What Is Tuberculosis?

Tuberculosis (TB) is a serious bacterial infection that usually attacks the lungs but can also attack other body organs. It can be fatal without proper treatment.

About one-third of the people in the world and 10 percent of Americans have M. tuberculosis, the bacterium that causes tuberculosis, in their bodies. It can be in one of two forms:

  • Latent TB infection (LTBI): People with LTBI have no symptoms, do not feel sick and are not able to pass the disease on to someone else. A positive TB skin test may be the only indication they have the disease. Without treatment, they may develop active TB disease at some point in their lives.
  • TB disease: This is an active infection with symptoms that make people feel very sick. People with TB disease can spread the infection to others through the air by coughing, sneezing, talking and singing.

Many years ago, TB was the number one cause of death in the United States. Now it is usually successfully treated with medications. Anyone can get TB, but people at the highest risk:

  • Are elderly
  • Have a weakened immune system
  • Live or work in a residential facility, such as a nursing home or prison
  • Spend time with people who traditionally have high transmission rates, including:
    • Homeless people
    • Intravenous drug users
    • People who are HIV positive
  • Travel to or have immigrated from parts of the world where active TB is commonplace