Histoplasmosis (say: hiss-toe-plaz-mo-sis) is an infectionin your lungs caused by the fungus Histoplasmacapsulatum. In severe cases, it can spread through the whole body.
Most healthy people who are infected with histoplasmosisnever experience any symptoms, because their bodies fight off the disease. Inpeople who do experience symptoms, the following are the most common:
More severe cases of histoplasmosis include the followingsymptoms:
The fungus that causes histoplasmosis grows in the ground.Farming, construction, gardening or any activity that disturbs the soil canrelease fungus spores into the air. If you breathe in those spores, you can getthe infection.
You can't catch histoplasmosis from another person or froman animal. Birds do not carry the infection, but their droppings provide foodfor the fungus in the ground (so you can get histoplasmosis in areas such aschicken coops). The droppings of bats also feed the fungus in the ground (soyou can get histoplasmosis in areas where bats live, such as caves).
The Histoplasmacapsulatum fungus is the most common type of fungus in the United States.However, most people who are infected with histoplasmosis have few or nosymptoms.
Histoplasmosis occurs in places that have moderatetemperatures and moisture. It is very common in the Ohio, Missouri andMississippi river valleys due to the damp, rich soil found in those areas.
Farmers, landscapers, construction workers, archaeologistsand geologists are at an increased risk for histoplasmosis.
Severe infections may develop in infants and young childrenand in older adults. People who have human immunodeficiency virus (HIV), arereceiving chemotherapy treatment for cancer, are taking long-termcorticosteroids (such as prednisone) or are taking anti-rejection medicinesafter an organ transplant are at an increased risk for developing severe casesof histoplasmosis. A chronic infection can occur in patients who have lungdiseases 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 andcomputerized tomography (CT) scans are helpful for detecting inflammation inthe lungs, but your doctor can't be sure you have histoplasmosis just bylooking at an X-ray or a CT scan.
The treatment depends on how serious the infection is andhow long the illness has lasted. Many people don't need any treatment and thebody will fight the histoplasmosis infection on its own. Some people need totake an antifungal medicine, such as amphotericin or itraconazole. If you needto take medicine for histoplasmosis, your doctor will monitor you closely forpossible side effects on your kidney or liver from the medicine. You may needto take medicine for weeks or months. If you have acquired immunodeficiencysyndrome (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 therapyand intravenous fluids. Others can be treated at home. Most people respond wellwith treatment.
The best way to avoid infection is to stay away from placeswhere you could breathe in contaminated dust. Spraying soil with water beforedigging or spraying barns and chicken coops can reduce the dust that getsstirred up, and thus reduces the number of fungus spores in the air. If youwork in contaminated areas, you should wear protective clothing and face masks.
Overview of Histoplasmosis by R Kurowski, M.D. and M Ostapchuk, M.D. (American Family Physician December 15, 2002, http://www.aafp.org/afp/20021215/2247.html)
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