Progression to Active Tuberculosis, but Not Transmission, Varies byMycobacterium tuberculosisLineage in The Gambia
Open Access
- 1 October 2008
- journal article
- Published by Oxford University Press (OUP) in The Journal of Infectious Diseases
- Vol. 198 (7), 1037-1043
- https://doi.org/10.1086/591504
Abstract
Background. There is considerable variability in the outcome of Mycobacterium tuberculosis infection. We hypothesized that Mycobacterium africanum was less likely than M. tuberculosis to transmit and progress to tuberculosis disease. Methods. In a cohort study of patients with tuberculosis and their household contacts in The Gambia, we categorized 1808 HIV-negative tuberculosis contacts according to exposure to M. tuberculosis or M. africanum. Positive skin test results indicated transmission, and development of tuberculosis during 2 years of follow-up indicated progression to disease. Results. Transmission rates were similar, but rates of progression to disease were significantly lower in contacts exposed to M. africanum than in those exposed to M. tuberculosis (1.0% vs. 2.9%; hazard ratio [HR], 3.1 [95% confidence interval {CI}, 1.1–8.7]). Within M. tuberculosis sensu stricto, contacts exposed to a Beijing family strain were most likely to progress to disease (5.6%; HR relative to M. africanum, 6.7 [95% CI, 2.0–22]). Conclusions. M. africanum and M. tuberculosis transmit equally well to household contacts, but contacts exposed to M. africanum are less likely to progress to tuberculosis disease than those exposed to M. tuberculosis. The variable rate of progression by lineage suggests that tuberculosis variability matters in clinical settings and should be accounted for in studies evaluating tuberculosis vaccines and treatment regimens for latent tuberculosis infection.Keywords
This publication has 26 references indexed in Scilit:
- Incidence of Tuberculosis and the Predictive Value of ELISPOT and Mantoux Tests in Gambian Case ContactsPLOS ONE, 2008
- Risk Factors for Positive Tuberculin Skin Test in Guinea-BissauEpidemiology, 2007
- Using ELISPOT to Expose False Positive Skin Test Conversion in Tuberculosis ContactsPLOS ONE, 2007
- Mycobacterium africanumElicits an Attenuated T Cell Response to Early Secreted Antigenic Target, 6 kDa, in Patients with Tuberculosis and Their Household ContactsThe Journal of Infectious Diseases, 2006
- Inhibition of Respiration by Nitric Oxide Induces aMycobacterium tuberculosisDormancy ProgramThe Journal of Experimental Medicine, 2003
- Recombinant BCG exporting ESAT-6 confers enhanced protection against tuberculosisNature Medicine, 2003
- The Evolution of Virulence in Parasites and Pathogens: Reconciliation Between Two Competing HypothesesJournal of Theoretical Biology, 1994
- Transmission of Tuberculosis in New York City -- An Analysis by DNA Fingerprinting and Conventional Epidemiologic MethodsThe New England Journal of Medicine, 1994
- The Epidemiology of Tuberculosis in San Francisco -- A Population-Based Study Using Conventional and Molecular MethodsThe New England Journal of Medicine, 1994
- Coevolution of hosts and parasitesParasitology, 1982