Influenza Herd-Level Prevalence and Seasonality in Breed-to-Wean Pig Farms in the Midwestern United States

The Torremorell lab is continuing to explore swine influenza epidemiology in this recent publication from Dr. Fabian Chamba Pardo in Frontiers in Veterinary Science. After showing that multiple genome constellations of similar and distinct influenza viruses co-circulate in pigs, the group is now presenting new data about influenza herd-level prevalence in the Midwest, and how it is influenced by seasons. Click on the banner below to read the entire research article.

Influenza seasonal prevalence Midwest herds Chamba 2017

60 sow farms from a single Midwestern production system were enrolled in this study. Between one and seven oral fluid samples were collected at each farm weekly and meteorological data (air temperature and relative humidity) was compiled from stations located from the farms.

Swine herd level prevalence Chamba 201728% of submissions had at least one influenza positive result. All farms tested positive at least once during study period. Herd-level prevalence ranged from 7% to 57% as show in the figure above. Prevalence was low in summer, rose during fall, and peaked twice in both early winter (December) and late spring (May). August was the month with the lowest prevalence. Influenza herd-level prevalence was higher when both mean outdoor air temperature and air humidity were lower.

The most common clades identified were H1 delta 1, H1 gamma 1, and clusters H3 IV A  and H3 IV B. Furthermore, 21% of the farms had 3 different influenza genetic clades circulating during the study period and 18% had 2.

Abstract

Influenza is a costly disease for pig producers and understanding its epidemiology is critical to control it. In this study, we aimed to estimate the herd-level prevalence and seasonality of influenza in breed-to-wean pig farms, evaluate the correlation between influenza herd-level prevalence and meteorological conditions, and characterize influenza genetic diversity over time. A cohort of 34 breed-to-wean farms with monthly influenza status obtained over a 5-year period in piglets prior to wean was selected. A farm was considered positive in a given month if at least one oral fluid tested influenza positive by reverse transcriptase polymerase chain reaction. Influenza seasonality was assessed combining autoregressive integrated moving average (ARIMA) models with trigonometric functions as covariates. Meteorological conditions were gathered from local land-based weather stations, monthly aggregated and correlated with influenza herd-level prevalence. Influenza herd-level prevalence had a median of 28% with a range from 7 to 57% and followed a cyclical pattern with levels increasing during fall, peaking in both early winter (December) and late spring (May), and decreasing in summer. Influenza herd-level prevalence was correlated with mean outdoor air absolute humidity (AH) and temperature. Influenza genetic diversity was substantial over time with influenza isolates belonging to 10 distinct clades from which H1 delta 1 and H1 gamma 1 were the most common. Twenty-one percent of farms had three different clades co-circulating over time, 18% of farms had two clades, and 41% of farms had one clade. In summary, our study showed that influenza had a cyclical pattern explained in part by air AH and temperature changes over time, and highlighted the importance of active surveillance to identify high-risk periods when strategic control measures for influenza could be implemented.

Science Page: Uterine prolapses trend in production sow herds

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 study from Dr. Carmen Alonso and collaborators at Elanco.

Objectives of the study:

The objectives of the study, were: 1) to analyze the trends in prolapses of sows from 2012 to 2016, and 2) to evaluate the role of management practices, production parameters, and PRRS and PED disease status as covariates in the trend analysis of uterine sow prolapses.

Key points:

  • Uterine prolapse primarily affects sows around parturition and is still defined by an uncertain list of verified etiologies.
  • Since early 2013, swine companies have been experiencing an increase in the incidence of uterine prolapses in their herds.
  • Understanding the trends and potential risk factors would be crucial to improve the economics and welfare of the affected sow farms.

Uterine prolapses significant variables Alonso Results from this study indicate that the percentage of prolapsed sows has consistently increased every year (significant from 2014-2016) as a percentage of total deaths with the incidence being higher during the winter months and the lowest during the summer months. Total born, the use of toxin binder, assistance during farrowing, and PED health status had an association to sow deaths with prolapse per sows farrowed.

Click here to read the entire report on Uterine prolapses trends.

Dr. Connie Gebhart receives the BioMIC Excellence in Diagnostic Veterinary Microbiology Award

Dr. Connie Gebhart was honored during the last American Association of Veterinary Laboratory Diagnosticians (AAVLD) meeting  as the recipient of the BioMIC Excellence in Diagnostic Veterinary Microbiology Award.

Connie_Gebhart Supported by Biomic Inc, this prestigious AAVLD award recognizes distinguished scientist (s) for research accomplishments in the field that result in new scientific findings that have application for the betterment of veterinary medicine.
Dr. Connie Gebhart is full professor at the College of Veterinary Medicine at the University of Minnesota, USA. After obtaining both MS and PhD degrees in Veterinary Medicine from that college, she supervised multiple microbiology laboratories and projects until joining the faculty at the College of Veterinary Medicine in 2003. She currently holds a joint appointment with the Department of Veterinary and Biomedical Sciences and the Veterinary Diagnostic Laboratory as Faculty Advisor for Microbiology.
Dr. Gebhart has published over 100 peer reviewed manuscripts in internationally recognized journals and has co-authored seven chapters in books such as “Diseases of Swine”, “Bergey’s Manual of Systematic Bacteriology” and “Pathogenesis of Bacterial Infections in Animals”. She has been invited to speak at numerous national and international veterinary conferences such as the American College of Veterinary Internal Medicine, the American Association of Swine Veterinarians and the International Pig Veterinary Society, as well as for various universities and industries throughout the world.

As faculty, Dr. Gebhart is engaged in service, teaching and research concerning bacterial diseases, with special emphases on diagnosis and epidemiology of enteric diseases. Her research has focused on the obligately intracellular bacterium Lawsonia intracellularis and the novel porcine pathogen Brachyspira hampsonii. In particular, her laboratory was instrumental in identifying these new pathogenic species and continues to be active in studying all facets of these exceptional bacteria. Current research seeks to understand how L. intracellularis causes proliferation of enterocytes, by exploring processes such as interference with apoptosis, mechanism(s) of intracellular survival, alteration of normal cellular differentiation, and effect(s) on the enterocytes’ normal cell cycles.

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.”