Skip to main content

Free Content Mycobacterium tuberculosis drug resistance in a suburban community in Southern Mexico [The Eddie O'Brien Lecture]

Download Article:
(PDF 135.01953125 kb)


OBJECTIVE: To determine the impact of drug resistance (DR) on the clinical outcome and transmission of tuberculosis under programmatic conditions.

METHODS: Prospective cohort and molecular epidemiologic study in the Orizaba Health Jurisdiction of Mexico. Between March 1995 and July 1999, chronic coughers with positive acid-fast bacilli (AFB) detected in sputum smear underwent clinical and mycobacteriologic evaluation (species identification, drug susceptibility testing and IS6110-based genotyping). Treatment was provided in accordance with official norms.

RESULTS: Mycobacterium tuberculosis was isolated from 326/387 AFB-positive cases. The rate of DR was 24.2% and that of multidrug resistance (MDR, defined as resistance to both isoniazid and rifampin at least) was 7.7%; 78% were cured, 8% abandoned treatment, 6% failed treatment, and 5% died. An additional 13.5% received retreatment and 8.9% died during a median 28.6 months of follow up. Factors associated with DR by multivariate analysis were chronicity of tuberculosis (OR 4.8, 95%CI 2.7–8.4, P < 0.001), age >40 years (OR 1.9, 95%CI 1.1–3.2, P = 0.02) and indigenous origin (OR 0.3, 95%CI 0.13–0.75, P = 0.01). Cox-adjusted relative risks showed that MDR (RR 2.5, 95%CI 1.02–6.16, P = 0.04), HIV infection (RR 31.3, 95%CI 11.6–84.8, P < 0.001), and chronicity of tuberculosis (RR 2.1, 95%CI 1.0–4.4, P = 0.06) were associated with mortality, controlling for age. Predictors of retreatment were DR (not including MDR) (RR 2.2 95%CI 0.89–5.31, P < 0.087), MDR (RR 12.6, 95%CI 5.46–28.88, P < 0.001), and living in a household with an earthen floor (RR 2.8, 95%CI 1.27–6.13, P = 0.011). Being infected with MDR-TB was the only factor associated with a decreased likelihood of being in an RFLP cluster (OR 0.31, 95%CI 0.12–0.81, P = 0.02).

CONCLUSIONS: Although MDR-TB may have a decreased propensity to spread and cause disease, it has a profoundly negative impact on tuberculosis control.

Keywords: DOTS; RFLP; cluster; drug resistance; tuberculosis; tuberculosis control; tuberculosis treatment

Document Type: Miscellaneous

Affiliations: 1: Instituto Nacional de Salud Pública, Cuernavaca, México 2: Instituto Nacional de la Nutrición Salvador Zubirán 3: Instituto Nacional de Diagnóstico y Referencia Epidemiológicos 4: Stanford University, Stanford, California, USA

Publication date: 2000-12-01

More about this publication?
  • The International Journal of Tuberculosis and Lung Disease publishes articles on all aspects of lung health, including public health-related issues such as training programmes, cost-benefit analysis, legislation, epidemiology, intervention studies and health systems research. The IJTLD is dedicated to the continuing education of physicians and health personnel and the dissemination of information on tuberculosis and lung health world-wide.

    Certain IJTLD articles are selected for translation into French, Spanish, Chinese or Russian. They are available on the Union website

  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • International Journal of Tuberculosis and Lung Disease
  • Public Health Action
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more