fungal infections Flashcards
(37 cards)
what are the three main fungal pathogens ?
Aspergillus fumigatus
Candida albicans
Cryptococcus neoformans
Who is at risk of fungal infection ?
Impaired immune system
Chronic lung disease
Patients in ICU setting
what diseases does pneumocystis spp. cause ?
pneumocyctitis
pneumonia
what diseases does aspergillus spp. cause ?
allergic
aspergillosis
aspergilloma
what disease does candida spp. cause ?
thrush
candidemia
what does cyrptococcus spp. cause ?
meningitis
when is mucocutaneous candidiasis seen ?
antibiotic use
moist areas
inhalation steroids
neonates <3months
what are presenting symptoms of mucocutaneous candidiasis
primary immunodeficiency disorders
neutropenia
low CD4+ Tcells
impaired IL-17immunity
what are the different types of impaired IL-17 immunity
AD-Hyper IgE syndrome - deficit of IL-17 producing cells
Dectin-1 deficiency - reduced levels of IL-17
CARD9 deficiency - low proportion of circulating IL-17 T-cells
APECED syndrome - high titres of neutralising Ab against IL-17
what is invasive candidiasis and how does it present
a blood stream infection usually from gut commensal, common in premature neonates, high mortality 40%
presents as bacterial BSI
what are other risk factors of invasive candidiasis
broad spectrum antibiotics
intravascular catheters
total parenteral nutrition
abdominal surgery
how is invasive candidiasis diagnosed
blood culture or culture from normally sterile site.
Beta-d-glucan high NPV excludes
recent PCR development
how is aspergillus spread
airborne inhalation
sporulation
hydrophobic conidia
diameter 2-3 um
what are the different classifications of aspergillus disease
acute invasive pulmonary aspergillosis - neutropenic patients, post transplant stem cell, phagocyte defects
chronic pulmonary aspergillosis - >3 months, underlying lung condition
allergic aspergillosis - allergic bronchopulmonary aspergillosis in CF and asthma
what are features of acute invasive pulmonary aspergillosis ?
rapid and extensive hyphen growth
thrombosis and haemorrhage
angio-invasive and dissemination
absent or non-specific clinical signs and symptoms
persistent febrile neutropenia despite broad spectrum Abx
mortality 50%
who is susceptible to sub-acute invasive pulmonary aspergillosis ?
non-neutropenic host
graft-vs-host disease -stem cell
neutrophil disorders
what are the features of sub acute invasive pulmonary aspergillosis ?
non-angioinvasive limited fungal growth pyogranulomatous infiltrates tissue necrosis excessive inflammation non-specific clinical signs and symptoms mild to moderate systemic illness mortality 20-50%
what are feature of invasive aspergillosis as presenting symptom of primary immunodeficiency ?
congenital neutropenia
chronic granulomatous disease - phagocytic disorder
hyper IgE syndrome
CARD-9 deficiency
clinical presentation outside lungs - bone, spine, brain, abdominal
what are features of chronic pulmonary aspergillosis ?
pulmonary exacerbations
lung function decline
increased respiratory symptoms - cough, exercise tolerance, SOB
positive sputum cultures for aspergillus, 50% of CF patients infected
what are features of allergic bronchopulmonary aspergillosis ?
acute/subacute deterioration of lung function and respiratory symptoms
new abnormal chest imaging
elevated IgE
increased aspergillus specific IgE of positive skin-test
positive aspergillus specific IgG
what is pulmonary aspergilloma ?
a fungal mass that usually grows in lung cavities
when is pulmonary aspergilloma seen ?
tuberculosis sarcoidosis bronchiectasis bronchial cysts and bullae after pulmonary infections
how is aspergillosis diagnosed in non-neutropenic patients ?
cultures of sputum and/or bronchoalveolar lavage, biopsy
aspergillus specific IgG and IgE in chronic and allergic pulmonary aspergillosis
how is aspergillosis diagnosed in neutropenic patients ?
high resolution CT chest - halo/air-cresent sign
molecular markers in blood - galactomannan and PCR
BAL and biopsies
