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.
We hope our US readers had a great Thanksgiving surrounded by loved ones. We are grateful that all of you keep reading us week after week and we hope we can continue providing you with valuable content for a long time!
This week, Drs. Sunil Mor and Albert Rovira from the University of Minnesota Veterinary Diagnostic Laboratory explain how we can use whole genome sequencing during a PRRS outbreak investigation.
Viral recombination is documented in PRRSv
Whole Genome Sequencing can provide the detailed information to better understand recombination and PRRSv dynamics
This is a favorite on the blog. Once a month, we are sharing with you a presentation given at the Allen D. Leman swine conference, on topics that the swine group found interesting, innovative or that lead to great discussions.
We can find all of the presentations selected from the previous years’ conferences on the blog here.
Our ninth presentation is from Dr. Kim VanderWaal, our colleague at the University of Minnesota, who gives us a glimpse into a future when producers might be able to know when their farms are at risk of disease outbreaks.
Communication between veterinarians and farm managers can help unravel patterns that might seem unique in one system.
Even though the source of APP was not determined outbreak investigation can help to find common links between sources.
A series of Actinobacillus pleuropneumoniae (APP) outbreaks involving five farms belonging to three different production companies were reported. Serotype 8 was confirmed as the source of the clinical signs in all the cases. The outbreak started with the two southernmost located farms (Company A Farm 1 and Company B Farm), followed by Company C (Farm 1) four weeks later. The distance among these growing pig sites ranged from 0.6 to 8.3 miles and the region where they are located can be considered as a high hog density area (Picture 1).
Common links between several sites were revealed after conversations among veterinarians and production managers. The main transmission route for this bacterium is introducing APP carrier pigs. In this case, it can be easily ruled out as these are sites that flow independently.
Other possibilities include indirect transmission through fomites and aerosol. Although these production companies do not share employees or tools they do have a common link in that some did share the same rendering company which could have been servicing other sites that were APP positive. As for manure removal, companies do not use the same manure removal company. One company did have the same individual doing the manure removal procedure at one site while breaking and then proceeded to the next one. Airborne transmission has been suggested as another possibility and after preliminary wind direction analyses during the outbreak dates it was inconclusive.
Molecular characterization tools such as p146 sequencing for Mycoplasma hyopneumoniae (M. hyopneumoniae) can provide insight towards investigating elimination failures or new introductions within swine herds.