Preventing Tuberculosis

If you have become infected with TB, but do not have active TB disease, you may get preventive therapy. This treatment kills germs that are not doing any damage right now, but could so do in the future. The most common preventive therapy is a daily dose of isoniazid (INH) for 6 to 9 months.

If you take your medicine as instructed by your healthcare provider, it can keep you from developing active TB disease.

Not everyone who is infected with the TB germ develops TB disease. People who are at high risk for developing TB disease from the TB germ include:

  • people infected with HIV
  • people who were infected with TB bacteria in the last 2 years
  • babies and young children
  • people who inject illegal drugs
  • people who have other diseases that weaken the immune system
  • elderly people
  • people who were not treated correctly for TB in the past

There is a vaccine against TB called BCG, or bacille Calmette-Guerin. It is used in many foreign countries where TB is more common. However, it is not used very often in the United States because the chances of being infected with TB in the US is low, there are questions about how much protection it offers, and it can make TB skin tests less accurate. Recent evidence has shown that BCG is effective at reducing the incidence of TB in children by about half in populations with a high prevalence of active TB.