Pseudorabies Resources: Latest PRV Fact Sheet (Updated June 2024) & Additional PRV Resources/Links & Statement
Pseudorabies Resources: Latest PRV Fact Sheet (Updated June 2024) & Additional PRV Resources/Links & Statement
The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments.
The Swine Health Information Center, along with our US pork industry partners the National Pork Producers Council, National Pork Board, and American Association of Swine Veterinarians, are closely monitoring the recent detection of antibodies to pseudorabies virus in small swine herds in Iowa and Texas.
Find the SHIC PRV fact sheet here.
According to the USDA Animal and Plant Health Inspection Service (APHIS), the detection involves a limited number of animals tied to a known risk factor—exposure to feral swine. In a press release, the Iowa Department of Agriculture and Land Stewardship wrote, “The small commercial swine facility in Iowa received swine from the Texas herd in recent months. The Texas herd was housed outdoors with potential contact to feral swine. Though pseudorabies was eliminated from United States commercial swine herds in 2004, pseudorabies is still found in wild or feral swine populations, which remain a potential threat of exposure for domestic pigs.”
Federal and state animal health officials have acted quickly to contain the situation, including the depopulation of affected animals and the establishment of surveillance zones.
NPPC’s CEO Bryan Humphreys said, “We can say with confidence that consumers can continue eating and enjoying US pork products and that our pork supply remains safe thanks to the biosecurity protocols that are already in place. The officials in Iowa and Texas are administering the safety response protocols that we’ve talked about and put in place the last 20 years to ensure a rapid, effective disease response plan.”
Outdoor or transitional herds with potential exposure to wild pigs carry increased risk, and NPPC Director of Animal Health Dr. Anna Forseth noted that since PRV eradication, “We have seen an occasional case pop-up in non-commercial herds that have access to feral swine.”
SHIC emphasizes that it remains safe to eat pork, as pseudorabies does not present a food safety concern. In addition, this detection is not considered a risk to human health.
On this episode of SHIC Talk, Dr. Teng Teeh Lim shares insights from his Wean-to-Harvest Biosecurity Research Program project on novel entry systems. Joining him for the discussion are SHIC Associate Director Dr. Lisa Becton and our host, Barb Determan. Dr. Lim is an Extension professor and engineer at the University of Missouri.
Click here to listen to SHIC Talk.
Click here for the industry summary of Dr. Lim’s research report.
Program review includes details on deliverables
Launched in 2015 with Pork Checkoff funding, the Swine Health Information Center carries out a mission to protect and enhance the health of the US swine herd. Over the 10 years of the Center’s existence, deliverables to the pork industry have fulfilled that mission and paved the way for continued success of delivering key information to producers who fund its programming.
Read the Swine Health Information Center 10 Year Program Review here.
From the review:
SHIC effectively balances practicality with innovation to advance disease prevention, preparedness, and response. Over the past decade, its network of stakeholders, partners, and program deliverables has steadily expanded, strengthening its ability to serve the US pork industry and protect swine health. With a deliberate focus on meeting the needs of pork producers, SHIC maintains an intentionally agile and responsive structure—enabling rapid action on emerging threats while ensuring clear accountability for outcomes.
Collaboration remains central to SHIC’s approach. The organization works closely with swine industry associations, academic institutions, veterinary diagnostic laboratories, and government agencies. While each partner brings distinct priorities, all share a common mission: safeguarding swine health and advancing the US pork industry. This coordinated approach maximizes resources, reduces duplication, and fosters a culture of shared responsibility rather than competition.
Stewardship of financial resources is equally critical to SHIC’s success. By leveraging partnerships, maintaining lean operational overhead, and pursuing additional funding opportunities—such as collaborations with the Foundation for Food & Agriculture Research—SHIC extends the impact of its investments. This disciplined approach enables the organization to deliver consistent, high-quality results while providing a strong return on investment to the Pork Checkoff.
