Agència de Salut Publica de Catalunya, Barcelona, Spain.
Department of Medicina, Universitat de Barcelona, Barcelona, Spain.
Microbiol Spectr. 2022 Jun 29;10(3):e0011922. doi: 10.1128/spectrum.00119-22. Epub 2022 May 11.
We studied outbreaks of acute gastroenteritis due to norovirus in schools and summer camps during 2017-2019 in Catalonia (Spain). The overall attack rate was 21.27% in schools and 33.42% in summer camps (RR 0.64 [95% CI 0.58-0.70]) and 52.63% of outbreaks occurred in cold months and 47.37% in warm months. The mean delay in reporting was 5.61 days (SD 5.58 days) and the mean duration was 6.11 days (SD 6.08 days), with a Pearson correlation coefficient of 0.84 ( < 0.001) between these variables. In outbreaks with person-to-person transmission, the aOR was higher the longer the delay in reporting: 3.07 (95% CI 1.21-7.81) when the delay was 5-8 days and 3.81 when it was >9 days (95% CI 1.42-10.23). The cold months posed a higher risk than the warm months. In common source outbreaks the risk was higher in children in secondary-higher education and in summer camps. Norovirus is the main cause of viral acute gastroenteritis outbreaks worldwide. The low infectious dose and the lack of long-term immunity in infected persons means that norovirus often causes outbreaks in institutions and closed and semiclosed centers. Norovirus gastroenteritis are usually mild, with no complications, but occasionally can result in hospital admission. Understanding the risk factors involved in a norovirus outbreak can reduce the spread, severity, and duration of the outbreak and, when a vaccine becomes available, this understanding would help us identify the population groups need to get vaccinated. Here, we show the outbreaks due to norovirus in schools and summer camps, the correlation between the delay in reporting and duration of outbreaks and the relationship of the attack rate and the size of the groups.
我们研究了 2017-2019 年期间加泰罗尼亚（西班牙）学校和夏令营中诺如病毒引起的急性肠胃炎暴发情况。学校的总发病率为 21.27%，夏令营为 33.42%（RR 0.64 [95%CI 0.58-0.70]），52.63%的暴发发生在寒冷月份，47.37%发生在温暖月份。报告的平均延迟时间为 5.61 天（SD 5.58 天），平均持续时间为 6.11 天（SD 6.08 天），这两个变量之间的皮尔逊相关系数为 0.84（<0.001）。在人与人之间传播的暴发中，报告延迟时间越长，比值比越高：报告延迟 5-8 天为 3.07（95%CI 1.21-7.81），延迟>9 天为 3.81（95%CI 1.42-10.23）。寒冷月份的风险高于温暖月份。在共同来源暴发中，中学后教育和夏令营中的儿童风险更高。诺如病毒是全球病毒性急性肠胃炎暴发的主要原因。感染人的感染剂量低且无长期免疫力，这意味着诺如病毒经常在机构和封闭及半封闭中心引起暴发。诺如病毒肠胃炎通常较轻，无并发症，但偶尔会导致住院。了解诺如病毒暴发的相关风险因素可减少暴发的传播、严重程度和持续时间，并且当疫苗可用时，这一了解将有助于我们确定需要接种疫苗的人群。在这里，我们展示了学校和夏令营中诺如病毒引起的暴发情况、报告延迟与暴发持续时间之间的相关性以及发病率与群体规模之间的关系。
