a.k.a I had a dodgy kebab last night and now I’m vomiting lots.
Definition: acute inflammation of the lining of the GI tract, manifested by nausea, vomiting, diarrhoea and abdominal discomfort.
Aetiology/ risk factors:
-Viruses, bacteria, protozoa or toxins contained in contaminated food
–Commonly contaminated food, includes: improperly cooked meats (S.aureus, C.perfingens), old rice (S.aureus, B.cereus), eggs and poultry (Salmonella), milk and cheeses (Listeria, Campylobacter), canned foods (botulism).
Risk factors: HIV/immunosuppression, Proton Pump Inhibitors, recent antibiotic use, food poisoning outbreaks, travel, diet change, ill contacts
Viral– rotavirus, adenovirus, calcivirus, Norwalk virus
Bacterial– Campylobacter jejuni, E.coli (esp. 0157), Salmonella, Shigella, Vibrio cholerae, Listeria, Yersinia enterocolitica
Protozoal– Entamoeba histolytica, Cryptosporidium parvum, Giardia lamblia
Toxins– from Staphylococcus aurea, Clostridium botulinum, Clostridium perfringens, Bacillus cereus, mushrooms, heavy metals, seafood
Epidemiology: very common
-sudden onset nausea, vomiting, anorexia
-diarrhoea (bloody or watery)
Bloody diarrhoea (dysentery) = CHESS
-Campylobacter, Haemorrhagic E.coli, Entamoeba histolytica, Shigella, Salmonella
(Don’t know how I lasted this long without a HP insert)
Explosive diarrhoea = e.g. Cholera, Giardia, Yersinia, Rotavirus
-abdominal pain or discomfort
-Mushrooms: fits, renal or liver failure
-diffuse abdominal tenderness
-bowel sounds often increased
-dehydration (reduced skin turgor, dry mucosal membrane, prolonged capillary refill)
-peripheral shutdown- shock (cold peripheries, tachycardia)
Bloods: FBC (raised WCC, eosinophilia if parasites), ESR/CRP raised
Blood culture- identification of organism if bacteraemia present
U&Es- dehydration, electrolyte imbalances e.g. hypokalaemia
Stool: mild gastroenteritis, with no systemic illness (i.e. fever >39ºC, dysentery > 2wks) or special circumstances such as food poisoning outbreaks, immunocompromise, recent antibiotic use or recent travel, do not need stool cultures.
Microscopy for inflammatory cells, parasites, oocysts (baby parasites), culture (bacteria), electron microscopy (viruses), toxin analysis (C.diff toxin).
AXR/USS- exclude other causes of abdominal pain
Sigmoidoscopy- not needed, unless you need to exclude inflammatory bowel disease
-Food handlers should avoid work until stool sample negative
-Hospital outbreaks need to be carefully managed e.g. wards may need closing
-In hospitals, good infection control measures are necessary.
-admit to hospital if there is systemic illness: fever >39ºC, dysentery > 2wks
-fluid and electrolyte replacement with oral rehydration solution
-IV rehydration may be needed if severe vomiting (0.9% saline + 20mmol K+/L IV infusion)
-Antibiotics only if severe or the infective agent has been identified on stool culture (e.g. Ciprofloxacin, a fluoroquinolone, for Salmonella, Shigella, Campylobacter; Metronidazole for Giardia).
Botulism- botulinum antitoxin IM, manage in ITU
-pre-renal failure (due to volume depletion)
-sepsis and shock (particularly Salmonella & Shigella)
-Haemolytic Uraemic Syndrome, associated with toxins from E.coli 0157 (= haemolysis + thrombocytopenia + renal failure)
-Guillan-Barré Syndrome, weeks after recovery from Campylobacter gastroenteritis
-Respiratory muscle weakness or paralysis, with botulism
Prognosis: Generally good, as majority of cases are self-limiting.