CALICIVIRIDAE

• STRUCTURE: Small, spherical, non-enveloped, ss (+) RNA, infectious.

  • Structure similar to Picornaviruses.

  • "Calix" = "cup" -- cup-shaped depressions on capsid.

• REPLICATION: Cytoplasmic, like Picornaviruses. They do produce subgenomic mRNA for capsid proteins.

• HEPATITIS-E:

  • TRANSMISSION: Fecal-oral, often found in contaminated water. Found primarily in other countries -- India and central Asia.

  • MANIFESTATIONS: Acute infection similar to HAV.

    • High fatality rate among pregnant women, and high perinatal fatality.

• NORWALK AGENT: Little village in Ohio.

  • MANIFESTATIONS: Major cause of gastroenteritis. Short-incubation period.

    • Infection more common in adults.

  • TRANSMISSION: Fecal-oral.

  • TREATMENT: None.

  • IMMUNITY: Induced immunity is poor.

Category: Microbiology Notes