editorial: hepatitis e virus

Hepatitis e virus (hev), a member of hepeviridae family, is the major cause of waterborne hepatitis in tropical and subtropical countries. there are four genotypes and a single serotype of hepatitis e virus infection. genotype 1 is usually observed in the developing countries and causes community-level outbreaks, while genotype 3 is usually re- ported in the developed countries and does not cause out- breaks. identification of swine hepatitis e virus in many countries, such as japan and the united states, and its close relationship with human hev showed and proved that hev is a zoonotic infection. wild deer, domestic swine and boars are considered the reservoirs of hev in the nature. transmission of this infection usually occurs via the fecal oral route. recently many outbreaks occurred in war zones such as syria, iraq and afghanistan and in the refugee camps worldwide. it is estimated that 20 million infections (3.3 million acute cases) with 56,600 deaths occur annually. incubation period of this