Pathogen Prevalence Estimates and Diagnostic Methodology Trends in Laboratory Mice and Rats from 2003 to 2020

Area of Science:

• Veterinary Diagnostics
• Laboratory Animal Science
• Biomedical Research

Background:

• Specific pathogen-free (SPF) status is crucial for research rodents to prevent confounding variables.
• Health monitoring (HM) via laboratory testing assesses the efficacy of biosecurity measures.
• Data from Charles River Research Animal Diagnostic Services (CR-RADS) from 2003-2020 is analyzed.

Purpose of the Study:

• To summarize and analyze extensive health monitoring data for external clients.
• To identify trends in pathogen prevalence in research rodents over time.
• To evaluate the evolving role of diagnostic methodologies, particularly PCR.

Main Methods:

• Analysis of health monitoring (HM) data including direct examination, bacterial culture, serology, and PCR.
• Calculation of period prevalence estimates (%P_E) by diagnostic method and year.
• Utilized end-user business intelligence tools for data summarization.

Main Results:

• Significant reduction in prevalence of respiratory pathogens like Sendai virus.
• Persistent high prevalence of agents such as murine norovirus (MNV), Helicobacter, Rodentibacter, and parasites.
• Increasing adoption and utility of Polymerase Chain Reaction (PCR) due to its sensitivity, specificity, and broad applicability.

Conclusions:

• HM data reveals shifts in pathogen prevalence, with some agents successfully controlled and others remaining challenging.
• The rise of genetically engineered mutant (GEM) rodents may contribute to the persistence of certain pathogens.
• PCR is a critical advancement in HM, enabling earlier and more comprehensive pathogen detection.