fungal infection Flashcards
what are the 3 most important pathological fungi ?
aspergillus fumigatus
candida albicans
cryptococcus neoformans
who gets fungal infections ?
immunocompromised patients
patients with chronic lung disease
patients in ICU
what conditions does aspergillum cause ?
allergic and invasive
pulmonary aspergillosis
aspergilloma
what increases risk of mucocutaneous candidiasis ?
antibiotic use
moist areas
inhalation steroids
neonates <3 months
where does invasive candidiasis arise ?
gut commensal
endogenous origin
presents as blood stream infection
what are risk factors of invasive candidiasis ?
prematurity broad spectrum antibiotics IV catheters total parenteral nutrition abdo surgery
how is invasive candidiasis diagnosed ?
blood culture
beta-d-gluca high NPV excludes invasive candidiasis
PCR
how is pulmonary aspergillosis classed ?
acute invasive - neutropenic, post transplant,
chronic - >3 months, underlying chronic lung conditions
allergic aspergillosis - CF, asthma
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 circulation IL-17 Tcells
APECED syndrome - neutralising Ab against IL-17
when does fungal masses usually grow in lungs ?
TB sarcoidosis bronchiectasis bronchial cysts and bullae after pulmonary infections
how do you diagnose pulmonary aspergillosis ?
non-neutropenic - sputum culture, biopsy, specific IgG and IgE
neutropenic -CT chest
molecular markers
biopsy
what is the clinical presentation of cryptococcosis infection ?
headache confusion altered behaviour visual disturbance coma
how is cryptococcal disease diagnosed ?
CSF - Indian ink, high protein, low glucose
blood culture
what factors are associated with mortality in cryptococcal disease ?
delay in presentation and diagnosis lack of access to antifungals inadequate induction therapy delays in starting antiretrovirals immune reconstitutions syndrome
what are antifungals to treat invasive infection ?
amphotericin B - act of ergosterol - lysis
azoles - inhibit ergosterol synthesis
echinocandins - inhibit gluten synthesis
flucytosine - inhibit fungal DNA synthesis
