Histoplasmosis

What is histoplasmosis?

Histoplasmosis is an infection caused by the fungus Histoplasma capsulatum. This fungus lives in the environment, usually in association with large amounts of bird or bat droppings, and enters the body through the lungs. Many people with infection do not become sick, or they develop mild flu-like illness. Some people might develop pneumonia. Rarely, the fungus can spread to other organs and cause other symptoms.

Who can get histoplasmosis?

Anyone can get histoplasmosis, even people who are otherwise healthy. Infants, young children, and older people, particularly those with chronic lung disease, are at increased risk for developing severe disease. Severe disease is also common in people who have weakened immune systems, such as people with cancer or HIV/AIDS.

How is histoplasmosis spread?

The fungus grows in soil that has been enriched with bat or bird droppings. The fungus produces spores that get into the air if the contaminated soil is disturbed. Breathing in these spores causes infection.

You cannot get histoplasmosis from another person.

Where is the fungus that causes histoplasmosis found?

Histoplasma capsulatum is found throughout the world and is common in many areas of the United States, including parts of Virginia. The fungus grows in soils that are contaminated with bird or bat droppings, such as around old chicken houses, roosts of starlings and blackbirds, in decaying trees and in caves and other areas where bats live.

What are the symptoms of histoplasmosis?

Many people who are infected with the fungus do not show any symptoms. In areas of the world where the fungus is very common in the environment, many people may have been infected with Histoplasma capsulatum without having any symptoms. In people who develop disease, the most common symptoms are similar to those of pneumonia, and include fever, chest pains, and a dry or nonproductive cough. Some people may also experience joint pain. If the disease is not treated, it can spread from the lungs to other organs.

How soon after exposure do symptoms appear?

If symptoms appear, they usually develop within 3 to 17 days after exposure.

How is histoplasmosis diagnosed?

Multiple laboratory tests are available to diagnose histoplasmosis. These include fungal culture or microscopic examination of blood, other body fluids, or tissues, urine antigen testing to detect Histoplasma, and serologic tests to identify Histoplasma antibodies.

What is the treatment for histoplasmosis?

Treatment is not usually necessary for histoplasmosis because most people will recover without treatment. Anti-fungal medications are used to treat severe cases of histoplasmosis.

How can histoplasmosis be prevented?

There is no vaccine to prevent histoplasmosis, and it is not always possible to prevent exposure to the fungus in areas where the fungus is common in the environment. People should avoid areas with accumulations of bird or bat droppings, especially if they have weakened immune systems. Areas with accumulations of bird or bat droppings should be cleaned up by professional companies that specialize in the removal of hazardous waste.

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