A practical method to systematically identify tuberculosis (TB) epidemiologic links that can be integrated into routine TB control and prevention programs in public health settings were validated in a study of 44 clusters from 4 heterogeneous US jurisdictions. The study population included 401 Mycobacterium tuberculosis (Mtb) culture-positive patients from Georgia, Maryland, Massachusetts, and Houston, TX, with Mtb isolates genotyped by CDC’s National TB Genotyping Service (NTGS) from 2006 to October 2010. Researchers found:
- 44 clusters were randomly selected from the 4 study sites (401 patients).
- Epidemiologic links were identified for 47% (189/401) of study patients in a total of 201 linked patient-pairs.
- Numbers of linked patients identified in each cluster investigations steps: Step 1 (26.2%), Step 2 (3.9%), Step 3 (14.6%), and Step 4 (30%).
- Among with 189 linked patients, 28 (14.8%) were not identified in previous contact investigation.
- No epidemiologic links were identified in 30% of clusters.
Teeter LD, Vempaty P, Nguyen DTM, et al. Validation of genotype cluster investigations for Mycobacterium tuberculosis: Application results for 44 clusters from four heterogeneous United States jurisdictions. [Published online ahead of print October 21, 2016]. BMC Infect Dis. doi:10.1186/s12879-016-1937-9.