Hepatitis E virus (HEV) is a major cause of epidemics and sporadic cases ofenteric human viral hepatitis in underdeveloped tropical and sub-tropicalcountries; however, hepatitis E is a rare disease in industrialized countries.The usual vehicle for virus transmission during epidemics is fecally-contaminatedwater. Hepatitis E is characterized by a moderately severe jaundice that is aself-limited disease in most patients. Individuals likely to be targeted by thevirus are young adults, 15-40 years of age. The individuals most susceptible tohepatitis E infection during epidemics are pregnant women. While the overalldeath rate for individuals with hepatitis E infection is 0.5-3%, women infectedduring pregnancy may have a death rate as high as 15-25%. Hepatitis E virus is azoonosis in pigs. The virus isolated from the feces of pigs in the United Statesor Taiwan show a close genetic relationship to the human HEV strains isolatedfrom those areas. Therefore, pigs may be an important source for human hepaticdisease caused by HEV. Runoff waters from swine farms may pollute irrigationwaters leading to contamination of produce or may pollute coastal waters withresultant contamination of shellfish. The continuing globalization of foodmarketing creates the potential for HEV introduction into new areas as foodstuffsare increasingly imported from HEV endemic countries. Includes 57 references, tables.