Browsing by Subject "Blastomyces"
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Item Open Access Blastomyces helicus, a New Dimorphic Fungus Causing Fatal Pulmonary and Systemic Disease in Humans and Animals in Western Canada and the United States.(Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2019-01) Schwartz, Ilan S; Wiederhold, Nathan P; Hanson, Kimberly E; Patterson, Thomas F; Sigler, LynneBackground
Blastomyces helicus (formerly Emmonsia helica) is a dimorphic fungus first isolated from a man with fungal encephalitis in Alberta, Canada. The geographic range, epidemiology, and clinical features of disease are unknown.Methods
We reviewed human and veterinary isolates of B. helicus identified among Blastomyces and Emmonsia isolates at the University of Alberta Microfungus Collection and Herbarium, University of Texas Health San Antonio's Fungus Testing Laboratory, and Associated Regional and University Pathologists Laboratories. Isolates were selected based on low Blastomyces dermatitidis DNA probe values and/or atypical morphology. Species identification was confirmed for most isolates by DNA sequence analysis of the internal transcribed spacer with or without D1/D2 ribosomal RNA regions. Epidemiological and clinical data were analyzed.Results
We identified isolates from 10 human and 5 veterinary cases of B. helicus infection; all were referred from western regions of Canada and the United States. Isolates remained sterile in culture, producing neither conidia nor sexual spores in the mycelial phase, but often producing coiled hyphae. Isolates were most frequently cultured from blood and bronchoalveolar lavage in humans and lungs in animals. Most infected persons were immunocompromised. Histopathological findings included pleomorphic, small or variably sized yeast-like cells, with single or multiple budding, sometimes proliferating to form short, branching, hyphal-like elements. Disease carried a high case-fatality rate.Conclusions
Blastomyces helicus causes fatal pulmonary and systemic disease in humans and companion animals. It differs from B. dermatitidis in morphological presentation in culture and in histopathology, by primarily affecting immunocompromised persons, and in a geographic range that includes western regions of North America.Item Open Access Pulmonary blastomycosis presenting as primary lung cancer.(BMC infectious diseases, 2018-07-18) Hussaini, Syed Mohammed Qasim; Madut, Deng; Tong, Betty C; Pavlisko, Elizabeth N; Schell, Wiley A; Perfect, John R; Thielman, Nathan MBACKGROUND:Blastomycosis is an endemic mycosis in North America that is caused by the dimorphic fungus Blastomyces dermatitidis. The illness is a systemic disease with a wide variety of pulmonary and extra-pulmonary manifestations. The initial presentation of blastomycosis may easily be mistaken for other infectious or non-infectious etiologies. CASE PRESENTATION:We present the case of a 52-year-old African-American male and former smoker that presented to his primary care provider with a 2-week history of non-productive cough, night sweats and weight loss. Initially diagnosed with primary lung malignancy, the patient was subsequently found to have pulmonary blastomycosis mimicking lung cancer. The patient underwent a successful course of treatment with posaconazole. CONCLUSIONS:Chronic blastomycosis can present with clinical and radiographic features indistinguishable from thoracic malignancies. There is no clinical syndrome specific for blastomycosis, thus a high degree of suspicion is required for early diagnosis. In this case report, we review recent evidence in radiographic features, diagnostic considerations and treatment of the disease.