Histoplasmosis

What is histoplasmosis?

Histoplasmosis is an infection caused by a fungus that lives in the eastern United States (particularly the Ohio and Mississippi river valleys). It usually affects the lungs, but in more serious cases it can affect other parts of the body as well.

How does it occur?

You can get histoplasmosis by breathing the fungus into your lungs. The fungus is often spread:

• from bird or bat droppings
• when ground is dug up and the fungus gets into the air
• when an old building where birds or bats have lived is torn down.

The fungus is also found under bridges, along streams, and in caves.

What are the symptoms?

Many times the symptoms of histoplasmosis are so mild that you don't even know you have been infected. If you do have symptoms, they may be mild cold or flulike symptoms, including:

• fever
• chills
• headache
• a dry cough
• body aches.

How is it diagnosed?

Your health care provider will ask about your symptoms. Tell your provider if you have lived or visited the parts of the eastern US where histoplasmosis is common. Your provider will examine you and may order lab tests of your sputum, blood, skin, or urine.

You may not know you have had histoplasmosis until years later when, for some other reason, you may have a chest x-ray. The chest x-ray may show some scarring of your lungs from the infection.

How is it treated?

Most of the time no special treatment is necessary because the body can fight the infection without any help.

If the infection is severe or your immune system isn't strong, your health care provider will prescribe an antifungal medicine. This treatment usually takes several months to a year to complete.

How long will the effects last?

Most people feel sick for just a couple of weeks and then get better without any long-term problems. However, histoplasmosis can be a serious disease if your immune system isn't working well. It is serious, for example, if you have AIDS, take high doses of steroids for other medical problems, or are being treated for cancer. In these cases the disease may cause pneumonia or spread from the lungs to other parts of the body, such as the brain, stomach, intestines, skin, or adrenal glands. It is rare for histoplasmosis to spread like this but when it does, it can be fatal.

What can I do to help prevent histoplasmosis?

If you live in a region of the eastern US where histoplasmosis is common, you can help prevent infection by wearing a mask or respirator when you work in a dirty or dusty area. For example, you should take this precaution if you are collecting soil samples, demolishing buildings, cleaning chicken coops, cutting trees, or going into caves. If your immune system is weak, it is especially important to try to avoid places where you might be exposed to the fungus and to wear a mask when you risk exposure.

Unlike infections such as colds or flu, histoplasmosis isn't spread from person to person by coughing, so you don't have to worry about infecting other people.