Systemic/Endemic Mycoses Flashcards
what do bipaahsic/dimorphic soil fungi cause?
pulmonary +/- systemic disease
what dimorphic fungi are responsible for the systemic (endemic) mycose?
-coccidioides immitus/posadasii
-histoplasma capsulatum
-blastomyces dermatitidis
what is the morphology of coccidiodes immitus and posadasii while it is within the host?
spherules
what is the morphology of coccidiodes immitus and posadasii within the environment?
arthroconidia
how is coccidiodes immitis & posadasii transmitted?
transmission via aerosols
dust storms
not communicable
when is coccidiodes immitis & posadasii most prevalent?
after summer monsoons and dust storms
In what species is coccidiodes immitis & posadasii most often reported?
dogs (esp. large breeds) and humans
what is the pathogenesis of coccidiodes immitis & posadasii?
following inhalation exposure to arthroconidia, coccidiodes forms spherules in lungs -> spherules mature, rupture, and can then disseminate to other tissues and organs
what are the clinical presentations of coccidiodes immitis & posadasii?
disseminated disease seen in immunocompromised dogs
skin: grave prognosis
how do you diagnose coccidiodes immitis & posadasii?
-history of exposure is critical
-serology
-sputum and bronchoalverolar lavage: spherules on cytologic examination
-periodic acid-schiff
-culture
what is the treatment for coccidiodes immitis & posadasii?
triazoles
amphotericin B
how do you prevent and control coccidiodes immitis & posadasii?
vaccinate
limit outdoor activities
reduce dust
what region is histoplasma capsulatum most prevalent?
Ohio and Mississippi River valleys
how is histoplasma capsulatum transmitted?
aeroso transmission +/- ingestion of microcondia
where in the environment is histoplasma capsulatum ?
-soil-dwelling fungi
-soil enriched with bird droppings
-bat guano
is histoplasma capsulatum zoonotic?
not horizontally or zoonotically transmissible
in what type of patient does histoplasma capsulatum cause a more serious disease ?
disseminated disease more common/serious in immunosuppressed animals
what is the pathogenesis of histoplasma capsulatum?
what is the clinical presentation of histoplasma capsulatum in dogs?
lack of appetite
diarrhea
what is the diagnosis for histoplasma capsulatum?
-yeast in histo sections
-isolate and culture
-serology
-PCR
what is the treatment for histoplasma capsulatum?
dogs and cats: itraconazole
how do you prevent histoplasma capsulatum?
limit exposure
In what geographical area does blastomyces dermatidis most common?
Mississippi and ohio
In what environment does blastomyces dermatidis reside?
feces-enriched soils
what is the morphology of balstomyces dermatidis?
broad-based budding yeast
in what breed is blastomyces dermatitis most common?
most often seen in dogs, sporting breeds
Is blastomyces dermatidis zoonotic?
nontransmissible from animals to humans or humans to humans
what can the hematogenous spread of blastomyces dermatidis result in?
skin, kidney, vertebral/skeletal and male reproductive lesions forming granulomas
what is the clinical presentation of blastomyces dermatidis?
-acute and chronic pulmonary disease
-disseminated disease: skin lesions
how do you diagnose blastomyces dermatidis?
-wet mount smear that may show broad-based yeast
-PCR
what is the treatment for blastomyces dermatidis?
itraconazole
(CNS involvement carries poorest prognosis)
