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Blastomycosis due to Blastomyces dermatitidis and Blastomyces gilchristii is a significant cause of respiratory mycoses in North America with occasional reported outbreaks. We developed a highly sensitive, specific, and reproducible TaqMan duplex real-time PCR assay for the differentiation of B. dermatitidis and B. gilchristii The new assay permitted retrospective analysis of Blastomyces cultures (2005 to 2019) and primary clinical specimens from blastomycosis cases (2013 to 2019) from New York patients. We identified B. dermatitidis as the predominant pathogen in 38 cases of blastomycosis, while B. gilchristii was a minor pathogen involved in five cases; these findings expand understanding of blastomycosis in New York. The duplex real-time PCR assay could be implemented in reference and public health laboratories to further understand the ecology and epidemiology of blastomycosis due to B. dermatitidis and B. gilchristii ., (Copyright © 2021 American Society for Microbiology.)

Blastomyces dermatitidis, the etiologic agent of blastomycosis, is a thermally dimorphic fungus that grows as a filamentous mold in the environment and as budding yeast in human tissue. This pathogen is endemic to North America, particularly in the states bordering the Mississippi and Ohio rivers, the Great Lakes, and the St. Lawrence Seaway. Infection with B. dermatitidis causes a broad array of clinical manifestations ranging from asymptomatic infection to fulminant sepsis with acute respiratory distress syndrome and death. B. dermatitidis can infect almost any organ in the body, but has a predilection for lungs and skin. There have been recent advances in the understanding of the pathogenesis, diagnosis, and treatment of this fungus. The Infectious Diseases Society of America published updated guidelines in 2008 to guide clinicians in the treatment of this important pathogen., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Cutaneous North American blastomycosis most often results from the hematogenous spread of Blastomyces dermatitidis following pulmonary infection. Cutaneous lesions, which may be either verrucous or ulcerative plaques, commonly occur on or around orifices contiguous to the respiratory tract. We report the case of a 57-year-old man with cutaneous North American blastomycosis who presented with a well-demarcated, firm, moist, verrucous perianal plaque 4 months following the onset of a prolonged upper respiratory tract infection. Dissemination of B dermatitidis to the perianal skin is rare, but North American blastomycosis should be considered in the broad differential diagnosis of perianal lesions in any patients who have lived in or traveled to endemic regions.

Blastomyces dermatitidis is acquired in almost all cases via inhalation, and pulmonary disease is the most frequent clinical manifestation of blastomycosis. Pulmonary disease can range from asymptomatic infection to rapidly severe and fatal disease. Most cases will present as pneumonia, either acute or chronic, or as a lung mass. In rare cases pulmonary blastomycosis is associated with the acute respiratory distress syndrome. Blastomycosis can present as isolated pulmonary disease or along with coexisting extrapulmonary disease that usually will involve the skin, bony structures, genitourinary tract, or central nervous system. Diagnosis is largely based on isolation of the organism via culture or visualization of the organism in clinical specimens. Detection of urinary Blastomyces antigen is a recent addition to diagnostic options. Itraconazole is the drug of choice for most forms of the disease; amphotericin B is reserved for the more severe forms. Newer azoles such as voriconazole and posaconazole have a limited role in the treatment of pulmonary blastomycosis., (© Thieme Medical Publishers.)

The most common systemic mycoses imported into France are the histoplasmosis caused by H. capsulatum, which comes from Black Africa and from the French overseas departments and territories (Guyane, Martinique, Guadeloupe, New Caledonia), and the histoplasmosis caused by the larger H. duboisii, which is exclusively Central African. In recent years, histoplasmosis has become an opportunistic infection in immunocompromised patients, particularly those with AIDS. Blastomycosis, imported from North America as well as from North Africa and Central Africa, and paracoccidioidomycosis, imported from Latin America, are pulmonary mycoses with cutaneous manifestations on the face and extremities and with various deep localizations which often follow a chronic course. Coccidioidomycosis, strictly limited to the desertic regions in the western part of the American continent, is also a pulmonary mycosis with multiple granulomas in the skin, bones, lymph nodes and meninges. Penicilliosis caused by Penicillium marneffei is a mycosis from South-East Asia which has recently been observed in European AIDS patients who had travelled in that part of the world.