What is Tuberculosis (TB)?

March 24 was World TB day, under the theme, “It’s time to end TB”.  TB is a contagious disease that is transmitted from person to person through coughing and breathing in airborne droplets that contain bacteria.  TB primarily affects the lungs, but can affect any part of the body.  As one of the most common infections in the world, TB remains a major problem in many countries and among vulnerable populations.

TB is caused by slow-growing bacteria called Mycobacterium tuberculosis.  When these bacteria enter the lungs, they are usually walled off into harmless capsules (granulomas) in the lung, causing infection but not disease.  These capsules may later wake up weeks, months or decades later causing active TB disease.






TB disease symptoms are often initially mistaken for a smoker’s cough, allergies, or chronic bronchitis from a lingering cold or flu infection.  TB infection most often affects the lungs but can cause problems in other parts of the body.  The classic symptoms of TB in the lungs include:

  • Cough lasting more than three weeks
  • Unexplained weight loss
  • Low-grade fever
  • Night sweats

If you have these symptoms, you should check with your health care provider.





TB disease is suspected clinically when a person presents with the TB signs and symptoms usually together with abnormal findings on a chest x-ray.  The disease is often diagnosed by microscopic examination of three separate samples of sputum (phlegm) often collected on different days.  Bronchoscopy is sometimes needed to obtain lung samples if a patient is unable to produce sputum.  In addition, chest x-ray and CT chest imaging are performed to evaluate for any lung abnormalities.  If TB is suspected in a different part of the body, a different sample or a tissue biopsy may be needed.






TB disease is usually treated with TB medications for at least six months.  If TB is in the bones, brain or other hard-to-reach areas, treatment will be longer.








It is spread by tiny airborne droplets created by coughing.  It is not spread by sharing food, utensils, drinks, or touching, etc.  Covering the mouth and nose when coughing is an important way to stop the spread of TB and other airborne diseases.  If you have TB disease and are coughing, it is important to limit contact with others until your health care provider tells you that you are no longer contagious, while on treatment.  Finding out you have TB and seeking care right away is the best way to stop its spread, since treatment of disease helps stop being contagious, decreasing transmission.




Stay healthy, Premier Service Medical Aid Society – We Value Your Health!