, remaining high up to 14 days after, with risk also elevated in the 6--12 days before household infection. Younger students had a higher relative incidence following household infection, suggesting household transmission may play a more prominent role compared with older students. The relative incidence was also higher among students in the alpha variant dominant period. CONCLUSIONS This analysis suggests SARS-CoV2 infection in children, young people and staff at English schools were more likely to be associated with within-household transmission than from outside the household, but that a small increased risk of seeding from outside is observed.

中文翻译：

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2020-21 年英国学校以及学生和教职员工家庭中的 COVID-19 感染：自我对照病例系列分析。


背景 当大量儿童和工作人员在学校定期、频繁接触时，儿童和工作人员在家庭内外传播 SARS-CoV-2 中的作用仍未完全了解。方法 我们在 α 和 δ 主导时期使用自我对照病例系列方法，在一组英国中小学生中探讨家庭成员感染前后时期的感染率，相对于没有家庭感染的时期。 2020 年 11 月至 2021 年 7 月期间，学生和教职员工的感染相对发生率在家庭感染后 1-7 天内最高，并在 14 天后保持较高水平，并且在 6--家庭感染前12天。年龄较小的学生在家庭感染后的相对发病率较高，这表明与年龄较大的学生相比，家庭传播可能发挥更重要的作用。处于α变异主导时期的学生的相对发生率也较高。结论 这项分析表明，儿童、年轻人和英语学校工作人员的 SARS-CoV2 感染更有可能与家庭内部传播相关，而不是家庭外部传播，但观察到外部传播的风险略有增加。