{ "abstract": "Introduction: Contact investigation (CI) is a key strategy for ensuring tuberculosis (TB) diagnosis and prompt treatment initiation. However, its implementation remains limited, particularly for people with drug-resistant TB (DR-TB). This study summarises the approaches and presents yield cascades for DR-TB CI initiatives from five high-burden countries.\n\nMethods: CIs were implemented via the Stop TB Partnership’s TB REACH Wave 9 funding cycle in Bangladesh, Ethiopia, Pakistan, Nigeria and Vietnam. Narrative data were thematically synthesised to identify shared and context-specific implementation strategies. Quantitative data included the number of index individuals with DR-TB, contacts screened and tested and TB diagnoses by drug resistance. Results were compared across countries.\n\nResults: Three CI strategies were used: (1) symptom screening (Bangladesh, Ethiopia, Nigeria), (2) parallel symptom and chest X-ray screening (Pakistan) and (3) universal molecular testing (Vietnam). These were applied in diverse settings, including nomadic, displaced and urban populations. All sites conducted CI for people newly starting DR-TB treatment but CIs were also performed for historical cohorts of people with DR-TB in some contexts. A total of 3919 people with DR-TB were eligible for CI, and CI coverage was 95.2% (n=3732). A total of 11 184 household contacts were enumerated (average of 3.0 contacts per CI), and 10 901 (97.5%) were screened. 194 people were diagnosed with TB, of whom 165 (85.1%) were bacteriologically confirmed and 89 (53.9%) had rifampicin resistance. Drug-susceptible TB and DR-TB detection rates among DR-TB contacts were 1.5% (range 0.14–3.9%) and 0.8% (range 0–3.3%), respectively.\n\nConclusion: CI outcomes for DR-TB varied across settings. These findings support the scale-up of context-adapted CI to improve DR-TB detection and care. Scaling context-specific CI, linked with contact screening, diagnostic evaluation and preventive treatment, will be critical to disrupt DR-TB transmission and achieve End TB targets.", "abstract_shown": true, "affiliations": [ "Innovation and Grants Team, Stop TB Partnership, Geneva, Switzerland", "FIT RD Social Enterprise Company Limited (FIT RD), Ha Noi, Viet Nam", "Division of Infectious Diseases, Department of Medicine, Karolinska Institutet, Stockholm, Sweden", "Friends for International TB Relief, Ha Noi, Viet Nam", "Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden", "Division of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden", "Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden", "IRD Bangladesh, Dhaka, Bangladesh", "IRD Global, Republic Plaza, Singapore", "REACH Ethiopia, Addis Ababa, Ethiopia", "SUFABEL Community Development Initiative, State, Gombe, Nigeria", "PHTB Consult, Haren, The Netherlands", "Janna Health Foundation, Adamawa, Nigeria", "DOPASI Foundation, Islamabad, Pakistan", "New Dimension Consulting (T), Dar es Salaam, Tanzania, United Republic of", "KIT Health, KIT Royal Tropical Institute, Amsterdam, The Netherlands", "KIT Royal Tropical Institute, Amsterdam, The Netherlands" ], "article_type": "research article", "arxiv": null, "author_total": 18, "authors": [ { "affs": [ 0 ], "name": "Md Toufiq Rahman", "orcid": "0000-0003-3230-7990" }, { "affs": [ 1, 2 ], "name": "Han Thi Nguyen" }, { "affs": [ 3, 4 ], "name": "Andrew James Codlin" }, { "affs": [ 3, 4 ], "name": "Luan Nguyen Quang Vo", "orcid": "0000-0002-5937-6286" }, { "affs": [ 5, 6 ], "name": "Lina Davies Forsman" }, { "affs": [ 7 ], "name": "Manzur Ul Alam" }, { "affs": [ 7 ], "name": "Shamsher Alam" }, { "affs": [ 8 ], "name": "Tapash Roy" }, { "affs": [ 9 ], "name": "Desalegn Zerihun Negia" }, { "affs": [ 9 ], "name": "Meseret Aseffa" }, { "affs": [ 10 ], "name": "Suraj Abdulkarim" }, { "affs": [ 11 ], "name": "Miranda Brouwer" }, { "affs": [ 12 ], "name": "Stephen John" }, { "affs": [ 13 ], "name": "Kinz ul Eman", "orcid": "0009-0002-6682-067X" }, { "affs": [ 13 ], "name": "Syed Karam Shah" }, { "affs": [ 14 ], "name": "Sode Matiku" }, { "affs": [ 15, 16 ], "name": "Christina Mergenthaler", "orcid": "0000-0001-9936-9446" }, { "affs": [ 0 ], "name": "Jacob Creswell" } ], "bibtex": "https://research.draconitic.com/paper/e4hwaz6b77yak.bib", "cited_by": 0, "doi": "10.1136/bmjgh-2025-021870", "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13723779/", "id": "e4hwaz6b77yak", "issns": [ "2059-7908" ], "landing_url": "https://doi.org/10.1136/bmjgh-2025-021870", "language": "en", "licence": "CC-BY-NC-4.0", "licence_label": "CC BY-NC 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "1506" ], [ "heading", "Original Research" ], [ "openalex", "2725|Tuberculosis Research and Epidemiology" ] ], "openalex": "W7224079253", "pdf_url": "https://gh.bmj.com/content/11/10/e021870.full.pdf", "pmcid": "PMC13723779", "pmid": "42951284", "published": "2026-10-28", "publisher": "BMJ Publishing Group", "ris": "https://research.draconitic.com/paper/e4hwaz6b77yak.ris", "sources": [ { "first_seen": "2026-11-04T12:22:21Z", "native_id": "PMC13723779", "source": "pmc", "url": "https://doi.org/10.1136/bmjgh-2025-021870" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2725|Tuberculosis Research and Epidemiology", "subfield": "infectious-disease" } ], "title": "Real-world multicountry programmatic assessment of contact investigation for people with drug-resistant tuberculosis: evidence from five high-burden countries", "title_text": "Real-world multicountry programmatic assessment of contact investigation for people with drug-resistant tuberculosis: evidence from five high-burden countries", "type": "peer-reviewed", "updated_at": "2026-11-05T12:20:32Z", "url": "https://research.draconitic.com/paper/e4hwaz6b77yak", "venue": "BMJ Global Health", "versions": [] }