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"PRRS requires transboundary solutions"

About 25 years after its first detection, PRRS remains a major worry for pork producers around the globe. The tenth edition of the International PRRS Symposium – and the first outside the United States – was held in May in Beijing, China. “An international disease requires a transboundary solution,” says Prof Bob Rowland, the symposium’s executive director.

Pig Progress: The previous nine editions of the International PRRS Symposium were held in the United States. What made you decide to go abroad?
Prof Bob Rowland: “The first symposium was held in 2004 in Chicago – and we have held it annually ever since. We have always called it an international symposium as we have always seen Porcine Reproductive and Respiratory Syndrome as an international problem. What we wanted to get from the beginning were international participants as well. “There has always been some consensus that we should go abroad, but so far it used to stay in the US. Then Dr Hanchun Yang, of the China Agricultural University, graciously offered to host the meeting in Beijing – this way the conference would really be international. We aim to bring it back to the US in 2014. At the end of the Beijing meeting Hans Nauwynck from the University of Ghent offered to host the meeting in Ghent in 2015.”

Surely there can’t be a better place than China to have held a PRRS symposium these days?
“Yes – there were three obvious reasons to take this event to China. First, and foremost, China is where a lot of the diseases and emerging issues come together, not just PRRS, but also for instance avian influenza lately. From an infectious disease perspective, China is an exciting place, where we can witness some very interesting diseases. “Secondly, China is where half of the world’s pigs are. “Thirdly – the country’s pig industry is growing, so it offers an opportunity for all researchers who are in China. Here at Kansas State University we get a lot of Chinese students. We can now take the knowledge to China.”

Is PRRS still the number one viral pig disease at the moment?
“Yes, we can easily call it the number one viral disease. Annually, there is between 5-10% losses in the United States due to PRRS. That is not good considering we are living in a world with narrower profit margins. In addition, for our increasing amounts of exports, we need to be more competitive. Without PRRS, the growing efficiency would be a lot higher. “PRRS is a really unique virus as it is very well adapted to modern production systems. I usually consider it to be a disease of pig populations. In the old days, there was Classical Swine Fever, affecting just the output. PRRS however is affecting a whole population, the whole system. It has an effect on the growth of the pigs but it also affects reproduction. And even in reproduction there is a two-fold effect. On one hand we see an increase in abortions, on the other it also has an effect of a longer return to oestrus. “We need to find good solutions for it, like we did earlier with PCV2, which the industry dealt with quite nicely.”

How do you look at the Chinese swine industry from a veterinarian perspective?
“I’m not really an expert on the Chinese pig situation, but I do know that the demand for pork is increasing. With the growth of income, the demand for high quality pork products rises as well. There are also growing pains. Just building big barns is not sufficient. One has to have a proper infrastructure as well. In that sense, the US sets an example. We have had a good 100 years experience in building infrastructure supporting the pig industry. It takes time to build all these parts together.”

What is your view on highly pathogenic PRRS?
“HP-PRRS is an interesting disease. There is still a lot that we don’t understand. It is highly pathogenic and we still don’t really know how it works. Also we have seen that it can phase out and disappear quickly – which is odd.

“Think of the highly pathogenic PRRS-variety ‘Lena’, which is prevalent in Eastern Europe. That has brought PRRS to the forefront of swine science in Europe again – and posed a lot of concern. Why does it continue to propagate? Why does it not seem to go away? There is still a lot for us to know about it. And it changes constantly – it is crucial for us to be seeing the new pathogenic

Looking back, what have been the major take home messages for you?
“There is a lot of creative work being done in Chinese laboratories. The oral and poster presentations by students predict a very bright picture for the future of PRRS research. There is an amazing resource of talent that is emerging from US, EU and China research labs. “Looking back, for PRRS, this event is a tectonic shift in research and education. This meeting placed every PRRS researcher in the world – from the US, EU, and China – in the same room at the same time to solve many of the same problems. PRRS is a transboundary disease that requires transboundary solutions.”



Raymond ‘Bob’ Rowland is a professor in the Diagnostic Medicine and Pathobiology department of Kansas State University’s College of Veterinary Medicine. His current research interests center on addressing fundamental problems in infectious diseases caused by emerging pig viruses. The current focus is on molecular mechanisms of diseases caused by PRRS virus and PCV2. Besides research, Rowland is actively involved in the training of graduate, undergraduate and DVM students. He received a PhD in microbiology in 1989 from the University of New Mexico School of Medicine in Albuquerque and joined Kansas State University in 2001.


Tenth PRRS Symposium: Record-breaking edition
The tenth edition of the International PRRS Symposium was held in Beijing, China, May 20-22. In total, 40 talks of which three key note, were given at the event that attracted 700 registered attendees, from 25 countries. In total 171 abstracts were submitted. The event, not only focusing on PRRS but also on PCVAD, was set up by Kansas State University in cooperation with the Chinese Association of Animal Science and Veterinary Medicine. Key topics included virus replication, protein structure and function; vaccines and immunity; viral heterogeneity and evolution; genetics; virus-host interaction (pathogenesis); and epidemiology and disease control. Another 22 travel fellowships were awarded to graduate students and postdocs from seven different countries.

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