Research compiled over the years has given pork producers better “tools in their toolbox” to combat porcine reproductive and respiratory syndrome (PRRS), says Scott Dee, DVM, director of the Swine Disease Eradication Center at the University of Minnesota.
Dee, speaking at the 2009 World Pork Expo, reviewed many of the recent advancements in PRRS control strategies that are complementary and can fit production, health status and goals of each system.
“Today more than ever before, producers can take a holistic, systematic approach to managing PRRS with greater success. Our improved understanding of the dynamics of the virus; transmission, infection, diagnosis and monitoring; and vaccination protocols has helped us provide producers with highly effective tools to turn the tide on PRRS infections,” Dee says.
Geographical information systems help producers map and analyze PRRS virus in pig sites regionally, a fundamental tool in area PRRS control programs. “Extensive mapping and modeling of PRRS status and movement now allows us to more accurately predict and track PRRS spread in a region with greater accuracy based on pig movement, flows, transportation and delivery networks, biosecurity and other patterns,” Dee explains.
Allied to area control is aerosol transmission and air filtration. “Our research as it relates to area/regional PRRS control and elimination shows that the virus can travel long distances in the air and presents a significant risk factor in the spread of the disease under certain weather conditions,” he says.
Dee's research team at the University of Minnesota has proved that the PRRS virus and Mycoplasmal pneumonia can spread via aerosols out at least 2.8 miles. “Appropriate air filtration is an essential component of an effective biosecurity program for swine-dense regions,” he notes.
On-farm assessments help managers identify various risk factors for disease in their systems. “Conducted by individual farms, risk assessments are a critical first step to uncovering historical and current management and biosecurity issues that impact PRRS infection in a system,” he notes. “Individual farm assessments can be analyzed within a specific area or region to compare PRRS status and risk and improve disease control within that region.”
Showing promise as an aid in monitoring PRRS for area control surveillance programs is the use of oral fluid diagnostic sampling. The method, developed at Iowa State University, provides an easy and effective monitoring tool. “Using a simple cotton rope, the pigs' natural chewing behavior and polymerase chain reaction (PCR) lab diagnostics, this method may be effective in monitoring not only PRRS, but porcine circovirus type 2, swine influenza virus and other diseases,” Dee says.
He also presented information on how vaccination protocols can be used to reduce transmission of PRRS virus and improve response to infections and pig performance.
“The most effective and successful PRRS control and prevention within an area requires a high degree of cooperation, coordination and collaboration within and among production systems in a region,” Dee concludes. “Fortunately, producers have a number of effective tools available to better help them determine current status, assess PRRS risk, measure and monitor infection status and improve their disease-management decision making.”
The Minnesota researcher says all these actions came to fruition in just 2-3 years, demonstrating rapid progress over a very short period of time.