Fungal Infections Flashcards
What are the 3 main fungal pathogens focused on?
- Aspergillus fumigatus
- Candida albicans
- Cryptococcus neoformans
Which patients are most at risk of fungal infections?
- Patients with impaired immune systems (HIV / transplants / neonates / immunosuppressed)
- Patients with chronic lung diseases (CF / asthma / chronic obstructive lung disorders)
- Patients in ICU settings
What are some of the common diseases caused by fungal pathogens?
- Pneumocystitis pneumonia
- Allergic and invasive pulmonary aspergillosis
- Thrush / cadidiasis
- Meningitis
What is meant by “fungal infections are opportunistic”?
Means they don’t usually cause problems, but in susceptible patients they can
Are normally part of body flora without issue
How can infection with candida manifest itself?
- Mucocutaneous candida: thrush / yeast infection etc. Appears as erythematous patches of varying size / shape on the skin
- Invasive Candidiasis: infection mostly due to invasion of gut commensal, causes fever and chills at first and then can spread causing varying systemic effects (heart / brain / eyes / bones)
How is mucocutaneous candida treated?
- topical / oral antifungals
- Drying agents
How is invasive candidiasis diagnosed? How is it treated? Prognosis?
- Blood culture or culture from normally sterile site
- IV antifungals (echinocandins / Fluconazole)
- Up to 40% mortality
How is aspergillus transmitted? What diseases does it cause?
- Airborne (via inhalation)
- Acute invasive pulmonary aspergillosis
- Chronic pulmonary aspergillosis
- Allergic aspergillosis
What patients do acute and chronic pulmonary aspergillosis tend to manifest in?
Acute invasive pulmonary aspergillosis:
- Neutropenic patients (low neutrophils)
- Post transplant patients
- Patients with corticosteroid induced immunosuppression
Chronic pulmonary aspergillosis:
- Patients with underlying chronic lung conditions
How does acute pulmonary aspergillosis tend to present? Pathophysiology? Prognosis?
- Nonspecific respiratory systems common: SOB, haemoptysis / productive cough, wheeze, pyrexia, weight loss
- Fungus causes excessive inflammation & tissue necrosis
- Mortality: around 50%
How does chronic pulmonary aspergillosis tend to present?
- Pulmonary exacerbations (not responding to
antibiotics) - Lung function decline
- Increased respiratory symptoms as cough & SOB
How is pulmonary aspergillosis diagnosed?
In non-neutropenic patients:
- Cultures of sputum / bronchoalveolar lavage
- Aspergillus specific IgG and IgE
Neutropenic patients:
- High resolution CT-chest
- Molecular markers in blood: galactomannan and PCR-Aspergillus
- Bronchoalveolar lavage if condition allows
What is Allergic Bronchopulmonary Aspergillosis? Which patients are most susceptible to it?
- It’s a hypersensitivity response to Aspergillus fumigatus
- Most common in asthma / CF patients
How does Allergic Bronchopulmonary Aspergillosis present? How is it diagnosed?
- Deterioration of lung function and resp. symptoms (cough / SOB etc.)
- CXR / CT chest
- Elevated immunoglobulin E (IgE) level + Positive Aspergillus specific IgG
- positive skin-test
What is a pulmonary aspergilloma? Who does it tend to occur in?
- A fungal mass that grows inside lung cavities
Occurs in patients with residual lung cavities. Current / past:
- TB / sarcoidosis / bronchiectasis / bronchial cysts & bullae / after pulm. infection
