Lecture 23: Diarrhoea and Gastro illness Flashcards
Acute gastrointestinal illness signs and symptoms?
Vomiting
- Intoxifications
- nausea
Diarrhoea
- acute
- watery
- bloody - dysentry
- severe - 6x a day
Abdominal pain
Fever
Viral causes? Most likely?
Norovirus or Rotavirus
- Watery diarrhoes (not bloody)
- abd cramps and muscle aches
- low grade fever and headache
Colonisation of the small intestine
- norovirus, +ve strand ssRNA
- rotavirus, dsRNA, produces enterotoxin stimulating Cl- secretion
Generally self-limiting over 48h with supportive treatment and rehydration. Outbreaks are easily started through vomiting. Effective rotavirus vaccines are available now
Bacterial causes, most likely and method?
- Colonisation of intestines and the production of toxins (eg. vibro cholera)
- Colonisation of the intestines invasion of intestinal tissue (leading to diarrhoea and esp abdominal pain)
- Toxin produced in food and ingested, no infection = food poisoning (very quick normally mking you vomit)
Bacteria that colonise and secrete toxins?
- Clostridium difficile
- Shiga (or Vero) toxin-producing escherichia coli (STEC/VTEC)
- Shigella dysenteriae
- Enterotoxinigenic Escherichia coli
- vibro acholerae
(dysentry is common here)
Bacteria that colonise and invade?
- Campylobacter jejuni
- Non-typhoid slamonella
- Yersinia enterocolitica
- Enteroinvasive Escherichia coli
May see blood in stool and abdominal cramping is common due to inflammation leading to loss of absorbative function = diarrhoea
Bacteria that release toxins in food but don’t infect?
- Staphylococcus aureus
- Clostridium perfringens
- Bacillus cereus
- Vomiting likely within 2-7h of consumption
- Symptoms cleared within 1-2 days
- Identification most likely from remaining food
Protozoa causes? incubation, timeframe?
Eg. Giardia lamblia and cryptosporidium
Colonise the small intestine through ingestion food/water contaminated by human/animal faeces
Incubation period of 1+ weeks with symptoms lasting 4-6 weeks (diarrhoea, flatulence, foul smelling stools, abdominal cramps)
Mostly self limiting but antimicrobials may be necessary
Can cause serious illness in immunocompromised
Complications?
- Dehydration
- Bacteremia - salmonella and campylobacter
- Haemolytic uremic syndrome - STEC toxin effect on kidney
- Gullian Barre Syndrome - automimmune attack of motor neuron sheath
- Reactive arthritis - autoimmune, campylobacter
Treatment?
Fluid and electrolyte replacement is MOST important
- Absorbed in the small intestone and replaces the water and electrolyte ost in the faeces (water, salt and sugar)
- Easily digestable foods are also helpful
- Generally anti-motility drugs just concentrate the toxins near to the gut wall.
- Antibiotics are usually not required and only have small effects - however, can be used to decrease the number of bacteria being shed thus decreasing the re-infection rate. (are recommended for C. Difficile - vancomycin, metronidazole) - (salmonella/campylobacter if patients progresses to, or is at risk of, systemic infection)
Prevention?
Vaccines
- Not routine, limited efficacy, outbreak control
- Rotavirus, cholera vaccines available
Sanitation
Hygiene
Effective cooking
Avoid risky food and unclean water
