To better understand clinical and epidemiologic patterns of blastomycosis, we report on a large series of blastomycosis in Indiana.
All microbiologically and histopathologically confirmed cases of blastomycosis from four hospitals serving Central Indiana from 1985 to 2014 were identified. Available data were collected. Data on population estimates, annual precipitation, and construction in Indiana were evaluated for correlations with incidence rates of blastomycosis.
A total of 114 patients were identified. The mean age was 44.4 years; 27% had diabetes mellitus, and 16% were immunosuppressed. Most presented with pneumonia (90%); 48% had extrapulmonary disease (CNS involvement in 9%), and 15% developed ARDS. Cultures, cytopathology, and histopathology were positive in 86%, 27%, and 85% of the sample, respectively, and fungal antigen was positive in 76%. Amphotericin B was administered in 49%, and 87% received an azole. Total mortality was 12%. Immunosuppression (OR = 3.0), diabetes mellitus (OR = 2.9), and multilobar pneumonia (OR = 2.9) were associated with increased likelihood of ICU admission. There was a significant increase in incidence over time in Marion County. There was no correlation with amount of precipitation, but the rise in incidence coincided with a 2005 state initiative to expand Indiana’s highway infrastructure.
The incidence of blastomycosis in Central Indiana may be on the rise. Physicians in endemic areas should be aware of the potentially fulminant consequences of the disease.