AVMA News

PRRS diagnosis quicker thanks to new online tool

Reporting system is a collaborative effort among academic institutions and veterinary laboratories

Veterinary diagnostic laboratories are using a new web-based diagnostic tool to rapidly detect porcine reproductive and respiratory syndrome (PRRS), a highly contagious virus estimated to cost the U.S. swine industry more than $660 million annually.

With the support of a $1 million grant from the U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA), scientists at Iowa State University, Kansas State University, Ohio Animal Disease and Diagnostic Laboratory, Purdue University, South Dakota State University, and the University of Minnesota are using the Swine Disease Reporting System (SDRS) to rapidly detect new strains of PRRS.

The SDRS is a strategic collaboration between these six National Animal Health Laboratory Network–accredited veterinary diagnostic laboratories. The system collects, collates, and monitors diagnostic data of nine infectious agents in U.S. swine herds while keeping farm, producer, production system, veterinarian, and participant laboratory confidential. The project’s goal is to aggregate swine diagnostic data and report it through web dashboards and monthly reports that breakdown the dynamics of pathogen detection by polymerase chain reaction–based assays over time, specimen, age group, and geographical area.

Four pigs in a pen
Veterinarians and producers have a new tool to detect porcine reproductive and respiratory syndrome (PRRS), a highly contagious virus estimated to cost the U.S. swine industry more than $660 million annually.

Together, the SDRS recently launched a one-of-a-kind web-based tool called the Basic Local Alignment Search Tool, or SDRS BLAST Tool, which allows veterinarians, producers, and other users to compare genetic sequences of PRRS with those in the system.

“The launch of the SDRS BLAST Tool represents an important advancement on information technology for PRRS understanding, prevention, and control across various geographical levels,” said Dr. Andreia Arruda, associate professor at The Ohio State University College of Veterinary Medicine and chair of the American Association of Swine Veterinarians’ (AASV) PRRS Committee.

“This collaborative effort between academic institutions and veterinary labs, supported by USDA funding, underscores the collective commitment to tackling animal health challenges, empowering swine veterinarians and producers as end users,” Dr. Arruda said.

PRRSV is a devastating endemic disease. Recently, more aggressive PRRS strains have emerged, potentially increasing the economic burden of this pathogen due to increased mortality rates in the farms.

Dr. Giovani Trevisan, research assistant professor at Iowa State University, explained in an April press release, “For the first time in the swine industry, we can use private data, while keeping providers anonymous, to generate information and share it with stakeholders who can use it in the decision-making process to manage and control an economically important disease such as PRRSV.

“Therefore, the platform has the potential to rapidly inform U.S. citizens about health challenges affecting swine farms, which is critical for the sustainability and secure pork supply.”

Using retrospective data, the SDRS detected 133 new PRRS sequences from 2010-23. The majority of the new strains were detected in samples collected in Iowa, Minnesota, Indiana, and Illinois. Most of these new sequences were detected in grow-finish pigs, which highlights the importance of this age group on the ecology of PRRS and likely other pathogens. Knowing this can inform efforts to improve biosecurity and biocontainment to mitigate the risk of the emergence of new strains.

The SDRS team has been tracking the geographical spread of a particularly aggressive PRRSV strain named L1C.5. The L1C.5 emerged in 2020 in Minnesota, posing a devastating threat to affected breeding herds. Breeding herds that were naïve to PRRS went up to 10 weeks without any piglet production due to the devastating impact of this PRRS strain.

At the end of February, when the SDRS PRRS Blast tool had just been released, the L1C.5 PRRS was detected in South Carolina for the first time. The largest U.S. swine breeding inventory is located nearby in North Carolina, where this strain has never been seen before.

In addition, the SDRS Blast Tool helped identify that the South Carolina PRRS sequences had a 100% match with other sequences seen in other states that were not South Carolina’s neighboring states.

Researchers said the BLAST Tool has the flexibility to be adapted to receive sequences from other pathogens such as African swine fever (ASF). In the event of a detection of ASF in the United States, and if permitted by the USDA, participating laboratories could send the generated ASF sequences on a real-time basis to the SDRS to keep track of pathogen spread and genetic evolution.

“Providing epidemiological information to decision-makers can help in the decision-making process of disease prevention and control, safeguarding pork production and food security,” Dr. Trevisan said.

“Collaboration with industry stakeholders is critical to a timely disease response, and this project, in part through the SDRS Blast Tool, is building relationships needed on a day-to-day basis for endemic disease management,” said Dr. Michelle Colby, national program leader for animal biosecurity at NIFA. “Relationships that will be essential if we are ever faced with the need to respond to a transboundary or emerging disease within the U.S. swine industry.”