Drs Phil Gauger and Amy Vincent offer the following pointers concerning H3N2 human exposure risks for swine workers and veterinarians:
Monthly Archives: January 2018
Doc Tales
In another in our “out-of-the-mouths-of-babes” series comes this gem from Dr. Wesley Lyons. He relates the following story from church just before Christmas: During the service of Lessons and Carols, many members of the church were taking turns reading the Christmas story. Two young girls around 6-8 years old were teaming up to read the story of Gabriel announcing to Mary that she was to give birth to our Savior. As one little girl was reading the story, she read Mary’s surprised part, “But how can this be?! For I am a VEGAN!”
USDA Influenza Surveillance Report Published
The FY 2017 4th quarter IAV-S report has been posted to the USDA Monitoring and Surveillance website. The report can be accessed at https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/swine-disease-information/ctswinehealthmonitoringsurveillance. Some key report summary items are as follows: In FY 2017 Q4, 6,508 samples were submitted for IAV-S surveillance from 1,980 accessions. H1N2 was the predominant subtype. Over the past 8 quarters, H1N2 predominated in Regions 1, 2, 3, 4 and 5. When Regions are recorded as “unknown,” H1N2 predominates as well (see map in regional section). Limited accessions from a region can skew data and lead to misinterpretation. Therefore, less inference can be applied to results from Regions 3, 4, and 5. All IAV-S submissions are voluntary and based on clinical case submissions to veterinary diagnostics labs. These data are not a statistically representative sampling of the U.S. swine population. Due to the voluntary nature of this surveillance, the information in this report cannot be used to determine regional and/or national incidence, prevalence, or other epidemiological measures, but it may help identify IAV-S trends.
Veterinary Diagnostic Researchers Continuing Research on Swine Influenzas and Circoviruses with New Grants
Swine disease research at Kansas State University is now getting closer to developing new, reliable diagnostic tests for several swine disease viruses that occur across the globe. Two new research grants worth $173,400 from the Swine Health Information Center in Ames, Iowa, in 2018 will help continue research that began in 2016. [Source: KSU News and Communications, January 30, 2018]
SHIC Releases 2018 Plan of Work to Help Safeguard Swine Health
The Swine Health Information Center (SHIC) Plan of Work for 2018, with projects designed to quickly deliver results to safeguard the health of the US swine herd, was approved by the organization’s Board of Directors during their January 26 meeting. Just a few Plan of Work highlights include a focused effort to improve transportation biosecurity, the next steps for investigating feed as a possible vehicle for pathogen transport into the country and between farms, improving communication about international and domestic swine diseases, and continued testing of the ability to respond to emerging disease through the Rapid Response Corp.
High Dietary Zinc Feeding Promotes Persistence of Multi-Resistant E. coli in the Swine Gut
High levels of zinc oxide are used frequently as feed additive in pigs to improve gut health and growth performance and are still suggested as an alternative to antimicrobial growth promoters. However, we have recently described an increase of multi-resistant E. coli in association to zinc feeding in piglets. This previous study focused on clonal diversity of E. coli, observing the effect on multi-resistant strains by chance. To shed further light into this highly important topic and falsify our previous findings, we performed a zinc pig feeding trial where we specifically focused on in-depth analysis of antimicrobial resistant E. coli. Under controlled experimental conditions, piglets were randomly allocated to a high dietary zinc (zinc group) and a background zinc feeding group (control group). At different ages samples were taken from feces, digesta, and mucosa and absolute E. coli numbers were determined. A total of 2665 E. coli isolates were than phenotypically tested for antimicrobial resistance and results were confirmed by minimum inhibitory concentration testing for random samples. In piglets fed with high dietary zinc, we detected a substantial increase of multi-resistant E. coli in all gut habitats tested, ranging from 28.9-30.2% multi-resistant E. coli compared to 5.8-14.0% in the control group. This increase was independent of the total number of E. coli. Interestingly, the total amount of the E. coli population decreased over time. Thus, the increase of the multi-resistant E. coli populations seems to be linked with persistence of the resistant population, caused by the influence of high dietary zinc feeding. In conclusion, these findings corroborate our previous report linking high dietary zinc feeding of piglets with the occurrence of antimicrobial resistant E. coli and therefore question the feeding of high dietary zinc oxide as alternative to antimicrobial growth promoters. Ciesinski L, Guenther S, Pieper R, Kalisch M, Bednorz C, Wieler LH; High Dietary Zinc Feeding Promotes Persistence of Multi-Resistant E. coli in the Swine Gut; PLoS One. 2018 Jan 26;13(1):e0191660. doi: 10.1371/journal.pone.0191660. eCollection 2018. PMID: 29373597 DOI: https://doi.org/10.1371/journal.pone.0191660 10.1371/journal.pone.0191660 Click here to read the full article.
