The Distributions of Coccidioidomycosis and Histoplasmosis in the United States: Implications and Recommendations

Coccidioidomycosis and histoplasmosis are sometimes fatal diseases caused by unusual dimorphic soil fungi. The former is endemic in the Southwest, the latter in the east and central United States. This analysis indicates that there are significant areas of overlap in their distributions. Since both cause flu-like symptoms, and since there is a significant probability that tests for one will not detect the other, this has important implications both for patients and for medical personnel, who may be exposed to extremely virulent disease cultures. It is recommended that physicians whose patients live or travel in the overlap regions, and who suspect a patient may be infected with either disease, test for both.