Hepatovirus

Hepatovirus is a genus of small, non-enveloped, icosahedral viruses in the family Picornaviridae. The most notable member is Hepatovirus A, the causative agent of hepatitis A in humans.

Hepatoviruses have a positive-sense, single-stranded RNA genome of about 7.5 kb. The genome encodes a single polyprotein processed into structural and nonstructural proteins. The 5' untranslated region contains an internal ribosome entry site that enables cap-independent translation. Virions are non-enveloped and relatively stable in the environment.

Entry is by receptor-mediated endocytosis and replication occurs in the cytoplasm. Virions are assembled in the cytoplasm and released from infected cells.

Transmission is primarily fecal-oral, via contaminated food or water, with outbreaks linked to poor sanitation. The disease is usually acute and self-limited, presenting with fever, fatigue, and sometimes jaundice; chronic infection is rare and fulminant hepatitis is more likely in older individuals or those with liver disease. There is no chronic carrier state.

Diagnosis relies on serology (HAV IgM for acute infection; IgG indicating immunity) and, when needed, RNA detection by PCR. Treatment is supportive; there are no widely used antivirals. Prevention includes inactivated HAV vaccines and post-exposure prophylaxis with vaccine or immunoglobulin; vaccination is recommended for travelers and at-risk groups, along with improved sanitation. In taxonomy, Hepatovirus is a genus in Picornaviridae; its best-known member is Hepatovirus A (human hepatovirus A).