Best of 2017 Leman series #1: C. Vilalta – Novel sampling strategies for piglets

We are launching a new series on the blog today. Once a month, we will share with you a presentation given at the 2017 Allen D. Leman swine conference, on topics that the swine group found interesting, innovative or that lead to great discussions. If there is a presentation from this year’s conference that you would like to hear again, please fill out the form at the end of this note.

To launch this series, Dr. Carles Vilalta from the University of Minnesota shares novel PRRSV sampling strategies for piglets. To listen to his presentation, click on the image below.

Vilalta new PRRS sampling Leman 2017

To read more about processing fluids in PRRSV diagnostics, you may read this Science Page written on the same topic.

Science Page: Describing the cull sow and cull hog market networks in the US: A pilot project

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing a project from Dr. Jim Lowe at the University of Illinois.

Project rationale

“What is the range of locations of sows that enter a slaughter plant?, How many stops along the way do they make? and How long do they remain the slaughter channel?” These are the questions this project is planning to answer.

Key Points:

  • Little is known about the cull market, how culls are transported, and how they play a role in disease spread.
  • While most sows travel directly to slaughter, an important percentage most likely move through multiple collection points.
  • Cull sow movement are important for understanding disease transport related epidemiology.

Premise ID tags were collected during an entire week at a cull harvest plant. Animals originated from 297 unique source farms, located in 21 US states and Canada.

distance from farm to marketResults are shown in the histogram on the left.

The majority of culls (86%) originate less than 240km from the final collection point. This interaction is deemed to be a primary interaction, meaning that it is very likely the culls moved direct from the farm of origin to the final collection point. 14% of the culls travel a distance greater than 240km to the terminal collection point. Of these 14%, 17.7% or 2.5% of all culls, traveled 5 times as far to the last point of collection from the farm than they did from collection point to plant.

Click here to see the entire report on the cull sows and cull hogs market.

NHF: Here’s how co-opetition fits in thriving pork industry

Our latest collaboration with the National Hog Farmer develops the concept of co-opetition and how it fits in the pork industry. Dr John Deen, professor at the University of Minnesota explains what co-opetition with the following:

“With co-opetition, the argument is that the best businessperson is one that does not only excel at production but also works cooperatively with competitors to address common opportunities.”

NHF Deen coopetition swine industry

The article develops two examples for which co-opetion can be useful, one of them being infectious diseases. The Morrison’s Swine Health Monitoring Project is a clear example of a successful initiative in this regard, with competing production systems voluntarily sharing information on their farms’ health status.

More importantly, co-opetition is happening in a variety of productions. Dr. Rebecca Liu from Lancaster University compared cooperation and competition with co-opetition, and how it helped other industries to thrive during her keynote presentation the 2017 Allen D. Leman swine conference. To listen to Dr. Liu’s talk, click on the image below.

Liu Coopetition keynote 2017 Leman.gif

 

Dr. Wantanee Kalpravidh received the Distinguished Research Alumnus Award

The 2017 Points of Pride Research Day was held earlier this month and the swine group was well represented. Among the awardees, Dr. Montse Torremorell received the highest research reward at the College level: the Zoetis Award for Research Excellence for her impressive work on swine influenza, PRRSV and biosecurity approaches to mitigate pathogen transmission. Additionally, Dr. Bob Morrison, who passed away earlier this year, was recognized for the impact of his entire career with the Mark of Excellence Award.

Wantanee_distinguished alumnus
From left to the right: Dean Trevor Ames, Dr. Wantanee Kalpravidh, Dr. Sriram Rao, and Dr. Peter Davies

The distinguished Research Alumnus Award was given to Dr. Wantanee Kalpravidh in recognition of her work and research efforts. Dr Kalpravidh graduated from the University of Minnesota in 1993 when she completed after only 2 years, her PhD in Veterinary Medicine under the supervision of Dr. Bob Morrison. Dr. Kalpravidh then returned to her home country of Thailand where she began her career with the Division of Disease Control at the Thailand Department of Livestock Development. Her work in coordinating disease control efforts crossed national borders and she is now the Regional Manager for the Asia-Pacific region at the Emergency Center for Transboundary Animal Disease (ECTAD) in the Food and Agriculture Organization (FAO).

Before starting her seminar, Dr. Wantanee Kalpravidh thanked the two groups of people without whom she believes she would not have had such a successful career : her family and more particularly her father who kept telling her to keep dreaming and her mentors, among them Dr. Morrison.

IMG_2930
The 44 countries in the Asia-Pacific region for which Dr. Wantanee Kalpravidh coordinates efforts in disease control.

The area under her supervision is impressive: 44 countries of the Asia-Pacific region in which she coordinates the efforts to deliver veterinary assistance to countries responding to the threat of transboundary animal health crises. Some of the diseases and areas she has had to focus on in the past are: Foot and Mouth Disease, PRRSV and other swine infectious diseases, Antimicrobial Resistance, zoonotic Influenza, and zoonotic Emerging Infectious Diseases.

Dr. Wantanee Kalpravidh made hers the FAO mission of collaboration and capacity building with the countries, applied epidemiology and implementation of laboratory diagnosis.

A recent example of her work was her implication in the Highly Pathogenic Avian Influenza epidemic in Vietnam and her evaluation of the feasibility of a poultry vaccination campaign.

To paraphrase Dr. Davies’ words: “There is no-one more deserving of this award than Wantanee and we are very proud of how she used her PhD.”

