Review article: hepatitis E—a concise review of virology, epidemiology, clinical presentation and therapy

Abstract

SummaryBackground: Hepatitis E virus (HEV) is a leading cause of acute icteric hepatitis and acute liver failure in the developing world. During the last decade, there has been increasing recognition of autochthonous (locally acquired) HEV infection in developed countries. Chronic HEV infection is now recognised, and in transplant recipients this may lead to cirrhosis and organ failure.Aim: To detail current understanding of the molecular biology of HEV, diagnostic and therapeutic strategies and propose future directions for basic science and clinical research.Methods: PubMed was searched for English language articles using the key words "hepatitis E", "viral hepatitis", "autochthonous infection", "antiviral therapy", "liver transplantation", "acute", "chronic", "HEV", "genotype", "transmission" "food-borne", "transfusion". Additional relevant publications were identified from article reference lists. Future work should focus on increasing awareness of HEV infection in the developed world, emphasising the need for clinicians to have a low threshold for HEV testing, particularly in immunosuppressed patients. Patients at potential risk of chronic HEV infection must also be educated and given advice regarding prevention of infection.

Incidence of hepatitis E virus infection among blood donors in a high endemic area of Central Italy

“…The results of our exposure analysis are important because they are consistent with others’ and our previous findings, stressing the role of certain dietary habits in determining the spread of HEV infection in some geographic areas …”

“…Studies conducted among the general population and blood donors in Europe found variable anti‐HEV seroprevalence rates, with important variation even within the same country . Despite the lack of a concerted satisfying definition of the levels of HEV endemicity, also in Europe some areas showing seroprevalence rates approaching to and over 50% have been classified as hyperdendemic . The great variability in prevalence was also confirmed by comparing studies using the same anti‐HEV assay .…”

“…In developed countries, autochthonous hepatitis E virus (HEV) infection is mostly caused by genotypes 3 and 4 and is mainly a zoonosis acquired by eating contaminated raw or undercooked meat (including organs) from infected animals (pigs, wild boars, deer and rabbits) or by contact with them . Transmission may also occur by ingesting vegetables, shellfish and water contaminated by waste from infected animals and humans . Finally, transmission by blood transfusion or transplanted solid organs has been well documented .…”

“…Finally, transmission by blood transfusion or transplanted solid organs has been well documented . Genotypes 3 and 4 usually cause a mild self‐limited infection, but immunocompromised persons may develop chronic hepatitis and cirrhosis …”

Patterns of mutation within an emerging endemic lineage of HEV‐3a

“…In most symptomatic patients with no underlying conditions, an HEV infection resembles typical acute viral hepatitis and usually resolves spontaneously . However, in immunocompromised patients, HEV can cause chronic infections that last longer than 3 months . An understanding of the viral mutations that arise in patients with an impaired or weakened immune response may yield insights into fundamental viral mutational patterns and biases, as well as the rate of turnover in dominant viral sequence.…”