Lecture 17: Viral Enteric Pathogens Flashcards
Viruses
List enteric pathogens (bacteria)
Salmonella spp.
Shigella spp.
E. coli (specific types)
Campylobacter spp
Yersinia spp.
Clostridium difficile
List enteric pathogens (viruses)
Rotavirus
Norovirus
Astrovirus
Adenovirus
Enterovirus
List parasitic enteric pathogens
Entamoeba
histolytica
Giardia lamblia
Cryptosporidium
Viral gastroenteritis is when a patient has
Syndrome of acute nausea and vomiting, typical in winter months and lasts for 1-3 days
What are the two possible syndromes of viral gastroenteritis?
Mild afebrile disease with watery diarrhea, or more severe with vomtitng, headache etc..
Astrovirus
Especially amongst the paediatric
population
Adenovirus
-Enteric
-Alot of pets inpatient diarrhea
What are caliciviruses?
Those that are not noro
List a few likely and emerging pathogens
- Caronaviruses
- Enteroviruses
- Especially echovirus types 11, 14 and
18 - Torovirues
- Picrobirnaviruses, Picotrimaviruses.
- Pestiviruses.
What type of virus is a norovirus?
Non-enveloped, isochahedral virus
SS positive sense RNA Genome
Which virus looks like a cupcake?
Noro ,a member of the calicivirdae family
How is noro transmitted?
Vomitus and airborne transmission
100 particles needed for transmission
Incubation period for norovirus?
18-72h, virus shedding happens in stool
How long can virus particles get picked up on after a noro infection with PCR?
3 weeks after illness
What happens with most noro outbreaks?
They terminate spontanoeously
How do you treat Noro?
Isotonic liquids, symptomatic treatment, NO antibiotics
How long are you on contact precautions with noro?
Until symptoms resolve, hand washing, ID and elimination of common surfaces
Describe the characteristics associated with the Rotavirus
Only double-stranded RNA genome, non-enveloped virus
What is characterized by “empty” particles with dark centres which lack genomic RNA
Rotavirus
Group A,B,C rotavirus
Human and non-human diseases
Group A Rota
Most important clinically; causes endemic GE in kids
Group B and C
Epidemic GE affecting all ages
Group D to G Rotavirus
Non-human disease
How is rotavirus transmitted?
Fecal-oral transmission ; detected by 4-10 days in 57 days PCR
What are some possible pathogenesis of rotavirus ?
a) Malabsorption of related mucosal damages and depression of disaccharides
b) Shortened and blunted villi in duodenum, with crypt hypertrophy, and mononuclear infiltration
What reflexes are activated in the enteric nervous system and what do they cause?
Secretary reflexes, fluid secretions
Signs and symptoms of rotavirus?
Vomiting and Fever, profuse diarrhea, more severe symptoms with dehydration than other pathogens
Why is there death is rotavirus?
Death due to dehydration and severe electrolyte abnormalities leading to cardiac arrest
Treatment of Rotavirus
Rehydration, electrolytes, oral rehydration solutions are preferred, IV, NOT antibiotics
Why is it hard to control rotavirus infections?
Physically hardy, non-enveloped
Rotavirus is a vaccine in Ontario (T/F)
TRUE
Disease burden of rotavirus peaks in…
Winter-spring, but this declined since the publicly funded vaccine program introduction in 2011
How do you propagate an enteric virus in vitro?
you DONT
How do you diagnose rotavirus in a lab?
Take advantage of high viral loads in stool and use electron microscopy to diagnose, or PCR, or antigen detection
