Fungal Endemicity: Beyond the Classic Geographic Map

Histoplasmosis, blastomycosis, and coccidioidomycosis - the three major endemic mycoses - have long been taught as geographically confined diseases requiring travel to classic endemic zones for clinical consideration. Emerging epidemiologic data challenges this paradigm. National surveillance studies now document clinically significant incidence of all three fungi across 47–94% of US states, with locally acquired cases confirmed well outside historical boundaries. Climate-driven range expansion, rising immunosuppressed populations, and improved diagnostics are converging drivers. The diagnostic delay - averaging 29 days, with 42% of patients initially misdiagnosed - carries measurable clinical and economic cost. This mini review synthesizes contemporary data on geographic redistribution, identifies key drivers of expansion, and proposes a risk-stratified, geography-independent diagnostic framework centered on immune status and clinical pattern rather than zip code.