A Better Way of Screening TB Contacts

An interferon-γ-release assay identified more contacts who developed active tuberculosis than did the usual skin test.

The tuberculin skin test (TST) is a flawed diagnostic test for latent tuberculosis, but, until recently, it was all we had. Now, however, interferon (IFN)-γ-release assays appear to be better at identifying people who might need preventive treatment.

German researchers assembled a cohort of people at high risk for developing active TB: All were close contacts of individuals with smear-positive disease. The participants were tested with both a TST and an IFN-γ-release assay (QuantiFERON-TB-Gold In-Tube assay) and followed for about 3 years; during follow-up, 19 of 903 people who had received no prophylactic therapy developed active tuberculosis.

Using the CDC's 5-mm induration standard for TSTs that should initiate preventive treatment in clos…

Reviewing Author

Abigail Zuger, MD

Disclosures

Nothing to disclose

Abigail Zuger, MD

Disclosures

Nothing to disclose

A Better Way of Screening TB Contacts

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Reviewing Author