Blastomycosis in Northwestern Ontario, 2004 to 2014

Abstract

Blastomycosis is an invasive fungal disease that has a wide spectrum of clinical presentations. Since the removal of blastomycosis from the list of reportable diseases, the number of patients diagnosed with the disease in Ontario has increased substantially. The clinical characteristics of 64 patients diagnosed with blastomycosis are reviewed in this study. The authors also discuss the reinstatement of the disease to the list of reportable diseases in Ontario.

Blastomycosis in Minnesota, USA, 1999–2018

“…Infections can disseminate hematogenously, most commonly to skin, bone, and the central nervous system (2). Case-fatality rates range from 6% to 22% (3)(4)(5). Most patients are male (60%-75%) (3)(4)(5)(6)(7)(8) and middle-aged (median age 41-44 years) (3,5,7,8).…”

“…Case-fatality rates range from 6% to 22% (3)(4)(5). Most patients are male (60%-75%) (3)(4)(5)(6)(7)(8) and middle-aged (median age 41-44 years) (3,5,7,8). Diagnosis is often delayed because community-acquired bacterial pneumonia has a similar presentation (9,10) and index of suspicion for blastomycosis is low among healthcare providers (1,11).…”

Red Fox as Sentinel forBlastomyces dermatitidis, Ontario, Canada

“…These findings suggest that B. dermatitidis –associated lesions in red foxes would be easily identifiable, regardless of time of year and disease manifestation. Future sampling should target foxes in northern Ontario, where risk for human infections is highest, the annual incidence is increasing, and diagnostic testing is less available ( 2 , 8 , 14 ). Furthermore, in remote northern regions, defining the range and prevalence of blastomycosis could have positive public health effects on healthcare workers and indigenous human populations.…”

“…Recently, increased numbers of human blastomycosis cases have been detected in the provinces of Quebec, Saskatchewan, Manitoba, and Ontario, Canada ( 2 , 5 – 7 ). Despite this increased detection, human blastomycosis is probably underdiagnosed ( 2 , 8 ). …”

“…We retrospectively reviewed blastomycosis case data for wildlife and companion animals in Ontario, which contains areas where blastomycosis is endemic and areas of likely emergence ( 2 , 3 , 5 , 8 ). Once a candidate sentinel species is identified, a targeted surveillance system can be developed to identify high-risk areas and assess risk factors associated with disease.…”