Severe Histoplasmosis in Travelers to Nicaragua

Histoplasmosis is a systemic infection caused by the dimorphic fungus, Histoplasma capsulatum. Infection results from inhaling spores, usually through exposure to bat and bird droppings in barnyards and caves. Although outbreaks have occurred after visits to bat-infested caves, histoplasmosis has not been frequently recognized as travel-related and has rarely led to serious illness among young, healthy travelers. This fungus is endemic in the United States along the Ohio and Mississippi River valleys and many other parts of the world, particularly Latin America. Histoplasmosis is often asymptomatic in endemic settings, but infection can result in a spectrum of illness, ranging from mild influenzalike illness to acute pulmonary infection and disseminated extrapulmonary disease. Immunocompromised persons and the elderly are at greater risk for disseminated disease (1). This report describes a recent outbreak of histoplasmosis among U.S. adventure travelers to Nicaragua that was associated with a high attack rate and hospitalizations among previously healthy travelers.