Epidemiological characteristics of hepatitis A in Jiangsu, 2005−2022

Objective To analyze the epidemiological characteristics and possible spatiotemporal incidence clustering of viral hepatitis A in Jiangsu province during 2005−2022, and provide evidence for the effective prevention and control of hepatitis A.

Methods The incidence data of hepatitis A in Jiangsu during 2005−2022 were collected from China Disease and Prevention Information System for a descriptive epidemiological analysis. Software SPSS 17 was used for the evaluation of the time and gender specific differences in the incidence. Software Joinpont 4.8.0.1 was used to analyze the change trend of the incidence over time. Software Arcgis 10.3 was used to visualize the area distribution of hepatitis A incidence. Software SaTScan9.7 was used for a retrospective spatiotemporal scanning analysis.

Results A total of 18 862 cases of hepatitis A were reported in Jiangsu during 2005−2022, with an average annual incidence rate of 1.31 per 100 000. The incidence rate decreased from 3.14 per 100 000 during 2005−2007 to 0.59 per 100 000 during 2020−2022 (average annual percentage change=−9.10%, 95% confidence interval: −12.20% – −6.00%). Hepatitis mainly occurred in spring during 2005−2007 (shortly after hepatitis A vaccination was included in national immunization program), but the incidence seasonality has gradually disappeared by now. The male to female ratio of hepatitis A cases was 2.30∶1 during 2005−2007, but 0.97∶1 during 2020−2022. The cases were mainly distributed in age group 45−55 years. Farmers, workers, the jobless or unemployed and retirees were the mostly affected. The incidences of hepatitis A were high in coastal areas and river net areas, such a: Huqiu near Taihu lake, Jiawang near Weishanhu lake, Xinghua and Jiangdu near Gaoyou lake. During 2005−2022, spatiotemporal scanning detected a incidence clustering area in coastal area in southeastern Jiangsu.

Conclusion The reported incidence of hepatitis A in Jiangsu during 2005−2022 showed a downward trend, the effect of hepatitis A immunization was obvious, and the population distribution was gradually stable, but area specific difference was observed. It is necessary to strengthen the surveillance for hepatitis A and conduct targeted prevention and control of hepatitis A in key populations and areas.