How can we distinguish a highly pathogenic PRRS strain from the rest? Is there something different in the genome of these viruses?
Great question, to the best of our knowledge, there are no repeatable/consistent genome markers or predictors of high virulence that are known at this time. Same thing for immunologic predictors of protective immune response from the pig side.
At this moment, the only reliable tool is the pig itself – observing clinical expression (respiratory signs, survivability, or growth performance).
Having said that, our group (and others) have been accumulating PRRS virus whole genome data and linking that with population-based data such as time to stability and total productivity loss following outbreaks.
We are still building the database to reach enough sample size and expect to dig more on this very topic in the near future. We will be happy to continue share as we learn more about it.
If you want to know more about highly pathogenic PRRS strain read out chapter: “Virulent strains”