EN
Hepatitis A virus (HAV) is the most common cause of hepatitis in humans all over the world. Non-enveloped HAV is classified to the Picornaviridae family. The virus is highly resistant to physico-chemical factors. The genome contains the single-strand RNA encoding a long polyprotein. This polyprotein is used to form four structural and seven non-structural proteins in the post translating process. All polyprotein cleavage sites have not been identified, yet infection with HAV frequently occurs through the consumption of contaminated food or water. The disease is often asymptomatic in young children. In older children and adults different clinical symptoms may be observed, from mild (without jaundice) to severe liver failure. In many regions of the world the disease occurs endemically and in developed countries outbreaks and epidemics are noted. Inactivated vaccines are used in specific protection.