[Epidemiological analysis of viral hepatitis E in China, 2004-2017]

Objective: To analyze the changing epidemiological characteristics of hepatitis E cases in China, in order to promote in preventing and controlling hepatitis E. Methods: Data of hepatitis E and outbreaks reported through national notifiable diseases reporting system were analyzed from 2004 to 2017, but data of Hongkong, Macau and Taiwan were not included. Data of hepatitis E were divided into three phases as 2004-2007, 2008-2011 and 2012-2017, representing eight years before, four years before and years after the postmarketing of hepatitis E vaccine. Linear regression was used for analyzing the trend of hepatitis E, improved muster method was used for analyzing the seasonal intensity. Results: From 2004 to 2017, 329 519 hepatitis E cases were reported and the annual incidence were increasing from 1.27/100 000 to 2.10/100 000 (t=6.87, P<0.001). The concentrations of hepatitis E during 2004-2007, 2008-2011 and 2012-2017 were 17.43, 16.06, 11.17, respectively, with low seasonal intensity. Number of cases reported by Jiangsu, Guangdong and Zhejiang accounted for 31.54% of national cases. The incidence were lower in central (1.45/100 000) and western (1.11/100 000) region than that in eastern region (2.67/100 000), but were increasing continuously. There was an increasing trend of incidence with growing ages (t=7.85, P<0.001). The incidence was higher than 2/100 000 among cases aged ≥40, and was the highest (5.22/100 000) in the age group of 65-69 years old. Farmers, retired persons, houseworkers and unemployees accounted for 67.46% of total cases. A total of 7 outbreaks were reported, among which 3 were in nursing homes. Conclusion: The incidence of hepatitis E in central and western regions were increasing continuously and the surveillance should be strengthened. There was higher risk among middle-aged population, farmers and nursing homes, so strategy for immunization among those population was in great need.