Blastomycosis in northwestern ontario.

Nine cases of blastomycosis were seen at the Sioux Lookout Zone Hospital in northwestern Ontario from 1970 to 1983. Although this region has been described as a focus of endemic infection, little published information is available. Seven male and two female Canadian Indians, aged 4-54 years, acquired the infection. Three children were infected; a mother and her son became ill one month apart. All cases presented as progressive pulmonary disease and no extrapulmonary involvement was found. Delay in diagnosis ranged from 11 days to eight weeks, with a mean of 31 days. Patients generally responded favorably to treatment with amphotericin B. Epidemiologic data suggest that environmental, geographic, occupational and recreational determinants are necessary factors in disease acquisition.