Self-Study Modules on Tuberculosis
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3: Diagnosis of Tuberculosis Infection and Disease
The Tuberculin Skin Test
Patients with symptoms of TB disease are often given a tuberculin
skin test to detect exposure to and infection with TB. However, as
many as 20% of patients found to have TB disease have a negative tuberculin
skin test reaction. For this reason, patients with symptoms
of TB disease should always be evaluated for TB disease, regardless
of their skin test results.
Furthermore, for patients with symptoms of TB disease, clinicians
should not wait for tuberculin skin test results (48 to 72 hours)
before starting other diagnostic tests.
A tuberculin skin test is not necessary for patients known to have
had a previous positive tuberculin skin test reaction.
|Study Questions 3.21-3.24
are the four steps in diagnosing TB disease?
3.22. What parts of a patient's medical history should
lead a clinician to suspect TB?
3.23. What are the common symptoms of pulmonary TB disease?
What are the general symptoms of TB disease (pulmonary or
3.24. For patients with symptoms of TB disease, should
clinicians wait for tuberculin skin test results before
starting other diagnostic tests?
Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
Division of Tuberculosis Elimination - http://www.cdc.gov/tb
Please send comments/suggestions/requests
CDC/Division of Tuberculosis Elimination
Communications, Education, and Behavioral Studies Branch
1600 Clifton Rd., NE - Mailstop E-10, Atlanta, GA 30333