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20 Cards in this Set
- Front
- Back
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What does 'reo' stand for in Reoviridae?
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Respiratory adn Enteric Orphan viruses
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What type of nucleic acid do Reoviridae contain in their genome?
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Double-stranded RNA with a 10- to 12-part segmented genome
Reoviridae are "orphan" viruses because they are the only dsRNA viruses |
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What is the capsid geometry of Reoviridae?
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Icosahedral
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Do Reoviridae contain an envelope?
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NO
They are nonenveloped |
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Which genus is clinically important?
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Rotavirus
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Where do Reoviridae replicate?
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Cytoplasm
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What enzyme is needed to aid in the replication of the rotavirus genome?
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Virus encoded RNA-dependent RNA polymerase.
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What is the characteristic morphology of rotaviruses?
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Wheel-and-spoke structure
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How many viral coats does rotavirus have?
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Three
Which is why it is also called a triple-layered particle |
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What proteins are found in the outer coat of Reoviridae?
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Viral proteins (VP) 4, 6, 7, and integrins VP4 is cleaved to form VP5 and VP8, which are important for cell adhesion
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How are newly synthesized rotaviruses released?
How does this affect the structure of the virus? |
By cell lysis
Rotaviruses lack envelopes because they are released form cells by lysis, unlike enveloped viruses that acquire their envelope form cell budding. |
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How is rotavirus trasmitted?
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Fecal-oral transmission
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What does rotavirus cause?
How does this present clinically? |
Gastroenteritis in infants and young children.
Often as outbreaks of non-inflammatory, nonbloody diarrhea in day care centers or schools |
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How common are rotavirus infections?
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Most common cause of gastroenteritis which accounts for approximately 40% of severe diarrhea in children younger than 2 years old
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What cells do rotavirus show tropism for?
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Epithelial cells of the small intestine, primarily the jejunum.
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What histologic changes occur with rotavirus infection?
What clinical effect do these changes have? |
Shortening and atrophy of villi
Flattening of epithelial cells Denuding of microvilli They decrease surface area and production of brush-border enzymes resulting in malabsorption and diarrhea |
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What is the incubation period for rotavirus?
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48 hours or less
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How is rotavirus diagnosed?
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Clinical diagnosis or by detection of virus in the stool with either radioimmunoassay or ELISA
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How is rotavirus treated?
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Supportive treatments only, with rapid replacement of fluid and electrolytes.
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Is there a vaccine for rotavirus?
Why is it not used? |
YES
RotaShield is a live-attenuated virus containing 4 serotypes It is associated with intussusception in infants. |
