Gastroenteritis

Question 1

What are the 3 main syndromes of anthrax disease?

• what do they result from
• how do they present

Answer 1

1. Cutaneous anthrax
   - results from introduction of the spore through the skin
   barrier (e.g. via abrasions or injections) or hair follicles;
   - characterized by localized itching, followed by a painless papule which turns vesicular and enlarges, ulcerates, and develops into a painless, depressed black eschar usually surrounded by oedema
2. Gastrointestinal anthrax
   - results from ingestion of contaminated undercooked meat;
   - rapid onset of abdominal pain with haemorrhagic ascites
   - Shock and death may occur within 2-4 days of symptom onset
3. Inhalation anthrax
   - results from inhaling spores aerosolized by industrial processing of contaminated animal products (e.g. hair, bone, hides), among persons working with contaminated animal products or bioterrorism
   - initially presents as non-specific flu-like symptoms lasting 4-5 days.
   - followed by a fulminant phase characterized by acute respiratory distress and sepsis.
   - may also present as acute haemorrhagic mediastinitis. A widened mediastinum without infiltrates on chest X-ray in a previously healthy patient without trauma is pathognomonic for anthrax.

Question 2

how is campylobacter transmitted?

Answer 2

Consumption of undercooked food (notably poultry), unpasteurised milk and contaminated food or water. Transmission can also occur via direct contact with infected animals (e.g. farm animals, domestic pets) or animal products.

Question 3

how do patients with campylobacter present?

Answer 3

Majority of cases present with abdominal pain and diarrhoea (which may be bloody). There may be a prodromal period of fever and malaise a day preceding gastrointestinal symptoms.

Symptoms last several days to 2 weeks (average 7 days)

Question 4

what are the complications of campylobacter?

Answer 4

e reactive arthritis and Guillain-Barré syndrome

Question 5

how is campylobacter managed?

Answer 5

• Campylobacteriosis is usually mild and self-limiting. Treatment is generally supportive.
• Antibiotics (e.g. azithromycin) are not indicated except for patients with severe symptoms or at risk of invasive disease.
• Features of severe disease include bloody stools, high fever, extra-intestinal infection or symptoms lasting more than a week.

Question 6

how to treat viral gastroenteritis?

Answer 6

Self-limiting, often necessary to rehydrate to prevent dehydration (PO for preventing/early dehydration; IV for severe dehydration/shock)

Question 7

how to treat bacterial gastroenteritis?

Answer 7

Non CHESS bacteria

• Treatment usually involves PO rehydration (PO is almost alwaysadequate)
• If severe, PO ciprofloxacin 500 mg BD is usually prescribed + IV rehydration

CHESS bacteria (bacterial dysentry)

• Antimotility drugs is C/I in all bacterial dysentery
• Campylobacter 🡪 macrolides (e.g. azithromycin)
• Shigella 🡪 ciprofloxacin, TMP/SMX
• Salmonella: If enteritis 🡪 treat only if increased risk of bacteraemia (neonates, age > 50, immunocompromise, sickle cell disease, prosthetic valves, vascular grafts
• EHEC: Abx should be avoided (as it kills EHEC 🡪 release more toxin 🡪 increases chance of precipitating haemolytic uraemic syndrome [HUS])

Question 8

how to treat parasitic gastroenteritis?

Answer 8

• Giardia: metronidazole x 10/7
• Cryptosporidium: in immunocompromised, treat w/ nitazoxanide. Is self-limiting (< 10 days of symptoms) in immunocompetent individuals
• Entamoeba histolytica: Paromomycin or iodoquinol (intraluminal agent) + metronidazole (invasive disease)