C.diff modules (pie)

Question 1

What is C.difficile ?

Answer 1

A spore forming bacteria present in 2-5% of the population which can live with the normal bowel flora without causing harm

Question 2

What is the microscopic appearance of C.diff?

Answer 2

• Gram positive spore-bearing bacillus
• The spores are more resistant to disinfectants

Question 3

What is a C.difficile infection ?

Answer 3

• Some antibiotics or enteral feeds can interfere with the balance of normal bowel flora (antibiotics kill both good and bad bacteria) if this is the case C/difficile can multiply and produce toxins which cause illness with symptoms such as diarrhoea
• Known as a C/difficile infection

Question 4

What are the antibiotics most associated with causing C.difficile ?

Answer 4

1. Clindamycin
2. Cephalosporins
3. Ciprofloxacin
4. Co-amoxiclav

The 4 C’s

Question 5

What is the main risk factor for the development of C/difficile ?

Answer 5

Previous exposure to antibiotics

Question 6

what is the most common cause of healthcare associated GI infection ?

Answer 6

C.difficile

Question 7

How may patients squire C.difficile in hospital?

Answer 7

Question 8

For a patient to get a C.difficile infection what 3 things must occur ?

Answer 8

1. Bowel flora must be altered
2. Bowel must be colonised with a toxic strain of C.difficile
3. C.difficile must then grow and produce its toxins

Question 9

What is the mechanism of action by which C.difficle causes diarrhoea ?

Answer 9

Organism produces 2 toxins; toxin A (enterotoxin) and toxin B (cytotoxin)

Question 10

What are the main risk factors for C.difficile infection?

Answer 10

Question 11

How long after antibiotic treatment commencement do symptoms of C.difficile occur and how late can they present ?

Answer 11

• Usually occur 4-9 days after antibiotic treatment
• Can occur upto 8 weeks after discontinuation of antibiotic treatment

Question 12

What is the most common symptom of C.diff infection ?

Answer 12

Diarrhoea - sometimes bloody

Question 13

what are the symptoms of mild C.diff infection (CDI)?

Answer 13

Usually only diarrhoea

Question 14

what are the additional symptoms for moderate and severe CDI ?

Answer 14

• abdo cramps
• fever
• Raised WCC
• Even more frequent stools

Question 15

When may other symptoms be present in CDI ?

Answer 15

In severe cases e.g. pseudomembranous colitis, toxic megacolon and peritonitis

Question 16

Is severe CDI always associated with diarrhoea ?

Answer 16

No - should be suspected in patients showing ileus (bowel obstruction) or sepsis with risk factors of CDI

Question 17

Define what is meant by diarrhoea

Answer 17

Question 18

How does CDI spread?

Answer 18

• C.diff produces spores which are released into the environment via faeces
• The main source is the faecal-oral route - indirect/direct contact with an infected person or surface and then touching their mouth/eating the spores

Question 19

When should treatment for CDI be started ?

Answer 19

Immediately - it should be initiated based on ssymptoms and severity of disease do not wait for microbiology results

Question 20

How frequently does recurrence of CDI occur ?

Answer 20

20% of the time

Question 21

What 5 things must you do to prevent cross transmission when an individual has known or suspected CDI?

Answer 21

1. Isolate patient if symptomatic - until 48hrs symptom free and bowels returned to normal. After this a terminal clean of patients room done
2. Review antibiotic regime
3. Use PPE correctly - gloves and apron should be worn prior to each care activity
4. Decontaminate equipment and patients immediate environment
5. Perform hand hygiene correctly (with warm liquid and soap not alcohol gel)

Question 22

when is a patient considered to be clear of a CDI ?

Answer 22

• Clear if asymptomatic for 48hrs and bowel habits have returned to normal (specimens to confirm this are not required or accepted by the lab)
• Precautions should continue until these criteria are met

Question 23

How is C.diff diagnosed ?

Answer 23

• 1st line = Screening test for presence of the organism (GDH)
• 2nd line If GDH positive = test for presence of toxin (toxin A&B)

Screening test neg = negative result

Screening test pos, toxin test pos = positive result

Screening test pos, toxin test neg = indeterminate result = assess patient, send repeat specimen (usually also indeterminate result)

If repeat is indeterminate – clinical decision required!

Question 24

How is the severity of C.diff assessed ?

Answer 24

Severe if one or more of the following severity markers:

• Temperature > 38.5°C
• Ileus, colonic dilatation >6cm on AXR/CT, toxic megacolon and/or pseudomembranous colitis
• WBC >15 cells x 109 L
• Acute rising serum creatinine >1.5 x baseline
• Has persisting CDI where the patient has remained symptomatic and toxin positive despite 2 courses of appropriate therapy

Question 25

What is the treatment of non-severe C.diff ?

Answer 25

• 1st line = Metronidazole PO
• 2nd line = Vancomycin

Question 26

What is the 1st and 2nd line treatment of severe C.diff?

Answer 26

• 1st line = PO Vancomycin if oral not available give via NG tube
• 2nd line = If ileus is detected or NG route not available treat with IV metronidazole + vancomycin (via NG or intracolonic) until ileus is resolved.

Question 27

What is classified as recurrent C.diff infection and what is the treatment of it ?

Answer 27

• Recurrent if positive CDI in previous 8 weeks
• Fidaxomicin +/- Vancomycin tapering regime