Surveillance of the ‘bud event of norovirus-associated gastroenteritis’ in schools: does it work in the prevention of norovirus infection outbreaks in Shanghai?

Abstract

Outbreaks of norovirus-associated gastroenteritis have been reported in schools in recent decades in China. For early warning and response to infectious disease outbreaks, the Shanghai Infectious Diseases Bud Event Surveillance System (IDBESS) was established in 2016. Bud event is a term used for the early sign of a potential infectious disease outbreak in public settings when the first few cases appear. This study aimed to describe the epidemiological characteristics of Norovirus-associated gastroenteritis bud events from June 2016 to December 2017 and to understand factors influencing the severity of events. Data were extracted from the IDBESS, supplemented by field investigations and school absence surveillance. In total, 189 bud events of Norovirus-associated gastroenteritis were reported in schools and kindergartens, affecting 3827 individuals and 52.38% happened in primary schools. The attack rate of Norovirus-associated gastroenteritis was 3.82% on average in students in the affected schools. In each event, case numbers varied between 5 and 148, with a median of 16. The duration of bud events lasted for 2 days on average. School absence happened in 47.93% (1797/3749) of affected students and the average duration of absence was 3.07 days. It was found that a longer delay before reporting was associated with a longer-lasting duration of bud event (OR = 2.25, 95% CI: 1.65, 3.07). In conclusion, ascribed to the sensitive threshold for alerting and the timely field investigation, the surveillance of bud events of Norovirus-associated gastroenteritis is effective in the control of Norovirus infection among preschool children and students in Shanghai.

Outbreaks of Gastroenteritis Due to Norovirus in Schools and Summer Camps in Catalonia, 2017–2019

“…The mean number of people affected in each outbreak (34 people per outbreak) is in line with the results found by Lian et al in a study conducted between 2014 and 2017 in China (mean of 34 people per outbreak) ( 27 ) and is not very different from that described by Wikswo et al in outbreaks of person-to-person transmission in the US in 2009–2010 (mean of 44 people per outbreak) ( 24 ) or from the mean of 40 people per outbreak observed by the same authors in 2009–2013 ( 28 ). He et al found a median of 16 persons affected by outbreaks (range 5 to 148) in Shanghai schoolchildren between June 2016 and December 2017 ( 11 ).…”

“…Lian et al in China between 2014 and 2017 found that 47.98% of affected schoolchildren were in primary school versus 16.86% in early childhood education ( 27 ). Wang et al found that 54.9% of affected children in Shanghai in 2017 were primary school children compared with 39.73% in early childhood education ( 25 ) and He et al in Shanghai between June 2016 and December 2017 found that 61.08% of affected children were in primary school ( 11 ).…”

“…In England from 2014 to 2019, 18.4% of all suspected or confirmed norovirus outbreaks occurred in educational settings ( 10 ). In Shanghai in 2016 and 2017 there were 215 outbreaks of norovirus reported, 87.91% (189 outbreaks) of them occurred in schools and kindergartens ( 11 ). In the United States between 2013 and 2018 there were 1409 norovirus outbreaks in schools and universities affecting 83,669 people ( 12 ).…”

Types of gastrointestinal disorders and symptoms

“…In addition, there is the norovirus, which is a well-known infectious gastrointestinal disease. It is so severe in Chinese schools that in 2016 the Shanghai government implemented a detection system to warn of pervasive virus infection [5]. Sadly, no specific treatment has yet been discovered [6].…”