Enhanced Surveillance for Histoplasmosis-9 States, 2018-2019

Background. Histoplasmosis is often described as the most common endemic mycosis in the United States, but much re- mains unknown about its epidemiology among the general population. Methods. We conducted enhanced surveillance in 9 states during 2018-2019 by identifying cases through routine surveillance and interviewing 301 patients about their clinical features and exposures. Results. Before being tested for histoplasmosis, 60% saw a health care provider >= 3 times, and 53% received antibacterial medication. The median time from seeking health care to diagnosis (range) was 23 (0-269) days. Forty-nine percent were hospitalized, and 69% said that histoplasmosis interfered with their daily activities (median [range], 56 [2-3960] days). Possible exposures included handling plants (48%) and bird or bat droppings (24%); 22% reported no specific exposures. Only 15% had heard of histoplasmosis before their illness. Conclusions. Histoplasmosis can be severe and prolonged. Additional educational efforts to increase public and provider awareness and reduce delays in diagnosis are needed.