This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
Natalia Martinez, Cesar A. Corzo, Gustavo Machado, Abel B. Ekiri, Inaki Deza-Cruz, and Joaquin M. Prada share a study showing how vehicle cleaning can combat disease spread in this week’s Science Page.
Highlights:
- Direct and indirect trucks/trailers movements impact disease transmission between farms
- Results showed high cleaning adherence in multisite systems ensuring good disease control
Background: Porcine reproductive and respiratory syndrome virus (PRRSV) continues to challenge the swine industry, particularly in multi-site production systems where animals are regularly transported between farms. These frequent movements can turn vehicles into silent disease carriers if cleaning practices are not thorough and consistent.
Materials and methods: This study utilised data from the University of Minnesota’s Morrison Swine Health Monitoring Program to investigate four PRRSV outbreaks at sow farms. The study involved analysing over 1,190 vehicle movements and more than 753 visits to wash stations before and after the outbreaks. We assessed the frequency of vehicle cleaning and its impact on the risk of disease. Through network simulations, we examined three scenarios: actual events (realistic), an ideal situation with perfect cleaning frequencies (optimistic), and a scenario with no cleaning (pessimistic).
Results: In the realistic scenario, even with good cleaning and disinfection (C&D) practices, growing farms (nursery and wean-to-finish units) were identified as potential sources of infection and sites highly vulnerable to infection spread. This shows that even strong C&D routines may not fully eliminate transmission risks on certain types of farms.
In addition, sow and gilt isolation sites were significantly better protected when vehicles followed the cleaning protocols. In the worst-case scenario, the risk of infection increased by over 7% in some cases. Interestingly, the difference between the real-world and best-case scenarios was small, suggesting that current practices are already quite effective, as long as the C&D practices follow the recommended protocols and are carried out properly.
Conclusions and implications: This research shows how even behind-the-scenes actions like vehicle cleaning can make a big difference in keeping diseases like PRRSV from spreading. This epidemiological model also offers swine producers and veterinarians data-driven insights into which farm types are most vulnerable, where to focus biosecurity efforts, and how to follow the movements and risk probabilities during an outbreak. By integrating real transport data with disease modelling, our findings support smarter, more targeted interventions, helping the industry protect herd health while maintaining efficient operations.
This study was recently published and is available online and in print in Preventive Veterinary Medicine https://doi.org/10.1016/j.prevetmed.2025.106539
Martinez, N., Corzo, C. A., Machado, G., Ekiri, A. B., Deza-Cruz, I., & Prada, J. M. (2025). Truck cleaning and disinfection, and the risk of PRRSV dissemination in multi-site pig production systems in the United States: A network-epidemiological model approach. Preventive Veterinary Medicine, 240, 106539. https://doi.org/10.1016/j.prevetmed.2025.106539