Fungal infections Flashcards
What are the 3 main Fungal pathogens?
Aspergillus
Candida
Cryptococcus
Who is at risk of fungal infection?
Immunocompromised patients - Opportunistic pathogens
Patients with chronic illness
Patients in ICU setting
What are important conditions caused by fungal infections?
Pneumocystis pneumonia Allergic and invasive pulmonary aspergillosis Aspergilloma Thrush Candidemia Meningitis
What fungal species causes thrush?
Candida
What fungal species causes meningitis?
Cryptococcus
Who is at risk of contracting mucocutaneous candidiasis?
Antibiotic use
Moist areas
Inhaled steroids
Nenonates <3 months
How does mucocutaneous candidiasis present?
Neutropenia
Low CD4+ T-cells
Impaired IL-17 immunity
What causes invasive candidiasis?
Gut commensal organisms
What are risk factors for invasive candidiasis?
Use of broad spectrum antibiotics
Intravascular catheters
Total parenteral nutrition
Abdominal surgery
How is invasive candidiasis diagnosed?
Blood cultures or culture from a normally sterile site
Beta-d-glucan - good test to exclude invasive candidiasis
PCR
How is aspergillus transmitted?
Sporulation
Hydrophobic conidia
Airborne/inhalation
How is acute invasive pulmonary aspergillosis classified?
Neutropenic
Post transplants
Patient with defects in phagocytes
How is chronic pulmonary aspergillosis classified?
Patients with underlying lung conditions
Duration >3months
How is allergic aspergillosis classified?
Allergic bronchopulmonary aspergillosis in CF and asthma
What are features of acute invasive pulmonary aspergillosis?
Rapid and external hyphal growth
Thrombosis and haemorrhage
Angio-invasive and dissemination
Persistent febrile neutropenia
Where is clinical presentation of invasive aspergillosis often seen?
Bones
Spine
Brain
Abdominal
How is pulmonary aspergillosis diagnosed?
Non-neutropenic patients - Sputum cultures, biopsy, Aspegillus specific IgG and IgE
Neutropenic patients - CT chest, molecular markers in blood
How is cryptococcus transmitted?
Inhalation
What is clinical presentation of cryptococcal meningitis?
Headache Confusion Altered behaviour Visual disturbances Coma
How is cryptococcal disease diagnosed?
Indian ink preparation CSF culture High protein and low glucose in CSF Cryptococcus antigen Blood culture
What are factors associated with mortality in cryptococcal meningitis?
Delay in presentation and diagnosis Lack of access to antifungals Inadequate induction therapy Delays in starting antiretroviral therapy Immune reconstitution syndrome
What antifungals are used to treat invasive fungal infections?
Amphotericin B
Azoles
Echinocandins
Flucytosine
