2016-2018年成都市GⅠ和GⅡ群诺如病毒感染疫情分析

Analysis on GⅠand GⅡNorovirus Epidemics From 2016 to 2018 in Chengdu

目的探索不同群别诺如病毒感染疫情的差异和相关因素。方法共纳入2016-2018年成都市227起诺如病毒感染聚集性疫情,分别采用卡方检验和t检验比较分类和连续性资料,采用二元非条件Logistic回归分析不同群别诺如疫情相关因素。结果 GⅠ群疫情20起(8.81%),GⅡ群207起(91.19%)。GⅠ群疫情占比随着年份增加而增加,2018年最高为12.82%。近郊(12.68%)的GⅠ群占比高于主城区(6.02%)。1-3月(11.48%)、4-9月(17.31%)的GⅠ群占比高于10-12月(3.51%)。GⅠ群诺如疫情的罹患率为1.82%,低于GⅡ群的3.05%。分析显示,相较于主城区,近郊区的诺如疫情更可能为GⅠ(OR=0.21,95%CI:0.06~0.73);相较于10-12月,1-3月(OR=0.16,95%CI:0.03~0.77)或4-9月(OR=0.14,95%CI:0.03~0.63)的诺如疫情更可能为GⅠ;GⅡ群诺如疫情罹患率更高(OR=1.97,95%CI:1.02~3.78)。结论成都市诺如疫情主要由GⅡ群导致,GⅠ、GⅡ群诺如疫情在时间分布、区域分布以及罹患率上存在差异。

Objective To explore the differences and related factors of GⅠand GⅡNorovirus epidemics from 2016 to 2018 in Chengdu.Methods A total of 227 epidemics were included from 2016 to2018.Chi-square and t-test were used to compare categorical and continuous data respectively.Unconditional logistic regression was applied to analyze the associations.Results There were 20(8.81%)GⅠNorovirus epidemics,while there were 207(91.19%)GⅡepidemics.The percentage of GⅠepidemics increased from 2016 to 2018,reaching to the top in 2018(12.82%).The percentage of GⅠepidemics in the suburb area(12.68%)was higher than that in the center district(6.02%).The percentage of GⅠepidemics from January to March(11.48%)and from April to September(17.31%)than that from October to December(3.51%).The attack rate of GⅠNorovirus epidemics(1.82%)was lower than that of GⅡepidemics(3.05%).The suburb area had more GⅠepidemics compared to the center district(OR=0.21,95%CI:0.06-0.73).The period of January to March(OR=0.16,95%CI:0.03-0.77),and April to September(OR=0.14,95%CI:0.03-0.63)had more GⅠepidemics compared to the period of October to December.GⅡepidemics had a bigger attack rate(OR=1.97,95%CI:1.02-3.78).Conclusion Most Norovirus epidemics in Chengdu were caused by GⅡ.Differences of GⅠand GⅡNorovirus epidemics were found in the time and region distribution,as well as the attack rate.