Tuberculosis - Description

Some parts of the population are at higher risk of getting TB than others. For instance, tuberculosis is more common among elderly people. Typically, more than one-fourth of the TB cases reported in the United States occur among people above age sixty-five.

Elderly people are especially vulnerable for a number of reasons. First, the disease can take years to become active, so an older person may have gotten the disease earlier in life and only discovered it after it became active. Second, people who live in nursing homes and similar facilities are often in close contact with each other and the disease can spread more easily in such conditions. Third, the body's immune system becomes weaker as a person grows older and older people may find it more difficult to hold off an attack of the tubercle bacillus. The immune system is the body's network system for fighting off disease and infection.

Race also can be a factor in determining the risk of getting tuberculosis. TB occurs most commonly among African Americans. Other minorities are also at higher risk. Currently about two-thirds of all TB cases in the United States affect African Americans, Hispanics, Asians, and people from the Pacific Islands. Another one-fourth of cases in the United States affect people born outside the country.

People who are infected with the human immunodeficiency virus (HIV) are also at high risk for tuberculosis (see AIDS entry). HIV can damage a person's immune system, making it difficult for the body to fight off the TB bacterium. People who abuse alcohol and illegal drugs are also at high risk for the disease.