新冠流行前后江苏省诺如病毒食源性感染特征

Characteristics of norovirus foodborne infection in Jiangsu Province before and after COVID-19 epidemic

目的了解江苏省诺如病毒监测情况,并对新冠流行前和流行期间检出特征进行比较。方法通过江苏省食源性疾病监测网络收集2015—2021年诺如病毒病例标本检测和分型结果,采用描述性流行病学方法,对诺如病毒检测结果进行分析,并比较2015—2019年(新冠流行前)与2020—2021年(新冠流行期间)诺如病毒检出情况。结果2015—2021年江苏省共检测73190份样本,诺如病毒阳性率5.68%;7年检出率在4.35%~10.59%,差异有统计学意义(χ^(2)=586.24,P<0.01)。诺如病毒阳性检出率以14~34岁组(7.03%)、冬季(10.81%)、有呕吐症状(9.26%)、进食场所为集体食堂(9.82%)、可疑食品为肉与肉制品(6.72%)较高,不同年龄组、季节、症状、进食场所、可疑食品类型的检出率差异均有统计学意义(χ^(2)值为12.75~827.56,P值均<0.05)。流行前阳性检出率(6.26%)高于流行期间(4.46%);与流行前阳性检出率相比,春、夏、秋季降低为22.25%~50.96%,冬季提高了42.81%,以上差异均有统计学意义(χ^(2)值为16.14~86.45,P值均<0.05)。7年共成功分型诺如病毒2657份,基因型以GII型为主(占71.70%),其次依次为GI型(占23.71%)和GI/GII型(占4.59%);流行前和流行期间的基因型构成比顺位相同,但分布差异有统计学意义(χ^(2)=1840.71,P<0.05)。结论针对COVID-19流行的防控措施可降低诺如病毒食源性感染的流行水平。

Objective To understand the surveillance of norovirus in Jiangsu Province in recent years;to compare and analyze the detection characteristics before and during the epidemic of COVID-19.Methods The norovirus detection and typing results of case specimens from 2015 to 2021 were collected through the the Jiangsu Provincial Foodborne Disease Surveillance Network,which were subjected to descriptive epidemiological analysis for the norovirus detection results;the detection rates of norovirus between 2015-2019(before COVID-19 epidemic)and 2020-2021(during COVID-19 epidemic)were compared.Results A total of 73,190 samples were detected from 2015 to 2021,resulting a positive rate of 5.68%.The annual detection rate ranged from 4.35%to 10.59%,with a statistically significant difference(χ^(2)=586.24,P<0.01).The positive detection rate of norovirus was highest among the 14 to 34-year age group(7.03%),in winter(10.81%),with vomiting symptoms(9.26%),eating place of dining hall(9.82%),and suspicious food of meat or meat products(6.72%),with statistically significant differences among different age groups,seasons,symptoms,eating places,and suspicious food types(χ^(2) values were 12.75-827.56,all P<0.05).The positive detection rate before the epidemic(6.26%)was higher than that during the epidemic(4.46%).Compared with the positive detection rates before epidemic,the positive detection rates in spring,summer,and autumn decreased by 22.25%to 50.96%,and in winter increased by 42.81%,all with statistically significant differences(χ^(2) values were 16.14-86.45,all P<0.05).A total of 2657 cases were typed successfully,h the GII subtype was the domi-nant genotype(71.70%),followed by GI(23.71%)and GI/GII(4.59%);The genotype compositions before and during the epidemic were the same in order,but the distribution was statistically significant(χ^(2)=1840.71,P<0.05).Conclusions Prevention and control measures in response to the COVID-19 pandemic may reduce the prevalence of norovirus foodborne infections.