ABSTRACT
Objective To understand the epidemiological characteristics of norovirus detection based on the diarrhea syndromic surveillance in Pudong ,Shanghai .Methods Diarrhea syndromic surveillance program was conducted in outpatient and emergency departments of 12 sentinel hospitals during 2012 -2016 .The clinical and epidemiological data of diarrheal patients were collected .The fecal specimens were also sampled . The detections for norovirus by polymerase chain reaction and gene sequencing were performed .Chi-square test or Fisher exact probability test was used to compare the detection rate .Binary logistic regression was used to explore the impact factors of norovirus infection among diarrheal patients . Results The detective rate of norovirus among diarrheal patients was 21 .59％ ,peaking from October to next March .Among all the age groups ,the detection rate was highest among patients with 25 - 64 years old .The patients with more severe diarrhea symptoms (> 5 times a day) were more likely to be infected with norovirus than those with diarrhea 3 - 5 times a day (χ2 = 21 .167 ,P< 0 .01) .Vomiting was also an indicator of norovirus infection .Patients presented with vomiting had a higher norovirus detection rate (χ2 = 198 .543 , P < 0 .01) . Norovirus G Ⅱ was the predominant genotype .Conclusions The recent epidemic of norovirus infection in diarrheal patients in Pudong new district has an apparent seasonality peaked from October to next March .Adult ,patients with vomiting and more severe diarrhea symptoms are at risk of norovirus infection .The long-term surveillance is critical for the norovirus infection control .