Fungal infections Flashcards
fungal infections epidemiology
- immune compromise
- geographic region (recent travel)
Pneumocystic carinii (aka pneumocystis jirovecii) is diagnosed by (4)
- BAL (bronchoalveolar lavage)
- transbronchial biopsy
- Tracheal aspirate
- pleural fluid
Pneumocystis jirovecii (or carinii) is identified by which lab tests (3)?
- giemsa
- methaenamine silver stain
- fluorescent Ab
Pneumocystis jirovecii (carinii) transmission
respiratory droplets
Pneumocystis jirovecii (carinii) infective state? reproductive?
- cyst forms
- trophic forms (trophozoite & precyst)
precyst contains infectie spores
Which fungi has chitin in its cell wall?
p. jirovicii
which fungi is the most virulent?
c. immitus
which 3 fungi that infect the lung are dimorphic?
- c. immitus
- h. capsulatum
- blastomyces dermatitidis
Coccidioides immitis are endemic to which geographical regions?
- San Joaquin, CA
- Maricopa, Pima Counties of AZ
- Southwestern TX
low rainfall, airid climate
C. immitus characteristics
- mold form barrel-shaped arthroconidia
- spherules with endospores
Erythema multiforme, erythema nodosum and arthritis can be seen in allergic reaction to which fungi?
c. immitus
C. immitus infects by which route?
inhaled, small enough to avoid immune cells in upper airway
Histoplasma capsulatum is endemic to which 3 areas
- ohio
- mississippi
- missouri
areas w/high nitrogen in soil
why is histoplasmosis called cave disease?
bat and bird guano is abundant and people who go into caves are exposed to H. capsulatum
H. capsulatum progession of disease
- inhalation of microconidia in areas contaminated with bird and/or bat droppings
- microconidia phagocytosed by macrophages in pulmonary parenchyma
H. capsulatum key dx feature
- macroconidia by latex agglutination
- Enzyme immuno assay (EIA) in blood
H. capsulatum infectious form
microconidia: infectious form
Cryptococcus neoformans characteristics
Heavily encapsulated yeast
Which fungi is found in soil and pigeon droppings?
Cryptococcus neoformans
Cryptococcus neoformans is dx by which 2 lab tests ?
- detection of capsule using India Ink stain
- ELISA: serological tests to detect cryptococcal capsular antigen
- cultures: sabouraud dextrose
5 sx of cryptococcus infection
- SOB
- cough
- fever
- chest pain
- fever
cryptococcus neoformans complications
CNS infection
2nd MC fungal infection after candida
aspergillus (4 species)
infectious process of aspergillosis
conidia inhaled –> germinate –> hyphae growth –> dissemination
asperginllosis xray finding
fungus ball
aspergillosis sx
- pneumonia like
- allergic reactions
Aspergillosis can spread to which organs (4)?
- brain
- liver
- heart
- bone
blastomycosis: aka, Gilchrist disease, Chicago disease is endemic to which 2 regions?
Mississippi and Ohio River basins
2 forms of blastomyces dermatitidis
mycelial: soil
yeast: body
blastomyces dermatitidis sx
- flu-like symptoms
- cough, weight loss, chest pain, fever
- -ulcerative skin and bone lesions (as it progresses)
blastomycosis is identified with which lab finding?
methenamine silver stain: budding yeast cells
disseminated blastomycosis may cause which conditions?