Tuberculosis (TB) is a global public health threat, which is driven by social factors, including poverty, inadequate housing, malnutrition, and substance use. In the United States (US), TB disproportionately impacts homeless populations. When compared to the general population, homeless persons have a 10-fold increase in TB incidence. Lack of stable housing and living in congregate settings are predisposing factors for TB Infection (TBI). Homeless persons who develop active TB disease are also at higher risk of death during TB treatment due to mental illness and substance use. Even one TB case among a homeless person can easily lead to widespread TB transmission due to crowded, poorly ventilated, and congregate living situations. Therefore, an extensive public health response is needed for each case of infectious TB disease that develops among homeless persons.

Given the significant public health impact of TB among homeless persons, development of effective interventions to prevent TB among homeless persons that are theoretically-based and advance science in the area of best adherence strategies to minimize these health disparities can lead to significant benefits for patients and further reduce the disparity in TB rates between homeless and housed persons. While adherence to traditional TBI treatment with 6 to 9 months of isoniazid (INH) has been dismal, over the last few years, a promising treatment option in form of a 12-dose combination therapy (3HP; rifapentine \[RPT\] plus isoniazid \[INH\]), delivered once weekly as directly observed therapy (DOT), has achieved treatment completion rates of 82%. However, homeless populations who are at high risk for TBI have complex, multi-dimensional barriers to TBI treatment adherence. Thus, TBI treatment programs in this population have yielded marginal results of 65% completion to date. Among homeless persons, health disparities are accentuated by additional barriers to TBI treatment adherence, including substance use, mental disorders, and unstable housing.

Given the complex factors that affect TBI treatment adherence among homeless persons, the research team developed a theoretically-based novel model of care that has been successfully investigated in other disadvantaged populations. This model involves understanding the behavioral, psychological, and environmental influences on health and developing culturally-tailored interventions to reduce health disparities, and promote health. By engaging nurses, physicians, and community health workers (CHW), the investigators have developed a team-based approach to better understand and support medication adherence by engaging individuals as active partners in managing their own health. This scientific contribution has the potential to be highly significant as new models of care are being proposed to improve timely entry, engagement and retention in care, and supportive services for homeless persons and other vulnerable populations affected by complex health disparities impacting treatment adherence. The pilot study builds on the investigators' extensive three decades of research with homeless persons in improving health, including TBI treatment adherence, HBV vaccination, and adherence to HIV therapy.

This study will assess the impact of the TBI program that the investigators have developed, as a single arm intervention study, among 76 eligible TBI homeless adults on completion of 3HP treatment, decrease in drug and alcohol use, improved access to care and mental health, and shelter stability. Completion of 3HP will be compared to a minimum standard completion rate of 65%. This small pilot will generate the effectiveness data for a future R01 application to evaluate the intervention in a definitive randomized-controlled trial (RCT).