|Medical Services ● Disease Control|
Tuberculosis (TB) is a disease that is spread from person to person through the air. When a person with pulmonary or laryngeal TB coughs or sneezes, droplet nuclei containing Mycobacterium tuberculosis are expelled into the air. These tiny particles (1-5 microns in diameter) can remain suspended in the air for several hours, depending on the environment. If another person inhales air containing these droplet nuclei, he or she may become infected. The chance that TB infection will occur depends on three factors: the infectiousness of the person with TB, the environment in which exposure occurred, and the duration of exposure.
TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. People with latent TB infection do not feel sick and do not have any symptoms. However, they may develop TB disease at some time in the future.
The general symptoms of TB disease include feeling sick or weak, weight loss, fever, and night sweats. The symptoms of TB of the lungs include a productive, prolonged cough (duration of 3 weeks or longer), chest pain, and coughing up blood. Other symptoms depend on the part of the body that is affected. These persons are given therapy to cure the disease.
In contrast, people who have latent TB infection but who do not have TB disease do not have symptoms and can not spread TB to other people; such persons usually have a positive reaction to the tuberculin skin test. About 10% of infected persons will develop TB disease at some time in their lives, but the risk is considerably higher for persons who are immuno-suppressed, especially those with HIV infection. Persons with latent TB infection may be given treatment to prevent the infection from progressing to disease.
Copyright � 2006 North Dakota Department of Health