Diabetes increases the risk of recent-transmission tuberculosis in household contacts in São Paulo, Brazil

SETTING: A cohort of household contacts of tuberculosis (TB) index cases from four public health clinics in São Paulo, Brazil.OBJECTIVE: To measure the association between diabetes mellitus (DM) among household contacts and recent-transmission TB (RT TB).DESIGN: Index TB cases (n = 263) identified from 2001 to 2002 in São Paulo, whose household contacts (n = 1383) were monitored for active TB until December 2010.RESULTS: From 2001 to 2010, there were 29 cases of RT TB among household contacts (cumulative incidence 2.1%, 95%CI 1.4-2.9). DM in household contacts was associated with RT TB (OR 3.96, 95%CI 1.33-11.79) even after adjustment for human immunodeficiency virus (HIV) status, smoking and alcohol use (adjusted OR [aOR] 3.21, 95%CI 1.01-10.19). HIV infection was also associated with RT TB (OR 6.40, 95%CI 1.40-29.40; aOR 4.81, 95%CI 0.96-24.18). Household contact DM was not associated with non-RT TB (OR 1.27, 95%CI 0.30-5.40). The time to diagnosis of TB was shorter in household contacts with and without DM (P = 0.035) and in household contacts with and without HIV (P = 0.0002).CONCLUSION: Household contact DM was associated with an increased risk of RT TB in a cohort in Brazil, lending support to the active screening of household contacts with DM for TB in Brazil.