Background. To end tuberculosis, a substantial expansion of active case-finding and tuberculosis preventive treatment is urgently needed. Furthermore, these biomedical interventions, which form the backbone of the global tuberculosis response, should be integrated with socioeconomic interventions to address the poverty-related risk factors principally driving tuberculosis incidence. This research aimed to inform the implementation and integration of these interventions for contacts of patients with tuberculosis.

Methods. The research was divided into three phases, all of which were undertaken in Lima, Peru:
i) FUNDAMENTALS. A cohort study characterising tuberculosis epidemiology and case-finding among adult contacts of patients with infectious tuberculosis. An individual-level risk score predicting tuberculosis was derived and validated in a separate cohort.
ii) CRESIPT. The score was integrated within a community randomised trial of socioeconomic supported for tuberculosis-affected households (the CRESIPT study). The impact of this intervention on access to healthcare and long-term health outcomes of contacts was evaluated.
iii) POST-CRESIPT. Experiences during the CRESIPT study informed the derivation of a household-level risk score predicting tuberculosis. This score was derived using data from one cohort and validated in a separate cohort.

Results. The first phase demonstrated that: adult contacts of patients with TB have a high and prolonged risk of tuberculosis; active case-finding can make an important contribution to tuberculosis case-finding; and tuberculosis can be predicted using a simple individual-level score. The second phase demonstrated that integrating this score with socioeconomic support achieved large increases in the proportions of contacts who completed active case-finding and tuberculosis preventive treatment; and reduced the risk of tuberculosis by approximately 40%. The third phase demonstrated that tuberculosis can be predicted using a simple household-level score.

Conclusions. The research presented in this thesis provides rigorous evidence to support a novel, transformative, and holistic approach to the management of contacts of patients with tuberculosis.