Fungal Infections Flashcards
Which groups of patients are most at risk for fungal infections?
Patients with an impaired immune system:
- Primary immunodeficiencies
- HIV/AIDs
- Malignancies and transplants
- Premature neonates
Chronic Lung Diseases
- Asthma
- CF
- COPD
Patients in ICU
What are the features of mucocutaneous candidiasis?
- Antibiotic use
- Moist areas
- Inhalation steroids
- Neonates < 3 months
- Presenting symptom of Primary Immunodeficiency Disorders: Neutropenia, low CD4+ T cells and impaired IL-17 immunity
What are the additional risk factors for invasive candidiasis?
- Broad spectrum antibiotics
- IV catheters
- TPN
- Abdominal surgery
How can invasive candidiasis be diagnosed?
- Blood culture or culture from normally sterile site
- Beta-d-glucan high NPV (to exclude invasive candidiasis)
- Potentially PCR assays
How can Pulmonary Aspergillus be diagnosed?
- Acute Invasive: neutropenic patients, post transplants (stem cell > solid organ) and patients with defects in phagocytes
- Chronic: patients with underlying chronic lung conditions
- Allergic: in patients with CF and asthma
What are the features of Acute Invasive Pulmonary Aspergillosis?
- Rapid and extensive hyphal growth
- Thrombosis and haemorrhage
- Absent/non-specific signs and symptoms
- Persistent febrile neutropenia despite broad-spectrum antibiotics
What are the features of Subacute Invasive Pulmonary Aspergillosis?
- Non-angioinvasive
- Limited fungal growth
- Pyogranulomatous infiltrates
- Tissue necrosis
- Excessive inflamm.
- Non specific signs and symptoms
Which Primary Immunodeficieny conditions can have invasive aspergillosisi as a symptom?
- Congenital neutropenia
- Chronic granulomatous disease
- Hyper IgE syndrome
- CARD-9 Deficiency
What are the features of Chronic Pulmonary Aspergillosis?
- Pulmonary exacerbations not responding to antibiotics
- Lung function decline
- Increased resp. symptoms
- Positive sputum cultures
What are the features of Allergic Bronchopulmonary Aspergillosis?
- Acute/subacute deterioration of lung function and resp. symptoms
- New abnormalities on chest imaging
- Elevated IgE level
- Increased Aspergillus specific IgE or positive skin test
- Positive Aspergillus specific IgE
What is a Pulmonary Aspergilloma?
A fungal mass that usually grows in lung cavities
Which virus can cause a pulmonary aspergilloma?
Influenza
How can pulmonary aspergillosis be diagnosed in non-neutropenic patients?
- Sputum cultures +/- bronchoalveolar lavage +/- biopsy
- Aspergillus specific IgG and IgE
How can pulmonary aspergillosis be diagnosed in neutropenic patients?
- High resolution CT chest
- Molecular markers in blood
- BAL and biopsies
What are the features of Cryptococcosis?
- Transmitted by inhalation
- Pulmonary infection: asymptomatic to pneumonia
- Dissemination to brain causing meningoencephalitis in HIV/AIDS patients
- Presentation: headache, confusion, altered behaviour, visual disturbances and coma
How can cryptococcal disease be diagnosed?
- CSF: Indian Ink preparation, culture, high protein, low glucose and Cryptococcus antigen
- Blood: culture and Cryptococcus antigen
Which antifungals can be used to treat invasive fungal infections?
- Amphotericin B: acts on ergosterol
- Azoles: inhibits ergosterol synthesis
- Echinocandins: inhibiting glucan synthesis
- Flucytosine: inhibiting fungal DNA synthesis
Which antifungals can be used for invasive candidiasis?
Echinocandins and Fluconazole
Which antifungals can be used for acute invasive aspergillosis?
Voriconazole and Isavuconazole
Which antifungals can be used for antifungal prophylaxis?
Itraconazole and Posaconazole
Which antifungals are used for cryptococcal meningitis?
AmB + flucytosine followed by fluconazole
What are the current problems with antifungals?
- Toxicity, drug interactions, resistance
- Diagnostics: sensitivity, specificity, portability, cost and feasibility
- No vaccines and no immunotherapies
