Background: Blastomycosis, an endemic mycosis of immunocompetent individuals, is typically seen after exposure to waterways within rural wooded regions. It is not considered a disease of urban environments. Infection can be solely pneumonic or disseminate to skin, bone or central nervous system. Unknown factors influence disease acquisition and severity in children. Methods: We analyzed acquisition risks and disease characteristics of blastomycosis in children seen at a tertiary care center from 1998 to 2018 to identify potential exposure sources, measure disease severity and assess the effect of race upon disease severity. Results: Of 64 infected children, mean age was 12.9 years, with median time to diagnosis 38.5 days. About 72% were male, 38% resided in urban counties and 50% had typical environmental exposure. Isolated pulmonary infection occurred in 33 (52%). The remainder had evidence of dissemination to skin (N = 13), bone (N = 16; 7 clinically silent) and cranium (N = 7; 3 clinically silent). Infection was moderate/severe in 19 (30%). Two children (3%) died. About 79% of children with moderate/severe disease (P = 0.008) and 71% of urban children (P = 0.007) lacked typical environmental exposure. Comparing children from urban counties to other residences, 63% versus 5% were black (P < 0.001) and 71% versus 35% developed extrapulmonary dissemination (P = 0.006). Moderate/severe disease was seen in 7/17 (42%) black children but only 12/47 (26%) children of other races (P = 0.23). Conclusions: Blastomycosis, can be endemic in urban children in the absence of typical exposure history, have frequent, sometimes clinically silent, extrapulmonary dissemination and possibly produces more severe disease in black children.

Background Blastomycosis is an endemic mycosis of immunocompetent individuals, typically seen after exposure to wooded areas near rivers, lakes, and streams in rural locations, and often not considered a disease of urban environments. Disease can be isolated to lung, or disseminate to skin, bone, or central nervous system. Factors influencing disease acquisition and severity in children are unknown. Methods We analyzed acquisition risk factors and disease characteristics of blastomycosis in children treated at a tertiary care center from 1998–2018 to identify exposure source and measure disease severity, to identify cases without “typical exposure”, and to measure the effect of race on disease severity. Results Of 64 children, median age was 13.3 years, 72% were male, 38% resided in urban counties, and 50% had typical environmental exposure. Isolated pulmonary infection occurred in 33 (52%). The remaining children had evidence of dissemination including skin (N=13), bone (N=16; 7 clinically silent), and central nervous system (N=7; 3 clinically silent). Infection was moderate/severe in 19 (30%). Two children (3%) died. 79% of children with moderate/severe disease (p=0.008) and 71% of urban children (p=0.007) had no typical environmental exposure. Comparing children from urban counties to other residences, 63% versus 5% were black (p&lt;0.001) and 71% versus 35% developed extrapulmonary dissemination (p=0.006). Moderate/severe disease occurred in 7/17 (42%) black and 12/47 (26%) children of other race (p=0.23). Conclusions Blastomycosis, endemic in urban children in the absence of typical exposure history, has frequent, sometimes clinically silent, extrapulmonary dissemination, with a trend toward more severe disease in black children.