Global Burden and Evolving Understanding of Hepatitis E Virus

Abstract

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis worldwide, recognized as a significant global public health concern. Recent advancements in understanding the natural history of HEV infection have shed light on its epidemiology and clinical implications. The primary mode of HEV transmission is fecal-oral, occurring through contaminated water or food. Parenteral transmission, particularly through blood transfusions, was initially overlooked but has been increasingly recognized in both developing and industrialized countries. Acute HEV infection typically manifests as self-limiting jaundice, particularly in immunocompetent individuals. However, recent data suggest that acute infection can progress to a chronic form in various immunosuppressive conditions, including solid organ transplantation, hematological malignancies, and human immunodeficiency virus (HIV) infection. Chronic HEV can lead to cirrhosis, which may progress rapidly in some cases. Extrahepatic manifestations, particularly neurological complications, have also been reported. HEV remains underdiagnosed globally due to a lack of awareness among healthcare providers in many regions. Advances in serological and molecular assays have facilitated reliable diagnosis, both in immunocompetent and immunocompromised patients. Ribavirin monotherapy has proven effective in treating chronic HEV infection in immunosuppressed individuals and is currently widely recommended. However, its efficacy in acute HEV remains inconclusive. In 2011, an effective and well-tolerated HEV vaccine was developed and approved in China. This vaccine holds promise for high-risk populations, particularly individuals with cirrhosis and travelers to endemic regions.