Study objective: To determine the epidemiology and clinical consequences of drug-resistant TB in Guatemala.
Design: A prospective study conducted for 12 months.
Setting: A thoracic referral hospital in western Guatemala.
Patients: Three hundred and seventy-six patients with confirmed TB.
Results: Of 376 confirmed cases, 335 (89%) were culture-positive. Tests of drug sensitivities to four first-line antituberculous drugs were performed in 172 (51%) of the culture-positive cases. Fifty-one patients (30%) were resistant to at least one antimicrobial agent, and 26 (15%) were resistant to at least two drugs. In a multivariate model of clinically available patient characteristics, only cavitary disease (odds ratio=2.1; 95% confidence interval, 1.1-6.6) and a history of taking anti-TB medication for >2 weeks (OR=3.0; 95% CI, 1.5-10.3) were independent predictors of resistance to two or more anti-TB agents. Resistance to two or more anti-TB drugs was the single independent predictor of treatment failure (OR=6.4; 95% CI, 2.3-17.8). Twenty-four of 172 patients (14%) who denied having received prior anti-TB therapy were infected with resistant organisms, suggesting ongoing transmission of drug-resistant strains. Although 84% (69 of 82 cases) of patients with fully susceptible organisms and 89% (17 of 19 cases) with singly resistant organisms were cured, only 45% of patients (10 of 22 cases) infected with organisms resistant to two or more agents were successfully treated.
Conclusions: At this sentinel site for complicated TB, a substantial subset of cases who are infected with drug-resistant bacteria cannot be easily identified or treated.