Division of Epidemiology
275 East Main Street
Frankfort, KY 40621
What is histoplasmosis?
Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. This fungus grows in soil, especially soil contaminated with bird or bat droppings. H. capsulatum is found throughout the world. The Ohio and Mississippi river valleys, as well as areas along the St. Lawrence and Rio Grande rivers, are areas in the U.S. where this organism is more prevalent in the soil.
How is histoplasmosis spread?
Histoplasmosis is not spread from person-to-person. Infection occurs from breathing in the airborne spores after contaminated soil or material has been disturbed. Approximately 80% of the population living in areas like the Ohio River valley (which includes Kentucky) will skin-test positive for histoplasmosis exposure.
Symptoms of histoplasmosis
Most infected persons have no apparent illness. If symptoms occur, they will start within 3 to 17 days after exposure. Persons developing disease usually present with an influenza-like illness with fever, cough, headaches, and muscle aches. Acute pneumonia, chronic pneumonia or a disseminated form that affects other organs can occur. Chest x-rays will show distinct patterns and the chronic form can resemble tuberculosis. Histoplasmosis can be a fatal illness if persons exhibiting disease symptoms are not treated.
How is histoplasmosis diagnosed?
Histoplasmosis is diagnosed by a variety of laboratory tests that either isolate the organism or detect antigens of the organisms in either blood serum or urine. The histoplasmin skin test denotes exposure but does not indicate disease and is not a diagnostic test.
Treatment for histoplasmosis
Antifungal medications are used to treat severe cases of acute, chronic and disseminated disease. Mild disease usually does not require treatment.
How histoplasmosis can be prevented
Avoid areas that may harbor the fungus, to include:
-Accumulation of bird or bat droppings
-Poultry house litter
-Caves or areas harboring bats
Before starting a job or activity having a risk for exposure to H. capsulatum, consult the National Institute for Occupational Safety and Health (NIOSH) document Histoplasmosis: Protecting Workers at Risk. This document contains information on work practices and personal protective equipment that will reduce the risk of infection. A copy can also be obtained by requesting publication no. 97-146 from:
National Institute for Occupational Safety and Health
4676 Columbia Parkway
Mail Stop C-13
Cincinnati, OH 45226-1998