4-Fungal Infections Respir Tract Flashcards
zygomycoses/mucormycosis
from zygomycetes family- dz/infection uncommon but fatal
-molds common found @ foods, vegetation, soil
risk factors: immunosup, diabetes, burns, neonates
zygomycetes fungi
- rhizopus
- absidia
- mucor
non septate hyphae + sporangia with sporangiospores
rhinocereberal zygomycosis
primarily in diabetic pts
og @ sinuses when inhale spores > extends to neighboring tissues (nose, hard palate, eye, brain)
nasal congestion + blood tinged rhinorrhea + tender sinuses + headache + fever > facial/periorbital edema > mental status, coma, death
dx zygomycoses
observe hyphal elements in clinical material/samples
-broad aseptate hyphae with branching at right angles @ blood vessels
treat with amphotericin B
candidiasis
C. albicans
-normal flora as yeast form @ skin, mucus membranes, GI tract
-exist in hyphal form @ tissue, pathologic
thrush presentation
oral candidiasis
common infants, AIDS, adults on steroids, antibiotics, antineoplastic drugs
diffuse erythema + white patches/plaques on buccal mucosa, throat, tongue, gums
-lesions are combo of yeast and pseudohyphal forms C. albicans
thrush dx
direct observation
-not need culture, do germ tube test
treat oral formulations of nystatin or azoles as mouth wash or lozenges
systemic mycoses
acquired by inhalation of fungi from environment as hyphae or spores
-non opportunistic so can cause dz in healthy indivs
all start with pulmonary infection
fungi systemic mycoses
- coccidioides immitis-dimorphic
- paracoccidioides brasiliensis-dimorphic
- blasomyces dermatitidis-dimorphic
- hisoplasma capsulatum
hyphae to yeast in tissues
histoplasmosis
@mississipii and ohio river valleys
from histoplasma capsulatum in soil under humid climate conditions (bird and bat droppings)
-micro or macro conidia inhalation with round bump appearance
aka darlings/cave dwellers/ spelunkers dz
histoplasmosis clinical
usually asymptomatic but may be hospitalized
-macrophages will phagocytose yeast forms so will resolve without intervention unless replicate within macro
mild flu like symps, dry cough, fever, fatigue
-calcification of pulmonary lesions, chest pain
chronic pulmonary/disseminated histoplasmosis
in immunocomp people so acute/fatal OR chronic/debilitating
-fever, night sweats, anorexia, weight loss, fatigue + respir symps
-hepatosplenomegaly + lymphadenopathy if spread
simialr to TB
histoplasmosis dx
direct observ in tissues as yeast form
-antigen detection in urine
amphotericin B or itraconazole + suppressive therapy for AIDS pts to prevent relapse
blastomycosis
exist in moist soil high in decaying vegetation content @ohio, miss river valley + missouri, ark river basins
aka gilchrist, chicago’s, north american blastomycosis
dimorphic fungus- yeast have really thick cell walls and thick bud base, large size
-disting from H capsulatum
also infect dogs and horses
blastomycosis clinical
primary pulmonary dz + ulcerative lesions @ skin, bone, urogenitial tract
acute cough, fever, chills. flu like > chronic night sweat, weight loss, sputum production > disseminated bone necrosis, granuloma formation, prostate infection
-most asymp tho
blastomycosis dx
observe distinct yeast forms
-antigen testing urine
treat with amphotericin B for disseminated or immunosup OR azoles if uncomplicated pulmonary
paracoccidioidomycosis
PCM
@south and central america
-paracoccidioides brasiliensis dimorphic
men (bc estrogen may inhibit)
PCM clinical
most asymptomatic > chronic cutaneous and mucocutaneous ulcers
yeast form has multi buds ‘ship wheel’ or ‘mickey mouse ears’
coccidioidomycosis
highly endemic @ san joaquin valley cali and southern arizona aka drought rain drought pattern
-arthroconidia (brittle hyphae) blows around in dust
aka valley fever
coccidioidomycosis clinal
C. immitis or C. posadasii
-when arthocondida inhaled converts to spherule (multinuc structure)
some asymp but some moderate influenza like > disseminate rarely with infection in bones, joints, skin, CNS
coccidioidomycosis dx
direct obs spherules, antigen
will resolve spont in a few weeks
coccidial meningitis
subtype of coccidioidomycosis
devs slowing with inc headaches, fever, stiff neck, neuro signs
-frequently fatal if untreat
cryptococcosis
leading form of fungal meningitis
from C. neoformans/ C. gatti in abundant soil contam with bird/pigeon droppings
cryptococcosis clinical
asymp or mild spont resolving flu like
>meningitis: intermittent bouts of headaches, irritability, dizziness, other CNS
>disseminated = skin and bone lesions
esp AIDS or immunosup pts
cryptococcus dx
india ink stain from spinal fluid, skin lesions, sputum
treat meningitis with long term combo of amphotericin B + 5 fluorcytosine or fluconazole, suppressive therapy if AIDS
pneumocystis jirovecii/carinii pneumonia
PCP
highly lethal form of pneumonia
-almost exclusively in AIDS pts
not totally fungi just closely related, similar processes to protozoa
pneumocystis carinii.jirovecii
PCP clinical
inhale cysts
dyspnea, nonprod cough, fever > interstitial pneumonitis with cellular infiltrate, cyanosis, tachypnea > death from asphyxiation
PCP dx
id organisms (trophozoite, sporozoites, cysts) from biopsy, aspiration, bronchial washing
-special stain for carbs
treat trimethoprim-sulfamethoxazole to interfere with folate syn + prophylaxis and suppressive therapy for AIDS
aspergillosis
aspergillus rarely pathogenic in normal immune status
-unless immuno comp
**A. fumigtus and flavus **
-true mold, septae
acute pulmonary infection
aspergillomas
aka fungus balls
-colonize pre existing lung lesions, unilateral
-usually asymp unless see on xray
a
aspergillosis dx
hyphal elements in sputum (hyphae within matrix of fibrin and cellular debris)
-v shaped branching at 45 degrees esp in blood vessles
treat with azoles, echinocandin, amphotericin B, surgery
