Geographic predictors of primary multidrug-resistant tuberculosis cases in an endemic area of Lima, Peru.

SETTING: Peru reports among the highest multidrug-resistant tuberculosis (MDR-TB) rates in the Americas, with a growing proportion in previously untreated tuberculosis (TB) cases. The identification of clusters of primary MDR-TB compared with drug-susceptible TB (DS-TB) could help prioritize interventions. OBJECTIVE: To examine the clustering of primary MDR-TB case residences and their proximity to high-risk locations in San Juan de Lurigancho District, Lima, Peru. DESIGN: Enrolled primary MDR-TB and primary DS-TB cases were interviewed and their primary residence was recorded using handheld Global Positioning System devices. Kuldorff's spatial scan statistic was used for cluster detection (SaTScan(TM), v. 9.1.1). Identified clusters were visualized in Quantum Geographic Information Systems software (v1.8.0). The following cluster centers were tested: a health centre with the highest TB and MDR-TB rates (Clinic X), a hospital and two prisons. Using regression analyses, we examined predictors of primary MDR-TB cases. RESULTS: A statistically significant cluster of primary MDR-TB cases was identified within a 2.29 km radius around Clinic X. Proximity to Clinic X remained a significant predictor of primary MDR-TB in adjusted regression analyses. CONCLUSION: We identified a hotspot of primary MDR-TB cases around Clinic X in a TB-endemic area. Causes of this clustering require investigation; targeted interventions for this high-risk area should be considered.

Bodyweight gain to predict treatment outcome in patients with pulmonary tuberculosis in Peru.

SETTING: Tuberculosis control programmes of two health care centres in the central rainforest of Peru. OBJECTIVE: To evaluate if bodyweight gain (BWG) predicts treatment outcome in patients with pulmonary tuberculosis (PTB). DESIGN: Retrospective cohort study of adults with PTB diagnosed between 1995 and 2004. BWG was assessed after month 1 of treatment, after the initial phase and at the end of treatment. Patients were stratified into two BWG categories, < or = 5% and >5%. Failures and relapses were grouped together as unsuccessful treatment outcome. RESULTS: A total of 650 patients were included: 7.2% (n = 47) had an unsuccessful outcome. Unsuccessful outcome was associated with BWG < or = 5% at the end of treatment (RR 2.05, 95%CI 1.10-3.80), but not at the completion of month 1 (RR 0.99, 95%CI 0.52-1.88) or at completion of the initial phase (RR 1.46, 95%CI 0.82-2.57). Median BWG at completion of the initial phase was higher in cured patients (P = 0.007). BWG < or = 5% at end of treatment (RR 2.35, 95%CI 1.17-4.72), initial sputum smear 2+ (RR 2.48, 95%CI 1.14-5.31) and positive smear microscopy at month 2 (RR 4.0, 95%CI 1.30-12.31) were independent predictors of unsuccessful treatment outcome. CONCLUSION: BWG < or = 5% at the end of treatment, high bacterial load and lack of sputum conversion correlate with unsuccessful treatment outcome in this setting. New discriminative cut-offs for BWG are proposed.