Overview
Hepatitis E is inflammation of the liver caused by infection with the hepatitis E virus (HEV). It is classified among the viral hepatitides and typically produces an acute, self-limiting illness, though outcomes vary by patient group and viral genotype. For basic virology information see hepatitis E virus and for broader context see viral hepatitis and hepatitis.
Transmission and clinical features
The principal route of transmission is fecal–oral, commonly through contaminated water supplies in areas with limited sanitation, which makes its epidemiology similar to hepatitis A (see hepatitis A). Signs and symptoms are like other acute hepatitis syndromes and may include fatigue, jaundice, abdominal discomfort, dark urine and elevated liver enzymes. Most healthy adults recover fully, but severe illness is more likely in certain groups.
Who is at higher risk
- Pregnant people—especially in the later stages of pregnancy—can develop severe disease and complications.
- Immunocompromised patients may develop chronic HEV infection, sometimes leading to progressive liver damage.
- People exposed to contaminated water or certain animal reservoirs through food or occupation.
Virology and genotypes
Multiple HEV genotypes infect humans. Some genotypes are primarily human-to-human, while others are zoonotic and can be transmitted from animals (for example, through undercooked pork or game). Zoonotic transmission is an important cause of sporadic cases in higher-income settings. Chronic infection is most often described with particular genotypes in people who have weakened immune systems.
History and epidemiology
Large outbreaks of hepatitis E have been recognized in regions with poor sanitation; a notable early epidemic occurred in New Delhi in the mid-20th century. The hepatitis E virus was identified later, during investigations of outbreaks in Asia. HEV remains an important cause of acute hepatitis globally, with distinct patterns in endemic and non-endemic regions.
Diagnosis, management and prevention
Diagnosis relies on detecting HEV-specific antibodies or viral RNA in blood or stool. Management of acute hepatitis E is mainly supportive care; antiviral therapy or reduction of immunosuppression may be considered in chronic cases. Preventive measures focus on safe water, sanitation, food hygiene and cooking pork and game thoroughly. A vaccine has been developed and used in some countries but is not yet globally available. For comparisons with other human hepatitis viruses see hepatitis B, hepatitis C and hepatitis D.
Further reading and resources: general virology and public health guidance are available from authoritative sources; for virology details visit hepatitis E virus and for disease overviews consult pages on viral hepatitis and hepatitis. Historic outbreak accounts include events in New Delhi and other endemic areas.