Science Page: Introducing Dr. Cesar Corzo

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Cesar Corzo
Dr. Cesar Corzo will be leading the MSHMP efforts.

Dr. Cesar A Corzo has recently joined the Swine Group at the University of Minnesota College of Veterinary Medicine as the Allen D. Leman Chair in Swine Health and Productivity.
As the new Leman Chair, Dr. Corzo will focus on leading the Morrison Swine Health Monitoring Project by strengthening the link between producers and research, and support producers to make science-based decisions to improve swine health.

Dr. Corzo’s appointment brings a unique and diverse level  of experience to the Morrison Swine Health Monitoring Project. His producer and veterinarian focused approach will help achieve Dr. Bob Morrison’s vision for the project to deliver short term value to producers while strengthening the long term disease preparedness of the swine industry.

Click here to learn more about Dr. Corzo.

A constellation of strains co-circulate in pigs during influenza epidemics

This recent publication in Nature comes from the Torremorell’s lab and aims at answering the question of the number of strains circulating in pigs during an influenza outbreak and how genetically different they may be. The full article is available in open access, click on the banner below to access it.

Constellation influenza banner Torremorell

To answer the question of multiple strains of influenza in pigs, the group followed a cohort of 132 pigs placed in a 2,200-head a wean-to-finish barn, endemic for influenza. All the pigs originated from the same sow farm . The history of past influenza episodes did not include any information regarding the strain of viruses circulating in the barn. Nasal swabs were collected for each individual pig and were tested in the laboratory by PCR.

Results from this study showed that:

  • Only 2 pigs out of 132 tested negative every week during the entire duration of the study.
  • Around 88% of the pigs tested positive for influenza more than once.
  • 20.5% of pigs were positive for influenza at weaning.
  • Weekly influenza prevalence ranged between 0% and 65%.
  • 3 different viral groups were identified VG1, VG2, and VG3.
  • Groups belonged to the swine H1-gamma, H1-beta and H3-cluster-IV influenza A respectively. (Here is a review of the H1 genetic clades and one of the H3 genotype patterns)

The figure below shows the genetic make up of the influenza strains isolated each week, the viral group each genetic segment belonged to and the number of times this specific combination was found.

For example, the second line can be interpreted as: during week one, one sample in which 10 sequences were recovered, had influenza virus with segments 1, 2, 3, 4, 5, and 7 belonging to the Viral Group 1 (H1 gamma) and segments 6 and 8 were from Viral groups 1 and 3.

Influenza constellation Torremorell

In conclusion, this study shows that influenza infections in pigs after weaning and under field conditions are complex. The influenza virus genome is diverse and changes rapidly. Prolonged persistence of influenza viruses in pigs could be the result of multiple influenza epidemic events that take place repeatedly over time or the re-infection with influenza viruses that are closely related to each other.

Abstract

Swine play a key role in the ecology and transmission of influenza A viruses (IAVs) between species. However, the epidemiology and diversity of swine IAVs is not completely understood. In this cohort study, we sampled on a weekly basis 132 3-week old pigs for 15 weeks. We found two overlapping epidemic events of infection in which most pigs (98.4%) tested PCR positive for IAVs. The prevalence rate of infection ranged between 0 and 86% per week and the incidence density ranged between 0 and 71 cases per 100 pigs-week. Three distinct influenza viral groups (VGs) replicating as a “swarm” of viruses were identified (swine H1-gamma, H1-beta, and H3-cluster-IV IAVs) and co-circulated at different proportions over time suggesting differential allele fitness. Furthermore, using deep genome sequencing 13 distinct viral genome constellations were differentiated. Moreover, 78% of the pigs had recurrent infections with IAVs closely related to each other or IAVs clearly distinct. Our results demonstrated the molecular complexity of swine IAVs during natural infection of pigs in which novel strains of IAVs with zoonotic and pandemic potential can emerge. These are key findings to design better health interventions to reduce the transmission of swine IAVs and minimize the public health risk.

Science Page: Use of processing fluids for PRRSV diagnostics

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Key points

  • Using processing fluids as a diagnostic tool can help us to detect lower PRRS prevalence in the herd.
  • Testicles and tails should be collected in a pail as they are potential spreaders of PRRS in the farrowing room.
  • We should target young parity sows for PRRSV sampling.

Processing fluids PRRS table.gif

What are processing fluids?

In sow farms, piglets get processed during the first week of life. This means that their tails is docked and the males are castrated. The farmer usually collect tails and testicles in a pail to be discarded at a later time.

We propose to use the fluids accumulating at the bottom of the pail to assess the farm PRRSV status.

How did we test those fluids?

The fluids were tested for PRRSV by PCR and the results were compared to the gold standard for this diagnostic: PCR on serum. Sampling was set in a farm that just went through a PRRSV outbreak and 10 litters from various parity sows were selected each week for 8 weeks.

What were the results?

Processing fluids were efficient in detecting PRRSV even if there was only one piglet positive in the litter (determined with the serum samples). Compared to the serum tests, there were 4 false negative samples that were explained by the fact that the virus load in the piglets serums was low and the dilution effect of the processing fluids caused the samples to get negative results. We also found 4 false positive resutls that could be due to cross-contamination of the samples despite the extreme care with which the samples were handled.

Are processing fluids a worthwhile sample?

The agreement between processing fluids and serum results was good and the sensitivity and specificity of the technique was respectively of 83% and 92%. Additionally, this technique requires no further handling of the piglets or use of extra supplies to collect samples and submit them to the laboratory.