A Swine Health Information Center-funded study aimed to develop and validate capture probe-based enrichment for whole genome sequencing (WGS) of PRRSV. Led by Dr. Leyi Wang at the University of Illinois Urbana-Champaign, the project sought to improve the diagnostic performance of PRRSV WGS through the evaluation of a capture method that acts as a genetic magnet to pull viral material out of complex samples. Study results demonstrate that the enrichment method increased PRRSV genome coverage in oral fluids, processing fluids, lung tissue, and serum, consistently capturing >90% of the whole genome. Higher genome recovery using convenient, non-invasive sample types provides more accurate diagnostic results. The validated capture enrichment-based method for WGS enables faster identification of new variants, better differentiation between vaccine and wild-type strains, and more precise biosecurity decisions to protect herd health.
Read the industry summary for study #24-030 here.
WGS of PRRSV is a commonly used diagnostic tool for genotyping, providing significantly higher discriminatory power than ORF5 sequencing and improving viral genomic surveillance. PRRSV WGS has been growing as the preferred approach over traditional ORF5 sequencing because it captures the entire genome, whereas ORF5 sequencing captures only about 4% of the genome. Although WGS provides a complete genetic fingerprint of PRRSV, its sensitivity is often insufficient in commonly collected farm samples, such as oral fluids and processing fluids, which may have low viral loads. To address this limitation, the overarching goal of this project was to develop and validate capture probe-based enrichment for WGS of PRRSV in different sample types, including serum, lung, oral fluids, processing fluids, and tongue tip fluids.
Objectives of the study described herein include: 1) capture probe design and optimization by using over 28,000 PRRSV complete and partial genomic sequences available at the GenBank database; 2) measure sensitivity of the capture probe method through serial dilutions of available PRRSV-1 and PRRSV-2 isolates; 3) investigate clinical applications and validation through processing PRRSV-positive clinical samples and using for sequencing with capture probe enrichments. While amplicon-based methods are common for other viruses, they are poorly suited for PRRSV due to its high mutation rate and frequent genomic rearrangements. Probe-based methods offer a more robust alternative due to the increased tolerance of genetic diversity and lack of requirement for precise sequence matches to detect new variants.
A total number of 28,721 PRRSV complete and partial genomes were downloaded from GenBank, containing 1,604 complete or near complete-genomic sequences and 27,117 partial genomic sequences, that were utilized for probe selection and development. Sensitivity measurements for capture probe enrichment of PRRSV WGS utilized PRRSV laboratory strains (three North American strains 11604, PA8, VR2332, one EU strain Lelystad) which had been previously sequenced and serially diluted for evaluation. Clinical application and validation of the new technique was evaluated using 110 swine samples (30 serum samples, 33 processing fluids, 24 oral fluids, 23 lung tissues) for both probe-capture based enrichment and non-enrichment-based sequencing.
For laboratory isolates, the probe capture enrichment method effectively enhanced genome coverage, ranging from 2.6% to 95%, and achieved >90% genome coverage for RNA with Ct values up to 29.8 for three PRRSV-2 strains (11604, PA8, and VR2332). For the PRRSV-1 strain (Lelystad), the genome coverage ranged from 2.2% to 32.5%, with >90% genome coverage for samples with Ct values up to 30.2.
Results demonstrated a significant breakthrough on clinical samples: the enrichment method increased PRRSV genome coverage by nearly 46% in oral fluids, 32% in processing fluids, 25% in lung tissue, and 24% in serum. It consistently captured >90% of the whole genome even at lower viral loads (Ct 26–27) for serum, processing fluids, and lung tissue. Even in samples with Ct values as high as 33.8, enrichment significantly boosted data recovery. When probe enrichment was combined with prior ribosomal RNA (rRNA) removal in tissue samples, further enhancement of PRRSV genome coverage occurred. The data demonstrates that probe capture-based enrichment significantly increases PRRSV WGS and genome surveillance.
