TextA Histoplasmosis

Histoplasmosis is infection caused by the fungus Histoplasma capsulatum that occurs mainly in the lungs but can sometimes spread throughout the body.

The spores of Histoplasma are present in the soil and are particularly common in the eastern and midwestern United States. Farmers and others who work with soil are most likely to inhale the spores; severe disease can result when large numbers of spores are inhaled. People with human immunodeficiency virus (HIV) infection are more likely to develop histoplasmosis, especially the form that spreads throughout the body.

Symptoms and Diagnosis

Most people with histoplasmosis do not have any symptoms. However, three forms of histoplasmosis do cause symptoms: acute, progressive disseminated, and chronic cavitary.

In acute histoplasmosis, symptoms usually appear 3 to 21 days after a person inhales the spores. The person may feel sick and have a fever and a cough. Symptoms usually disappear without treatment in 2 weeks and rarely last longer than 6 weeks. This form of histoplasmosis is very rarely fatal.

Progressive disseminated histoplasmosis does not normally affect healthy adults. This infection usually occurs in infants and in people with a weakened immune system (such as those with AIDS). Symptoms are vague at first. People may experience fatigue, weakness, and a general feeling of illness (malaise). Symptoms may worsen very slowly or extremely rapidly. The liver, spleen, and lymph nodes may enlarge. Less commonly, the infection causes ulcers to form in the mouth and intestines. In rare cases, the adrenal glands may be damaged, causing Addison's disease. Without treatment, this form of histoplasmosis is fatal in 90% of people. Even with treatment, death may occur rapidly in people with AIDS.

Chronic cavitary histoplasmosis is a lung infection that develops gradually over several weeks, producing a cough and increased difficulty in breathing. Symptoms include weight loss, a mild fever, and a general feeling of illness (malaise). Most people recover without treatment within 2 to 6 months. However, breathing difficulties may gradually worsen, and some people may cough up blood, sometimes in large amounts. Lung damage or bacterial invasion of the lungs eventually may cause death.

To make the diagnosis, a doctor obtains samples of an infected person's sputum, bone marrow, urine, or blood. Samples may also be taken from the liver, lymph nodes, or any mouth ulcers that are present. These samples are sent to a laboratory for culture and analysis.

Prognosis and Treatment

People with the acute form of histoplasmosis rarely require drug treatment. Those with the progressive disseminated form do need treatment and often respond well to amphotericin B given intravenously or to itraconazole given by mouth. In the chronic cavitary form, itraconazole or amphotericin B may eliminate the fungus, although the destruction caused by the infection leaves behind scar tissue. Breathing problems similar to those caused by chronic obstructive pulmonary disease usually remain. Therefore, treatment should begin as soon as possible to limit lung damage.

Notes:

histoplasmosis микоз, вызываемый диморфным грибом, гистоплазмоз

histoplasma capsulatum возбудитель гистоплазмоза

Дата добавления: 2015-11-16