The hepatitis E virus (HEV) causes acute hepatitis in healthy persons and can cause chronic hepatitis in immune suppressed persons. Most acute infections are mild; however, pregnant women and persons with chronic liver disease are at risk for severe infection with high mortality rates. Hepatitis E occurs most often in countries with poor sanitation and communities where undercooked pork or pig products are eaten. Hepatitis E is the leading cause of acute viral hepatitis in developing countries.
Mode of Transmission
In countries with poor sanitation, HEV is transmitted by the feco-oral route by consuming contaminated water or food.
In developed countries, most cases are due to consumption of raw or undercooked pork meat, pork liver, or game (wild boar and deer) meat.
- HEV has been found in 11% of pig livers obtained from grocery stores in the U.S., 10% of pork sausages in the U.K., 10% of wild boars in northern Italy, and 17% of figatelli (traditional Corsican sausages made from pig liver) in southern France, where consumption of figatelli has been linked to outbreaks of hepatitis E.
An outbreak on a cruise ship was attributed to shellfish.
In contrast to hepatitis A, interpersonal transmission of hepatitis E is uncommon; however, during pregnancy HEV is transmitted from mother to child, with poor fetal outcomes.
HEV infections occur worldwide (with the possible exception of Australia). The highest incidence is in Asia, Africa, Middle East, the Indian subcontinent, and Central America.
Travelers to countries with poor sanitation are at risk from eating food that has not been hygienically prepared (e.g., salads) or that has been contaminated by infected water (e.g., mollusks) or from drinking untreated water.
Travelers in Europe, the U.S., Japan, China, and possibly elsewhere are at risk of HEV infection from eating raw or undercooked domestic pig or wild boar meat, especially liver, as is traditional in many cultures.
- In Japan, the consumption of wild boar, deer, and pig livers and intestines has caused hepatitis E.
Handling pigs and drinking water contaminated with pig feces may also be sources of infection.
Most HEV infections are mild or symptomless. When symptoms do appear, they include: jaundice (yellow eyes and skin and dark urine), fever, influenza-like symptoms, abdominal pain, vomiting, weight loss, and aching muscles. Symptoms usually resolve in 4-6 weeks. Rarely, neurological symptoms develop.
Non-vaccine: In countries with poor hygiene, travelers should follow standard food and beverage precautions. See Food and Beverage Precautions.
Worldwide, including Europe, the U.S., and Japan, travelers should avoid eating pork that may be raw or inadequately cooked, including traditional regional products such as figatelli sausages in southern France.
Vaccine: A vaccine has been licensed in China but none are available elsewhere.
Need for Medical Assistance
Symptoms of hepatitis are non-specific and have many possible causes.
Travelers who develop the symptoms noted below in the weeks following travel should seek medical assistance to establish the diagnosis (and especially if the traveler is pregnant, immunosuppressed, or has a preexisting liver disease).
- Jaundice (yellow eyes and skin, dark urine)
- Fever, aching muscles, influenza-like symptoms
- Abdominal pain
- Vomiting, loss of appetite, weight loss
Most cases of hepatitis E resolve spontaneously within a few weeks. Treatment is mainly supportive, but an antiviral drug called ribavirin may be indicated in rare instances.