10. Fungal infections Flashcards
What are the three main fungal pathogens?
Aspergillus species (aspergillus fumigatus)
Candida species (candida albicans)
Cryptococcus species- Cryptococcus neoformans
Who gets fungal infections?
Patients with immunodeficiencies Patietns with malignancies Premature neonates Asthma CF COPD ICU Patients
What is the mucocutaneous candidiasis?
Presents with priamry immunodeficiency disorders characterised by :
Nautropenia
Low CD4 and T cells
Imapired IL-17
Affects moist areas, people who use inhaled steroids, neonates <3 months and some people on antibiotics
What is invasive candidasis?
Gut commensal that invades into places it shouldn’t be e.g. lungs, bone, liver, blood
Presents as a typical bloodstream infection
Additional risk factors include broad-spectrum antibiotics
Intravascular catheters
Total parental nutrition
Abdominal surgery
How do you diagnose invasive candidiasis?
Blood culture from normally sterile sites
How is aspergillus transmitted?
Sporulation
Hydrophobic conida
Airborne inhalation
How do you classify pulmonary aspergillus disease?
Acute invasice- Neutropenic Post transplant Patients with defects in phagocytes Chronic pulmonary aspergillus- 3 months Patients with chronic lung conditions Allergic aspergillosis Allergic bronchopulmonary aspergillosis in CF and asthma Asthma or CF with fungal sensitisation
Describe the pathological process of acute pulmonary aspergillosis
Rapid and extensive growth
Thrombosiss and heamorrhage
Angio-invasive and dissmiantion
Absent or non-specific clinical signs and symptoms
Persistent febrile neutropenia despite vroad spectrum antibiotics
Mortality rates around 50%
If someone has no leukaemia, No HIV and fungus what does this suggest?
Immune deficiency such as
Congential neutropenia
Chronic granulomatous disease (phagoctic disorder)
Hyper IgE syndrome (Job’s syndrome) phagocytic and IL-17 impaired
CARD-9 innate immune pathways kill defect
How does chronic pulmonary aspergillois present?
Pulmonary exacerbations that dont repsond to antibiotics
Lung fucntion decline
Incerased respiratory symptoms, decreased exercise tolerance
What is pulmonary aspergilloma?
A fungal mass that usually grows in lung cavities occurs in tuberculosis sarcoidosis bronchiecstasis bronchial cysts and bullae After pulmonary infections
How do you look for pulmonary aspergillosis in non neutropenic patients?
Cultures of sputum and/or bronchoalveolar lavage, and/or biopsy
Aspergillus specific IgG and iGE in chrnic and allergic pulmonary aspergillosis
How do you diagnose pulmonary aspergillosis in neutropenic patients
High resolution CT-chest
Halo sign and air crescent sign
Molecular markers in blood (glactomannan and PCR-aspergillus)
BAL and biopsises in condition allows
How are cryptococcuses spread?
Transmitted by inhalation
Can be found on the bark of a variety of trees, bird faeces and organic matter
Pulmonary infection from asymptomatic to pneuonia
Dissemination to brain (meningoencephalitis in HIV)
How does cryptococcuses present in the brain?
Headache, confusion, altered behaviour, visual disturbance, coma due to raised ICP
