Low yield of chest radiography in a large tuberculosis screening program

Area of Science:

• Radiology
• Infectious Disease
• Occupational Health

Background:

• Pre-employment screening for healthcare workers often includes tuberculosis (TB) testing.
• Positive tuberculin skin test (TST) results necessitate further evaluation to rule out active disease or assess latent infection.
• Chest radiography is a common imaging modality used in TB screening protocols.

Purpose of the Study:

• To determine the frequency and types of abnormalities found on chest radiographs in asymptomatic healthcare workers with positive TST results.
• To evaluate the utility of routine chest X-rays in pre-employment TB screening.
• To assess if chest radiography aids in identifying active TB or LTBI reactivation risk.

Main Methods:

• Retrospective analysis of 2586 asymptomatic healthcare workers with positive TST results undergoing pre-employment evaluation.
• Review of chest radiographic reports and images for evidence of active TB or latent TB infection (LTBI).
• Independent radiologist review for discrepancies and evaluation of any follow-up imaging.

Main Results:

• Only 6.1% of chest radiographs showed abnormalities; none were consistent with active TB.
• Common findings included calcified granulomas, pleural thickening, fibrous scarring, and small noncalcified nodules.
• One case of primary lung malignancy and one necrotizing granuloma were incidentally found.

Conclusions:

• Universal chest radiography in pre-employment TB screening has a low yield for detecting active TB.
• The screening approach offers minimal benefit in identifying individuals at increased risk for LTBI reactivation.
• Chest X-rays do not assist in prioritizing healthcare workers for LTBI treatment.