Tuberculosis Screening

Patients with high suspicion for Active Tuberculosis require induced Sputum and other direct testing for organism
Tuberculosis Screening is used only to identify Latent Tuberculosis
1. Neither IGRA vs TST can differentiate latent and Active Tb, nor predict progression of Tb

Low risk patients
1. Routine, universal screening not recommended
2. Screen only if symptoms suggest possible Tuberculosis without meeting risk factors below
High risk patients
1. See Tuberculosis Risk Factors for Tuberculosis Screening Indications

Cases in which IGRA is preferred over TST
1. Unreliable follow-up for TST testing (homeless patients, Illicit Drug use)
2. No healthcare worker available to read PPD In 2-3 days
3. Patients with prior BCG vaccine
4. Live Virus Vaccine in prior 4 weeks (False Negative TST risk)
5. Cost difference between TST ($50-100) and IGRA ($150-225) is not an issue for patient
  1. IGRA is overall a better test (more reproducible and accurate regardless of BCG)
Cases in which TST is preferred over IGRA
1. Children under age 5 years old
2. Low resource environments with cost limitations or lack of lab facility
Cases in which either IGRA or TST are acceptable
1. Periodic screening for occupational exposure to Tuberculosis
2. Recent exposure to person with known or suspected Active Tuberculosis
Cases in which both tests might be considered together (if equivocal or mixed results expected)
1. Indeterminate initial testing
2. Higher risk population for exposure or progression but negative initial testing
  1. Immunocompromised
  2. Child under age 5 years
3. Clinical suspicion for Active Tuberculosis based on history, exam, imaging but with negative initial testing
4. Positive initial tests but confirmatory testing is desired by either the patient or provider
  1. Suspicion of False Positive, or low risk for progression