Acute pulmonary histoplasmosis is a respiratory infection that is caused by inhaling the spores of the fungus Histoplasma capsulatum.
Histoplasma capsulatum, the fungus that causes histoplasmosis, is found in the central and eastern United States, eastern Canada, Mexico, Central America, South America, Africa, and Southeast Asia. It is commonly found in the soil in river valleys. It gets into the soil mostly from bird and bat droppings.
You can get sick when you breathe in spores that the fungus produces. Every year, thousands of people worldwide are infected, but most do not become seriously sick. Most have no symptoms or have only a mild flu-like illness and recover without any treatment.
Have more symptoms, and more serious symptoms, than others who get the disease
Risk factors include traveling to or living in the central or eastern United States near the Ohio and Mississippi river valleys, and being exposed to the droppings of birds and bats. This threat is greatest after an old building is torn down, or when exploring caves.
Most people with acute pulmonary histoplasmosis have no symptoms or only mild symptoms. The most common symptoms are:
Joint pain and stiffness
Muscle aches and stiffness
Rash (usually small sores on the lower legs)
Shortness of breath
Acute pulmonary histoplasmosis can be a serious illness in the very young, elderly, and people with weakened immune systems, including those who:
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.