Bovine adenovirus prevalence and its role in bovine respiratory disease complex: A systematic review and meta-analysis.

Bovine adenoviruses (BAdVs) are major contributors to the bovine respiratory disease complex (BRDC). A systematic review and meta-analysis were carried out to explore the epidemiology of BAdV across diverse cattle populations using different detection methods. The study showed a higher BAdV prevalence of 0.66 in general cattle populations using antibody detection, compared with 0.28 in cattle showing clinical signs. The study identified significant prevalence differences between BAdV-3 (0.87) and BAdV-7 (0.21) in general cattle populations. However, in clinical cattle, BAdV-3 and BAdV-7 showed similar prevalence at 0.27 and 0.32, respectively. Moreover, a high herd-based BAdV seroprevalence of 0.82 was observed. When nucleic acid detection methods were used in general cattle populations, a lower BAdV (0.05) prevalence was observed, in contrast to the higher prevalence (0.32) in cattle exhibiting clinical signs. In contrast, using antigen detection in cattle with clinical signs of disease showed a prevalence of 0.06, compared to 0.32 with nucleic acid methods, indicating detection method-specific sensitivity and specificity. The study also highlighted the role of BAdV in BRDC, particularly BAdV-3 and BAdV-7. Existing empirical evidence on BAdV epidemiology and pathobiology is scarce and requires further investigation; however, the current findings offer insights into the epidemiology of BAdV and its role in the BRDC, which could potentially inform and enhance disease control strategies.