Non-adherence and drug-related interruptions are risk factors for delays in completion of treatment for tuberculosis.

SETTING: A key program performance objective established by the Centers for Disease Control and Prevention (CDC) is that ≥93% of tuberculosis (TB) cases complete treatment within 12 months. OBJECTIVE: To determine the rate of and risk factors for delay in anti-tuberculosis treatment completion. DESIGN: Nested case-control study among TB cases reported to the Tennessee Department of Health between 1 January 2000 and 31 December 2010. Time to complete treatment was calculated using treatment start and stop dates documented in the Tuberculosis Information Management System (TIMS). RESULTS: Of 2627 cases, 261 (9.9%) required >12 months to complete treatment. In adjusted conditional logistic regression analyses, cavitary disease and positive cultures after 2 months of therapy (OR 5.85, 95%CI 1.98-17.32, P = 0.001), non-adherence (OR 4.13, 95%CI 1.76-9.72, P < 0.001), and interruptions in treatment due to drug-related issues (OR 6.91, 95%CI 3.76-12.70, P < 0.001) were independently associated with delay in completion of TB treatment. CONCLUSION: From 2000 to 2010, the proportion of TB cases completing treatment within 12 months increased from 84.6% to 94.9%, and remained above the CDC target during 2009-2010. Efforts to improve patient adherence and reduce interruptions in treatment due to anti-tuberculosis drug-related issues could improve the proportion of TB cases completing treatment within 12 months.

Chronic lung disease and HIV infection are risk factors for recurrent tuberculosis in a low-incidence setting.

SETTING: Programmatic data from the United States on tuberculosis (TB) recurrence are limited. OBJECTIVES: To determine the TB recurrence rate and to determine if chronic lung disease (CLD) and human immunodeficiency virus (HIV) infection are risk factors for recurrence in this population. DESIGN: Nested case-control study among TB cases reported to the Tennessee Department of Health between 1 January 2000 and 31 December 2006. Time at risk for recurrence was through 31 December 2007. Multiple imputation accounted for missing data. RESULTS: Of 1431 TB cases, 20 cases recurred (1.4%, 95%CI 0.9-2.1). Median time at risk for recurrence was 4.5 years (interquartile range 2.7-6.1). Initial and recurrent Mycobacterium tuberculosis isolates were available for genotyping for 15 patients; 12 were consistent with relapse (0.8%, 95%CI 0.4-1.5) and three with re-infection (0.2%, 95%CI 0.04-0.6). HIV infection (OR 5.01, P = 0.04) and CLD (OR 5.28, P = 0.03) were independently associated with recurrent TB, after adjusting for a disease risk score. HIV infection was a risk factor for TB re-infection (P < 0.001). CONCLUSIONS: In this low-incidence US population, the TB recurrence rate was low, but CLD and HIV were independent risk factors for recurrence. HIV infection was also a risk factor for TB re-infection.

Potentially preventable tuberculosis among HIV-infected persons in the era of highly active antiretroviral treatment.

OBJECTIVE: To characterize the proportion of tuberculosis (TB) cases that could have been prevented among human immunodeficiency virus (HIV) infected persons receiving care in the era of highly active antiretroviral treatment (HAART). DESIGN: We conducted an observational cohort study among HIV-infected patients with >or=2 out-patient visits at the Comprehensive Care Center, Nashville, Tennessee, USA, between 1 January 1998 and 31 December 2005. METHODS: A potentially preventable TB case was defined as a case in which the patient received no screening tuberculin skin test (TST) prior to TB diagnosis or a case in which a patient with a positive screening TST did not complete treatment for latent infection. RESULTS: Of 3601 HIV-infected persons in care (13 905 person-years [p-y] of follow-up), 29 developed TB (230/100,000 p-y). Of the 29, 20 (69%) had not had TST performed as part of routine screening. Of the nine patients screened, four had a positive test, three of whom completed treatment for latent TB infection. Of 29 TB cases, 21 (72%) were therefore potentially preventable. CONCLUSIONS: Most TB cases in this cohort were potentially preventable had the patients undergone a screening TST followed by treatment of latent infection if they had a positive TST.