Infections in Immunocompromised
Aetiology
Innate immunosuppression
Acquired immunosuppression (Combined deficiencies)
Mild to moderate immunosuppresion
Clinical Features
Signs
Investigations
Bedside: sputum/ bronchoscopy (PCR (PJP), Fungal stain/ culture (PJP, aspergillus))
Management
Details
PJP
Aspergillus
Cryptococcus
Legionella
CMV
VZV
Source
Dr Gregory Haug 2014
Innate immunosuppression
- Hypogammaglobulinaemia (B cell)
- T cell problems (very susceptible to: viral, fungal (PJP, aspergillus, cryptococcus, candida), TB, parasitic, bacteria (Legionella*, GN)
- Combined
Acquired immunosuppression (Combined deficiencies)
- Chemo (RA - methotrexate, IBD - azathioprine/ methotrexate, GPA - cyclophosphamide)
- HIV
- Cancers (myeloma, lymphoma)
- Transplant pt (no T cells)
Mild to moderate immunosuppresion
- Bronchiectasis
- Smoking
- Alcoholism
- Pregnancy
- Diabetes
- CF
Clinical Features
Signs
- Fungal usually high fever (>40)
Investigations
Bedside: sputum/ bronchoscopy (PCR (PJP), Fungal stain/ culture (PJP, aspergillus))
Management
- General principle: treat what you suspect empirically
- If transplant pt/ very immunosuppressed, treat aggressively. Find PJP, aspergillus
- IV macrolide (cover Legionella)
- Prophylaxis: Bactrim, viral prophylaxis, fungal prohylaxis
Details
PJP
- Affects children in famine conditions (immunocompromised)
- Chemotherapy (long term + high dose - methotrexate)
- Looks like other pneumonia, higher hypoxemia even on 100% O2
Aspergillus
- It's everywhere!
- Transplant pt most affected
- High fever (>40)
- Rx: -conazole drugs (not fluconazole)
Cryptococcus
- Bat faeces
- CFx like normal pneumonia
- CXR will show consolidation
- If doesn't resolve, think of this
- May cause cryptococcal meningitis (not typical infective confusion)
- Rx: -conzaole (including fluconazole)
Legionella
- It's everywhere! (all strains)
- Affects transplant pt
CMV
- BM transplant patients particularly
- Donor mismatch (CMV positive donor --> CMV negative recipient. Rx: Aciclovir prophylaxis)
- Ix: Serology (IgM response 1st)
VZV
- Shingles recurrence
- High mortality
Source
Dr Gregory Haug 2014