Faculty of Information Technology, Monash University, Clayton, Victoria, Australia.
Centre for Learning Analytics at Monash, Monash University, Clayton, Victoria, Australia.
J Glob Health. 2022 Oct 1;12:05034. doi: 10.7189/jogh.12.05034.
Stringent public health measures have been shown to influence the transmission of SARS-CoV-2 within school environments. We investigated the potential transmission of SARS-CoV-2 in a primary school setting with and without public health measures, using fine-grained physical positioning traces captured before the COVID-19 pandemic.
Approximately 172.63 million position data from 98 students and six teachers from an open-plan primary school were used to predict a potential transmission of SARS-CoV-2 in primary school settings. We first estimated the daily average number of contacts of students and teachers with an infected individual during the incubation period. We then used the Reed-Frost model to estimate the probability of transmission per contact for the SARS-CoV-2 Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron variant (B.1.1.529). Finally, we built a binomial distribution model to estimate the probability of onward transmission in schools with and without public health measures, including face masks and physical distancing.
An infectious student would have 49.1 (95% confidence interval (CI) = 46.1-52.1) contacts with their peers and 2.00 (95% CI = 1.82-2.18) contacts with teachers per day. An infectious teacher would have 47.6 (95% CI = 45.1-50.0) contacts with students and 1.70 (95% CI = 1.48-1.92) contacts with their colleague teachers per day. While the probability of onward SARS-CoV-2 transmission was relatively low for the Alpha and Delta variants, the risk increased for the Omicron variant, especially in the absence of public health measures. Onward teacher-to-student transmission (88.9%, 95% CI = 88.6%-89.1%) and teacher-to-teacher SARS-CoV-2 transmission (98.4%, 95% CI = 98.5%-98.6%) were significantly higher for the Omicron variant without public health measures in place.
Our findings illustrate that, despite a lower frequency of close contacts, teacher-to-teacher close contacts demonstrated a higher risk of transmission per contact of SARS-CoV-2 compared to student-to-student close contacts. This was especially significant with the Omicron variant, with onward transmission more likely occurring from teacher index cases than student index cases. Public health measures (eg, face masks and physical distance) seem essential in reducing the risk of onward transmission within school environments.
严格的公共卫生措施已被证明会影响 SARS-CoV-2 在学校环境中的传播。我们使用 COVID-19 大流行前采集的精细身体定位轨迹，研究了有和没有公共卫生措施的小学环境中 SARS-CoV-2 的潜在传播情况。
我们使用了来自一所开放式小学的 98 名学生和 6 名教师的大约 1.7263 亿条位置数据，来预测小学环境中 SARS-CoV-2 的潜在传播。我们首先估计了潜伏期内学生和教师与感染个体的每日平均接触人数。然后，我们使用 Reed-Frost 模型来估计 SARS-CoV-2 Alpha（B.1.1.7）、Delta（B.1.617.2）和 Omicron 变异株（B.1.1.529）每一次接触的传播概率。最后，我们构建了二项分布模型，以估计有和没有公共卫生措施（包括戴口罩和保持身体距离）的学校中疾病传播的概率。
一名具有传染性的学生每天会与同学有 49.1（95%置信区间[CI]：46.1-52.1）次接触，与教师有 2.00（95%CI：1.82-2.18）次接触。一名具有传染性的教师每天会与学生有 47.6（95%CI：45.1-50.0）次接触，与同事教师有 1.70（95%CI：1.48-1.92）次接触。虽然 Alpha 和 Delta 变体的 SARS-CoV-2 传播概率相对较低，但 Omicron 变体的风险增加了，特别是在没有公共卫生措施的情况下。在没有公共卫生措施的情况下，Omicron 变体的教师到学生的 SARS-CoV-2 传播（88.9%，95%CI：88.6%-89.1%）和教师到教师的 SARS-CoV-2 传播（98.4%，95%CI：98.5%-98.6%）风险更高。
我们的研究结果表明，尽管密切接触的频率较低，但与学生密切接触相比，教师与教师之间的密切接触每一次接触 SARS-CoV-2 的传播风险更高。在 Omicron 变体中，这种情况更为显著，从教师的病例到学生的病例的传播更有可能发生。公共卫生措施（如口罩和保持身体距离）似乎对于降低学校环境中疾病传播的风险至关重要。
