Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis, which can be treated with antibiotics. There are two stages of TB: infection and disease. Worldwide, TB is the second leading infectious disease killer after COVID-19. An estimated 200,000 people in Washington have latent TB infection (LTBI), which may progress to TB disease without treatment.

Provider Information

Visit the Tuberculosis Page for Providers to find treatment information, reporting guidelines, and other resources.


A positive TB skin test or TB blood test only indicates that a person has been infected with TB bacteria; it cannot tell whether the person has latent TB or is sick with TB disease. A chest x-ray, a sample of sputum, and possibly other tests, are needed to diagnose TB disease.

TB tests are generally not needed for people with no risk of infection from TB. Some people should be tested because they are more likely to get TB disease. People who should be tested include:

  • People who have been in close contact with someone who has infectious TB disease.
  • People with HIV infection or another medical problem that weakens the immune system or before taking prescribed medication that intentionally suppresses the immune system.
  • People who have symptoms of TB disease (fever, night sweats, cough, and weight loss).
  • People who have lived or worked in a country where TB disease is common (includes any country other than the United States, Canada, Australia, New Zealand, or a country in western or northern Europe).

If you think you may need to get tested for TB, or want more information, talk to your health care provider and Island County Public Health.