Improvement in PRRSV WGS can result in higher genome recovery when using convenient, non-invasive population-based sample types. The evaluation of capture probe-based enrichment demonstrates a significant advancement in the industry’s ability to monitor PRRSV and other viral swine diseases, particularly in challenging sample types common in modern production systems. Enhancing diagnostic capabilities to improve accurate detection of pathogens in swine samples aligns with SHIC’s efforts for surveillance and discovery of emerging diseases.
A Swine Health Information Center-funded study aimed to develop a sensitive and cost-effective NGS method for detecting viral pathogens in swine samples. Led by Dr. Leonardo Cardia Caserta at Cornell University, the project developed an alternative method for enriching viral sequences in swine biological samples when conventional enrichment methods are not feasible. By removing host and bacterial genetic material from samples, there was improved detection sensitivity and percent genome coverage of several viruses. The novel sequencing method detected viruses from 35 genera across 250 swine respiratory samples. Development and validation of diagnostic methods support earlier detection of emerging viruses and strengthens disease surveillance in the swine industry.
Read the industry summary of study #24-012 here.
Emerging infectious diseases pose an ongoing risk to the US pork industry, making early detection critical for protecting herd health. While PCR tests are fast and accurate, they only detect known pathogens, leaving new or mutated viruses often undetected. NGS offers broader detection without prior pathogen knowledge, but its routine use is limited by low viral signal in samples and high costs. One of the primary factors contributing to low sensitivity of NGS is the abundance of host and other non-target sequences in clinical samples.
Therefore, the objectives of the study herein included 1) to develop and optimize host and bacterial ribosomal RNA depletion procedures to increase sensitivity of NGS for viral disease surveillance in swine; and 2) to evaluate and establish cost-effective NGS procedures for emerging viral disease surveillance in swine.
In this study, a procedure was developed that removes host and bacterial ribosomal RNA from samples before sequencing, allowing viral genetic material to be more easily detected. Researchers evaluated an rRNA depletion–based enrichment method using biotinylated probes and streptavidin-coated beads to improve viral detection in swine respiratory samples, particularly when enzymatic pre-treatments are not feasible due to the use of nucleic acid preservation media.
A total of 250 samples were tested in this study, including samples known to be positive for porcine astrovirus 4 (PAstV4), porcine parainfluenza virus 1 (PPIV1), porcine hemagglutinating encephalomyelitis virus (PHEV), PCV2, PRRSV, and SVA, as well as samples known to be negative for these emerging pathogens. Application of the new method enabled detection of viruses from 35 genera in the clinical swine respiratory samples. Viruses with single-stranded DNA genomes represented the most viral reads, including parvoviruses and torque teno viruses, which may indicate a bias towards viruses with small DNA genomes. However, RNA viruses such as pestiviruses and pegiviruses were also detected and resulted in high genome coverage, demonstrating the ability of this method to detect RNA viruses.
Targeted analysis of select viruses, including porcine parvovirus 4 (PPV4), porcine parvovirus 6 (PPV6), porcine circovirus 3 (PCV3), and atypical porcine pestiviruses (APPV), demonstrated improved genome coverage following rRNA depletion. An exogenous mengovirus control confirmed consistent viral recovery across samples. While enzymatic cocktail pretreatment achieved higher sensitivity for some RNA viruses such as PRRSV and SVA, the probe-based depletion method showed strong performance for DNA viruses. This method has potential as a cost-effective approach for unbiased viral surveillance and detection of emerging pathogens in swine.
The method developed here allows NGS library preparation directly from the extracted nucleic acid, removing the need to re-extract the sample and decreasing hands-on processing time. Nucleic acid that has already been extracted for a PCR test, for example, can be used directly for metagenomic sequencing using the rRNA depletion method developed in this study. The approach improved the detection and genome coverage of several viruses and demonstrated strong performance for DNA viruses. With an estimated cost of $31.54 per sample, this novel and cost-effective method shows promise for improved detection of emerging viruses through NGS.
