Screening and Testing

TB disease is spread through the air from person to person. There are two kinds of tests that are used to find out if a person is infected with TB bacteria: the TB skin test and TB blood tests.

A positive test only shows that the person has TB bacteria, but not whether those bacteria are active or not. Other tests like a chest x-ray and a sample of sputum are needed to see whether the person has TB disease or not. Factors in selecting which test to use are the reason for testing, test availability, and cost. It's usually not recommended that you take both tests. 

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