8.Fungal Infections Flashcards
(27 cards)
What is the mortality rate of invasive Mycological Disease?
> 50% - about 1,350,000
Who do Fungal Pathogens affect?
They are Opportunistic Infections:
1. Patients with an Impaired Immune System (Primary imunodeficiencies, HIV/AIDS, Malignancies etc)
2. Patients with Chronic Lung Diseases (Asthma, Cystic Fibrosis)
3. Patients in ICU Settings
What are the “Big 3” Fungal Pathogens?
- Candida Species (Albicans) - Yeast
- Aspergillus Species (Fumigatus) - Spores in the Air
- Cryptococcus Species (Neoformans) - Yeast
What is the most common type of Candida Species infection?
Mucocutaneous Candidiasis (Nappy Rash, Thrush)
Note - it can cause a lot of different diseases
When / Where does Candida Species infection occur?
Candida Species are a commensal (on the Skin) and is found:
1. When the patient is on Antibiotics
2. When the patient is on Inhaled Steroids
3. When the patient has a Primary immunodeficiency disorder
4. When the patient is a Neonate (< 3 months)
5. Moist Areas of the Skin
What is the Pathology of Invasive Candidiasis?
- Candida Species are a Gut commensal (infections mostly Endogenous origin)
- If the patient is immunocompromised, the Candida may become more aggressive
- Same clinical course as bacterial infection in Sepsis
Note - Candida Species are the 4th most common Bloodstream Infection
How is Aspergillosis transmitted from person to person?
Sporulation, when the spores are then dispensed into the air where they are inhaled
Note - pulmonary infections are common
Note - If the immune system is in tact, there will be no problem
What are the 3 classifications of Pulmonary Aspergillus Disease?
- Acute Invasive Pulmonary Aspergillosis
- Chronic Invasive Pulmonary Aspergillosis
- Allergic Aspergillosis
What predisposes patients to Acute Invasive Pulmonary Aspergillosis?
- Neutropenic Patients
- Patients with defects in Phagocytes
What predisposes patients to Chronic Invasive Pulmonary Aspergillosis?
Patients with underlying chronic lung conditions
What predisposes patients to Allergic Aspergillosis?
- Allergic Bronchopulmonary Aspergillosis in Cystic Fibrosis and Asthma
- Extrinsic Allergic (Broncho)Alveolitis
- Asthma or Cystic Fibrosis with Fungal Sensitisation
What causes Acute Invasive Pulmonary Aspergillosis?
Rapid and Exensive Hyphal (Aspercillus) Growth - Spores cause the infection and these will just grow through any body wall
What are the Clinical Signs / Symptoms of Acute Invasive Pulmonary Aspergillosis?
- Thrombosis and Haemorrhage
- Persistent Febrile Neutropenia, despite broad-spectrum antibiotics
What is the definition of a Pulmonary Aspergilloma?
A Fungal Mass that grows in Lung Cavitiy
Note - As long as it is within the cavity it isnt a problem, but it can go through and cause bleeding
What are some common Pulmonary Aspergilloma?
- Tuberculosis
- Sarcoidosis
- Bronchiectasis
- Bronchial Cysts and Bullae
- After Pulmonary infections
How is Cryptococcosis transmitted from person to person?
Inhalation
Where can Cryptococcal Species be found?
- On the bark of trees
- Bird faeces
- Organic matter
Which Cryptococcosis is the most concerning, in patients with HIV / AIDS?
Cryptococcal Meningitis:
Subacute meningoencephalitis after a latent infection
How is Cryptococcal Meningitis diagnosed?
Indian-Ink CSF
What are the 3 classes of Anti-Fungals?
- Polyenes
- Azoles
- Echinocandins
What are the most common Polyene Antifingual Drug?
- Amphotericin B
- Griseofulvin
- Nystatin
What are the most common Azole Antifungal Drugs?
- Fluconazole
- Voriconaxole (more recently developed)
- Posaconazole (more recently developed)
What are the most common Echinocandin Antifungal Drugs?
- Anidulafungin
- Caspofungin
- Micafungin
How is Invasive Aspergillosis treated?
- I.V. and Oral Azoles (Voriconazole / Isavuconazole)
OR
I.V. Polyene (Liposomal Amphotericin B) if serious infection occurs
