Fungal Infections Flashcards
What are the main fungal infections?
Aspergillosis - Aspergillus Fumigatus
Candidiasis - Candida Albicans
Cryptococcosis - Cryptococcus Neoformans
How is Aspergillus transmitted?
Airborne Spores
Aspergillosis has several different presentations, how does Acute Invasive Aspergillosis present?
Neutropenic & post-transplant patients
They are persistently febrile despite abx
Its angio-invasive and may cause thrombosis & haemorrhage
Aspergillosis has several different presentations, how does chronic pulm. Aspergillosis present?
When acute is present for more than 3 months.
Chronic lung disease patient who get an acute exacerbation that unresponsive to abx may be aspergillus.
Aspergillosis has several different presentations, describe Allergic Bronchopulmonary Aspergillosis?
It is a Type I/II hypersensitivity to A. fumigatus.
Usually CF or Asthma patients who acutely deteriorate in lung function &resp symptoms
Present with SOB, sputum, cough, dyspnea
Aspergillosis has several different presentations, describe a pulmonary aspergilloma?
A non-invasive infection in a pre-existing cavity e.g. post-TB, sarcoid, bronchiectasis or pulm infection.
Aspergillosis has several different presentations, describe influenza associated aspergillosis?
Flu patients who get intubation, oseltamavir, CCS and/or Abx can then develop aspergillosis
Literally just aspergillosis in a patient with Flu
How do you test for aspergillus?
If they’re neutropenic
- CT chest
- PCR
- Bronchoalveolar lavage + biopsy
If not:
- Sputum culture
- Bronchoalveolar Lavage
- Biopsy
How can test for chronic pulmonary or allergic bronchopulmonary aspergillosis
Blood tests for Aspergillus specific IgG & IgE
How is aspergillus treated?
Voriconazole & Isavuconazole
Who gets candida infection?
Mucocutaneous candiasis:
- Young neonates
- Abx/inhalation steroids
- Primary immunodeficiency disorders
Invasive candidiasis:
- Broad spectrum Abx
- Vascular catheters
- Parenteral nutrition
- Abdo Surgery
How does candidiasis present?
Invasive looks like a bacterial BSI
Mucocutaneous = thrush
How do we test for and treat candidiasis?
Blood culture & PCR
We treat with echinocandins and fluconazole
How does cryptococcosis develop?
Mostly HIV associated:
Starts with a pulm infection that disseminates to the brain causing meningoencephalitis
How is cryptococcus spread?
By inhalation
Its found in some tree bark & bird faeces
How does cryptococcosis present?
- LRT symptoms
- Consitutional symptoms
- Headache
- Confusion
- Altered behaviour
- Visual Disturbance
- Coma (raised ICP)
How do we test for cryptococcosis?
Get CSF for:
- India ink preparation
- Culture
- High protein/low glucose
- Cryptococcus Antigen
Get blood for:
- Culture
- Cryptococcus Antigen
How is cryptococcosis treated?
Induce therapy with AmB &a Flucytosine
Maintain it with fluconazole
Classes of anti-fungals?
Azoles:
- Fluconazole (Cryptococcosis & Candidiasis)
- Voriconazole &Isavuconazole (Aspergillosis)
Polyenes:
- Amphotericin B (Cryptococcosis)
Echinocandins (Candidiasis)
Flucytosine (Cryptococcosis)
How do azoles work?
Prevent ergosterol synthesis
How does echinocardins work?
prevent synthesis of gluons
How does amphoteracin B work?
Breaks down ergosterols in cells walls of fungi
How does flucytosine work?
Inhibits fungal DNA
