Gastroenteritis

Question 1

Viral gastroenteritis

Answer 1

• Most common kind of gastroenteritis
• Highly contagious
• Caused by:
  
  • Rotavirus
  • Norovirus
  • Adenovirus (less common and presents as subacute diarrhoea)

Question 2

E. coli

Answer 2

• E. coli 0157 produces shiga toxin
• Causes abdominal cramps, diarrhoea and vomiting
• Shiga toxin destroys blood cells and can lead to HUS
• Antibiotics increase the risk of HUS and so should be avoided if E. coli considered

Question 3

Campylobacter jejuni

Answer 3

• Common cause of travellers diarrhoea and is most common cause worldwide
• Spread by raw or improperly cooked food, untreated water and unpasteurised milk
• Incubation period is 2-5 days, symptoms resolve after 3-6 days
• Symptoms include abdominal cramps, diarrhoea often with blood, vomiting and fever
• Antibiotics considered in severe cases or thse with risk factors like HIV or HF
• Common antibiotics used are azithromycin or ciprofloxacin

Question 4

Shigella

Answer 4

• Spread by faeces contaminated drinking water, swimming pools and food
• Incubation is 1-2 days and symptoms usually resolve within 1 week
• Can produce shiga toxin and cause HUS
• Treat severe cases with azithromycin or ciprofloxacin

Question 5

Salmonella

Answer 5

• Spread by eating raw eggs or poultry and food contaminated with infected faeces of small animals
• Incubation is 12 hours to 3 days and symptoms reslove within 1 week
• Symptoms are watery diarrhoea with mucus or blood, abdominal pain and vomiting
• Antibiotics only necessary in severe cases

Question 6

Bacillus cereus

Answer 6

• Gram positive rod spread through inadequately cooked food or food not immediately refrigerated after cooking (i.e. rice)
• Produces a toxin called cereulide that causes abdominal cramping and vomiting within 5 hours of ingestion
• Causes a watery diarrhoea
• Symptoms usually resolve within 24 hours

Question 7

Yersinia enterocolitica

Answer 7

• Gram negative bacilllus - pigs are carriers and eating raw or undercooked pork can cause infection
• Most frequently affects children causing water or bloody diarrhoea, abdominal pain, fever and lymphadenopathy
• Incubation is 4-7 days and illness can last 3 weeks or more
• Older children and adults can present with right sided abdominal pain due to mesenteric lymphadenitis
• Antibiotics only necessary in severe cases

Question 8

Staphylococcus aureus toxin

Answer 8

• Can produce enterotoxins when growing in food such as eggs, dairy and meat
• Cause diarrhoea, perfuse vomiting, abdominal cramps and fever
• Symptoms start within hours of ingestion and settle within 12-24 hours

Question 9

Giardiasis

Answer 9

• Giardia lamblia is a microscopic parasite
• Lives in the small intestines of mammals
• Animals release cysts in stools which contaminate food or water and can be ingested
• Infection may not cause any symptoms but can cause chronic diarrhoea
• Diagnosis by stool microscopy
• Treat with metronidazole

Question 10

Principles of gastroenteritis management

Answer 10

• Good hygiene and isolation for prevention (i.e. barrier nursing)
• Sample faeces for microscopy, culture and sensitivities
• Assess for dehydration and give fluids as required - can also give ORS
• Slowly introduce light diet
• Antidiarrhoeal medication are generally not recommended and should be avoided in E. coli 0157 and shigella as well as where there is bloody diarrhoea and high fever
• Antibiotics to patients at risk of complications

Question 11

Complications of gastroenteritis

Answer 11

• Lactulose intolerance
• IBS
• Reactive arthritis
• Guillain-Barre syndrome