Mycobacterium tuberculosis bacteria cause the treatable infection tuberculosis (TB). TB typically occurs in the lungs but can affect any part of the body. Not everyone with TB becomes sick.  Symptoms of the disease include cough, fatigue, weight loss, fever and night sweats.

TB has 2 stages—latent TB infection (LTBI) and active TB disease.  Many people with LTBI never develop active TB disease. Others progress from LTBI to active TB disease—often due to a weakened immune system.  Active TB disease can be life-threatening. Always screen patients for TB disease prior to starting on LTBI treatment. You can find our Tuberculosis Infection Screening Form here.

TB Disease (Active TB)

  • May show symptoms.
  • May feel ill.
  • May be contagious.
  • Have positive TB test results.
  • If TB is in their lungs, will have abnormal chest x-rays.
  • Requires treatment to be cured

TB Infection (Latent TB)

  • Do not show symptoms.
  • Do not feel ill.
  • Not contagious.
  • May have positive TB skin reaction and blood tests.
  • Usually have normal chest x-ray.
  • May develop active TB disease, if left untreated.
  • Groups at higher risk of progression to TB disease include:
    • Children under 5
    • Persons living with HIV
    • Persons living with uncontrolled diabetes