扬州市2015~2017年诺如病毒感染聚集性疫情分子流行病学特征分析

Molecular epidemiology of norovirus gastroenteritis outbreaks in Yangzhou city from 2015 to 2017

Objective To analyze the epidemic characteristics of norovirus gastroenteritis outbreaks in Yangzhou city in 2015~2017. Methods Epidemiologic data and specimens of 26 gastroenteritis outbreaks in Yangzhou city from January 2015 to December 2017 were collected. All 452 specimens were detected for norovirus nucleic acid by using real-time RT-PCR method. Results There were 26 norovirus gastroenteritis outbreaks with 452 cases in Yangzhou City during 2015~2017 with attack rates from 1.07% to 15.02% and positive rate of 40.71%. Fifteen outbreaks occurred in primary schools, 6 outbreaks occurred in middle schools and 5 outbreaks occurred in nurseries. Outbreaks occurred with a higher incidence in cold seasons. Twenty-three outbreaks occurred during December and April of the following year. All 26 outbreaks were induced by genogroup II norovirus infection. Conclusion Norovirus has become one of the most major pathogens causing acute gastroenteritis outbreaks in Yangzhou City, and genogroup II norovirus is identified as the predominant strains. Outbreak of norovirus infection usually occurs in schools and nurseries during winter and spring. The surveillance for norovirus infection should be strengthened in schools and nurseries, especially in cold seasons.