Pandemic H1N1, PEDV, Seneca Virus A...What is Next? By: Dr. Jim Lowe, Production Animal Consultation The pork industry has had its share of excitement over the last 5 years. Pandemic H1N1 (pH1N1) did little to pigs but disrupted exports and caused market crashes, Porcine Epidemic Diarrhea Virus (PEDV) killed thousands of pigs, shifted markets and created the highest prices and highest levels of profit for the industry on record and Seneca virus A (SVA) has been around for a long time in the US but over the last 6 months has created an outbreak across the US resulting in disruptions to marketing and the most intensive period of foreign animal disease investigations that anyone can remember. Where did these diseases come from? Are we going to see more new diseases? Is this what we should expect? All are questions that I hear on a regular basis. While none of us know the answers to those questions with certainty, understanding what has happened with both PEDV and SVA can help us understand where the industry has vulnerability and how we might be prepared for “the next” issue. The likely causes of the three outbreaks share many common factors but the origin of the outbreaks are very different and the response from both the industry and regulators has been different. These similarities and differences should help us understand how we might address the next issue before it creates significant damage on individual producers or the industry at large and should help other protein industries understand where they are susceptible to novel disease challenges. Let’s start with the differences between these outbreaks to see what we can learn. pH1N1 and PEDV were both novel (i.e., new) diseases to the US prior to the outbreak. This means that they were moved into the country highlighting the global world that we live in. Based on the best available data pH1N1 entered the country with infected people which shed the virus back to pigs. This is called a “reverse zoonosis” where an infection moves from man to animals. The bigger story is that pH1N1 was a combination of two swine origin viruses and human viruses that infected
humans. This disease is another in a long line of diseases that move between species (HIV: primates to humans; Classical Swine Influenza: birds to humans to pigs; PRRSV: rodents to pigs) to create new diseases. Controlling these kinds of disease introduction will be hard but there are many smart people working on how to detect these issues early and stop their movement. PEDV was introduced to the US sometime in 2013 on what we now think was contaminated transport “totes” for feed ingredients originating in Asia. This virus was first identified in May of 2013 but based on retrospective sample analysis had been in the country at least six months before it was identified. PEDV has been a significant disease for decades in Asia with large outbreaks in China in 2012. The introduction of PEDV demonstrates how our collective supply chain can impact our business, how little we know about our supply chain and how dependent we are on foreign suppliers to make our businesses function daily. In one investigation, on a single swine breeding herd, Carthage Veterinary Service, Ltd, Carthage, IL, found over 100 products that at least partially originated in China. While a global supply chain has been great for business by lowering costs it has created risks that as food producers we do not fully understand. SVA is different from the first two diseases we have looked at. It has been in the country for years, causing sporadic disease that is almost always self-limiting. The challenge with SVA is that it produces lesions that cannot be differentiated from Foot and Mouth Disease (FMD). What has changed this year is that there has been a sustained outbreak starting in July that has been maintained through early November. Little is known about why this outbreak started and why it appears to be waning. What we do know about all three of these diseases is that they moved across the industry very quickly and effected producers of all sizes. This disease pattern shows us how interconnected our industry is: Millions of pigs move across state lines each week, feed ingredients are common across large geographic regions, the vast majority of pigs pacdvms.com 21
