Identification and definition

Tuberculosis (TB), is a disease that is caused by bacteria called Mycobacterium tuberculosis. This bacteria usually attacks the lungs, however, it can attack other parts of the body, such as, the kidneys, spine, and the brain.

TB germs can live in your body and not have any symptoms. This is referred to as latent TB infection, which means you have inactive TB germs in your body. The inactive germs cannot be passed on to anyone else. However, if these germs become active in your body and multiply, they will cause TB disease.

Signs and symptoms of Tuberculosis

Symptoms depend on what part of the body is affected.

People with TB disease often feel

  • Weak or sick
  • Lose weight
  • Have fever
  • Night sweats

If their TB disease is in the lungs, they may also cough and have chest pain, and they might cough up blood.

Disease history

Mycobacterium tuberculosis, the bacteria that cause tuberculosis (TB) was discovered on March 24, 1882, by Dr. Robert Koch. During that time, TB killed one out of every seven people living in the United States and Europe and was responsible for more human deaths than any other pathogen today. In 1921, Albert Calmette and Camille Guerin administered the first BCG (TB vaccine).

How is TB transmitted?

TB can be spread from one person to another through the air. When a person who has TB of the lungs or throat coughs, sneezes, speaks, or sings, the bacteria is put into the air. Any person near by may breath in the bacteria and become infected. TB can only be spread through the air, it is not spread through sharing silverware or cups, or sharing saliva when kissing.


If not treated properly, TB disease can be fatal. The bacterial infection can cause permanent damage to the lung tissue. This damage can make breathing difficult for the person affected. Untreated tuberculosis typically affects the lungs, but can spread to other parts of the body through the bloodstream.

Other parts of the body include:

  • Bones- Spinal pain and joint destruction may result from TB that infects the bones.
  • Brain- It can cause meningitis, which is sometimes fatal due to the swelling of the membranes that covers the brain and spinal cord.
  • Liver or kidneys- The liver and kidneys filter waste from the bloodstream. If TB affects the liver and kidneys those functions can become impaired.
  • Heart- TB can infect the tissues surrounding the heart. It can cause inflammation and fluid collections that may interfere with the heat's ability to pump effectively.

Other complications include:

  • Adult respiratory distress syndrome (ARDS)
  • Lung failure
  • Relapse of the disease

Recommended control for TB

There is a BCG vaccine available. It is used in many countries with a high prevalence of TB to prevent childhood tuberculous meningitis and miliary disease. It is not a recommended vaccine in the United States because there is a very low risk of becoming infected with the bacteria. BCG vaccine should be considered only for individuals who meet a specific criteria.

Children- BCG vaccination should only be considered for children who have a negative tuberculin skin test and who are continually exposed, and cannot be separated from, adults who are untreated of ineffectively treated.

Health Care Workers- BCG vaccination of health care workers should be considered on an individual basis in settings in which there is a high percentage of TB patients, there is ongoing transmission, or where TB infection- control precautions have not been successful.

Health care workers considered for BCG vaccination should be counseled regarding the risks and benefits associated with both BCG vaccination and treatment of Latent TB Infection.

Contraindications include

Immunosuppression. BCG vaccination should not be given to persons who are immunosuppressed such as a persons who is infected with HIV or who are likely to become immunocompromised (candidates for organ transplant).

Pregnancy. BCG vaccination should not be given during pregnancy. Although no harmful effects of BCG vaccination on the fetus have been observed, further studies are needed to prove its safety.