中国扩大国家免疫规划前后不同流行区甲型肝炎报告发病率变化的中断时间序列分析

Interrupted time series analyses of hepatitis A incidence in different endemic areas of China before and after introduction of hepatitis A vaccine into the national Expanded Program on Immunization

目的分析中国扩大国家免疫规划(Expanded Program on Immunization,EPI)前后不同流行区甲型病毒性肝炎(甲肝)报告发病率变化。方法利用中国传染病报告信息管理系统收集1991-2020年甲肝报告发病率,采用中断时间序列(Interrupt time series,ITS)方法分析2008年甲肝疫苗(Hepatitis A vaccine,HepA)纳入EPI前后全国和中、低、极低流行区甲肝报告发病率变化。结果中国HepA纳入EPI前(1991-2007年)、纳入当年(2008年)和纳入后(2009-2020年)甲肝年或年均报告发病率分别为19.96/10万、2.39/10万和1.81/10万,1991-2020年报告发病率呈线性下降趋势(Z=-20.35,P<0.0001)。ITS模型分析显示,HepA纳入EPI后全国全人群甲肝发病率的斜率为-0.03;中、低、极低流行区发病率的斜率分别为-0.10、0.44、0.68;HepA纳入EPI后全国0-14岁儿童甲肝发病率的斜率为-0.47,中、低、极低流行区发病率的斜率分别为-0.54、-0.13、0.95。结论HepA纳入EPI后全人群特别是儿童甲肝报告发病率显著下降,但下降趋势放缓。

Objective To analyze trends of reported incidences of hepatitis A in different endemic areas of China before and after the 2008 introduction of hepatitis A vaccine(HepA)into the national Expanded Program on Immunization(EPI).Methods We obtained hepatitis A incidences for 1991 through 2020 from the National Notifiable Disease Reporting System.We used interrupted time series(ITS)analyses to determine changes of reported hepatitis A incidence nationwide and in medium,low,and extremely low endemic areas before and after the 2008 introduction of HepA into EPI.Results The annual or annual average reported incidences of hepatitis A before(1991-2007),during the introduction year(2008),and after HepA introduction(2009-2020)were 19.96,2.39,and 1.81 per 100000 population,respectively,with a monotonic decline of incidence from 1991 through 2020(Z=-20.35,P<0.0001).ITS analyses showed that the slope of hepatitis A incidence among the national population was-0.03 after HepA introduction,with incidence slopes in medium,low,and extremely low endemic areas being-0.10,0.44,and 0.68,respectively.The hepatitis A incidence slope among 0-14-year-olds nationwide after introduction of HepA was-0.47,with slopes in medium,low,and extremely low endemic areas being-0.54,-0.13,and 0.95.Conclusions The reported national incidence of hepatitis A declined significantly after introduction of HepA into EPI,especially among children,but the downward trend slowed.