One full year of experiences with Porcine Epidemic Diarrhoea virus (PEDv) has taught the US pork industry millions of lessons, but it is still not clear which way the epidemia will go in a few months from now.
That was the key message by Dr Tom Burkgren, executive director for the American Association of Swine Veterinarians (AASV) at the PEDv Summit, held at World Pork Expo in Des Moines, IA.
Burkgren said, "What will the PEDv situation look like next fall? The truth is that if we don't learn enough of what caused it to come into the country – and why it spread, and if we don't understand what sow immunity is, then next fall and next winter it could be as bad. And I must admit that keeps me awake at night."
Burkgren said, "What we see is probably a declining trend. We like to see this being related to the virus not being stable in warmer summer months. And we like to think this is because biosecurity has been stepped up. But I'm not going to tell you that it is going to go away. Even stronger – some farms have seen a re-occurrence of the virus, eight to nine weeks post-infection. That poses questions about sow immunity."
Burkgren pointed to numerous research achievements that were made over the last 12 months. He said, "A year ago, we did not know a lot about PEDv. Now we know a tremendous lot about it. And we are talking about tremendous amounts of money being used for that. But we don't know enough yet."
He described PEDv as 'a surprising virus'. "We know how to close a herd. We have known cases of farms that have really high biosecurity standards – they simply do everything right. Still, PEDv broke out. Maybe we don't know everything there is to know."
He continued, "Similarly, I know of local farms where they did not get it – or in other cases they were back in production within three weeks."
In PED virus two strains have been identified, and so has the Swine Deltacorona Virus; one vaccine has been developed, by Harrisvaccines.