TB Testing: Who Needs It, What a Positive Result Means

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Tuberculosis (TB), a contagious bacterial infection primarily affecting the lungs, remains a health risk in the U.S. Though cases declined for decades, recent increases — including ~10,347 cases in early data from 2024 — suggest testing and treatment of latent TB is needed more than ever.  Testing is crucial both for diagnosing latent TB (where bacteria are present but symptoms are absent) and active TB disease (which is contagious and manifests symptoms). People who should be tested include those with persistent cough or chest symptoms, immunocompromised individuals (e.g., with HIV, cancer, or on immunosuppressive medications), those who’ve been exposed to TB, and people in high-risk living or travel situations or from regions with high TB prevalence. Testing methods include the skin test (TST) and blood tests (interferon-gamma release assays, IGRA). A positive test indicates the presence of TB bacteria but does not distinguish latent vs active infection — further diagnostics like chest X-rays and clinical assessments are required. Treatment depends on whether TB is latent or active: Active cases require multi-drug antibiotic regimens lasting several months; latent infections may also be treated to prevent progression. Timely testing, especially among vulnerable populations, is emphasized to control spread and reduce morbidity.

Author:

Scripps Health – Family Medicine staff

Audiences:

Educators, General Public, Outreach Workers, Physicians

Topic:

TB Prevention, TB Treatment

Language:

English