3.5 Gastroenteritis Flashcards
8 differential diagnoses for diarrhoea / loose stools?
- infection (gastroenteritis)
- IBD
- lactose intolerance
- coeliac disease
- CF (+steatorrhoea)
- Toddler’s diarrhoea
- IBS
- meds eg Abx
Viral causes of diarrhoea?
Viral:
- rotavirus
- norovirus
- (adenovirus, more subacute diarrhoea)
Bacterial causes of diarrhoea?
Bacterial:
- E. coli
- Campylobacter jejuni
- Shigella
- Salmonella
- Bacillus cereus
- Yersinia enterocolitica
- Staph aureus toxin
- Giardiasis (parasite)
How can you spread E. coli?
- infected faeces, unwashed salad, contaminated water
(normal intestinal commensual)
What strain of E. coli is worst and why?
- 0157 strain produces Shiga toxin
What does the shiga toxin from O157 E. coli do?
- Shiga toxin destroy RBCs and leads to haemolytic uraemia syndrome (HUS)
Along with shiga toxin what else increases the risk of HUS in E. coli gastroenteritis?
- Abx increase HUS risk
AVOID Abx in E. coli
What is the most common bacterial cause of gastroenteritis worldwide?
Campylobacter jejuni
What causes travellers diarrhoea?
Campylobacter jejuni
How can you get Campylobacter jejuni gastroenteritis?
- raw / undercooked poultry, untreated water, unpasteurised milk
What is a typical presentation / symptoms of Campylobacter jejuni gastroenteritis?
- cramps
- diarrhoea maybe with blood,
- vomit
- fever
incubate 2-5, Sx resolve after 3-6days
If you isolate Campylobacter jejuni what should you consider giving?
severe symptoms or HIV or heart failure, then treat:
Abx: azithromycin or ciprofloxacin
How is shigella spread?
- faeces in drinking water or swimming pool or food
Typical symptoms and course of shigella?
- bloody diarrhoea, cramps and fever
- 1-2 days incubation, Sx resolve in a week
What can the toxin from shigella cause?
shiga toxin (like O157 e. coli)
causes HUS
How would you treat severe cases of shigella?
Abx: azithromycin or ciprofloxacin
How is salmonella spread / aquired?
- raw eggs or poultry, or reptile infected food
Typical salmonella symptoms and course?
- watery diarrhoea maybe mucous or blood
- incubation 12hr to 3days and Sx resolves in 1week
- abx only in severe and guided by stool C+S
How is Bacillus cereus spread / acquired?
- inadequately cooked food / not refrigerated eg rice
- gram +ve rod
What causes you to cramp and vomit with 5hrs of Bacillus cereus infection?
- cereulide toxin; cramp and vomit within 5hours
What is the typical course / symptoms of Bacillus cereus?
- cereulide toxin; cramp and vomit within 5hours
- watery diarrhoea within 8hrs
- resolves within 24hrs
classic course so exam worthy
If Bacillus cereus is a gram +ve rod, what is a gram -ve bacillus?
Yersinia enterocolitica
How do you spread / acquire Yersinia enterocolitica?
- pigs, so undercooked pork
- urine or faeces of rats / rabbits
Typical course / symptoms of Yersinia enterocolitica?
- 4 to 7 days incubation
- watery or bloody , fever, pain
- lymphadenopathy
How can Yersinia enterocolitica present in older children / adults?
fever and right sided abdo pain
= mesenteric lymphadenitis
(gives appearance of appendicitis)
What else can, like Bacillus cereus, see recovery within 24hrs?
STAPH AUREUS TOXIN:
- enterotoxins on eggs, diary or meat
- start within hours and settle within 12 to 24
- D+V, cramps, fever
How do you diagnose and treat giardia?
- stool microscopy
- metronidazole
Key facts about each of the bacterial causes of gastroenteritis? - E. coli
- Campylobacter jejuni
- Shigella
- Salmonella
- Bacillus cereus
- Yersinia enterocolitica
- Staph aureus toxin
- Giardiasis (parasite)
E. COLI:
- infected faeces, unwashed salad, contaminated water
- 0157 strain produces Shiga toxin
- Shiga toxin destroy RBCs and leads to haemolytic uraemia syndrome (HUS)
- Abx increase HUS risk
- avoid Abx in E. coli
CAMPYLOBACTER JEJUNI:
- most common bacterial cause worldwide - travellers diarrhoea
- raw / undercooked poultry, untreated water, unpasteurised milk
- incubate 2-5, Sx resolve after 3-6days
- cramps, diarrhoea maybe with blood, vomit, fever
- Abx if bacteria identified or risks eg HIV or heart failure
- Abx: azithromycin or ciprofloxacin
SHIGELLA:
- faeces in drinking water or swimming pool or food
- 1-2 days incubation, Sx resolve in a week
- bloody diarrhoea, cramps and fever
- Shiga toxin and HUS
- severe then use Abx azithromycin or ciprofloxacin
SALMONELLA:
- raw eggs or poultry, or reptile infected food
- incubation 12hr to 3days and Sx resolves in 1week
- watery diarrhoea maybe mucous or blood
- abx only in severe and guided by stool C+S
BACILLUS CEREUS:
- gram +ve rod
- inadequately cooked food / not refrigerated eg rice
- cereulide toxin; cramp and vomit within 5hours
- watery diarrhoea within 8hrs
- resolves within 24hrs
- classic course so exam worthy
YERSINIA ENTEROCOLITICA:
- gram -ve bacillus
- pigs, so undercooked pork
- urine or faeces of rats / rabbits
- 4 to 7 days incubation
- watery or bloody , fever, pain
- lymphadenopathy
- mesenteric lymphadenitis in older children (appears like appendicitis)
STAPH AUREUS TOXIN:
- enterotoxins on eggs, diary or meat
- start within hours and settle within 12 to 24
- D+V, cramps, fever
GIARDIASIS:
- G. lamblia parasite in mammals
- cysts from faecal oral transmission
- chronic
- stool microscopy
- metronidazole
Principles of gastroenteritis management?
- isolate and barrier nursing
- oral fluid challenge every 10 mins and keep it down and not dehydrated then can go home
- dioralyte ie ORS
- dehydrated / cant keep fluid challenge down the IV fluids
- avoid loperamide (antidiarrhoeal) and anti-emetics
- abx only if at risk and ID on organism
4 post gastroenteritis complications?
- lactose intolerance
- IBS
- reactive arthritis
- Guillain-Barre syndrome
