Risk factors for hepatitis E virus infection and disease.

Hepatitis E, caused by hepatitis E virus, is a disease of global significance, causing 20 million infections each year. Genotypes 1 and 2 have vastly different epidemiological patterns from genotypes 3 and 4. In genotype 1 and 2 endemic areas, most infections and illness occur in persons 15-30 years of age, with pregnant women being the most likely to experience severe disease. In genotype 3 and 4 endemic areas, most infections and illness occur in those of age 40-60 years, with males representing a large portion of those with severe disease. However, the lack of an easily accessible serologic assay in many countries continues to be a barrier to the diagnosis and recognition of hepatitis E virus.