Histoplasmosis | Causes & Risk Factors


How did I get histoplasmosis?

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).

Who is most likely to get histoplasmosis?

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).


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)

Written by familydoctor.org editorial staff

Reviewed/Updated: 03/14
Created: 04/03