Hepatitis E virus (HEV) is a non-enveloped, positive-sense, single-stranded, RNA microbe. There is no vaccination to prevent infection from it in humans, and no pre- or post-exposure prophylaxis preparation is available. Like hepatitis A virus infection, it can be zoonotic, as pigs, cows, non-human primates, sheep, goats, and rodents may acquire the disease and transmit it to humans.
Nevertheless, the natural host for this infection is humans. Like hepatitis A, it does not lead to chronic infection. It tends to be a self-limiting medical condition which resolves in a short period of time with supportive treatment and without adverse sequelae. It does not appear that hepatitis E transmits sexually.
Disease Distribution
Epidemics of HEV infection have taken place in Asia, the Middle East, Africa, and Central America. Americans can acquire the disease if they travel to regions of the world where hepatitis E is endemic. In developed countries, it generally afflicts people who are at least 45 years old, and the disease is more likely to infect men than women there.
This condition is common in developing countries where it tends to affect people between the ages of 15 and 44. Although most patients who acquire HEV infection recover completely, pregnant women with the condition are at risk for fulminant hepatitis and death. Hence, pregnant clients who have hepatitis E may require hospitalization.
The transmission of HEV infection is, like hepatitis A, via the fecal-oral route, especially in food and water which have acquired contaminants. This is particularly the case in areas where sanitation is poor and the water supply is not purified. However, it is possible to boil and chlorinate unclean water and thus inactivate the virus.
Otherwise, people should avoid the consumption of water in developing countries where it has not undergone purification. Epidemics have also resulted from the consumption of raw or uncooked shellfish in countries where hepatitis E virus is endemic. Moreover, travelers to developing countries should not eat uncooked fruit or vegetables that have not been peeled and which they did not prepare themselves (World Health Organization, 2005).
People who reside in refugee camps or overcrowded temporary housing after a natural disaster will be at risk for HEV infection.
Clinical Diagnosis
To diagnose this condition, there may be a history of travel to a region of the world where HEV is endemic and contact with individuals who have jaundice. These travelers may have consumed uncooked food. The physician may note complaints of fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, jaundice, dark urine, clay-colored bowel movements, and joint pain. The physical examination may indicate liver enlargement.
Laboratory tests that will confirm the diagnosis include an HEV RNA test or hepatitis E antibody test. Serologic markers for hepatitis A, B, and C will be negative.
Sources
- Centers for Disease Control. (2011). Viral hepatitis. Retrieved July 12, 2011.
- World Health Organization. (2005). Hepatitis E fact sheet. Retrieved July 19, 2011.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact their physician for advice.
Michael Koger - Dr. Koger obtained his medical education at Meharry Medical College and specialized in Internal Medicine.
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