[Epidemiological analysis of viral hepatitis A in China, 2004-2015].

Objective: To analyze the epidemiological characteristics of hepatitis A cases in China from 2004 to 2015. Methods: Data of hepatitis A were reported through national notifiable disease information reporting system, which covered the 31 provinces (Hong Kong, Macau and Taiwan excluded). The inclusion criteria was: date of illness onset was between January 1(st) 2004 and December 31(st) 2015, the status of reported card was confirmed, the case was classified as laboratory confirmed or clinical diagnosed, the disease was Hepatitis A. The information such as sex, date of birth, date of illness onset, place of residence was collected. The data was divided into three phases, 2004-2007, 2008-2011, 2012-2015, which represented the phase before expanded program on immunization (EPI), first 4 years after EPI, second 4 years after EPI. Results: From 2004 to 2015, there were totally 574 697 hepatitis A cases in China, the mean annual incidence was 3.62/100 000. The risk ratio of hepatitis A in 2015 was 0.23 when compared with 2004. Sichuan, Xinjiang and Yunnan contributed to 27.27% of the total cases in China. In 2012-2015, the incidence of western (3.46/100 000) region was significantly higher than that in central (1.21/100 000) and eastern (1.08/100 000) regions. From 2004-2015, number of cases in each age group declined greatly, with number of cases declining from 43 711 to 5 938 in the age group of 5-9 years, from 29 722 to 3 438 in 10-14, from 23 212 to 3 646 in 15-19. The number of cases declined from 24 079 to 10 304 in the age group of 0-4 (declined by 57.21%), but in 2012-2015, the incidence of 0-4 age group was still the highest, with 77.72% cases in Xinjiang and Sichuan. Famers, students and scattered children accounted for 69.95% of total cases, with student cases declined from 24.08% (2004-2007) to 8.67% (2012-2015). Conclusion: The incidence of hepatitis A in China is decreasing year by year, the risk has been decreasing to a relatively low level. However, in western regions and children under age five, the risk is still high. Precision intervention is needed for further prevention and control of hepatitis A.