Does directly observed therapy (DOT) reduce drug resistant tuberculosis?

Abstract

BackgroundDirectly observed therapy (DOT) is a widely recommended and promoted strategy to manage tuberculosis (TB), however, there is still disagreement about the role of DOT in TB control and the impact it has on reducing the acquisition and transmission of drug resistant TB. This study compares the portion of drug resistant genotype clusters, representing recent transmission, within and between communities implementing programs differing only in their directly observed therapy (DOT) practices.MethodsGenotype clusters were defined as 2 or more patient members with matching IS6110 restriction fragment length polymorphism (RFLP) and spoligotype patterns from all culture-positive tuberculosis cases diagnosed between January 1, 1995 and December 31, 2001. Logistic regression was used to compute maximum-likelihood estimates of odds ratios (ORs) and 95% confidence intervals (CIs) comparing cluster members with and without drug resistant isolates. In the universal DOT county, all patients received doses under direct observation of health department staff; whereas in selective DOT county, the majority of received patients doses under direct observation of health department staff, while some were able to self-administer doses.ResultsIsolates from 1,706 persons collected during 1,721 episodes of tuberculosis were genotyped. Cluster members from the selective DOT county were more than twice as likely than cluster members from the universal DOT county to have at least one isolate resistant to isoniazid, rifampin, and/or ethambutol (OR = 2.3, 95% CI: 1.7, 3.1). Selective DOT county isolates were nearly 5 times more likely than universal DOT county isolates to belong to clusters with at least 2 resistant isolates having identical resistance patterns (OR = 4.7, 95% CI: 2.9, 7.6).ConclusionsUniversal DOT for tuberculosis is associated with a decrease in the acquisition and transmission of resistant tuberculosis.

Risk Factors for Drug-Resistant Tuberculosis

“…The use of directly observed therapy (DOT) is highly recommended to promote treatment adherence [16] [26]. Recent studies suggest that resistance is less likely to develop or to be transmitted when TB patients are under DOT [16] [28].…”

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

“…Strengthening DOTS programmes was credited with stopping the outbreaks of MDR tuberculosis in many regions in the USA, especially in New York City, the Dallas-Fort Worth Metroplex, and Baltimore. [161][162][163][164] Emergence of acquired drug resistance eventually became equated with poor adherence, and high rates of acquired drug resistance were considered to be an indicator of poor performance of DOTS programmes. Thus, high numbers of patients defaulting from therapy is now considered an indicator of poor treatment outcomes in its own right, as bad as therapy failure.…”

Treatment Outcome of Tuberculosis Patients in Azezo Health Center, North West Ethiopia

“…The implementation of DOTS has been associated with high rate of successful treatment outcome and reduced development of drug resistance [11][12][13] . Monitoring the outcome of treatment is essential in order to evaluate the effectiveness of DOTS program and serves as a proxy of quality of TB treatment in a health care system 14,15 .…”