Effectiveness of the standard WHO recommended retreatment regimen (Category II) for tuberculosis in Kampala,Uganda: A prospective cohort study

Background: each year,10%-20% of patients with tuberculosis (tb) in low- and middle-income countries present with previously treated tb and are empirically started on a world health organization (who)-recommended standardized retreatment regimen. the effectiveness of this retreatment regimen has not been systematically evaluated. methods and findings: from july 2003 to january 2007,we enrolled smear-positive,pulmonary tb patients into a prospective cohort to study treatment outcomes and mortality during and after treatment with the standardized retreatment regimen. median time of follow-up was 21 months (interquartile range 12-33 months). a total of 29/148 (20%) hiv-uninfected and 37/140 (26%) hiv-infected patients had an unsuccessful treatment outcome. in a multiple logistic regression analysis to adjust for confounding,factors associated with an unsuccessful treatment outcome were poor adherence (adjusted odds ratio [aor] associated with missing half or more of scheduled doses 2.39; 95% confidence interval (ci) 1.10-5.22),hiv infection (2.16; 1.01-4.61),age (aor for 10-year increase 1.59; 1.13-2.25),and duration of tb symptoms (aor for 1-month increase 1.12; 1.04-1.20). all patients with multidrug-resistant tb had an unsuccessful treatment outcome. hiv-infected individuals were more likely to die than hiv-uninfected individuals (p<0.0001). multidrug-resistant tb at enrolment was the only common risk factor for death during follow-up for both hiv-infected (adjusted hazard ratio [ahr] 17.9; 6.0-53.4) and hiv-uninfected (14.7; 4.1-52.2) individuals. other risk factors for death during follow-up among hiv-infected patients were cd4<50 cells/ml and no antiretroviral treatment (ahr 7.4,compared to patients with cd4≥200; 3.0-18.8) and karnofsky score <70 (2.1; 1.1-4.1); and among hiv-uninfected patients were poor adherence (missing half or more of doses) (3.5; 1.1-10.6) and duration of tb symptoms (ahr for a 1-month increase 1.9; 1.0-3.5). conclusions: the recommended regimen for retreatment tb in uganda yields an unacceptable proportion of unsuccessful outcomes. there is a need to evaluate new treatment strategies in these patients. © 2011 jones-lópez et al.