Skin-Test Screening and Tuberculosis Transmission among the Homeless

摘要

We describe the implementation of a mandatory tuberculosis (TB) screening program that uses symptomscreening and tuberculin skin testing in homeless shelters. We used the results of DNA fingerprinting ofMycobacterium tuberculosis isolates to evaluate the effect of the program on TB incidence and transmis-sion. After the program was implemented, the proportion of cases among homeless persons detected byscreening activities increased, and the estimated TB incidence decreased from 510 to 121 cases per100,000 population per year. Recent transmission, defined by DNA fingerprinting analysis as clusteredpatterns occurring within 2 years, decreased from 49% to 14% (p=0.03). Our results suggest that the shel-ter-based screening program decreased the incidence of TB by decreasing its transmission among thehomeless