Histoplasmosis is a fungal infection that affects the lungs and may occasionally invade other parts of the body. It is an uncommon disease. In 1999, there were 15 cases reported among New York City residents (rate of 0.2 cases per 100,000 persons).
Anyone can get histoplasmosis. It is recognized more often in immunocompromised individuals, such as AIDS patients. Birds (especially chickens), bats, dogs, cats, rats, skunks, opossum, foxes, and other animals can get histoplasmosis and may have a role in spreading the disease.
The disease is acquired by inhaling the spore stage of the fungus. Outbreaks may occur in groups with common exposures to bird or bat droppings or recently disturbed, contaminated soil found in chicken coops, caves, etc. Person-to-person spread of histoplasmosis does not occur.
Symptoms vary from mild to severe, ranging from a flu-like illness to serious lung infections. In immunocompromised patients, the disease may spread to the bone marrow, lungs, liver, and lymph nodes.
Symptoms may appear within 5 to 18 days (usually 10 days) after exposure. However, most people do not experience any symptoms.
Infection usually results in increased protection against repeat infection, although the immunity is not complete.
Histoplasmosis is diagnosed by isolating the fungus from body fluids or tissues, visualizing the fungus under the microscope, or by an antibody test.
Specific treatments, such as amphotericin B, are available for patients with severe illness.
Minimize exposure to dust in contaminated and enclosed environments, such as chicken coops and their surrounding soil. Use a protective mask and spray the area with water to minimize exposure to dust.