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Tuberculosis (TB) - Prevention

Avoid getting active TB

Active tuberculosis (TB) is an infection that is spreading in a person's body, and it is very contagious.

The World Health Organization (WHO) estimates that one-third of the world's population is infected with the bacteria that causes TB. To avoid getting an active TB infection:

Do not spend long periods of time in stuffy, enclosed rooms with anyone who has active TB until that person has been treated for at least 2 weeks.
Use protective measures, such as face masks, if you work in a facility that cares for people who have untreated TB.
If you live with someone who has active TB, help and encourage the person to follow treatment instructions.

Prevent latent TB from becoming active

Usually, treatment with isoniazid for about 9 months or rifampin for 4 months can prevent a latent TB infection from developing into active TB. Treatment is recommended for anyone with a skin test that shows a TB infection, and is especially important for people who:

Are known to or are likely to be infected with the human immunodeficiency virus (HIV).
Have close contact with a person who has active TB.
Have a chest X-ray that suggests a TB infection, and have not had a complete course of treatment.
Inject illegal drugs.
Have a medical condition or take medicines that weaken the immune system.
Have had a tuberculin skin test within the past 2 years that did not show a TB infection but now a new test indicates an infection.

Can the TB vaccine help?

A TB vaccine (bacille Calmette-Guerin, or BCG) is used in many countries to prevent TB. But this vaccination is almost never used in the United States because:

The risk of getting TB is low in the U.S.
The vaccine is not effective in adults who receive it.
The BCG vaccine may cause a tuberculin skin test to indicate a TB infection even if a person is not infected with TB. This complicates the use of the tuberculin skin test to check people for TB.

WebMD Medical Reference from Healthwise

Last Updated: April 23, 2009

This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.