Swine Experts Warn PRRS is Entering a More Unpredictable and Costly Phase

DES MOINES, Iowa — One of the most closely watched scientific discussions at the ongoing World Pork Expo (WPX26) has focused on the evolving epidemiology of Porcine Reproductive and Respiratory Syndrome (PRRS), with leading swine health experts warning that the virus is becoming increasingly difficult to predict and control.

Speaking during technical sessions at the event, Dr. Nic Lauterbach highlighted emerging field observations indicating that PRRS is no longer behaving according to traditional epidemiological patterns that have guided disease management for decades.

According to Lauterbach, veterinarians and producers are now observing increasing viral virulence, a loss of the virus’s historical seasonal pattern, more sporadic and unpredictable outbreaks, and greater production losses across affected swine operations. These changes are complicating disease prevention efforts and challenging long-established assumptions regarding PRRS transmission dynamics.

The shift has significant implications for commercial pork producers. Historically, many farms have relied on seasonal disease expectations and targeted biosecurity interventions during periods of elevated risk. However, experts now suggest that PRRS surveillance and control programmes may need to evolve toward continuous, year-round monitoring, supported by enhanced biosecurity, rapid diagnostics and improved herd health management.

“Producers should recognize that PRRS risk has changed,” Lauterbach noted, emphasizing that disease preparedness can no longer be concentrated around traditional high-risk seasons.

PRRS remains one of the most economically devastating diseases affecting the global swine industry. The virus causes reproductive failure in breeding herds, respiratory disease in growing pigs, reduced growth performance, increased mortality and substantial increases in veterinary and production costs. In the United States alone, PRRS is estimated to cost the pork industry hundreds of millions of dollars annually, making it one of the sector’s most expensive endemic diseases.

The discussion at WPX26 underscores growing concern that ongoing viral evolution and changing epidemiological behavior could further increase the economic burden on producers unless surveillance systems and herd health strategies are adapted. Industry experts believe greater emphasis will be placed on continuous monitoring, molecular diagnostics, regional disease reporting and strengthened biosecurity protocols as producers seek to mitigate the impact of an increasingly unpredictable pathogen.

As global pork production continues to face pressure from transboundary diseases, feed cost volatility and evolving market conditions, the changing behavior of PRRS is expected to remain a central focus of veterinary research and swine health management in the years ahead.