Abstract / Description
Rodent health-monitoring programmes are essential for maintaining colony health, supporting health-related aspects of animal welfare and personnel biosafety, and providing relevant contextual information for the interpretation of experimental data. Subclinical infections may remain unnoticed while influencing animal physiology, experimental variability, and colony-management decisions. However, long-term retrospective descriptions of pathogen trends and programme-level changes in conventional animal facilities remain limited. This retrospective study aimed to describe long-term trends in microbiological findings in a conventional rodent facility, identify recurrent or emerging pathogens, and explore how observed changes over time coincided with programmatic modifications in housing, husbandry, hygiene, personnel training, and diagnostic procedures. We performed a retrospective analysis of 20 years of health monitoring (March 2006-December 2025) in a conventional neuroscience facility housing mice and rats. The dataset comprised 135, 558 diagnostic assays (pathogen-specific test records). Positivity to pathogens was defined as positives/(positives+negatives), with 95% Wilson confidence intervals. Temporal trends were tested using binomial logistic regression on yearly aggregated counts (odds ratio per year), with pathogen-level p-values controlled by Benjamini-Hochberg FDR. Genotype comparisons were restricted to binary batches (Genetically Modified vs Non-Genetically Modified), and seasonality to predefined surveillance months. Overall positivity for the presence of pathogens showed a significant decrease over years in both species (p