[Incidence and spatiotemporal clustering of hepatitis B in China, 2006-2020]

Objective: To analyze the incidence and spatiotemporal clustering of hepatitis B in China from 2006 to 2020 and provide reference for hepatitis B prevention and control. Methods: The incidence data of hepatitis B in 31 provinces (autonomous regions and municipalities) from 2006 to 2020 were collected from National Notifiable Infectious Disease Reporting System of China Information System for Disease Control and Prevention. The incidence trend analysis was conducted by using software Joinpoint 5.0.2, and the spatiotemporal scan analysis was performed by using software SaTScan 10.1.2. Results: From 2006 to 2020, a total of 1 049 546 cases of acute hepatitis B were reported in China. The average annual reported incidence rate was 5.17/100 000. The reported incidence rate showed a decreasing trend during this period. The incidence decreased from 3.00/100 000 to 0.41/100 000 in age group 0-14 years, from 14.15/100 000 to 3.44/100 000 in age group 15-34 years, and from 6.87/100 000 to 3.72/100 000 in age group ≥35 years, the differences were all significant (all P<0.001). From 2006 to 2020, a total of 10 732 017 cases of chronic hepatitis B were reported in China. The average annual reported incidence rate was 52.85/100 000. The reported incidence of chronic hepatitis B varied in different age groups, which decreased from 11.38/100 000 to 2.18/100 000 in age group 0-14 years, and from 73.17/100 000 to 61.40/100 000 in age group 15-34 years, while increased from 48.07/100 000 to 90.75/100 000 in age group ≥35 years, the differences were all significant (all P<0.05). Spatiotemporal scan analysis indicated that the age of reported acute hepatitis B cases became older over time, and the regions with high-incidence gradually shifted from western China to southwestern China. The overall reported incidence of chronic hepatitis B in those aged ≥35 years showed an upward trend, and the regions with high-incidence were mainly found in coastal area in southeastern China and in southwestern China. Conclusions: From 2006 to 2020, the overall reported incidence of acute hepatitis B in China showed a continuous downward trend, while the reported incidence of chronic hepatitis B in those aged ≥35 years showed an upward trend. It indicated that the need to improve the diagnosis and treatment of chronic hepatitis B in adults in coastal area in southeastern China and southwestern China.