Expanding Host Range and Cross-Species Infection of Hepatitis E Virus

Hepatitis E is an important public health disease 1. Although the mortality rate is less than 1% in the general population, it can reach up to 25% in infected pregnant women. According to the World Health Organization, each year an estimated 20 million infections occur worldwide resulting in >3 million symptomatic cases and 56,600 hepatitis E-related deaths (http://www.who.int/mediacentre/factsheets/fs280/en/). Large explosive waterborne outbreaks of hepatitis E are generally seen in developing countries with poor sanitation conditions, whereas in industrialized countries, sporadic and cluster cases of hepatitis E have been reported. Hepatitis E is a self-limiting acute disease that normally does not go into chronicity. However, recently, chronic hepatitis E has become a significant clinical problem in immunocompromised individuals such as organ transplant recipients 2. The discovery of animal strains of hepatitis E virus (HEV) 3 that infect across species barriers revolutionizes the way we used to think about this important disease. Hepatitis E is now recognized as a zoonotic disease, and animal reservoirs exist 4. Herein, I briefly discuss the ever-expanding host ranges, cross-species infection, zoonotic risk, and food safety of HEV.