Flashcards in L81 Deck (25)
What are the major viral causes of diarrhea?
Enteric adenovirus, astrovirus
DOUBLE stranded RNA
"Wheel with spokes"
What are VP4 & VP7? Similarities vs differences?
Rotovirus OUTER capsid antigens
Both involved in neutralization
VP7 : G protein
VP4 : P protein
G + P determine serotype
How do you diagnose rotavirus?
VP6 = inner capsid antigen
Stool sample --> immuno-assay for this
What is the most common rotavirus serotype?
How and where is rotavirus activated?
Proteases remove VP7
Which surface antigen mediates attachment for rotavirus?
Attachment to gut
How is rotavirus released from host cells?
Lysis - naked virus
What type of diarrhea does rotavirus cause? Name the 3 possible mechanisms.
1. Cytolytic infection of intestine villi --> blunting of microvilli --> less water absorbed
In response, secretory crypt cell migrate out to repair damage faster, but they are immature --> increased water secretion
2. Entertoxin mediated by NSP4 (non-structural) protein
3. ENS activated - increased secretions
Fecal-oral... makes sense
Is rotavirus more common in adults or kids?
Incubation and disease timelines for rotavirus
Incubate = 2 days
Sick = 4-8 days
Where in the world is rotavirus common?
Bangladesh or West Africa
Describe current rotavirus vaccines
Live, oral, attenuated
Very effective - given example of herd immunity
Enteric adenovirus genetics - include relevant serotypes
Icosahedral capsid w/ penton fibre at each apex
2 serotypes - 40 & 41
If enteric adenovirus has the same symptoms as rotavirus, how do you tell them apart?
Enteric = longer timeframe
- 5-12 days sick
Astrovirus transmission and duration of illness
P2P transmission (or food/water)
3-7 days sick
2 major caliciviruses
Infection with these is SUPER common
What is the seasonality of calico viruses?
Noro peaks in winter
But environmentaly stable
Calici virus transmission
**LOW infectious dose
Air - kids daycare
Which blood type has increased risk for calico infection