Enhanced Surveillance for Histoplasmosis—9 States, 2018–2019

Abstract Background Histoplasmosis is often described as the most common endemic mycosis in the United States, but much remains 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.