Despite the successful sequencing of a wide range of RNA and DNA viral genera, further optimizations are still necessary to increase the detection sensitivity for RNA viruses such as PRRSV and SVA. Additionally, optimization to reduce the cost per sample is needed. Continued development of this protocol will lead to a streamlined workflow and a highly sensitive method for unbiased detection of emerging viruses in swine.
As one of the Swine Health Information Center’s most accessed resources, swine disease fact sheets provide specific information on emerging and re-emerging pathogens. Fact sheets on PCV3, PAstV, and FMDV have recently been updated and published. New information encompasses disease outbreak demographics and impacts, virology and surveillance strategies, and incorporates peer-reviewed research results addressing multiple components of disease management. A key component of SHIC’s mission is to generate and communicate information for prevention, preparedness, mitigation, and response efforts for emerging swine disease threats. Providing current and up-to-date information through the curation of swine disease fact sheets supports this mission.
SHIC’s fact sheet informational framework is supported by an in-depth literature review for each respective pathogen. Each section presents pathogen-specific information such as importance to the pork industry, public health impacts, epidemiology, pathogenesis, diagnostic detection, clinical presentation, and treatment for swine, as well as steps for prevention and control. Each fact sheet covers a disease-causing agent with pathogen-specific information.
PCV3 has been associated with clinical signs similar to those caused by porcine circovirus 2, a major swine pathogen. However, many infections are subclinical, co-infections are common (including with PCV2), and PCV3 pathogenicity studies have yielded mixed results. PCV3 is considered an emerging swine pathogen with potential economic importance. The PCV3 fact sheet provides new details describing the differences between PCV2 and PCV3, including clinical presentation and diagnostic criteria for PCV3-associated disease. Implications for surveillance, control measures, and potential vaccine strategies to mitigate disease are also included.
The PAstV fact sheet describes the various lineages that are known to circulate in US swine herds, with PAstV types 1, 2, and 4 being most commonly reported. Their roles as primary pathogens are not fully clear. The virus has been linked to gastrointestinal, neurological, and respiratory disease in pigs; however, PAstV has also been found in healthy animals and co-infections are common. Recent research has confirmed that PAstV-4 can be detected in the upper respiratory tract of clinically ill pigs and can cause tracheitis and bronchitis in piglets. Further research is needed across all aspects of this virus to better understand and prevent PAstV infection.
FMD is a highly contagious vesicular disease of cloven-hoofed animals, including cattle and swine. The US has been negative for FMDV since the last reported case in 1929. In endemic areas and during outbreaks, FMD causes production losses and impacts on international trade. More recently, FMD has been detected in countries that have been negative for decades including Germany, Hungary and Slovakia. There are seven serotypes of FMDV (A, O, C, SAT1, SAT2, SAT3, Asia 1). Recent detection and rapid spread of SAT1 and SAT2 noted in the April 2026 SHIC Newsletter, raise concerns regarding potential changes in introduction and transmission risks across the globe. The new FMD fact sheet highlights the history of the virus, viral characteristics, epidemiology, and immunity. The fact sheet reiterates that FMD should be considered a significant global pathogen for livestock and the changing transboundary routes of transmission could pose a risk to US swine.
Providing publicly available, science-based fact sheets supports SHIC’s mission of minimizing the impact of emerging disease threats through coordinated communication of key resources and improving swine health information.
All SHIC swine disease fact sheets can be found here.
The Swine Health Information Center supports forward-looking research that fulfills its mission to strengthen the industry’s ability to detect and respond to emerging disease threats. A recent study published in March 2026 in the journal Pathogens, led by principal investigator Dr. Kim VanderWaal at the University of Minnesota, directly addresses that mission by advancing knowledge of PRRSV-2 strains across countries in North America. Understanding routes for transboundary spread of endemic viruses such as PRRSV-2 helps inform emerging disease risks and mitigation strategies.
The full study can be accessed in the journal Pathogens here.
