Closing delivery gaps in the treatment of tuberculosis infection: Lessons from implementation research in Peru

Abstract

Background Targeted testing and treatment of TB infection to prevent disease is a pillar of TB elimination. Despite recent global commitments to greatly expand access to preventive treatment for TB infection, there remains a lack of research on how best to expand preventive treatment programs in settings with high TB burdens. Methods We conducted implementation research in Lima, Peru, around a multifaceted intervention to deliver TB preventive treatment to close contacts of all ages, health care workers, and people in congregate settings. Key interventions included use of the interferon gamma release assay (IGRA), specialist support for generalist physicians at primary-level health facilities, and treatment support by community health workers. We applied a convergent mixed methods approach to evaluate feasibility and acceptability based on a care cascade framework. Findings During April 2019-January 2020, we enrolled 1,002 household contacts, 148 non-household contacts, 107 residents and staff of congregate settings, and 357 health care workers. Cumulative completion of the TB preventive care cascade was 34% for contacts <5 years old, 28% for contacts 5–19 years old, 18% for contacts ≥20 years old, 0% for people in congregate settings, and 4% of health care workers. IGRA testing was acceptable to adults exposed to TB. Preventive treatment was acceptable to contacts, but less acceptable to physicians, who frequently had doubts about prescribing preventive treatment for adults. Community-based treatment support was both acceptable and feasible, and periodic home-visits or calls were identified as facilitators of adherence. Conclusions We attempted to close the gap in TB preventive treatment in Peru by expanding preventive services to adult contacts and other risk groups. While suboptimal, care cascade completion for adult contacts was consistent with what has been observed in high-income settings. The major losses in the care cascade occurred in completing evaluations and having doctors prescribe preventive treatment.

Assessing the quality of tuberculosis care using routine surveillance data: a process evaluation employing the Zero TB Indicator Framework in Mongolia

“…This compares favourably to the 20%–53% who completed contact investigation in prior studies, and the number needed to screen of 13 was far below the 56 reported in a prior systematic review 34 35 49 50. Nevertheless, over half of child contacts eligible for TPT did not start it, similar to results reported elsewhere,50–52 and the likelihood of initiation decreased substantially with increasing age of index patients. In a prior systematic review,36 a low perceived risk of active TB for one’s children was among the most frequent reasons for low uptake, emphasising the need for personalised education and counselling to address parental concerns.…”

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“…By the time a diagnosis is made, household contacts have already been exposed to the patient’s infection, and the likelihood of contact infection decreases rapidly when treatment is initiated. Even in cases of patients who have MDR-TB or XDR-TB, community-based treatment models have been successfully implemented in a variety of settings [ 150 - 152 ]. - Isolation or detention should be limited to exceptional circumstances when the patient is: contagious, and refuses treatment and all reasonable measures to achieve compliance have been attempted with unsuccessful outcome.…”

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“…The TB care cascade has been identified as a framework for measuring the quality of TB care (Subbaraman et al, 2020). It includes case detection, contact detection, diagnosis, linkage to care, case retention, and post-treatment follow-up (Yuen et al, 2021) (Amisi et al, 2021). The cascade provides methods to quantify gaps in the TB cascade (Subbaraman et al, 2019).…”