Bovine tuberculosis (bTB), caused predominantly by Mycobacterium bovis, remains a major constraint to livestock productivity, zoonotic tuberculosis control, and One Health surveillance efforts. Current diagnostic strategies for bTB rely primarily on immunological assays for ante-mortem screening and post-mortem confirmation through lesion detection, histopathology, or culture. While these approaches are well established, they are inherently limited by indirect detection, delayed confirmation, and reduced sensitivity during early or subclinical infection. Importantly, definitive confirmation of bTB in live animals is frequently not possible unless characteristic pathological lesions have developed, allowing prolonged undetected transmission within herds. Advances in molecular diagnostics and non-invasive sampling strategies in human tuberculosis have demonstrated that Mycobacterium tuberculosis DNA can be reliably detected from oral surfaces, including tongue swabs, using PCR-based methods. These findings challenge conventional assumptions regarding specimen selection and highlight the diagnostic potential of alternative sampling sites. Drawing on biological and epidemiological parallels between human and bovine tuberculosis, this review critically synthesizes current knowledge on bTB etiology, transmission, and diagnostic limitations, and evaluates the rationale for investigating tongue swab–based molecular screening in cattle. The integration of tongue swab PCR as an adjunct diagnostic approach may enhance early detection, reduce reliance on lesion-dependent confirmation, and strengthen herd-level surveillance within One Health–oriented control frameworks. Rigorous field validation studies are required to define its diagnostic performance and operational feasibility in bovine populations. Keywords: Bovine tuberculosis; diagnostic limitations; early detection; molecular diagnostics; Mycobacterium bovis; non-invasive sampling; One Health; tongue swab PCR
Abel et al. (Fri,) studied this question.