Epidemiology Investigation
Epidemiological characteristics of norovirus outbreaks in Shenzhen during 2005 to 2017
Zhen Zhang, Yuan Li, Hailong Zhang, Yan Lu, Shujiang Mei, Jialiang Du, Xu Xie
Published 2019-09-30
Cite as Chin J Microbiol Immunol, 2019, 39(9): 693-697. DOI: 10.3760/cma.j.issn.0254-5101.2019.09.009
Abstract
ObjectiveTo investigate the epidemiological characteristics of norovirus outbreaks in Shenzhen during 2005 to 2017 in order to provide reference for disease control and prevention.
MethodsMonitoring data of norovirus outbreaks in Shenzhen from January 1, 2005 to December 31, 2017 were collected from Shenzhen Communicable Disease Information System and China Information System for Disease Control and Prevention. Descriptive epidemiological methods were used for data analysis.
ResultsFrom January 2005 to December 2017, 346 norovirus outbreaks (five or more cases in one community within one week) were reported in Shenzhen, of which 6.36% (22/346) were public health emergency events. Fewer outbreaks were reported during 2006 to 2013 and they were mainly caused by GⅡ.4 genotype, but the number increased sharply since 2014 with 57.80% (200/346) occurred in 2016—2017 and the epidemic genotype changed from GⅡ.4 to GⅡ.17 and GⅡ.2. The outbreaks peaked during November to March (76.88%, 266/346). There were 63.87% (221/346) reported in urban areas, 67.05% (232/346) in nurseries and 23.70% (82/346) in primary/middle schools. Among the 22 public health emergency events, 40.91% (10/22) were caused by person-to-person contacts, 40.91% (10/22) by foodborne transmission and 13.64% (3/22) by waterborne transmission. Moreover, 75.80% (238/314) of the outbreaks in nurseries and primary/middle schools were confined to one classroom and most were due to contact transmission.
ConclusionsNorovirus outbreaks increased obviously since 2014, which might be related to the changes of the predominant genotype from GⅡ.4 to GⅡ.17 and GⅡ.2. It is necessary to strengthen a comprehensive prevention and control in key units such as nurseries and primary/middle schools in winter and spring.
Key words:
Norovirus; Outbreak; Public health emergency; Genotype
Contributor Information
Zhen Zhang
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
Yuan Li
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
Hailong Zhang
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
Yan Lu
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
Shujiang Mei
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
Jialiang Du
Division of Enteric Viral Vaccines, National Institutes for Food and Drug Control, Beijing 102629, China
Xu Xie
Information and Technology Division, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
