Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 8, Number 11—November 2002
Tuberculosis Genotyping

Tuberculosis Genotyping Network, United States

DNA Fingerprinting of Mycobacterium tuberculosis Isolates from Epidemiologically Linked Case Pairs

Diane E. Bennett*Comments to Author , Ida M. Onorato*, Barbara A. Ellis*, Jack T. Crawford*, Barbara Schable*, Robert Byers*, J. Steve Kammerer*, and Christopher R. Braden*
Author affiliations: *Centers for Disease Control and Prevention, Atlanta, Georgia, USA;

Main Article

Table 3

Logistic regression modela showing factors associated with transmission unconfirmed by DNA fingerprinting in tuberculosis case pairs identified in contact investigations in seven sites, 1996–2000

Factor Adjusted odds ratio (95% confidence intervals) p value
Smear-negative source case 2.0 (1.2 to 3.1) 0.001
Foreign-born secondary case 3.4 (2.0 to 6.0) <0.0001
Secondary case <15 yrs 0.3 (0.2 to 0.8) 0.01
Secondary case >65 yrs 1.7 (0.8 to 3.6) 0.2
Workplace setting 2.7 (0.9 to 5.7) 0.08

aThe model also included in the multiple logistic regression analysis all levels of the following factors that were not significantly associated with unconfirmed transmission: cavitary disease in source case, race/ethnicity of case pair, and HIV status of secondary case. In the goodness-of-fit test, full model’s p value was 0.885; and the p value for a reduced model containing only the variables with significant associations was 0.725. Thus, both models fit adequately. For the full model, –2 x log likelihood was 564.044; for the reduced model, –2 x log likelihood was 571.469. The difference was distributed as a chi-square variable with 1 degree of freedom. The full model gave a better fit than the reduced model and was retained (p=0.0064, chi square >7.425).

Main Article