Cluster of Pediatric Blastomycosis Cases

Advisory Alert

September 9, 2017

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Dear Colleagues:

I am writing today to inform you of a cluster of three confirmed cases and one suspect case of blastomycosis in pediatric residents of the Manitoulin district. These individuals were symptomatic and were admitted to hospital within the last week.

Health care practitioners are reminded that Sudbury and Manitoulin districts are endemic for blastomycosis. Given that delays in diagnosis can contribute to illness and death, clinicians should consider blastomycosis in their differential diagnoses of lung, skin, and bone infections, particularly if the patient does not respond to conventional antimicrobial drug therapy. This Advisory Alert provides information about blastomycosis to support prompt diagnosis and treatment of patients suspected of blastomycosis infection.

What is blastomycosis and how might my patients be exposed?

Blastomycosis is caused by Blastomyces dermatitidis, a fungus found in warm, moist soil, especially in wooded areas along waterways such as lakes or rivers. Exposure occurs by inhalation of airborne spores during activities such as camping, forestry work, farming, and hunting in endemic areas.

What are the signs and symptoms?

Up to 50% of cases may be asymptomatic, however, anyone is susceptible to the infection and immunocompromised individuals are more likely to suffer severe illness. Symptoms can appear between 3 to 15 weeks after initial exposure. In Ontario, exposure most often occurs in the summer and fall months as the activities that would expose an individual usually occur during that time of year. Clinical presentation is therefore most common in the fall and early winter, but can occur at any time of the year.

Clinical manifestations include pulmonary, cutaneous, and disseminated disease (skin, bones, joints, genitourinary tract). Untreated disseminated or chronic pulmonary blastomycosis can be fatal. Pulmonary blastomycosis can present with generalized symptoms that can be mistaken for other illnesses such as the “flu” or pneumonia. Chest X‐ray can reveal pulmonary infiltrates that can cavitate. Resolution occurs spontaneously in one to three weeks; however extrapulmonary manifestations may be present in the absence of respiratory symptoms.

Cutaneous involvement is common and presents with erythematous papules progressing to wart‐like, crusted or ulcerated lesions affecting the face and distal extremities.

Consider blastomycosis in the differential diagnosis of febrile patients presenting with respiratory or “flu like” symptoms and risk behaviours for exposure.

For additional information, please contact: Sudbury & District Health Unit at 705.522.9200, ext. 464.

P. Sutcliffe, MD, MHSc, FRCPC
Medical Officer of Health

This item was last modified on September 12, 2017