L10 - The Role of Antibiotics in Gastrointestinal Infection

Question 1

What are the five most common clinical syndromes concerning infection of the GI tract?

Answer 1

Acute Gastroenteritis
Dysentery
Traveller's Diarrhoea
Post antibiotic Diarrhoea
Chronic Diarrhoea

Question 2

How does Acute Gastroenteritis present?

Answer 2

Diarrhoea (>3 loose stools/day)
Nausea & Vomiting
Abdominal Pain
Fever

Question 3

What pathogens are responsible for causing Acute Gastroenteritis?

Answer 3

Bacteria - Campylobacter, Salmonella, Shigella, Escherichia coli, E. coli O157, C. diff
Viruses - Norovirus, Rotavirus, Adenovirus
Protozoa - Cryptosporidium, Giardia lamblia, Entameobea histolytica

Question 4

What pathogens are responsible for causing Dysentery?

Answer 4

Bacteria - Campylobacter, Salmonella, Shigella, Escherichia coli, E. coli O157, C. diff
Protozoa - Entamoeba histolytica

Question 5

What pathogens are responsible for causing Traveller’s Diarrhoea?

Answer 5

Bacteria - Campylobacter, Salmonella, Shigella, Escherichia coli
Viruses - Norovirus, Rotatvirus, Adenovirus
Protozoa - Cryptosporidium, Giardia lamblia, Entameobea histolytica

Question 6

What proportion of Postantibiotic Diarrhoea is caused by C. diff?

Answer 6

Antibiotic associated diarrhoea 20-30%
Antibiotic associated colitis 50-75%
Pseudomembranous colitis >90%

Question 7

What are the five main steps in general management of chronic diarrhoea?

Answer 7

Rehydration (oral/i.v.)
Analgesia
Antiemetics
Avoid antidiarrhoeal agents
Isolation

Question 8

When should C. diff diarrhoea be suspected?

Answer 8

Post antibiotic

>4 loose stools/day (bloody?)

Question 9

How should Traveller’s diarrhoea caused by bacteria (80%) be treated?

Answer 9

Ciprofloxacin

500mg stat OR 500mg b.d. for 5 days

Question 10

How should Traveller’s diarrhoea caused by parasites be treated?

Answer 10

Metronidazole (Giardia, Entaemoeba histolytica)

Nitazoxanide (Cryptosprodium)

Question 11

Should antibiotics be given for Acute Gastroenteritis?

Answer 11

Shortens duration of illness but no effect on mortality/severity - Controversial
Ciprofloxacin
Macrolides (Campylobacter)

Question 12

What are the risks of antibiotic therapy for acute gastronenteritis?

Answer 12

Prolong the duration of carriage
Cause antibiotic associated diarrhoea
Can induce antibiotic resistance
ADRs
Risk of complications w/ E. coli O157 - Haemolytic Uraemic Syndrome

Question 13

What sort of toxin does E. coli O157 produce?

Answer 13

Verotoxins (Shiga toxins)

Question 14

What proportion of E. coli O157 sufferers develop Haemolytic Uraemic Syndrome?

Answer 14

15%

Question 15

What are the three defining symptoms of HUS?

Answer 15

Haemolytic anaemia
Thrombocytopenia
Renal failure

Question 16

What is the mortality of HUS?

Answer 16

5%

Question 17

What are Oral rehydration solutions made up of?

Answer 17

Water, salt, sugar

Cereal based

Question 18

Are probiotics beneficial in treating diarrhoea?

Answer 18

Benefit in preventing antibiotic associated diarrhoea