The infection caused by the Hepatitis E virus (HEV) which was discovered in 1990, is essentially a waterborne disease. After an incubation period of about two to nine weeks, a self–limiting, acute viral hepatitis appears, lasting for a period of several weeks, which is followed by recovery. No case of chronic disease has been reported. Mainly young adults, aged about 15 to 40 years have been affected by acute Hepatitis E. The first major epidemic was reported in New Delhi in the winter of 1955–56. After the flooding of the Yamuna river, 30,000 cases of jaundice were described and retrospectively attributed to Hepatitis E.
Hepatitis E appears to be a widespread problem in developing countries where there are problems in providing safe drinking water and adequate sewage disposal. General precautions against infection are as outlined for Hepatitis A. No vaccine or specific immunoglobulin prophylaxis is available.