Latent tuberculosis infection workflows in four primary healthcare systems in the United States

Background: Latent tuberculosis - infection (LTBI) reactivation accounts for most tuberculosis (TB) cases in the United States (U.S.). Expanding primary care LTBI services can improve detection and treatment, but real-world implementation is not well described. Objective: Describe how LTBI screening and treatment workflows are operationalized into practice in diverse U.S. primary care health systems. Design: Descriptive, multi-site study. Setting: Four U.S. primary care health systems participating in the U.S. Centers for Disease Control and Prevention (CDC) Tuberculosis Epidemiologic Studies Consortium III (TBESC-III, 2020-2022). Patients: Patients visiting any study site (N = 3,522,077). Measurements: Electronic medical record (EMR) data on patient demographics, TB test type, and results. Using narrative reporting and study documentation, LTBI care workflows were summarized by site into six domains: patient registration, TB testing evaluation, TB testing, TB disease assessment, LTBI diagnosis, and LTBI treatment. Results: Sites implemented recommended practices for testing and treatment: interferon-gamma release assays were the predominant test, and short-course rifamycin-based regimens were the primary treatment. Follow-up care practices and documentation of treatment outcomes varied. Country of birth was not consistently recorded at all sites, limiting TB screening capability based on nativity. Physician training, EMR decision-support tools, and patient education resources differed in scope and availability. Limitations: Descriptive design using self-reported workflows; may not generalize to all primary care settings or reflect physician-level variations. Conclusion: We provide a descriptive snapshot showing how LTBI care workflows varied in approach and consistency at four primary care systems with integrated LTBI services. These real-world examples may serve as templates for U.S. primary care systems seeking to expand TB testing and treatment. Primary Funding Source: U.S. Centers for Disease Control and Prevention (TBESC-III).