Tuberculosis is a bacterial disease that can occur anywhere in the body. It usually infects the lungs. According to the World Health Organization, one-third of people worldwide are infected with tuberculosis; a new person is infected every second. Of those infected, only 5 to 10 percent develop an active infection. In others, the immune system overcomes the bacteria and coats them with a thick waxy substance, rendering them dormant. The bacteria can remain dormant for years, but may become active if the person's immune system is weakened.
Cause and Diagnosis
The bacterium that causes tuberculosis is called Mycobacterium tuberculosis. The Cleveland Clinic advises that only people with an active infection are contagious. People with dormant tuberculosis are not. When people with an active pulmonary tuberculosis infection cough, sneeze, talk, sing or laugh, they can spread the bacteria through the air to be inhaled by others. Tuberculosis can be positively identified through a skin or blood test, but even a latent infection triggers a positive result.
Contributing Factors
The risk of infection is greater when there is prolonged and close contact with an infected person, such as in a family or in certain settings where people are in constant close contact. According to the Cleveland Clinic, the risk of exposure to or infection with tuberculosis is higher in prisons and jails, hospices, nursing homes and health care facilities. Employees of mycobacteriology labs also are at risk.
The World Health Organization advises that the chance of the infection becoming active increases if the person's immune system is weakened due to HIV or other disease, age, illicit drug use or malnutrition. Tuberculosis is endemic in Eastern Europe, Africa, Asia, the Caribbean and much of Latin America. People from those areas or people who have been in close prolonged contact with people from those areas are more at risk of exposure to and development of tuberculosis.
Treatment and Prevention
The Centers for Disease Control and Prevention advise both latent and active tuberculosis can be cured, but it requires long-term drug therapy. Latent tuberculosis requires taking one drug for nine months, while active infection requires taking several drugs for six to 12 months. People being treated have to take the medication as prescribed and finish the course of therapy; otherwise, the bacteria can become resistant to the drugs.
There is a vaccine for tuberculosis called the BCG vaccine; it is not widely used in the United States. According to the Centers for Disease Control and Prevention, it does not always protect people from getting the disease and it causes a positive skin test even without infection. Other methods of reducing infection are good ventilation systems in high-risk facilities and quick identification and prompt treatment of persons with a possible infection.
