Viral Gastroenteritis Flashcards
How does one normally acquire viral gastroenteritis and what is the normal incubation period?
Faecal-oral route.
24 hours.
Name four causes of gastroenteritis.
Rotavirus.
Adenovirus.
Astrovirus.
Noroviruses.
Symptoms of viral gastroenteritis? Duration?
Emesis.
Diarrhoea (secretory)
Self-limiting and lasts 2-3 days.
Outline the pathogenesis of viral gastroenteritis.
Enterocytes of upper small bowel effected > inflammation and transient blunting of villi
What kind of antibodies confer immunity against viral gastroenteritis.
IgA (mucosal surfaces)
Which two surface proteins is protective immunity directed towards regarding rotavirus?
G (VP7)
P (VP4)
Why can people suffer repeated infections with rotavirus?
There are numerous antigenic ally different G and P subtypes.
Repeated infections tend to be less severe.
Feature of the rotavirus genome and why is this of importance?
Segmented genome:
- therefore reassortment of different rotaviruses can occur
How is immunity protective against severe rotavirus illness.
Infection is followed by partial immunity:
- immunity is cross-protective therefore severe disease usually only seen in first exposure
When are children most vulnerable to severe disease by rotavirus?
During first year of life.
Maternal antibody may ameliorate disease severity in neonatal period.
Name the two types of rotavirus vaccines and what kind of vaccine are they?
Rotarix
Rotateq
*oral live attenuated
Features of the rotarix vaccine?
Live attenuated monovalent vaccine derived from human rotavirus.
Induces broadly cross-reacting immunity to many rotavirus serotypes.
Features of the rotateq vaccine?
Pentavalent human and bovine rotavirus re assortment vaccine.
Bovine rotavirus + 4 commonest G protein serotypes + commonest P serotype in human viruses.
Do the rotavirus vaccines prevent viral gastroenteritis?
Person may still become sick, but less severe disease.
Which rotavirus vaccine is administered in SA and when?
Infants: 10/14 weeks (2 doses).
Which viruses are responsible for food-bourne outbreaks (epidemics) around the world?
Noroviruses.
*cruise ships and other gatherings
How are noroviruses spread?
Faecal-oral route.
Aerosolised droplets.
Symptoms of norovirus infection?
Emesis and Diarrhoea.
*noth are highly infectious
Can one get gastroenteritis more than once due to norovirus?
Yes, immunity is short-lived.
*no vaccine available
What conditions are adenoviruses responsible for?
Respiratory, GIT, ocular, urinary tract conditions.
Which two adenovirus subtypes cause gastroenteritis?
Adenovirus 40 and 41 (group F adenoviruses)
Vaccine for adenovirus or astrovirus?
None.
How may one detect gastroenteritis causing viruses?
Rapid antigen detection tests.
Specimen = stool
Management of viral gastroenteritis?
Supportive.
Rehydration.
Why is it imperative to be hygienic and ensure effective infection control practices to prevent spread of viral gastroenteritis?
Viruses are highly resistant to inactivation and can remain viable on environmental surfaces.
Why is it recommended to breastdfeed infants with regards to avoiding viral gastroenteritis?
Potentially contaminated feeds avoided.
Maternal IgA antibody conveys some immunity.
Ways to prevent viral gastroenteritis?
Clean water.
Sanitation.
Hygiene.
