Gastroenteritis Flashcards
Chronic diarrhoea?
> 4 weeks duration
persistent diarrhoea?
2-4 weeks
acute diarrhoea?
<2 weeks with sudden onset
Acute gastroenteritis?
Inflammation of the lining of the stomach, small or large intestine.
What are the mechanisms through which enteric pathogens cause infection?
- stimulation of fluid and electrolyte secretion
- increase of propulsive contractions
- mucosal destruction and increased permeability
- nutrient malabsorption
Enterotoxigenic E.coli?
Traveller’s diarrhoea
- Adheres to intestinal mucosa by fimbrae
- produces enterotoxins, which increase intracellular levels of cAMP, causing cell leakage
E.coli 0157?
- Causes enterohaemorrhgic gastroenteritis
- can cause post-diarrhoeal haemolytic uraemic syndrome (acute renal injury, drop in cirulating platelets)
- microangiopathic hameilytic anaemia (RBC fragmentation due to narrowing of small blood cells)
Sources of salmonella?
- reptiles
- eggs
- poultry
Campylobacter?
- causes bloody diarrhoea
- can cause Guillain-Barre syndrome (limb paralysis)
- treat with Clarythromycin if severe
What causes bloody diarrhoea?
- Campylobacter
- Shigella
- E.coli
- amoeba
-also: IBD, malignancy, ischaemia
Typhoid fever?
- blood and urine cultures are key to diagnosis
- treatment: Chlramphenicol and Ciprofloxacin
Important clinical history questions are…
-nocturnal diarrhoea?
-colour and consistency?
-blood in stool?
-pain, vomiting, fever, urgency, incontinence
-others affected?
-travel?
-occupation/other exposure
medication
-antibiotic or PPI use
Examinations?
fever rashes dehydration (pulse, BP) abdo tenderness distension rectal exam - stool, blood, tenderness
Investigations?
-stool mictroscopy
-stool culture
-stool toxin (Salmonella, Campylobacter, Shigella)
-blood cultures (Shigella)
PCR (viruses)
FBC (WCC to asses severity)
Urea, electrolytes
Abdo X ray
When should antibiotics be used?
- enteric fever (typhoid)
- Shigellosis
- Enterotoxigenic E.coli
- Cholera
- C. difficile
- Giardiasis
- Amoediasis
- Invasive salmonellosis
