Definition

Histoplasmosis is a fungal infection. It usually affects the lungs. It ranges from mild to severe. People with severe or long lasting symptoms need treatment.

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Causes

Histoplasmosis is caused by a certain fungus. It is found in soil contaminated with bat or bird droppings. When the soil gets stirred up, the fungus gets into the air. People can get infected when they inhale the fungus.

Risk Factors

Things that raise the risk of histoplasmosis are:

• Exposure to soil with bird or bat droppings
• Living in or traveling to places where the fungus is more common, such as:
  • Mississippi, Ohio, Kentucky, Illinois
  • Indiana, Missouri, or Tennessee
  • Southeast Asia, Africa, or Eastern Canada
  • Mexico, Central or South America

Some people will not get infected, despite contact with the fungus.

Others may be at risk for serious and lasting problems. They include people who:

• Are older
• Have certain health conditions
• Have a weak immune system

Symptoms

Histoplasmosis often does not cause symptoms. When symptoms happen, they may be:

• Fever, sweats, or chills
• Feeling weak or tired
• Achy muscles, joints, and headaches
• Lack of hunger and weight loss
• Problems breathing, chest pain, and cough
• Mouth sores, belly pain, and diarrhea
• Changes in behavior
• Vision problems

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done.

Tests depend on the type and severity of symptoms. Tests look for the fungus and other problems. They may include:

• Blood tests and culture
• Sputum culture
• Skin testing
• Urine tests
• Cerebrospinal fluid tests

Pulmonary function tests may be done to check lung function.

Imaging tests may be done to see areas of infection. They may include:

• X-rays—to check the lungs and bones
• CT scans—to check the lung
• MRI—to check the brain and spinal cord

Treatment

Treatment is often not needed for those with mild or no symptoms.

Antifungal medicine may be needed if symptoms last for more than 1 month. It may be used for life in those with weak immune systems.

Surgery may be used if growths develop in the lungs.

Prevention

The risk of histoplasmosis may be reduced by:

• Using protective masks when near soil, bird, and bat droppings
• Avoiding areas with bird and bat droppings