Seroepidemiological survey of hepatitis E virus infection in Nantong City during 2010-2015

Objective：To investigate the infection status of hepatitis E virus (HEV) in the population of Nantong city during 2010-2015 and explore its epidemic features, thereby to provide data for the prophylaxis and treatment of hepatitis E. Methods：A total of 6 772 patients from the Affiliated Hospital of Nantong University during 2010-2015 who were all received serological detection of HEV were enrolled. Serum anti-HEV antibodies (IgM and IgG) were detected with ELISA. The infection rates of HEV were analyzed according to different years, ages, and genders, respectively, and the incidence of hepatitis E was evaluated. Results：During the recent six years, the total positive rate of anti-HEV antibody including IgM or/and IgG in 6772 subjects was 3.35%. The annual positive rates of anti-HEV during 2010 to 2015 were 6.92%, 1.74%, 3.53%, 0.90%, 3.50%, and 2.13%, respectively. The positive rates of anti-HEV in five groups of < 20, 20-29, 30-39, 40-49, and 59-59 years old increased with age (P=0.001). The positive rates of anti-HEV in patients whose age over 50 years declined gradually. The positive rate of anti-HEV in male patients was significantly higher than that in female patients (P=0.001). The apparent infection rate in the 227 patients with positive anti-HEV antibody was 72.25%, among whom the incidence of acute icteric hepatitis was significantly higher than that of acute anicteric hepatitis (P=0.001). In patients infected with HEV, the overlapping infection rate of HBV-HEV, HCV-HCV, and HAV-HEV were 21.15% and 0.88%, 0.44%, respectively. There were no statistical differences in the serum levels of ALT, AST, and TBIL between the patients with overlapping infection of HBV-HEV and those with only hepatitis E. However, the level of prothrombin activity (PTA) and serum albumin (ALB) in the overlapping infection group were lower than that in the simple hepatitis E group (P<0.01). Conclusions：In the population of Nantong city, the infection rate of HEV in 2010 was 6.92%, which remained at a low level during the following 5 years (0.90%-3.53%). The infection rate of HEV in males was higher than that in females. There was a relative high risk for HEV infection in 40-59 years old people. After the HEV infection, the manifestation of most patients was acute icteric hepatitis. For chronic hepatitis B patients overlapped with HEV infection, the liver injury might be aggravated.