ABSTRACT
BACKGROUND: Directly 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. METHODS: Genotype 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. RESULTS: Isolates 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). CONCLUSIONS: Universal DOT for tuberculosis is associated with a decrease in the acquisition and transmission of resistant tuberculosis.
Subject(s)
Directly Observed Therapy , Drug Resistance/genetics , Genotype , Mycobacterium tuberculosis/genetics , Tuberculosis/drug therapy , Adult , Aged , Child , Child, Preschool , Cluster Analysis , Female , Humans , Logistic Models , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Epidemiology , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/isolation & purification , Texas , Tuberculosis/microbiology , Tuberculosis/transmissionABSTRACT
RATIONALE AND OBJECTIVES: Identifying and treating persons with latent tuberculosis (TB) infection (LTBI) at high risk for developing TB is part of the current TB elimination strategy. There are no specific criteria, other than medical risks, to designate groups as high risk for developing TB. We hypothesized that, if location-based screenings were done in communities where persons with genotypically clustered Mycobacterium tuberculosis resided, then persons with LTBI from recent transmission and with undiagnosed TB could be identified. METHODS: Location-based TB screenings were done in partnership with multiple community-based organizations using resources previously used for other types of screening. MAIN RESULTS: Location-based screenings identified one person with TB for every 83 screened, and one person with LTBI for every five screened. The yield of this targeted screening program for discovering persons with TB and LTBI exceeded what would be expected from nontargeted screening in a county with a TB incidence of 5.7 per 100,000 population. CONCLUSIONS: Genotyping combined with geographic information systems analysis can potentially be used to define high-risk status and to define areas for location-based TB screenings.
Subject(s)
Carrier State/diagnosis , Geographic Information Systems , Mass Screening/methods , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Pulmonary/diagnosis , Adolescent , Adult , Aged , Carrier State/epidemiology , Cluster Analysis , Female , Genotype , Humans , Male , Middle Aged , Texas , Tuberculin Test , Tuberculosis, Pulmonary/epidemiologyABSTRACT
This article reviews the basic principles of drug treatment of tuberculosis, individual pharmacologic agents, current treatment recommendations, and several special situations that clinicians are likely to encounter in medical practice.
