Dr. Matt Sturos, diagnostic pathologist at the University of Minnesota, Veterinary Diagnostic Laboratory will be presenting the latest information on Senecavirus A in swine, tomorrow at 4pm in a learning session organized by the Minnesota Veterinary Medical Association (MVMA). Participants can join in person at the MVMA conference room or online via WebEX.
The UMN CVM students did a fantastic job at the 2017 American Association of Swine Veterinarians (AASV) meeting this past weekend. Four students presented their projects as an oral presentation. Zhen Yang, Alyssa Anderson, Hunter Baldry and Chris Deegan were all recognized by a jury for their hard work and commitment to the swine industry.
Taylor Homann, Donna Drebes, and Kevin Gustafson all got the opportunity to present their work as poster presentations.
Lastly, two out of the three awards given by Boehringer Ingelheim to advance the research on swine respiratory pathogens were given to Dr. Marie Culhane and Dr. Carlos Vilalta for their project on swine influenza and Porcine Reproductive and Respiratory Syndrome virus (PRRSV) respectively.
Next week-end will start the 48th American Association of Swine Veterinarians (AASV) meeting in Denver, CO. As usual, numerous UMN-CVM faculty and graduate students will be attending and presenting the results of their latest research. We hare looking forward to seeing you there!
Doug Marthaler: Porcine rotaviruses: what we know and what we are still missing
Maria Pieters: Current tools to approach Mycoplasma hyopneumoniae diagnostic cases
Michael Murtaugh: Broadly neutralizing antibodies to recent, virulent type 2 PRRSV isolates
Michael Rahe: Characterization of the memory immune response to PRRSV infection
Fabian Chamba Pardo: Effect of influenza prevalence at weaning on transmission, clinical signs and performance after weaning
Talita Resende: Mycoplasma hyorhinis associated with conjunctivitis in pigs
Peter Davies: Antibiotic use metrics
Managing the reproductive herd for high health and productivity
Maria Pieters: A pig’s early challenges
Alyssa Anderson: Use of molecular characterization tools to investigate Mycoplasma hyopneumoniae outbreaks
Hunter Baldry: Evaluation of positive pressure filtration to reduce aerosol transmission of PRRSV during an experimental challenge of farm access points
Chris Deegan: Dynamics of Mycoplasma hyopneumoniae colonization, seroconversion and onset of clinical signs in a population of gilts under field conditions
Zhen Yang: Investigating Porcine Circovirus Associated Disease (PCVAD) in commercial swine herd by next generation sequencing
Fabian Chamba Pardo: Influenza A virus prevalence and seasonality in midwestern US breeding herds
Donna Drebes: Trends in Lawsonia intracellularis PCR to the submissions to the UMN-VDL over a 10-year period
Kevin Gustafson: B-cell tetramer monitoring of the memory immune response to PRRSV
Taylor Homann: Characterizing piglet loss from PRRS outbreak
Models are primordial to develop the best control and eradication measures as well as to decrease response time in the event of a Foot and Mouth Disease (FMD) incursion on US soil. However, to be as representative of real-life situation as possible, these models need the most accurate information on disease biology. This scientific article, written by a U of M team of epidemiologists: Drs. Kinsley, Patterson, VanderWaal, Craft, and Perez, is a meta-analysis of the peer-reviewed literature defining what the exact values for the duration of various disease periods such as: latency, incubation and sub-clinical phases are. The total duration of infection is also examined.
Abstract: In the event of a foot-and-mouth disease (FMD) incursion, response strategies are required to control, contain, and eradicate the pathogen as efficiently as possible. Infectious disease simulation models are widely used tools that mimic disease dispersion in a population and that can be useful in the design and support of prevention and mitigation activities. However, there are often gaps in evidence-based research to supply models with quantities that are necessary to accurately reflect the system of interest. The objective of this study was to quantify values associated with the duration of the stages of FMD infection (latent period, subclinical period, incubation period, and duration of infection), probability of transmission (within-herd and between-herd via spatial spread), and diagnosis of a vesicular disease within a herd using a meta-analysis of the peer-reviewed literature and expert opinion. The latent period ranged from 1 to 7 days and incubation period ranged from 1 to 9 days; both were influenced by strain. In contrast, the subclinical period ranged from 0 to 6 days and was influenced by sampling method only. The duration of infection ranged from 1 to 10 days. The probability of spatial spread between an infected and fully susceptible swine farm was estimated as greatest within 5 km of the infected farm, highlighting the importance of possible long-range transmission through the movement of infected animals. Finally, while most swine practitioners are confident in their ability to detect a vesicular disease in an average sized swine herd, a small proportion expect that up to half of the herd would need to show clinical signs before detection via passive surveillance would occur. The results of this study will be useful in within- and between-herd simulation models to develop efficient response strategies in the event an FMD in swine populations of disease-free countries or regions.
