ABSTRACT
SETTING: Observational cohort study in Lima, Peru. OBJECTIVE: To determine the association between exposure to a smoking tuberculosis (TB) case and latent tuberculous infection (LTBI). METHOD: Between September 2009 and August 2012, we identified 2132 patients with drug-susceptible TB and their 2054 child household contacts. Data were collected on active and secondhand smoking status and other risk factors for infection specific to the index case, the household and the exposed contacts. Contacts underwent a tuberculin skin test (TST) to determine their tuberculous infection status at baseline, 6-month and 12-month follow-up. We estimated the association between exposure to a smoking index case and LTBI using a modified Poisson regression model. RESULTS: The 21 children (age â©¿15 years) exposed to smoking index TB patients were more likely to be TST-positive at baseline (RR 2.64, 95%CI 1.78-3.91), by 6 months (RR 1.91, 95%CI 1.40-2.60) and by 12 months (RR 1.48, 95%CI 1.07-2.06), than those who were not exposed. TST positivity among children at these time points did not vary with secondhand smoke exposure. CONCLUSIONS: TB patients who smoke may be more likely to transmit infection to their contacts. Interventions designed to reduce smoking among TB patients may minimise further spread of the disease.
Subject(s)
Latent Tuberculosis/epidemiology , Smoking/epidemiology , Tobacco Smoke Pollution , Tuberculosis/transmission , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Contact Tracing , Female , Follow-Up Studies , Humans , Infant , Latent Tuberculosis/diagnosis , Male , Middle Aged , Peru/epidemiology , Poisson Distribution , Risk Factors , Time Factors , Tuberculin Test , Young AdultABSTRACT
We examined the spatiotemporal distribution of laboratory-confirmed multidrug-resistant tuberculosis (MDR TB) cases and that of other TB cases in Lima, Peru with the aim of identifying mechanisms responsible for the rise of MDR TB in an urban setting. All incident cases of TB in two districts of Lima, Peru during 2005-2007 were included. The spatiotemporal distributions of MDR cases and other TB cases were compared with Ripley's K statistic. Of 11,711 notified cases, 1187 received drug susceptibility testing and 376 were found to be MDR. Spatial aggregation of patients with confirmed MDR disease appeared similar to that of other patients in 2005 and 2006; however, in 2007, cases with confirmed MDR disease were found to be more tightly grouped. Subgroup analysis suggests the appearance of resistance may be driven by increased transmission. Interventions should aim to reduce the infectious duration for those with drug-resistant disease and improve infection control.