Histoplasmosis is a disease caused by the fungus Histoplasma capsulate. The plant like fungus gives off microscopic spores its counterpart of seeds that are light enough to float in the air. Once inhaled, these spores take root in the lungs, growing and multiplying rapidly and causing symptoms that range from mild to life threatening, depending on the number of spores inhaled and the person’s general health. In rare cases, months or even years after the original infection, the disease infects the eyes, producing ocular histoplasmosis syndrome. Histoplasmosis spores are most frequently found in the droppings from bats, chickens, and pigeons and other birds. They flourish in the warm, moist, dark places where these droppings accumulate: barns, pigeon roosts, chicken houses, belfries, caves, and the undergrowth of city parks where starlings are abundant. Four types of histoplasmosis exist:
Mild histoplasmosis has symptoms similar to those of a benign case of the flufatigue, a slight fever, and occasional coughing. Many infected people don’t even notice them. This is the least serious of the four forms of histoplasmosis, and it commonly disappears after a few days without the need for any treatment.
Acute pulmonary histoplasmosis produces labored breathing, recurring fever and chills, and persistent coughing. It is confined to the lungs and is usually self limiting. Even without treatment, this variation of the disease is likely to clear up, although it may take a month or more.
Chronic pulmonary histoplasmosis is characterized by weight loss, recurring fever, malaise, and coughing that may produce blood. About one third of these patients improve spontaneously, whereas the remaining two thirds tend to worsen gradually.
Disseminated histoplasmosis occurs when a large number of spores have spread beyond the lungs, settling in various organs, including the liver, spleen, gastrointestinal tract, bone marrow, lymph nodes, eyes, and in rare cases, the brain. This form usually affects only people with immune systems weakened by immunosuppressive drugs, or by AIDS, cancer, or some other disease. Without treatment, 10 to 30 percent of patients with disseminated histoplasmosis die within 4 to 10 months of contracting the disease.
