Acute pulmonary histoplasmosis: progressive pneumonia resulting from high inoculum exposure

Histoplasmosis is endemic in certain areas of North, Central, and South America, especially within the Ohio and Mississippi River Valleys of the United States. We describe a case of histoplasmosis in a farm-dwelling resident of Kentucky who probably had multiple prior opportunities for exposure. However, during the gathering of topsoil containing chicken droppings for use as fertilizer, he was likely to have been exposed to such a high inoculum of the organism that he developed a severe pulmonary infection. He presented with a one-week history of malaise, myalgias, fever to 103 degrees F, and headaches. A chest X-ray showed bilateral reticulonodular infiltrates. He was initially treated for community-acquired pneumonia. When his symptoms did not resolve, a bronchoscopy was performed. Washings from the broncho-alveolar lavage grew Histoplasma capsulatum, and he responded well to itraconazole therapy. This case is presented to emphasize risks from high-inoculum exposure and the hazard imposed by harvesting certain types of organic material for use as fertilizer.