research – Page 17 – Swine in Minnesota

Air samples successful in detecting on-farm PRRSV, PEDV, and high-path avian influenza virus

Summary:

From Dr. Torremorell’s lab at the University of Minnesota, College of Veterinary Medicine
Porcine Reproductive and Respiratory Syndrome virus (PRRSV), Porcine Epidemic Diarrhea virus (PEDV), and High-Path Avian Influenza virus (HPAIV) are transmitted via aerosols.
Air samples taken out of positive farms were successful in isolating HPAIV and PEDV 61% and 69% of the time respectively whereas PRRSV was found 8% of the time.
For all three viruses, higher quantity of genetic material was found when the size of the particle was larger.

More articles on air samples as a method to study respiratory pathogens

Alonso 2017 Assessment of air sampling methods ans size distribution of virus-laden aerosols

Abstract:

Swine and poultry viruses, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), and highly pathogenic avian influenza virus (HPAIV), are economically important pathogens that can spread via aerosols. The reliability of methods for quantifying particle-associated viruses as well as the size distribution of aerosolized particles bearing these viruses under field conditions are not well documented. We compared the performance of 2 size-differentiating air samplers in disease outbreaks that occurred in swine and poultry facilities. Both air samplers allowed quantification of particles by size, and measured concentrations of PRRSV, PEDV, and HPAIV stratified by particle size both within and outside swine and poultry facilities. All 3 viruses were detectable in association with aerosolized particles. Proportions of positive sampling events were 69% for PEDV, 61% for HPAIV, and 8% for PRRSV. The highest virus concentrations were found with PEDV, followed by HPAIV and PRRSV. Both air collectors performed equally for the detection of total virus concentration. For all 3 viruses, higher numbers of RNA copies were associated with larger particles; however, a bimodal distribution of particles was observed in the case of PEDV and HPAIV.

Link to the full article

NEW: Read the Swine Health Monitoring Project – Science Page here, every Friday

The Swine Health Monitoring Project (SHMP) is a National program coordinated by Dr. Bob Morrison from the University of Minnesota, College of Veterinary Medicine. The goal of this initiative is to monitor the incidence and prevalence of relevant swine diseases in the US such as Porcine reproductive and respiratory syndrome (PRRS) or Porcine Epidemic Diarrhea (PED) for example. Participants are voluntarily sharing the health status of their farms in order to better understand, and in the future, control these illnesses. Each week participants receive a report including a one-page summary of a scientific fact of interest. From now on, the Science Page will be published on the blog here, every Friday.

This week’s edition

All of the previous Science Pages are compiled here.
If you want to know more about the Swine Health Monitoring Project, an article from the National Hog Farmer and one from the Swine Health Information Center will give you an overview of the program and its goals.

Beneficial but variable effect of vaccination to control Salmonella in pigs

In this meta-analysis conducted by the Center for Veterinary Health Surveillance (Madrid, Spain) in collaboration with Drs. Conrado, Perez, and Alvarez from the University of Minnesota, the efficacy of vaccination to control Salmonella infection in pigs was evaluated. The meta-analysis reviewed a total of 44 studies focusing on Salmonella typhimurium or Salmonella choleraesuis. Included protocols were using either inactivated (killed) or live-attenuated vaccines.

Results showed that both vaccine types had a similar efficacy and that the most successful control strategies among the ones reviewed were using killed vaccines to control Salmonella choleraesuis.

Abstract: Consumption or handling of improperly processed or cooked pork is considered one of the top sources for foodborne salmonellosis, a common cause of intestinal disease worldwide. Asymptomatic carrier pigs may contaminate pork at slaughtering; therefore, pre-harvest reduction of Salmonella load can contribute to reduce public health risk. Multiple studies have evaluated the impact of vaccination on controlling Salmonella in swine farms, but results are highly variable due to the heterogeneity in vaccines and vaccination protocols. Here, we report the results of an inclusive systematic review and a meta-analysis of the peer-reviewed scientific literature to provide updated knowledge on the potential effectiveness of Salmonella vaccination. A total of 126 articles describing the use of Salmonella vaccines in swine were identified, of which 44 fulfilled the inclusion criteria. Most of the studies (36/44) used live vaccines, and S. Typhimurium and S. Choleraesuis were the predominant serotypes evaluated. Vaccine efficacy was most often measured through bacteriological isolation, and pooled estimates of vaccine efficacy were obtained as the difference in the percentage of positive animals when available. Attenuated and inactivated vaccines had similar efficacy [Risk Difference = − 26.8% (− 33.8, − 19.71) and − 29.5% (− 44.4, − 14.5), respectively]. No serotype effect was observed on the efficacy recorded for attenuated vaccines; however, a higher efficacy of inactivated vaccines against S. Choleraesuis was observed, though in a reduced sample.

Results from the meta-analysis here demonstrate the impact that vaccination may have on the control of Salmonella in swine farms and could help in the design of programs to minimize the risk of transmission of certain serotypes through the food chain.

Link to the full article

AASV 2017: Another great year for the UMN-CVM students and faculty

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.

Congratulations to all!

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Efficacy of three disinfectants against Senecavirus A on five surfaces and at two temperatures

What disinfectant to use against Senecavirus A? Does it vary based on surface type or temperature? These are the questions that a group of researchers from the University of Minnesota – Veterinary Diagnostic Laboratory are answering in the latest issue of the Journal of Swine Health and Production (JSHAP).

The project tested:
3 disinfectants: Household bleach, a phenolic disinfectant, and a quaternary ammoniun-aldehyde
5 surfaces: aluminium, stainless steel, rubber, cement, and plastic
2 temperatures: 25°C (77F) and 4°C (39F)

singh-et-al-2017-disinfectants-against-senecavirus-a

Summary

Objectives: To evaluate the virucidal efficacy of three commercial disinfectants against Senecavirus A (SVA) on five different surfaces at ~25°C and 4°C.

Materials and methods: Household bleach, a phenolic disinfectant, and a quaternary ammonium-aldehyde disinfectant were tested at manufacturer’s recommended concentrations against a contemporary strain of SVA on aluminum, stainless steel, rubber, cement, and plastic surfaces at ~25°C and 4°C. Virus propagation and titration were performed on swine testicular cells. Viral titers were calculated before and after exposure to the disinfectant being tested.

Results: At ~25°C, household bleach at 1:20 dilution inactivated ≥ 99.99% of the virus within 10 to 15 minutes on aluminum, rubber, and plastic. On stainless steel and cured cement, it inactivated 99.97% and 99.98% of the virus, respectively. At 4°C, bleach inactivated ≥ 99.99% of the virus within 5 to15 minutes on all surfaces except rubber; on rubber, inactivation was 99.91% after 15 minutes. The phenolic disinfectant at the manufacturer’s recommended concentration inactivated only ≤ 82.41% of the virus at either temperature and on any surface, even after a 60-minute contact time. Results for the quaternary ammonium disinfectant were intermediate: 78.12% to 99.81% of the virus was inactivated within 60 minutes at both temperatures and on all surfaces. To detect differences between disinfectants, paired Wilcoxon tests were performed. At 10- and 15-minute time points, efficacies of the three disinfectants differed significantly.

Implications: Significant variation exists in the antiviral efficacies of different disinfectants. Hence, they should be tested against various pathogens before use in the field.