Key Objectives:
- Outline key data gaps in our understanding of the geographical ranges of the endemic mycoses in the United States
- Describe work examining coccidioidomycosis in endemic states and in states where it is not known to be endemic
- Discuss current effort to summarize multistate histoplasmosis surveillance data to better understand burden of disease and inform consensus case definition
- Discuss limitations in our knowledge of blastomycosis burden and geographical distribution
- Identify collaboration opportunities to better understand these underdiagnosed diseases
Brief Summary:
Blastomycosis, coccidioidomycosis, and histoplasmosis are the main endemic mycoses in the United States. They typically involve pulmonary infections that can mimic influenza and bacterial pneumonia; disseminated disease also occurs, carrying a significant risk of death. Whereas coccidioidomycosis is predominantly found in the desert southwest, blastomycosis and histoplasmosis are thought to occur primarily in overlapping regions of the eastern United States. However, numerous reports have documented cases outside of the endemic areas defined by skin testing over 60 years ago. Additionally, because interstate travel is common, people exposed in an endemic state—sometimes years previously—may develop illness in states not known to be endemic. The national burden of these diseases is poorly defined, hampering efforts to increase clinician awareness and availability of diagnostic tests. This lack of data likely contributes to substantial under-recognition of these diseases, as evidenced by the fact that patients found to have an endemic mycosis often receive 2–3 courses of antibacterial drugs before receiving the correct diagnosis. Although coccidioidomycosis is reportable in 19 states and is nationally notifiable, with thousands of cases reported each year, these numbers likely underestimate the true burden. Efforts are underway to estimate the burden of undiagnosed illness and to better characterize this disease in states not known to have high endemicity. Neither blastomycosis nor histoplasmosis are nationally notifiable, limiting our knowledge of their distributions and burdens. States and CDC are partnering to summarize the state-level histoplasmosis surveillance data accumulated under varying case definitions and to establish a consensus case definition. Preliminary work is underway to summarize blastomycosis surveillance data and better understand the burden of disease. A discussion among states, territories, and CDC about these diseases could lead to improved data collection and new opportunities for collaboration.