PRRSV-2 remains one of the most economically significant diseases affecting swine production globally, with substantial impacts on productivity, animal health, and international swine trade. This study provides one of the most comprehensive analyses to date of PRRSV-2 genetic diversity in Canada, while also offering critical insights into transboundary dynamics between Canada and the US. By analyzing more than 3,000 viral sequences collected over a 24-year period in five Canadian provinces, this research delivers a clearer picture of how the virus evolves, spreads, and persists across borders.
A key contribution of the study is its demonstration of how disease data availability can expand the understanding of disease dynamics. Historically, there were fewer publicly available PRRSV-2 sequences available from Canada for comprehensive analysis. The previous use of the lineage and sub-lineage classification was based on lineages established using sequences from before 2008, which differs from the current classification system accounting for more recent viral diversity. By significantly expanding the dataset, this research helps close that gap and provides a stronger foundation for future work. It also highlights the ongoing need for enhanced genomic surveillance, particularly in underrepresented regions.
The identification of previously unrecognized genetic diversity within PRRSV-2 populations in Canada is a central finding of the analysis. While 13 known sub-lineages were detected, approximately one-third of the sequences could not be assigned to any known sub-lineage. Through detailed phylogenetic analysis using global reference sequences, these unclassified viruses were grouped into four distinct clades. The four clades had genetic distances >9.5% from the recognized sub-lineages, leading to the identification of two novel lineage designations (sub-lineages 1K and 1L) while the other two clades were rare and last detected in 2021. These newly defined groups are highly divergent from previously known sub-lineages and have circulated in Canadian swine populations for decades, highlighting how much viral diversity remains to be fully characterized.
The discovery of these novel lineage groups is more than a taxonomic update. It provides practical advancements for surveillance and disease management. Accurate classification enables veterinarians, producers, and researchers to better track virus movement, understand epidemiological connections, and implement more targeted control strategies. The study also expands the variant classification system used in the US, aligning Canadian data with existing frameworks to improve communication and coordination across borders.
The forensic analysis reconstructing cross-border transmission histories reveals that several sub-lineages—including 1C, 1H, 1I, 1K, and 1L—originated in Canada, and sub-lineages such as 1A, 1B, and 1E were found to originate in the US and later enter Canada. These findings underscore the bi-directional nature of PRRSV-2 movement, although many transmission patterns were predominantly one-directional depending on lineage. Canada and the US maintain one of the most integrated swine trade relationships in the world, with millions of live pigs moving between the two countries annually. This movement can create opportunities for transboundary PRRSV-2 dynamics.
The data provides evidence for existing variation in transmission of different sub-lineages across borders. Some lineages had limited exchange, suggesting geographic structuring and possible containment through biosecurity measures, while others demonstrated more frequent transboundary movement, including repeated introductions and re-introductions between countries. Notably, sub-lineage 1K appears to have emerged in Canada and more recently spread into the US, though it has not yet become widely established. The detection of this recent introduction was only possible due to the new genetic classification system adopted by veterinary diagnostic labs in the US.
These findings offer important insights for guiding targeted surveillance and biosecurity strategies aimed at preventing the cross-border introduction of PRRSV-2 variants not yet detected in either country. By identifying where lineages originate and how they move, stakeholders can better focus monitoring and prevention strategies, particularly at national borders and in high-traffic trade corridors. Improvements in biosecurity protocols and practices, especially those implemented after the early 2000s, may be influencing more recent patterns of viral spread, as much of the inferred transmission between countries happened before the most recent decade.
From a broader perspective, the study illustrates the value of SHIC-funded research in advancing innovation. By supporting large-scale genomic analysis and the development of new classification tools, SHIC enables the industry to stay ahead of evolving disease threats. The ability to detect emerging, novel lineage groups and understand their transboundary movement is essential for protecting herd health and maintaining the resilience of the North American swine industry.
Ultimately, this research reinforces a key disease management principle: pathogen transmission does not stop at national borders. PRRSV-2 is a dynamic, evolving pathogen shaped by animal movement, trade, and local conditions. Continued collaboration, data sharing, and investment in research will be critical to staying ahead of its impact and translating lessons learned to the next emerging disease.
