Infection CPC

Question 1

What can be used to estimate the short-term outlook in ART naive HIV-1 patients

Answer 1

CD4 T cell count

Question 2

What is considered a high community prevalence of HIV in the community

Answer 2

2/1000 of population

Question 3

What are some atypical infections that can occur in immunocompromised patients (4)

Answer 3

Atypical mycobacteria
Fungal infections
Viral (CMV, HSV)
Toxoplasmosis

Question 4

What are the broad categories of immunodeficiency (2)

Answer 4

Inherited

Acquired

Question 5

What are some causes of acquired immunodeficiency (4)

Answer 5

Iatrogenic (e.g. steroids, chemotherapy, radiotherapy)
HIV
Chronic illness (diabetes, cancer)
Malnutrition

Question 6

What can occur with bacterial infections in a patient with a T cell defect

Answer 6

Sepsis

Question 7

What bacterial infections can occur in a patient with B cell defects (3)

Answer 7

Streptococcoal
Staphylococcal
Haemophilus

Question 8

What bacterial infection can occur in a patient with a neutrophil defect (2)

Answer 8

Staphylococcus

Pseudomonas

Question 9

What bacterial infection can occur in a patient with a complement defect

Answer 9

Neisserial

Question 10

What viral infection can occur in a patient with a T cell defect (4)

Answer 10

CMV
EBV
Varicella
Respiratory and intestinal infections

Question 11

What viral infection can occur in a patient with a B cell defect

Answer 11

Enteroviral encephalitis

Question 12

What fungal and parasitic infection can occur in a patient with a T cell defect (2)

Answer 12

Candida

PCP

Question 13

What fungal and parasitic infection can occur in a patient with a B cell defect

Answer 13

Giardia

Question 14

What fungal and parasitic infection can occur in a patient with a Neutrophil defect (3)

Answer 14

Candica
Nocardia
Aspergillus

Question 15

What type of infections occur in patients with T cell defects

Answer 15

Aggressive, often opportunistic infections

Question 16

What type of infection occurs in patients with B cell defects

Answer 16

Recurrent sinopulmonary infections

Question 17

What is ineffective in the treatment of osteomyelitis

Answer 17

Antimicrobial therapy alone is not curative in most cases.

Continuing drugs over a long period of time will lessen the amount of discharge, but it will not cure the disease because it cannot sterilise dead bone or cavities with necrotic content and rigid walls.

Question 18

What is the most important step in the management of prosthetic joint infections

Answer 18

Removal of prosthesis and adequate debridement.

Antibiotics play a secondary role.

Question 19

What prosthetic implants can give rise to osteomyelitis (4)

Answer 19

Prosthetic joint replacements. 
IV lines (venflons, central lines, pic lines, portacaths, etc...)
Prosthetic cardiac valves 
Prosthetic implants (cosmetic or reconstructive)

Question 20

What are the next steps if a patient has confirmed C.difficile infection (5)

Answer 20

Isolate in a single room.
Assess severity.
Stop offending antibiotics if possible.
Wash hands with soap and water before and after each patient contact and use gloves and aprons.
Commence C.difficile care pathway, fluid balance chart and Bristol stool chart.

Question 21

What are the Imperial guidelines to assess C.difficle severity (6)

Answer 21

Severe = 1 or more of the following:
T>38.5
HR >90
WCC>15
rising creatinine
Clinical signs of severe colitis, or colitis on radiology
Failure to respond to therapy at 72 hours.

Patients with a score of 1 or more warrant early surgical and gastroenterology review.

Question 22

What is the Imperial guideline for treatment of non-severe C.difficile infection

Answer 22

Metronidazole 400mg PO TDS for 10-14 days.

If intolerant of metronidazole, or if not responding to treatment at 72 hours (and no other indications of severity), consider changing to:
vancomycin 125mg PO QDS 10-14 days.

Question 23

What is the Imperial guideline for the treatment of severe C.difficile infection

Answer 23

Vancomycin 125mg PO QDS for 14 days plus consider adding metronidazole 500mg IV TDS

Higher doses of vancomycin may be appropriate in more severely ill patients, and should be discussed with micro/ID

Question 24

What is the Imperial guideline for the treatment of severe C.difficile infection with colonic dilatation

Answer 24

Vancomycin 125-250mg PO QDS plus metronidazole 500mg IV TDS for 14 days.

Also liase with ID/micro and gastro/surgeons.

Question 25

What is the Imperial guideline for the treatment of severe C.difficile infection and ileus/vomiting.

Answer 25

Consider intracolonic vancomycin.

Discuss with ID/micro and gastro/surgeons

Question 26

What is the significance of ribotype 027 c.difficile

Answer 26

Increased severity of disease.

Strain produces: 16 times more toxin A and 23 times more toxin B.

Question 27

What class of antibiotics are most prone to induce c.difficile

Answer 27

Fluoroquinolones

Question 28

How is c.difficile spread

Answer 28

Faeco-oral route through spores

Question 29

What are risk factors for acquiring c.difficile infection (4)

Answer 29

Administration of antibiotics (multiple antibiotics, long duration)
Age over 65 years
Duration of hospital stay (it has been reported than after 4 weeks, 50% of patients tested were culture positive)
Severe underlying disease

Question 30

What is C.difficile most associated with

Answer 30

Recent history of antibiotic use

Question 31

When does C.difficile occur

Answer 31

May occur during antibiotic therapy or in the weeks after a course of antibiotics

Question 32

What is the onset of c.difficile like

Answer 32

Onset is abrupt with explosive, watery, foul smelling diarrhoea.

Question 33

What is the most common complication os c.difficile infection

Answer 33

Pseudomembranous colitis

Question 34

How can c.difficile infection be prevented (2)

Answer 34

Cleanliness and hygiene measures

Restrictive approach to antibiotic prescribing