Reovirus

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Viruses - RNA Viruses

Key Points

Reoviruses (FA 2019 p167)
- Characteristics
  - RNA virus
    - replicate in the cytoplasm of cells
    - Double-stranded
    - + sense
  - Linear chromosome
  - 10-12 segmented genome
    - Capable of antigenic shift
      - Reassortment of entire genome segments as opposed to single point mutations (antigenic drift) lead to major shifts in phenotype, causing pandemics
  - No envelope
  - Icosahedral (double) capsid
- Presentation
  - Coltivirus
    - Transmission
      - by Rocky Mountain wood tick (Dermacentor spp.)
    - Presentation
      - Colorado Tick fever (fever, rash)
    - Diagnosis
      - RT-PCR
    - Treatment
      - Supportive
  - Rotavirus
    - Transmission
      - fecal-oral
      - Usually affects children during winter, esp. in daycare centers, kindergartens
    - Presentation
      - gastroenteritis
        watery diarrhea in US (may be fatal in children)
        Villous destruction with atrophy leads to decreased absorption of Na+ and loss of K+
    - Diagnosis
      - Stool rotavirus antigen
      - RT-PCR also used
    - Treatment
      - Supportive; rehydration therapy
    - Prophylaxis
      - Live-attenuated vaccine
        Rare risk of intussusception (1 in 10,000 infants)
        CDC recommends routine vaccination of all infants except those with a history of intussusception or SCID