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.

Alvarez swine salmonella vaccine 2017

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

Gary Louis, PhD confirmed as keynote speaker at the 2017 Allen D. Leman swine conference

The Allen D. Leman swine conference is only six months away! Our team is preparing an  exciting conference program for you this year and we will update you regularly on the speakers and topics that will be covered during this great event bringing science-driven solutions to the complex challenges facing the swine industry. We already shared with you that the recipient of this year’s Science in Practice award is Dr. Bob Thompson.

We are glad to announce that our first key note speaker for the conference will be Gary Louis, Executive Vice President of Seaboard Foods LLC where he is in charge of the live operations. We are delighted that he has accepted our invitation to share his tremendous experience and his vision of the swine production.

More information about the Allen D. Leman swine conference can be found here.