Description

Hepatitis E, which is caused by the hepatitis E virus (HEV), cannot be distinguished reliably from other forms of acute viral hepatitis except by specific serologic testing. Testing availability is limited, and no serologic test is licensed in the United States.

Occurrence

HEV, which is transmitted by the fecal-oral route, occurs both in epidemic and sporadic forms. Transmission is associated primarily with ingestion of feces-contaminated drinking water. The potential for HEV transmission from contaminated food is still under investigation, and there is no evidence of transmission by percutaneous or sexual exposures.

Hepatitis E occurs primarily in adults. The highest rates of symptomatic disease (jaundice) have been in young to middle-aged adults. Lower disease rates in younger age groups may be the result of subclinical HEV infection. Chronic infection does not occur.

Epidemics and sporadic cases of hepatitis E have been reported from areas of Asia (Afghanistan, Bangladesh, Burma [Myanmar], China, India, Indonesia, Kazakhstan, Kyrgyzstan, Malaysia, Mongolia, Nepal, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan), Mexico, the Middle East, Northern Africa, and sub-Saharan Africa. No outbreaks have been recognized in Europe, the United States, Australia, or South America. Hepatitis E usually occurs in persons who travel to or live in an endemic area. However, two cases have been identified in U.S. residents with no history of recent international travel. Studies are in progress to determine if hepatitis E is an endemic disease in the United States.

Clinical Presentation

The incubation period averages 40 days (range 15-60 days). Signs and symptoms, if they occur, include fatigue, loss of appetite, nausea, abdominal pain, and fever. Most patients with hepatitis E have a self-limiting course, and treatment is supportive. Hepatitis E has a low (0.5%-4.0%) case-fatality rate in the general population. Fulminant hepatitis, however, is more commonly associated with hepatitis E than with other types of viral hepatitis, particularly among pregnant women in the second or third trimester. Fetal loss is common. Case-fatality rates as high as 15%-25% have been reported among pregnant women. Perinatal transmission of HEV has also been reported.

Prevention

Vaccines to prevent hepatitis E are under development, but none are currently available. IG prepared from plasma collected in HEV-endemic areas has not been effective in preventing clinical disease during HEV outbreaks. IG prepared from plasma collected from parts of the world where HEV is not an endemic disease is unlikely to be effective. The best prevention of infection is to avoid potentially contaminated water and food, using measures recommended to prevent hepatitis A and other enteric infections.

Treatment

No specific treatment is available for hepatitis E. Treatment is supportive.

Health Information for International Travel 2003-2004

© 2003