Rotaviruses, Reoviruses, Coltiviruses, and Orbiviruses

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Rotaviruses, Reoviruses,Coltiviruses, and
Orbiviruses

• fackrel_at_Uwindsor.ca

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REO Viruses

• Structure
• Classification
• Multiplication
• Clinical manifestations
• Epidemiology
• Diagnosis
• Control

Barons Web Site
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Rota virus Structure

• wheel-shaped particles
• double-layered icosahedral capsid enclosing a
  core particle

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Genome

• 11 segments of double-stranded RNA, each segment
  representing one gene.

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Rotavirus antigenic specificities

• Group
• Group A major pathogens in humans and animals
• groups B and C found in humans
• not important pathogens
• Subgroup
• Serotype
• neutralization of one (VP7) of the two outer
  capsid proteins..

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RotavirusClinical manifestations

• enteric disease
• diarrhea, vomiting, abdominal discomfort, and
  fever
• mainly infants and young children.
• May cause fatal dehydration.

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REO virus Multiplication

• Endocytosis
• direct membrane penetration if activated by
  protease
• Replicates in the cytoplasm.
• Removal of the outer shell of the capsid in
  lysosomes activates the viral RNA polymerase.
• Outer capsid proteins acquired by budding
  through the endoplasmic reticulum,
• Virions are released by cell lysis.

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Rotavirus Epidemiology

• Group A rotaviruses are ubiquitous and infect
  most individuals by the third year of life.
• Single most important cause of severe diarrhea in
  infants and young children
• 30 to 50 of cases requiring hospitalization or
  treatment.
• In temperate climates, incidence peaks in the
  winter in the tropics, the disease occurs
  year-round

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Annual Incidence Viral food borne diseases

• Norwalk-like viruses
• 23,000,000
  
• Rotavirus
• 3,900,000
• Astrovirus
• 3,900,000
• Hepatitis A
• 83,391

• Total Viral food borne 30,883,391
  
  
  
• Total Microbial food borne incidence
• 38,629,64
  
  
  

CDC
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Rotavirus Diagnosis

• Clinical findings are nonspecific
• Detect virus in feces (e.g., by immunoassay)
• Demonstrate a serum antibody response

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Rotavirus Control

• Dehydration is treated by fluid and electrolyte
  replacement.
• Vaccine development is under way and appears
  promising

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DONE!!!