Laboratory-based Surveillance and Clinical Profile of Sporadic HEV Infection in Shanghai, China

The study aimed to describe the epidemiological, virological and clinical features of sporadic HEV infection in eastern China. A total of 6112 patient sera were tested for anti-HEV IgG or anti-HEV IgM during one consecutive year (between August 2018 and July 2019). HEV RNA presence was evaluated by RT-PCR and HEV sequences were phylogenetically analyzed. Clinical features of confirmed HEV-infected patients were delineated. The sero-positivity rate of anti-HEV IgG maintained stable around 40%, while an obvious winter spike of anti-HEV IgM prevalence was observed. A total of 111 patients were confirmed of HEV viremia by molecular diagnosis. Subtype 4d was predominant. Phylogenetic analyses suggest that certain strains circulate across species and around the country. Subjects with confirmed current HEV infection had a high median age (58 years) and males were predominant (62.2%). Most patients presented with jaundice (75.7%) and anorexia (68.0%). Significantly elevated levels of liver enzymes and bilirubin were observed. Remarkably, the baseline bilirubin level was positively correlated with illness severity. Pre-existing HBV carriage may deteriorate illness. The clinical burden caused by locally acquired HEV infection is increasing. Surveillance should be enforced especially during the transition period from winter to spring. Patients with higher level of bilirubin at disease onset had slower recovery from HEV infection.

Automated summary

This study aimed to describe the epidemiological, virological, and clinical features of sporadic HEV infection in eastern China. The results showed a stable anti-HEV IgG positivity rate and a winter spike in anti-HEV IgM prevalence. Phylogenetic analysis revealed predominant subtype 4d circulating across species and the country. Patients with confirmed HEV infection were typically older males presenting with jaundice and anorexia, with elevated liver enzymes and bilirubin levels. Notably, higher baseline bilirubin levels were correlated with illness severity and pre-existing HBV carriage could worsen illness outcomes. Surveillance should be enhanced, especially during the winter to spring transition period.