Histoplasmosis (say: hiss-toe-plaz-mo-sis) is an infection in your lungs caused by the fungus Histoplasma capsulatum. In severe cases, it can spread through the whole body.
Most healthy people who are infected with histoplasmosis never experience any symptoms, because their bodies fight off the disease. In people who do experience symptoms, the following are the most common:
More severe cases of histoplasmosis include the following symptoms:
The fungus that causes histoplasmosis grows in the ground. Farming, construction, gardening or any activity that disturbs the soil can release fungus spores into the air. If you breathe in those spores, you can get the infection.
You can't catch histoplasmosis from another person or from an animal. Birds do not carry the infection, but their droppings provide food for the fungus in the ground (so you can get histoplasmosis in areas such as chicken coops). The droppings of bats also feed the fungus in the ground (so you can get histoplasmosis in areas where bats live, such as caves).
The Histoplasma capsulatum fungus is the most common type of fungus in the United States. However, most people who are infected with histoplasmosis have few or no symptoms.
Histoplasmosis occurs in places that have moderate temperatures and moisture. It is very common in the Ohio, Missouri and Mississippi river valleys due to the damp, rich soil found in those areas.
Farmers, landscapers, construction workers, archaeologists and geologists are at an increased risk for histoplasmosis.
Severe infections may develop in infants and young children and in older adults. People who have human immunodeficiency virus (HIV), are receiving chemotherapy treatment for cancer, are taking long-term corticosteroids (such as prednisone) or are taking anti-rejection medicines after an organ transplant are at an increased risk for developing severe cases of histoplasmosis. A chronic infection can occur in patients who have lung diseases like emphysema (say: em-fa-see-ma).
Your doctor can test your blood or urine for histoplasmosis. He or she can also take a sample of tissue for testing. Chest X-rays and computerized tomography (CT) scans are helpful for detecting inflammation in the lungs, but your doctor can't be sure you have histoplasmosis just by looking at an X-ray or a CT scan.
The treatment depends on how serious the infection is and how long the illness has lasted. Many people don't need any treatment and the body will fight the histoplasmosis infection on its own. Some people need to take an antifungal medicine, such as amphotericin or itraconazole. If you need to take medicine for histoplasmosis, your doctor will monitor you closely for possible side effects on your kidney or liver from the medicine. You may need to take medicine for weeks or months. If you have acquired immunodeficiency syndrome (AIDS), you may need to take this medicine for the rest of your life.
Some people have to go to the hospital to get oxygen therapy and intravenous fluids. Others can be treated at home. Most people respond well with treatment.
The best way to avoid infection is to stay away from places where you could breathe in contaminated dust. Spraying soil with water before digging or spraying barns and chicken coops can reduce the dust that gets stirred up, and thus reduces the number of fungus spores in the air. If you work in contaminated areas, you should wear protective clothing and face masks.
Written by familydoctor.org editorial staff