Fungal infection Flashcards
What 3 fungal pathogens should you focus on
Aspergillus species
Aspergillus fumigatus
Candida species
Candida albicans
Cryptococcus species
Cryptococcus neoformans
Fungal pathogens are opportunistic in nature and affect patients with? give examples of the 3 main groups
impaired immune system
- Patients with primary immunodeficiencies
Patients with HIV/AIDS
Patients with malignancies (neutropenia) & transplants
Premature neonates (immature immune system)
patients with chronic lung diseases (pulmonary aspergillosis and other moulds) Asthma Cystic Fibrosis Chronic obstructive lung disorders
Affecting patients in ICU settings
Candida causes
thrush (oral too)
candidemia
cryptococcus causes
meningitis
Aspergillus- pneumocystis causes?
Pneumocystisis, allergic and invasive
Mucocutaneous Candidiasis- seen in
nappy rash
red rashes
Antibiotic use
Moist areas
Inhalation steroids
Neonates < 3 month
Mucocutaneous Candidiasis is a Presenting symptom of primary
immunodeficiency disorders
characterised by what? (3 main)
Neutropenia
Low CD4+ T-cells
impaired IL-17 immunity
Invasive Candidiasis is
Gut commensal
Invasive Candidiasis is the 4th most common
bloodstream
infection (BSI) in adults
What are additional risk factors for invasive candidiasis (4)
Broad-spectrum antibiotics
Intravascular catheters
Total parenteral nutrition
Abdominal surgery
Diagnosis of Invasive Candidiasis
Blood culture or culture from normally sterile site
β-d-glucan high NPV and performs very well to
exclude invasive candidiasis
Recent developments in PCR assays very promising
In infants and children performance lower due to
sampling issues
Transmission of Aspergillus and Aspergillosis (4)
sporulation
• hydrophobic conidia
• diameter 2-3 µm
• airborne / inhalation
Invasive pulmonary aspergillosis can go on to form
Neutropenia and tissue damage
Classification of pulmonary Aspergillus disease- name of all 3 plus examples of patients who would be affected
Acute invasive pulmonary aspergillosis - Neutropenic patients (incidence 1-10%)
• Post transplants: stem cell > solid organ (incidence up to 8%)
• Patients with defects in phagocytes
Chronic pulmonary aspergillosis (> 3 months) - Patients with underlying chronic lung conditions
Allergic aspergillosis
• Allergic bronchopulmonary aspergillosis in CF and asthma
(incidence 10-15%)
• Asthma or CF with fungal sensitisation (incidence 5-15%)
Acute Invasive Pulmonary Aspergillosis - features (5)
Neutropenic host - eg acute leukaemia
Rapid and extensive hyphal growth
• Thrombosis and hemorrhage
• Angio-invasive and dissemination
• Absent or non-specific clinical signs and symptoms
• Persistent febrile neutropenia despite broad-spectrum antibiotics
• Mortality rates around 50% (but depending on immune recovery)
(Sub) Acute Invasive Pulmonary Aspergillosis
non-neutropenic host
- has a limited fungal growth
- can cause tissue necrosis
- mild to moderate systemic illness
Invasive aspergillosis as presenting symptom of primary immunodeficiency (4)
- Congenital neutropenia
Chronic granulomatous disease - Hyper IgE syndrome (Job’s syndrome)
- CARD-9 deficiency
Invasive aspergillosis often presents clinically outside of the lungs- where else?
bones, spine, brain, abdominal
Chronic Pulmonary Aspergillosis is often seen in those with
asthma, cystic fibrosis, chronic obstructive lung disorders
Chronic Pulmonary Aspergillosis characteristics
Pulmonary exacerbations (not responding to antibiotics) Lung function decline - increased resp symptoms such as cough - postive sputum culture for aspergillum
up to 50% of CF patients will get?
chronic pulmonary aspergillosis
Allergic Bronchopulmonary Aspergillosis - immunological responses to a variety of antigens in the CF- host result in: (5)
Acute/subacute deterioration of lung function and
respiratory symptoms
New abnormalities chest imaging
Elevated immunoglobulin E (IgE) level
Increased Aspergillus specific IgE or positive skin-test
Positive Aspergillus specific IgG
What is Pulmonary Aspergilloma (6)
A fungal mass that usually grows in lung cavities Tuberculosis In 22% if residual cavities Sarcoidosis Bronchiectasis Bronchial cysts and bullae After pulmonary infections
Diagnosis of Pulmonary Aspergillosis - In non-neutropenic patients (2)
Cultures of sputum and/or bronchoalveolar lavage, and/or biopsy
• Aspergillus specific IgG and IgE in chronic and allergic pulmonary
aspergillosis
Diagnosis of Pulmonary Aspergillosis
In neutropenic patients:
- HIGH res CT chest
- biopsies
Cryptococcus and Cryptococcosis symptoms?
- Transmission by inhalation - faeces, organic matter, birds
- Pulmonary infection from asymptomatic to pneumonia
-
Cryptococcus and Cryptocococsis can cause
Dissemination to brain: meningoencephalitis in HIV/AIDS
Cryptococcus and Cryptocococsis - CLINCIAL presentation
headache, confusion, altered
behaviour, visual disturbances, coma (due to raised
intracranial pressure in 60-80%)
Diagnosis of cryptococcal disease
Cerebrospinal fluid: Indian Ink preparation (80%
sensitivity), culture, high protein and low glucose,
Cryptococcus antigen (lateral flow assay)
Blood: culture, Cryptococcus antigen
Outcome of cryptococcal meningitis
what factors can be associated with mortality ?
Africa: 3-month mortality 70%
US: 3-months mortality 25%
Delay in presentation and diagnosis Lack of access to antifungals Inadequate induction therapy Delays in starting antiretroviral therapy Immune reconstitution syndrome
Antifungal agents to treat invasive
fungal infections? (4)
- Amphotericin B formulations (iv)
- Azoles (iv, oral)
- Echinocandins (iv)
- Flucytosine (iv, oral)
maintenance for cryptococcal meningitis antifungals?
AmB + flucytosine followed by fluconazole
what anti fungal has the most broadest antifungal activity
AmB
Antifungals for invasive candidiasis
Echinocandins and fluconazole
Antifungals for (acute) invasive aspergillosis
Voriconazole and Isavuconazole
Antifungals for antifungal prophylaxis
Itraconazole and Posaconazole