Blastomycosis, a rare infection caused by the fungus Blastomyces, may be more common in the U.S. than previously thought, particularly in the Northeast, the CDC said Jan. 24.
The finding is based on an analysis of U.S. Census data and all-payer claims data, which CDC researchers used to calculate blastomycosis incidence rates in Vermont between 2011 and 2022.
In total, researchers identified 114 patients diagnosed with blastomycosis over the study period, with an estimated mean annual incidence of 1.8 case patients per 100,000 population. This incidence is higher than four out of five states that track blastomycosis cases.
Experts have historically considered the fungus endemic in the Midwest, South Central states and the Southeast, though this understanding is based on sporadic care reports and few recorded outbreaks, according to the CDC.
"Although Vermont has historically not been considered an area with high relative incidence of blastomycosis, [this incidence] suggests otherwise," the agency said. "Our findings … align with a growing body of evidence suggesting that the burden of endemic blastomycosis is greater than commonly appreciated."
CDC said physicians should consider blastomycosis in patients exhibiting symptoms such as fever, cough, muscle aches and weight loss.