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What Is Histoplasmosis?

Histoplasmosis (Ohio valley fever) is an infection caused by a fungus. The lung infection is usually mild, but it can be more severe in people with weak immune systems. Such people include those with HIV infection or cancer and those taking immunosuppressive drugs or steroids. Infections can sometimes spread to other parts of the body, including lymph glands, nervous system, and heart. Infants, very young children, and elderly people also have higher risk of severe infection.

What Causes Histoplasmosis?

The cause is the fungus Histoplasma capsulatum. It’s found in soil, especially that with bird or bat droppings. Breathing air containing the fungus gets it into the lungs. Histoplasmosis isn’t contagious.

What Are the Symptoms of Histoplasmosis?

Most people have few symptoms such as dry cough or low-grade fever. They may not know that they had histoplasmosis until years later. Symptoms are usually mild and flu-like. They include fever, chills, headache, and muscle aches. More severe symptoms from worse infections may last several weeks. Older people with lung disease (such as smokers with emphysema) can get a chronic infection. Symptoms include coughing up sputum, chest pain, weight loss, night sweats, and fatigue. People with weak immune systems may have widespread infections with severe and longer lasting symptoms of fever, headache, and weight loss.

How Is Histoplasmosis Diagnosed?

The health care provider makes a preliminary diagnosis from the medical history and physical examination, especially of the lungs and heart. Chest X-rays and tests of blood, urine, and sputum may also be done.

How Is Histoplasmosis Treated?

Mild infections in generally healthy people may go away without treatment. In most people, treatment with antifungal medicine is needed. This medicine can be given by mouth (orally) or intravenously. The intravenous amphotericin-B may be given for up to 3 weeks.

Antifungal medicine may be needed for a long time, often 1 year or more. People with weak immune systems may need lifelong treatment.

Antifungal medicines should always be finished. Stopping too soon may let the disease come back. Blood tests will make sure that the infection is gone.

A healthy lifestyle with regular exercise and good diet helps the body fight the infection. Smokers should stop smoking. Prevent more infections by avoiding places where contaminated dust can be breathed in. These include chicken houses, old buildings, and caves. Workers in dirty or dusty areas should wear facemasks and protective clothing.

DOs and DON’Ts in Managing Histoplasmosis:

  • DO visit your health care provider regularly.
  • DO take your medicines prescribed by your health care provider.
  • DO ask your health care provider about side effects of your medicines.
  • DO avoid exposures to contaminated areas such as farms.
  • DO use preventive measures, such as facemasks, if exposure is likely.
  • DO quit smoking.
  • DO have a flu shot yearly and a pneumonia immunization every 5 years.
  • DO contact your health care provider if you cough up blood or have new symptoms or worsening shortness of breath.
  • DON’T delay getting medical care if your symptoms get worse.
  • DON’T stop taking your medicine without talking to your health care provider.

Contact the following sources:

  • Centers for Disease Control and Prevention
    Tel: 404-639-3311
  • National Institute of Environmental Health Sciences
    Tel: (919) 541-3345
  • National Institute of Allergy and Infectious Disease
    Phone: 301-496-5717
    Web site:

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc.

Ferri’s Netter Patient Advisor