Reference:
Herrera da Silva JP, Paploski IAD, Charette R, Dufresne L, Messier S, Bolduc J, Kikuti M, Pamornchainavakul N, Corzo CA, VanderWaal K. Phylogenetic Lineages of PRRSV-2 from Canada Reveal Patterns of Transboundary Spread and Two Novel Sub-Lineages in North America. Pathogens. 2026; 15(4):346. https://doi.org/10.3390/pathogens15040346
The Swine Health Information Center partnered with the Foundation for Food & Agriculture Research and the Pork Checkoff in 2024 to fund a $4 million research program to enhance prevention, preparedness, mitigation, and response capabilities for H5N1 influenza in the US swine herd. As an outcome from one H5N1 funded project, a recent article, “How new approach methods are reshaping virology research,” was published in the March 2026 Journal of Virology. The article highlights how new approach methods (NAMs) are transforming virus research and offers important insights in support of SHIC’ goals to advance innovative tools and address emerging threats such as H5N1.
The complete article can be found here in the Journal of Virology.
Led by principal investigator, Dr. Cody Warren, Department of Veterinary Biosciences, The Ohio State University, the study’s central theme is the development and application of advanced in vitro systems that better replicate real-world viral infections. Highlighted technologies include air-liquid interface cultures, precision-cut lung slices, and organoids which allow researchers to model respiratory infections in ways that closely mimic natural disease processes.
This work underscores a broader scientific shift away from traditional animal models toward emerging technologies that are scalable, laboratory-based and computer driven. Through the SHIC/FFAR/NPB H5N1 Risk to Swine Program, research projects are helping to actively accelerate these technologies for further benefits to swine health and pork producers. For influenza viruses like H5N1, which pose risks to swine and human health, such models are particularly valuable for helping to understand characteristics such as cross-species transmission, tissue tropism, and pathogenicity. These systems preserve key structural and functional characteristics of tissues, enabling studies on how viruses infect hosts, replicate, and trigger immune responses. Relevant to pork producers and swine veterinarians, this can provide key knowledge for management of influenza viruses.
Swine health research contributes to innovation by supporting the development and refinement of these technologies for animal health applications. By investing in research that adapts or extends NAMs to swine and agricultural contexts, SHIC helps bridge the gap between human biomedical advances and livestock disease management. This includes improving experimental consistency, expanding access to high-quality biological models, and enabling earlier, more precise detection of emerging pathogens.
As outlined in the publication, another key advancement is the use of renewable cell systems such as those derived from induced pluripotent stem cells (iPSCs). These systems provide a consistent, scalable source of biologically relevant cells, helping to overcome limitations associated with donor variability and tissue availability. They also allow for genetic manipulation, enabling targeted investigation of host-virus interactions. For emerging influenza strains like H5N1, this capability is critical for identifying host susceptibility factors and evaluating potential intervention strategies. It is important that these tools are adapted to research on swine health for application to US pork production.
The article also emphasizes the growing role of computational biology as a component of modern virus research. Computer models have the capability to predict viral behavior, identify potential therapeutics, and simulate outbreak dynamics. The models are powered by large datasets and artificial intelligence, reducing the time and cost associated with traditional experimental methods. In the context of H5N1, computational tools can help forecast mutation patterns, assess transmission risk, and inform surveillance strategies. SHIC-funded initiatives that incorporate data-driven approaches contribute to a more proactive and predictive disease management framework, strengthening preparedness across the pork industry.
Importantly, the study highlights that while NAMs offer significant advantages, they are most effective when integrated into a broader, tiered research strategy. Early-stage screening and hypothesis generation can be conducted using computational and in vitro systems, followed by targeted validation in whole-animal models when necessary. This balanced approach can improve efficiency while maintaining scientific rigor.
