Risk factors for tuberculin skin test positivity in an industrial workforce results of a contact investigation.

Abstract

The objective of this study was to determine the prevalence of and risk factors for tuberculin skin test (TST) positivity among an industrial workforce employing many foreign-born workers after one employee was hospitalized for active tuberculosis (TB). A contact investigation was performed. We used crude odds ratios and a multivariate model to assess risk factors for TST positivity. The rate of TST positivity was 37.1% (N=97). Twenty-nine of 36 (80.6%) workers from higher TB prevalence countries versus seven of 61 (11.5%) workers born in low-prevalence countries were positive. Workplace risk factors included using the lunchroom, carpooling with the case, or working on the same or subsequent shift. A total of 66.7% of immigrant workers denied previous screening. TB contact investigations should probe into workplace transmission. Workplaces with workers from higher TB prevalence countries should consider pre-placement TB screening.