Tuberculosis transmission in nontraditional settings: a decision-tree approach

• Published in: American journal of preventive medicine 2005-02, Vol.28 (2), p.201-207
• Main Authors: Kammerer, J Steve, McNabb, Scott J N, Becerra, Jose E, Rosenblum, Lisa, Shang, Nong, Iademarco, Michael F, Navin, Thomas R
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Factors; Aged; Case-Control Studies; Child; Child, Preschool; Comorbidity; Continental Population Groups - statistics & numerical data; Decision Trees; Disease Transmission, Infectious - statistics & numerical data; Female; HIV Infections - epidemiology; Humans; Infant; Infant, Newborn; Male; Middle Aged; Multivariate Analysis; Mycobacterium tuberculosis - isolation & purification; Odds Ratio; Regression Analysis; Risk Assessment - methods; Risk Factors; Tuberculosis - epidemiology; Tuberculosis - microbiology; Tuberculosis - transmission; United States - epidemiology
• ISSN: 0749-3797
• DOI: 10.1016/j.amepre.2004.10.011

Tuberculosis (TB) transmission in nontraditional settings and relationships (non-TSR) often eludes detection by conventional contact investigation and is increasingly common. The U.S.-based National Tuberculosis Genotyping and Surveillance Network collected epidemiologic data and genotyping results of Mycobacterium tuberculosis isolates from 1996 to 2000. In 2003-2004, we determined the number and characteristics of TB patients in non-TSR that were involved in recent transmission, generated a decision tree to profile those patients, and performed a case-control study to identify predictors of being in non-TSR. Of 10,844 culture-positive reported TB cases that were genotyped, 4724 (43.6%) M. tuberculosis isolates were clustered with at least one other isolate. Among these, 520 (11%) had epidemiologic linkages discovered during conventional contact investigation or cluster investigation and confirmed by genotyping results. The decision tree identified race/ethnicity (non-Hispanic white or black) as having the greatest predictive ability to determine patients in non-TSR, followed by being aged 15 to 24 years and having positive or unknown HIV infection status. From the 520, 85 (16.4%) had non-TSR, and 435 (83.6%) had traditional settings and relationships (TSR). In multivariate analyses, patients in non-TSR were significantly more likely than those in TSR to be non-Hispanic white (adjusted odds ratio [aOR]=6.1; 95% confidence interval [CI]=1.7-21.1]) or to have an M. tuberculosis isolate resistant to rifampin (aOR=5.2; 95% CI=1.5-17.7). Decision-tree analyses can be used to enhance both the efficiency and effectiveness of TB prevention and control activities in identifying patients in non-TSR.