Case-Control study of Firefighters with documented positive tuberculin skin test results using Quantiferon-TB testing in comparison with Firefighters with negative tuberculin skin test results

• Main Authors: Gorter Forrest D, Kelley Patrick L, Dominguez John A, Reinhart Steven, Wernick Howard B, England Timothy L, Fleming James L, Papst Victor, LaDuke Alicia
• Format: Article
• Language: English
• Published: BMC 2006-12-01
• Series: Journal of Occupational Medicine and Toxicology
• Online Access: http://www.occup-med.com/content/1/1/28

<p>Abstract</p> <p>Background</p> <p>Phoenix Firefighters have had abnormally high rates of tuberculin skin test (TBST) results on medical surveillance. The objectives of this study were to evaluate our firefighters using QuantiFERON-TB (QFT), comparing the results to their TBST results.</p> <p>Methods</p> <p>Using QFT results obtained during the study, we compared previously positive TBST responders (Cases) to negative responders (Controls). We also compared both groups for QFT results for <it>Mycobacterium avium </it>(MA) exposure.</p> <p>Results</p> <p>QFT effectively monitored our working population. 12.9% of the 148 cases, and 3.2% of the 220 controls had a positive QFT result. Another 14.8% of cases and 4.5% of controls had conditionally positive QFT results. There was an unusually high rate of MA response on QFT testing in both groups.</p> <p>Conclusion</p> <p>Phoenix Firefighters have a higher than expected TBST and QFT results, which cannot be explained by the increased MA rate. The decreased level of QFT positivity in comparison to TBST results may indicate a considerable false positive TBST rate. The QFT offers many advantages as a surveillance method over TBST in exposed worker populations.</p>