HEV and HBV Dual Infection: A Review

Hepatitis E virus (HEV) is a global health problem, affecting about 20 million people worldwide. There is significant overlap of hepatitis B virus (HBV) and HEV endemicity in many Asian countries where dual infections with HEV and HBV can occur. Though the clinical course of HEV is largely self-limited, HEV superinfection in patients with chronic hepatitis B (CHB) can result in acute exacerbation of underlying CHB. HEV superinfection in patients with CHB-related cirrhosis has been identified as a risk factor for decompensated cirrhosis and an independent predictor of mortality. Whereas acute HEV infection in pregnancy can cause fulminant liver failure, the few studies on pregnant patients with dual HBV and HEV infection have shown a subclinical course. Immunosuppression is a risk factor for the development of chronic HEV infection, which can be managed by decreasing the dose of immune-suppressants and administering ribavirin. Vaccination for HEV has been developed and is in use in China but its efficacy in patients with CHB has yet to be established in the USA. In this review, we appraise studies on dual infection with HEV and HBV, including the effect of HEV superinfection and coinfection in CHB, management strategies used and the role of active vaccination in the prevention of HEV.