Tuberculosis (TB) recurrence can be due to reinfection or relapse. The contribution of each to TB incidence and the factors associated with recurrence are not well known. Effectiveness of TB control programs is assessed in part by recurrence rates. The aim of this study was to establish the recurrence rate of TB in Barcelona, the associated risk factors and the role of reinfection. A population-based retrospective longitudinal study was performed in Barcelona, Spain. TB patients with positive culture results who completed treatment between Jan 1^st, 2003 and Dec 31^st, 2006 were followed-up until December 31st, 2009 by the TB Control Program. The incidence rate of recurrence was calculated per person-year of follow-up (py). Kaplan-Meier and Cox regression methods were used for the survival analysis by calculating the hazard ratio (HR) with 95% confidence intervals (CI). Of the 1,823 TB cases identified, 971 fulfilled the inclusion criteria and 13 (1.3%) had recurrent TB. The recurrence rate was 341 cases per 100,000 py, 13 times higher than the TB incidence of the general population. Likelihood of TB recurrence at the 1st, 3rd and 5th year of follow-up was 0.1%, 1.4% and 1.6%, respectively. Factors associated with recurrence were HIV infection (HR: 4.7, CI: 1.4–15.7), living in the inner city district (HR: 3.9, CI: 1.3–11.8) and history of TB treatment (HR: 5.2, CI: 1.7–16.2). Genotyping results of recurrent cases were available for 6 patients (3 reinfections and 3 relapses). The rate of TB recurrence in Barcelona is low and most episodes occur within the first three years. Patients at higher risk of recurrence are co-infected with HIV, living in neighborhoods with high TB incidence or with a history of TB treatment. When available, genotyping results help determine whether the recurrence is due to reinfection or relapse.

The important increase in immigration during recent years has changed the epidemiology and control strategies for tuberculosis (TB) in many places. This study evaluates the effectiveness of intervention with community health workers (CHW) to improve contact tracing among immigrants.

Background: Little is known about recurrent tuberculosis (TB) in developed countries. The objective of this study was to determine the probability of TB recurrence and the associated risk factors among cured patients in a city with moderate TB incidence. Methods: A population-based retrospective longitudinal study was carried out in Barcelona, Spain. All patients with culture-confirmed TB and drug susceptibility testing were included between 1995 and 1997 and followed until December 2005. The authors defined recurrence as a new TB event after a patient was considered cured and had remained free of the disease for a minimum of 1 year. Kaplan–Meier and Cox regression were used in the statistical analysis. HRs with 95% CIs were calculated. Results: Among the 681 patients studied, the authors observed 29 recurrences (recurrence rate 0.53/100 person-years of follow-up). The mean incidence of TB in Barcelona from 1995 to 2005 was 36.25 cases per 100 000 inhabitants. The incidence of recurrence was 14.6 times higher in the cohort than the incidence of a first TB episode in the general population. The factors associated with recurrence at bivariate level were being male, being an immigrant, being an intravenous drug user (IDU), having human immunodeficiency virus, smoking, being an alcoholic, being in prison, and having both pulmonary and extrapulmonary TB. At multivariate level, only being an immigrant (HR 3.2, 95% CI 1.2 to 9), an IDU (HR 2.9, 95% CI 1.3 to 6.4) and male (HR 4.3, 95% CI 1.3 to 14.6) were associated. Conclusion: Having TB in the past is a risk factor for developing TB. Social policies must be implemented in populations at risk of recurrence, especially in immigrants and IDUs.

International travel and migration have been related with an increase of imported malaria cases. There has been considerable immigration to Barcelona from low-income countries (LIC) in recent years. The objective is to describe the epidemiology and to determine the trends of the disease in Barcelona.

Mortality among patients who complete tuberculosis (TB) treatment is still high among vulnerable populations. The objective of the study was to identify the probability of death and its predictive factors in a cohort of successfully treated TB patients. A population-based retrospective longitudinal study was performed in Barcelona, Spain. All patients who successfully completed TB treatment with culture-confirmation and available drug susceptibility testing between 1995–1997 were retrospectively followed-up until December 31, 2005 by the Barcelona TB Control Program. Socio-demographic, clinical, microbiological and treatment variables were examined. Mortality, TB Program and AIDS registries were reviewed. Kaplan-Meier and a Cox regression methods with time-dependent covariates were used for the survival analysis, calculating the hazard ratio (HR) with 95% confidence intervals (CI). Among the 762 included patients, the median age was 36 years, 520 (68.2%) were male, 178 (23.4%) HIV-infected, and 208 (27.3%) were alcohol abusers. Of the 134 (17.6%) injecting drug users (IDU), 123 (91.8%) were HIV-infected. A total of 30 (3.9%) recurrences and 173 deaths (22.7%) occurred (mortality rate: 3.4/100 person-years of follow-up). The predictors of death were: age between 41–60 years old (HR: 3.5; CI:2.1–5.7), age greater than 60 years (HR: 14.6; CI:8.9–24), alcohol abuse (HR: 1.7; CI:1.2–2.4) and HIV-infected IDU (HR: 7.9; CI:4.7–13.3). The mortality rate among TB patients who completed treatment is associated with vulnerable populations such as the elderly, alcohol abusers, and HIV-infected IDU. We therefore need to fight against poverty, and promote and develop interventions and social policies directed towards these populations to improve their survival.