1647. Dose-Response Relationship between Biochemical Measurement of Cigarette Smoke Exposure and Mycobacterium tuberculosis Infection
Session: Poster Abstract Session: Mycobacterial Infections
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • IDSA 2013 poster.pdf (343.3 kB)
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    Background:

    Cigarette smoking and tuberculosis are major global health concerns, and smoking has been shown to increase the risk for active tuberculosis disease. Cigarette smoking might also increase the risk of Mycobacterium tuberculosis (Mtb) infection, but few studies on this topic have used biochemical assays to determine smoking status. We describe the association between biochemical measures of smoking status and Mtb infection.

    Methods:

    A cross-sectional study was conducted among persons who inject drugs in Tijuana, Mexico. NicAlert, a semi-quantitative dipstick-based salivary cotinine assay, was used to measure tobacco smoke exposure. QuantiFERON TB Gold In-tube (QFT) was used to determine Mtb infection. Multivariable log-binomial regression models were used to determine the association between salivary cotinine levels and QFT positivity.

    Results:

    Among 234 participants, prevalence of QFT positivity for NicAlert cotinine categories 0 (nonsmoking), 1 (secondhand smoke exposure or low-level smoking), and 2-6 (regular smoking) were 42.1%, 46.4%, and 65.2%, respectively (Ptrend = 0.012). We found increasing trends in QFT positivity (Ptrend = 0.003; Figure 1) and interferon-γ concentrations (Spearman's r=0.200; P = 0.002; Figure 2) across cotinine levels 0 to 6. In multivariable models adjusted for education, cotinine levels were not associated with QFT positivity when included as smoking categories (1 and 2-6 vs. 0), but were independently associated with QFT positivity when considered as an ordinal variable (prevalence ratio = 1.09 per +1 cotinine level; 95% confidence interval; 1.02 1.16).

    Conclusion:

    Our findings suggest a dose-response relationship between tobacco smoke exposure and the risk for Mtb infection. Longitudinal studies that use biochemical measures for smoking status are needed to confirm our findings.

    Sanghyuk Shin, PhD1, Rafael Laniado-Laborin2, Patricia Gonzalez Moreno, MD3, Thomas Novotny4, Steffanie Strathdee3 and Richard Garfein3, (1)Joint Doctoral Program in Public Health (Global Health), San Diego State University/UCSD, San Diego, CA, (2)Universidad Autonoma de Baja California, Tijuana, Mexico, (3)University of California San Diego, San Diego, CA, (4)San Diego State University, San Diego, CA

    Disclosures:

    S. Shin, None

    R. Laniado-Laborin, None

    P. Gonzalez Moreno, None

    T. Novotny, None

    S. Strathdee, None

    R. Garfein, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.