MI: Infection CPC Flashcards
Describe the typical clinical findings in Pneumocystis jirovecii pneumonia.
Widespread, bilateral ground-glass shadowing with reduced exercise tolerance and low saturations.
How is PCP treated?
Co-trimoxazole
Which investigation can be used to confirm a diagnosis of PCP?
Bronchoalveolar lavage cytology
Which stain is used to identify PCP?
Silver stain (Grocott-Gomori stain)
List some causes of immunodeficiency.
- Inherited
- Immunosuppressive therapy
- Chemotherapy
- Radiotherapy
- HIV
- Chronic illness
- Malnutrition
Which organisms do the following defects make you susceptible to?
- T cell defect
- B cell defect
- Neutrophil defect
- Complement defect
T cell defect:
- Sepsis
- CMV, EBV, VZV
- Candida, PCP
- Usually aggressive opportunistic infections
B cell defect:
- Streptococcus, Staphylococcus, Haemophilus
- Giardia
- Usually recurrent sinopulmonary infections
Neutrophil defect
- Staphyloccocus, Pseudomonas
- Candida, nocardia, aspergillus
Complement defect
- Neisseria
What is Cryptococcus?
Yeast that causes fungal meningoencephalitis
What is Actinomyces and what does it cause?
Gram-positive rod that causes lung abscesses in immunocompromised patients (particularly alcoholics)
NOTE: it’s closely associated with Nocardia
What are the issues with investigatin and managing suspected Actinomyces infection?
Slow-growing (so difficult to culture) and difficult to treat
Describe the histological features of Actinomyces.
Basophilic sulfur granules
Gram-positive rods that branch as they grow
Why is it difficult to treat infected prosthetic materials?
Pathogens form biofilms which are difficult to penetrate with antibiotics
What are the general management principles of treating infected prosthetic material?
- Antibiotic treatment alone is not curative in most cases
- Removal of prosthesis and adequate debridement is the most important part of treatment
NOTE: treatment failure can occur without resistance
Which bacteria are all stool samples tested for?
- Salmonella
- Shigella
- E. coli O157
Which other bacterium will be tested for in stool stamples from patients > 65 years?
C. difficile
What are the steps in the management of a patient with C. difficile infection?
- Isolate in a single room
- Assess severity
- Stop offending antibiotics if possible
- Wash hands with soap and water after each patient contact and use gloves and aprons
- Commence C. difficile care pathway, fluid balance chart and Bristol stool chart