Tuberculosis Genotyping—United States, 2004-2010

Abstract

Tuberculosis (TB) genotyping is a laboratory-based genetic analysis of the bacteria that cause TB disease (i.e., any of the organisms in the Mycobacterium tuberculosis complex). When combined with epidemiologic data, TB genotyping has sufficient discriminatory power to help find TB cases likely to be in the same chain of transmission or determine that cases are not related. Since 2004, >70,000 M. tuberculosis isolates have been genotyped through partnerships between CDC, national genotyping laboratories, and state and local public health departments, with a goal to genotype at least one M. tuberculosis isolate for each case of culture-positive TB in the United States. National genotype surveillance coverage, or the proportion of culture-positive TB cases with a genotyped isolate, increased from 51.2% in 2004 to 88.2% in 2010. The TB Genotyping Information Management System (TB GIMS), accessible to public health departments through a secure, online web portal, was launched in 2010. TB GIMS enables systematic collection of genotyping results, which have been available since 2004, and integrates those results with epidemiologic, geographic, demographic, and clinical data collected by the National TB Surveillance System (NTSS) since 1993. Genotyping timeliness, represented by the median time from specimen collection until linked genotyping results and surveillance data are available to TB GIMS users, improved from 22 weeks in July 2010 to 11 weeks in December 2010. These improvements in genotype surveillance coverage and timeliness will improve outbreak detection efforts and enable more in-depth studies of TB epidemiology, leading to better use of limited public health resources.