Survival of LA-MRSA in Dust from Swine Farms
Dust is suspected to be an important factor in transmission of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) between pigs and pig farmers and their families. The aim of this study was to determine the rate of decay for Staphylococcus aureus and LA-MRSA in dust from swine farms. Electrostatic dust fall collectors (EDCs) were used for passive sampling of settling airborne dust in 11 stable sections from six swine farms. Extraction, plating, identification, and enumeration of cultivable S. aureus and LA-MRSA from the EDCs were performed after storage for 0-30 days postsampling. The survival of S. aureus was measured in 196 dust samples from all farms, and data were used to estimate the decay constant λ according to a model for exponential decay: N(t) = N0 × e-λt. The number of S. aureus colonies was up to 600-fold higher than the number of LA-MRSA colonies on MRSA selective agar. The data showed a good fit to the model (λ = 0.13, r2 = 0.86) even with a large difference in initial concentrations of S. aureus between stables. The loads of S. aureus and LA-MRSA in the dust were significantly reduced by storage time, and the half-life was 5 days for both S. aureus and LA-MRSA. In dust samples with high initial concentrations, LA-MRSA and S. aureus could still be cultivated 30 days after sampling. On all farms MRSA isolates belonged to the clonal complex (CC) 398, and at one farm some isolates also belonged to CC30. A screening for other Staphylococcus species in the farm dust revealed 13 different species numerically dominated by Staphylococcus equorum. Based on the exponential decay model, S. equorum had a half-life of 4 days. In conclusion, the presence of MRSA in airborne dust from five of six farms indicates that dust might be an important vehicle for transmission of LA-MRSA. LA-MRSA and S. aureus was found to survive well in farm dust with half-lives of 5 days, and dependent on the initial concentration they could be found in farm dust for weeks. The 99.9% die-off rate was 66 days for LA-MRSA. Thus, farm dust can pose an exposure risk for humans in the farm environment, but also when transported to other environments. On the other hand, the risk will decrease by time. These results provide important knowledge to diminish spread from farm environments to other environments on, e.g., tools or clothing, and in relation to cleaning of emptied LA-MRSA-positive stables. Feld L, Bay H, Angen Ø, Larsen AR, Madsen AM; Survival of LA-MRSA in Dust from Swine Farms; Ann Work Expo Health. 2018 Jan 20. doi: 10.1093/annweh/wxx108. [Epub ahead of print] PMID: 29365048 DOI: 10.1093/annweh/wxx108 Click here to read the full article.
Endowment Grows as Past Presidents Rise to the Challenge
The race is on! AASV Foundation Chairman Dr John Waddell has called upon each of his fellow AASV past presidents to recruit at least 3 new Leman, Heritage, or Legacy donors, in an effort to build the foundation endowment to $2 million by the 2019 AASV Annual Meeting.
ACAW Scholarship Available to Members Seeking Welfare Certification
The AASV Foundation Board of Directors continues to accept applications from AASV members seeking board certification in the American College of Animal Welfare (ACAW). The applicant must have a DVM or VMD degree and at least 5 years of continuous membership in the AASV.
People on the Move: Dr. Laura Batista
As of December 1st, 2017, Dr. Laura Batista joined PIC as a part-time Senior Health Advisor for Latin America. Her main responsibilities will be to work with PIC’s health, technical, and sales team. She will also provide services and solutions to key customers in order to minimize the impact of disease. Laura will continue to reside in Canada and will travel monthly to Latin America. Dr. Batista will also continue her private consulting with Batista & Asociados. Updated contact information for Dr. Batista is available at www.aasv.org/members/only/directory.php. Are you on the move? If so, let us know at aasv@aasv.org.