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Abstract
Statement of the Problem: Over 25 years of efforts the global TB epidemic remarkably improved in reducing suffering and death by enhancing access to diagnosis and treatment but failed to drive down tuberculosis epidemic. The goal of End TB Strategy to eliminate disease cannot be achieved if one TB case transmits and produces one or more cases among susceptible contacts. Therefore, an explicit focus on halting transmission is a critical component that is necessary for the success of End TB Strategy Goal: To understand factors driving on-going TB transmission in an urban African setting in order to expand control strategies to interrupt TB transmission at population-level. Aims: To measure the extent of TB transmission in the community by cumulative incidence of TB infection, and identify social behaviors and community-based settings associated with TB transmission Methods: We conducted a prospective, community-based cohort study of adults without TB infection in Kampala, Uganda from 2014 to 2016. All participants were retested with TST to evaluate incident infection after one year of following up. We visited participants for every 3 months to assess risk of acquiring a new TB infection and measure the amount of time spent in settings by using standardized questionnaires. Results: At least 29% of participants had recent contact with TB patients. The annual risk of infection was high (11.8%). Smokers, heavy alcohol users, and persons who contacted with TB patients before enrollment and during follow up were as high risk of getting TB infection as HIV-infected (20% per year). Being older, being men, non-religious Roman Catholic, contacting with TB patients before enrollment and during follow up, and spending time at worship centers and schools increased risk of acquiring LTBI, while attending drug shop and staying at own home lowered the risk. Conclusions: TB transmission occurs at high rate in urban African settings as high proportion of population contacted with TB patients. Smokers, heavy alcohol users, and persons who contacted with TB patients before enrollment and during follow up should be treated for TB infection. Worship centers and schools are environments that could be targeted for TB control programs.