NAMs may enable faster identification of emerging swine viruses, improve understanding of virus-host interactions, and help evaluate vaccines and therapeutics. For the swine industry, these advancements can translate into earlier detection of threats like H5N1, more effective surveillance systems, and enhanced capacity to mitigate disease impacts.
Projects funded through the SHIC/FFAR/NPB H5N1 Risk to Swine Research Program are helping to fill knowledge gaps on H5N1 for the US pork industry while also supporting innovation in new approach methods for virus research. Through its collaborative funding and strategic focus, SHIC’s funding of applied research helps to ensure that such methodologies are not only investigated but also translated into practical tools and protocols for industry use on real-world challenges. Next-generation technologies help to strengthen the industry’s ability to detect, understand, and control emerging swine diseases for the protection of US herd health.
Foundation for Food & Agriculture Research
The Foundation for Food & Agriculture Research (FFAR) builds public-private partnerships to fund bold research addressing big food and agriculture challenges. FFAR was established in the 2014 Farm Bill to increase public agriculture research investments, fill knowledge gaps and complement the U.S. Department Agriculture’s research agenda. FFAR’s model matches federal funding from Congress with private funding, delivering a powerful return on taxpayer investment. Through collaboration and partnerships, FFAR advances actionable science benefiting farmers, consumers and the environment.
Swine Health Information Center
The Swine Health Information Center, launched in 2015 with Pork Checkoff funding, protects and enhances the health of the US swine herd by minimizing the impact of emerging disease threats through preparedness, coordinated communications, global disease monitoring, analysis of swine health data, and targeted research investments. As a conduit of information and research, SHIC encourages sharing of its publications and research. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Megan Niederwerder at [email protected] or Dr. Lisa Becton at [email protected].
Reference:
Liu M, Faris JG, Panfil AR, Warren CJ. 2026. How new approach methods are reshaping virology research. J Virol 100:e01326-25. https://doi.org/10.1128/jvi.01326-25
This month’s Domestic Swine Disease Monitoring Report highlights several key findings. In April, PEDV case positivity remained outside the expected range; however, overall case positivity continued to decline following the March decrease. PDCoV case positivity has continued an upward trend since October 2025; while wean-to-market case positivity declined slightly from March, adult/sow farm case positivity has continued to increase, with overall PDCoV activity above expected levels. PRRSV overall case positivity had a modest upward trend, with wean-to-market case positivity increasing to nearly 46% in April, the highest April positivity observed over the past decade. IAV overall activity showed an uptick in April, with adult/sow farm case positivity declining since February, while wean-to-market case positivity increased over the same period, reaching 43% in April. This month’s bonus page provides an update on production impacts associated with the PRRSV 1C.5.32 variant. The accompanying podcast features Dr. Tom Petznick, a swine veterinarian based in Omaha, Nebraska, who notes that ongoing challenges with PRRSV and IAV are closely linked to system-level decisions, biosecurity practices, and long-term industry design. He also discusses how lessons from M. hyopneumoniae control – particularly the roles of diagnostics, discipline, and coordinated approaches – can help inform strategies for managing other persistent diseases.
In this month’s Global Swine Disease Monitoring Report, read about foot-and-mouth disease in the Eastern Mediterranean region. FMD continues to spread, with 24 new outbreaks reported in Greece and 54 in Cyprus. In Germany, African swine fever has re-emerged in Saxony following disease-free status achievement. Reminder: Please participate in the Global Swine Disease Monitoring Report survey here.
PRRS Cumulative Incidence for MSHMP
PEDV Cumulative Incidence for MSHMP
Six PRRSV variants are classified as Variants Under Monitoring (VUM) Category 2 or higher in this month’s report. Variants 1C.5.32, 1C.2, and 1C.5 remain Category 4, while variant 1C.5.35 remains Category 3. Variant 1H.18 was promoted to Category 3 (previously Category 2), and variant 1A.13.49 was promoted to Category 3 (previously Category 1). These updates are reflected in the new variant-specific situation reports; previous reports for all variants ever classified as VUM Category 2 or higher remain available.
