Histoplasmosis

Histoplasmosis is a disease caused by the fungus Hisfopldsmu 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, 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 flu; fatigue, 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.

Diagnostic Studies and Procedures

The goal of diagnostic procedures is to differentiate histoplasmosis from other diseases. In addition to chest X-rays, studies may include skin and blood tests. Laboratory examinations of sputum, urine, bone marrow, and a liver biopsy may also be ordered.

Medical Treatments

Depending on the extent of the infection, the medication of choice is either of two antifungal agents: ketoconazoie (Nizoral), which is given by mouth, or amphotericin B (Fungizone), which is administered intravenously. If the infection has reached the central nervous system, as might happen in people who have AIDS, amphotericin B is injected into the spinal column.

While the adverse side effects of ketoconazole -- nausea, diarrhea, abdominal pain, and itching -- are minor when compared with those of amphotericin B -- weight loss, anemia, fever, and kidney disorders -- both of these drugs must be monitored closely because of their potential to produce liver toxicity.

Antifungal medications are not effective for treating the histoplasmosis syndrome that affects the eyes. In these instances, treatment consists of a combination of corticosteroids, laser surgery, and radiation therapy, all directed to the retina.

In cases of extensive lung damage, the affected portions of the lung may be surgically removed.

Alternative Therapies

The chief role of alternative therapies in treating these diseases is the strengthening of the immune system io help fight the infection.

Herbal Medicine. Herbalists recommend echinacea (purple coneflower) tea, black walnut extract, or pau d'arco, available as capsules, extract, and tea.

Nutrition Therapy. A nutritionist may recommend a diet rich in vitamin A and beta carotene to boost immunity; vitamin C, which is said to increase levels of interferon, a group of proteins that fight infections; vitamin B6 (pyridoxine), to maintain a proper level of antibody production; and zinc supplements, which are also thought to strengthen the immune system.

Self-Treatment

Milder forms of histoplasmosis are treated with bed rest, extra fluids, abstaining from smoking, and avoidance of second-hand smoke. To reduce the possibility of infection, city dwellers should avoid pigeon and starting roosts. Rural residents have a more difficult problem because they are likely to be surrounded by the airborne spores. The American Lung Association recommends taking the following preventive measures:

• Keep far buildings, especially chicken houses, as clean and dry as possible. Before sweeping them out, wet down the floor to reduce dust.
• Wear a facial mask to keep from inhaling spores in areas where there are bat or bird droppings.
• Keep storm cellars clean and dry.

Other Causes of Lung Symptoms

Mild forms of the disease are often attributed to a cold or flu. various other fungal infections can also be confused with histoplasmosis.