This is the question that Drs. Carmen Alonso, Sagar Goyal, Peter Davies, and Montse Torremorell from the College of Veterinary Medicine studied in collaboration with Drs. Bernard Olson and Peter Raynor from the College of Science and Engineering and the School of Public Health respectively, in the following paper published in Aerosol Science and Technology this past month.
In this study, the team form the University of Minnesota compared the capacity of two different air samplers to detect PRRSv and SIV in an experimental setting. The challenge to detect viral aerosol is to find a technique capable of capturing small amount of virus in a large amount of air. This experiment found that the particle size, the media used for collection as well as the extraction technique (passive or active) all had a significant effect on the detection of the viruses.
Abstract: Detection and quantification of dilute viral aerosols, as encountered outside animal housing facilities, requires methods that are able to detect small numbers of viruses in large volumes of air. This study compared the performance of two size-differentiating cascade impactors; an Andersen 8-stage (ACI; 28.3 L/min) and a high volume Tisch (TCI; 1,133 L/min) to assess sampling efficiency for detecting porcine reproductive and respiratory syndrome virus (PRRSV) and influenza A virus (IAV). Samples of particles sorted by aerodynamic diameter were analyzed by quantitative polymerase chain reaction (qPCR) and collection efficiency was assessed by particle size. Collection media (minimum essential medium [MEM] and beef extract [BE]), elution technique (active versus passive), and sampling times (10, 20, and 30 min) were variables assessed for the TCI sampler. Extraction efficiency was 35% higher with BE as compared to that of MEM (p = 0.0007); active extraction technique was 19% more efficient than the passive technique (p = 0.03); time of sampling did not significantly affect the amount of virus recovered. The ACI sampler was more efficient in detecting both viruses from small and medium sized airborne particles (≤3 μm) as compared to the TCI sampler (p < 0.001). The latter sampler, however, was more efficient at IAV detection from large airborne particles (>3 μm) (p = 0.0025) indicating the potential of this sampler in detecting the presence of small amounts of viruses in aerosols under field conditions.
This past week-end, a dozen of veterinary students chose to meet with Drs. Maria Pieters and Perle Boyer at the University of Minnesota Southern research and outreach center in Waseca, MN to practice their pregnancy diagnostic skills over enjoying the unusually warm weather.
For over 3 hours, the first to third-year veterinary students each got the chance to perform an ultrasound examination on sows at various stages of gestation as well as on a sow that was not pregnant to appreciate the difference. Various tools were presented to them to compare and to get familiar with.
By the end of the lab, we are glad to say that all students were able to successfully tell if a sow was pregnant or not!
Dr. Fabio Vannucci, a University of Minnesota swine pathologist and his graduate student Dr. Talita Resende collaborated with a team from South Dakota State University to study the pathogenesis of Senecavirus A in finishing pigs. The results of their experiments were published online a few weeks ago in the Journal of General Virology and the printed version should be following shortly.
The importance of Senecavirus A in swine production resides in a striking resemblance in clinical signs with Food and Mouth Disease. Indeed, Senecavirus A causes vesicular lesions around the mouth and on the feet of pigs.
The collaborative work showed that Senecavirus A viremia occurred between 3 to 10 days post-inoculation (dpi), and that the neutralizing antibody response started 5 dpi. Clinical signs first observed 4dpi, lasted up to 10 days.
This study advances our understanding of Senecavirus A pathogenesis to hopefully be able to better manage it in the future.
Abstract: Senecavirus A (SVA) is an emerging picornavirus that has been recently associated with vesicular disease and neonatal mortality in swine. Many aspects of SVA infection biology and pathogenesis, however, remain unknown. Here the pathogenesis of SVA was investigated in finishing pigs. Animals were inoculated via the oronasal route with a contemporary SVA strain SD15-26 and monitored for clinical signs and lesions associated with SVA infection. Viremia was assessed in serum and virus shedding monitored in oral and nasal secretions and feces by real-time reverse transcriptase PCR (RT-qPCR) and/or virus isolation. Additionally, viral load and tissue distribution were assessed during acute infection and following convalescence from disease. Clinical signs characterized by lethargy and lameness were first observed on day 4 pi and persisted for ~2-10 days. Vesicular lesions were observed on the snout and feet, affecting the coronary bands, dewclaws, interdigital space and heel/sole of SVA-infected animals. A short-term viremia was detected between days 3-10 post-inoculation (pi), whereas virus shedding was detected between days 1-28 pi in oral and nasal secretions and feces. Notably, RT-qPCR and in situ hybridization (ISH) performed on tissues collected on day 38 pi revealed the presence of SVA RNA in the tonsil of all SVA infected animals. Serological responses to SVA were characterized by early neutralizing antibody responses (5 days pi), which coincided with a progressive decrease in the levels of viremia, virus shedding and viral load in tissues. This study provides significant insights on the pathogenesis and infectious dynamics of SVA in swine.