Four people were diagnosed with histoplasmosis during a 4-month period in Montana, an area where Histoplasma capsulatum, the fungi responsible for the disease, is not endemic, according to a report in Morbidity and Mortality Weekly Report.
Three patients reported no travel outside of Montana, and one patient reported travel to California, where she was exposed to potting soil that contained bat guano. H. capsulatum is found in soil enriched with bird droppings and bat guano and is endemic in the Ohio River and Mississippi River valleys.
The two males, aged 17 and 79 years, and two females, aged 59 and 76 years, had no epidemiologic links. Three of them started itraconazole therapy.
“Three patients experienced diagnostic delays, likely in part because none reported recent travel to areas where H. capsulatum is endemic,” the researchers wrote. “Health care providers should be aware of the possibility of H. capsulatum in Montana and the potential for histoplasmosis in patients with clinically compatible illnesses, even in the absence of a history of travel outside of Montana.”