Identification of factors for tuberculosis transmission via an integrated multidisciplinary approach

Department of Epidemiology, School of Public Health, University of Michigan, M5124 SPH II, 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA.
Tuberculosis (Edinburgh, Scotland) (Impact Factor: 2.71). 02/2011; 91(3):244-9. DOI: 10.1016/
Source: PubMed


It was reported previously that the major fraction of the recent decrease of tuberculosis incident cases in Arkansas had been due to a decrease in the reactivated infections. Preventing transmission of Mycobacterium tuberculosis is the key to a continued decline in tuberculosis cases. In this study, we integrated epidemiological data analysis and comparative genomics to identify host and microbial factors important to tuberculosis transmission. A significantly higher proportion of cases in large clusters (containing >10 cases) were non-Hispanic black, homeless, less than 65 years old, male sex, smear-positive sputum, excessive use of alcohol, and HIV sero-positive, compared to cases in small clusters (containing 2-5 cases) diagnosed within one year. However, being non-Hispanic black and homeless within the past year were the only two host characteristics that were identified as independent risk factors for being in large clusters. This finding suggests that social behavioral factors have a more important role in transmission of tuberculosis than does the infectiousness of the source. Comparing the genomic content of one of the large cluster strains to that of a non-clustered strain from the same community identified 25 genes that differed between the two strains, potentially contributing to the observed differences in transmission.

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Available from: Xinyu Zhang, Sep 08, 2014
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    • "non-clustered isolates with a high PPP). This selection process is useful to hone in on a crisp phenotype that is necessary to study bacterial factors associated with transmission, by means of genomic comparison in future whole-genome sequencing studies [21]. It would for example be interesting to subject the CDC1551 outbreak to our new approach in order to separate host risk factors from the true bacteriological component. "
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    Full-text · Article · Sep 2011 · Tuberculosis (Edinburgh, Scotland)
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