For Medical Providers

Who To Test:

Persons with a risk for TB.

Prioritize persons with risks for progression.

If health system resources do not allow for testing of all persons from countries with elevated TB rates, prioritize those with at least one of the following medical risks for progression:
   – diabetes mellitus
– smoker within past 1 year
   – end stage renal disease
– leukemia or lymphoma
– silicosis
– cancer of head or neck
– intestinal bypass/gastrectomy
– chronic malabsorption
– body mass index ≤ 20
– history of chest x-ray findings suggestive
of previous/inactive TB (no prior treatment).  Includes fibrosis or non-calcified nodules, but does not include solitary calcified nodule or isolated pleural thickening.

In addition to LTBI testing, evaluate for active TB disease.

TB Screening Matters

One out of four people alive today is affected by TB. If exposed to infectious TB, anyone can get infected and progress to disease. Most TB disease is diagnosed in private medical settings with city/county public health departments providing case management support and contact investigations to identify related TB infections and disease. Private providers, working with public health personnel provide prevent large and ongoing outbreaks of TB.

The CDC is offering the following web-based CME course, Interactive Core Curriculum on Tuberculosis: What the Clinician Should Know – Continuing Education Activities. (page updated May, 2016)

On September 6, 2016, the US Preventive Services Task Force made Recommendation: Screening for Latent Tuberculosis Infection in Adults was published here JAMA. 2016;316(9):962-969. doi:10.1001/jama.2016.11046.  Stating “…accurate screening tests for LTBI are available, treatment of LTBI provides a moderate health benefit in preventing progression to active disease, and the harms of screening and treatment are small.”

TB Risk Assessments:

The California Department of Public Health (CDPH) Tuberculosis Control Branch (TBCB), and the Curry International Tuberculosis Center (CITC) worked with CTCA volunteers to create four TB risk assessments. The risk assessments identify those in California at risk for TB infection which can become TB disease. We aim to find and treat TB infection before TB disease develops.

A 5/6/20 update to the School Staff and Volunteer Risk Assessment clarifies that telehealth/remote visits are an option for face to face administration of this Risk Assessment.

About BCG:

BCG, or Bacille Calmette-Guérin, is a vaccine for TB given to many born outside of the United States.

TB blood tests (interferon-gamma release assays or IGRAs), are not affected by prior BCG vacinnation, unlike the TB skin tests. IGRAs are not expected to give a false-positive result in persons who have received prior BCG vaccination.

BCG vaccine may cause a positive reaction to the TB skin test,  complicating decisions about treatment. Despite this potential for BCG to interfere with test results, the TB skin test (TST) is not contraindicated for persons who have been vaccinated with BCG. The presence or size of a TST reaction in these persons does not predict whether BCG will provide any protection against TB disease.  Furthermore, the size of a TST reaction in a BCG-vaccinated person is not a factor in determining whether the reaction is caused by latent TB infection (LTBI) or the prior BCG vaccination.

More on who to test and (last updated Dec 2011)