Tuberculosis is a disease caused by a bacteria (germ) that usually affects the lungs (pulmonary TB), but other parts of the body can be affected (extrapulmonary TB). Tuberculosis is spread through the air when a person with untreated pulmonary TB disease coughs or sneezes. People who breathe TB bacteria into their lungs can become infected; close contact for a long period of time is usually necessary for TB to be spread. Tuberculosis can affect anyone, including people of any age, nationality or income level.
Latent Tuberculosis Infection
Latent TB infection (LTBI) means TB bacteria are in the body but are not active, the person is not sick, has no TB symptoms, and cannot spread TB to others. The TB bacteria stay in the body, but for most people with LTBI, they will never become active. A tuberculin skin test (also called a Mantoux or PPD test) can show if a person has TB infection. There is also a recently licensed blood test that is used to test for LTBI in some situations.
Active TB Disease
Active TB disease is a serious illness that may happen shortly after the person is infected with TB, or after many years, when the body defenses are weakened. This may be the result of aging, a serious illness, drug or alcohol abuse, or HIV infection. A person with active TB disease has symptoms, and can infect other persons when he or she coughs or sneezes. The symptoms of TB include a cough that lasts a long time, fever, night sweats, constant tiredness, weight loss, loss of appetite, and/or coughing up blood.
Treatment of TB
People with latent TB infection should be evaluated by their doctor, or a TB clinic, have an examination and a chest x-ray taken. LTBI treatment may be prescribed, which must be taken for four to six months or longer.
People with active TB disease must take treatment with at least four different TB drugs, prescribed for six months or more. TB drugs must be taken exactly the way the doctor orders. A person with TB that is not treated adequately can spread TB to other persons, can become severely ill and may even die. Directly Observed Therapy (DOT) programs are recommended for all persons with TB disease to help them complete their TB treatment. In a DOT program, a trained health care worker meets with the person with TB to help them remember to take every dose of all their medicine.
Sometimes the drugs usually given for TB disease are not able to kill the TB bacteria. When this happens, it is called drug-resistant TB (also called MDR-TB). Drug-resistant TB occurs when people with active TB disease take their medicine incorrectly, or if they are not been given the right TB drugs. Although drug-resistant TB can take longer to treat, most persons can be cured.
Preventing the Spread of TB
The best way to stop the spread of TB is for persons with TB infection or disease to take all their TB medicine, exactly the way it is prescribed. Also, a person with active TB of the lungs should cover his or her mouth and nose when coughing and sneezing.