Is Tuberculosis (TB) Contagious?

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Tuberculosis (TB) Prevention

A vaccine against TB is commercially available; it is termed BCG, or Bacille Calmette-Guerin vaccine. However, the vaccine is not recommended for use in the U.S. because of the low risk for TB infections.

What is tuberculosis (TB)?

Tuberculosis (TB) is a disease (bacterial infection) caused by a bacterium named Mycobacterium tuberculosis that usually infects the lungs, but in some individuals, the bacteria can attack any part of the body. Before treatments were effective against TB, it was the leading cause of death in the United States.

Is tuberculosis (TB) contagious?

Yes, TB is highly contagious and can be transmitted from an infected person to an uninfected person, mainly when a person with TB coughs, sneezes, speaks, or even sings (known as airborne transmission or airborne disease). Other people who breathe in the aerosolized bacteria can become infected. Some individuals have TB infections but show no symptoms because their bodies prevent TB organisms from growing. Patients with this type of infection are termed as having latent (dormant) TB. Individuals with latent TB have the organisms suppressed; in this condition, the individuals are not contagious for TB when the organisms are dormant. However, if a person with latent TB is no longer able to suppress the TB organisms, that individual can then become contagious.

Mycobacterium tuberculosis organisms can survive for a while even in the deceased; to avoid getting TB, physicians who perform autopsies have to be careful not to spread the organisms into the air while they're doing their investigations.

How will I know if I have tuberculosis?

People may suspect they have tuberculosis if they have spent any length of time around coughing or sneezing individuals known to have tuberculosis. Symptoms and signs of TB include the following:

A physician can order skin tests, TB blood tests, and send sputum samples for specialized stains and culture to definitively diagnose tuberculosis in an individual.

Medically Reviewed by a Doctor on 8/16/2016

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