{
  "abstract": "Background: Tuberculosis contact investigation (TBCI) facilitates early detection of TB among household contacts. However, evidence on the additional contribution of repeat TBCI in high-burden settings remains limited. We assessed the contribution of repeat TBCI at 6 and 12 months to TB case detection in Kasama District, Zambia. Methods: We conducted a retrospective observational cohort analysis of routinely collected programme data from five purposively selected high-volume TB diagnostic facilities. Household contacts of bacteriologically confirmed TB patients notified between January 2023 and April 2024 underwent symptom-based TB screening at baseline and at 6 and 12 months. We estimated round-specific TB detection yields, the cumulative proportion diagnosed with TB, and the contribution of repeat investigations to overall case detection. Results: Among 1,250 index TB patients, 3,648 household contacts were identified and screened at baseline. TB was diagnosed in 143 (3.9%) contacts at baseline, 31 (0.9%) at month 6, and 25 (0.7%) at month 12. Overall, 199 (5.5%) contacts were diagnosed with TB across the three screening rounds, of whom 159 (79.9%) had bacteriologically confirmed disease. Repeat investigations identified 56 additional cases, representing 28.1% of all TB diagnoses. Conclusions: Repeat TBCI at 6 and 12 months identified additional TB cases beyond baseline screening, although detection yields declined across successive rounds. These findings support further evaluation of risk-based follow-up strategies and more sensitive baseline screening approaches to optimize TB case detection and resource utilization in high-burden settings.",
  "abstract_shown": true,
  "affiliations": [
    "CIDRZ: Center for Infectious Disease Research in Zambia"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 14,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "P. B. Mwaba"
    },
    {
      "name": "M. Mukupa"
    },
    {
      "name": "J. Sakala"
    },
    {
      "affs": [
        0
      ],
      "name": "I. Mwaba"
    },
    {
      "name": "D. Siameka"
    },
    {
      "name": "M. M. Maimbolwa"
    },
    {
      "name": "C. Chanda"
    },
    {
      "name": "M. Mputu"
    },
    {
      "name": "K. M. Zimba"
    },
    {
      "name": "N. Kasese-Chanda"
    },
    {
      "name": "R. Chimzizi"
    },
    {
      "name": "A. Mubanga"
    },
    {
      "name": "M. Muyoyeta"
    },
    {
      "name": "M. Kagujje"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dtx5v6h1k0sh4.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.05.26367344",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.11.05.26367344v1.full",
  "id": "dtx5v6h1k0sh4",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.11.05.26367344v1",
  "language": null,
  "licence": "CC0-1.0",
  "licence_label": "CC0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/publicdomain/zero/1.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "infectious diseases"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.11.05.26367344v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dtx5v6h1k0sh4.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T12:20:29Z",
      "native_id": "10.64898/2026.11.05.26367344",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.11.05.26367344v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:infectious diseases",
      "subfield": "infectious-disease"
    }
  ],
  "title": "Additional tuberculosis case detection through repeat household contact investigation at 6 and 12 months: a retrospective cohort study in Kasama, a peri-urban district in Zambia",
  "title_text": "Additional tuberculosis case detection through repeat household contact investigation at 6 and 12 months: a retrospective cohort study in Kasama, a peri-urban district in Zambia",
  "type": "preprint",
  "updated_at": "2026-11-08T00:21:01Z",
  "url": "https://research.draconitic.com/paper/dtx5v6h1k0sh4",
  "venue": "medRxiv",
  "versions": []
}