The Swine Health Information Center (SHIC) continues to fund investigation into possible pathways of foreign animal disease into the US. A recently completed SHIC-funded study looked at international transportation biosecurity practices of four cooperating US breeding stock companies. One question of high interest was about the possibility of transport crates being reused after exposure in another country and returning something other than pigs back into the US. In the process they found crates are not reused and are marked as “one-use” due to swine health biosecurity concerns. Investigators also found participating breeding stock companies have robust biosecurity procedures for both import/exports due to their investment in maintaining the health status of these pigs. Additionally, they discovered exports/imports are frequent, however, imports from outside North America occur less often. The complete research report can be found here.
This study had two primary objectives. The first was to determine the frequency of international breeding-stock exports or imports and their country of destination and/or origin as well as, the second, to characterize the procedures currently implemented by breeding stock companies during the export or import processes.
Based on official USDA records, between 2007 and 2018, a total of 839,152 pigs (e.g., gilts or boars) were imported into the US. Most of these pigs originated from Canada, while less than 3% were imported from Western Europe. On the other hand, breeding pig exports accounted for 382,118 pigs between 2007 and 2018 with Asia being the main destination (54.0%), followed by Mexico (31.3%), and South America (5.7%). A total of eight breeding stock companies were invited to participate in this study with half accepting the invitation and sharing import/export protocols.
Participating breeding stock companies shared their procedures related to exports and/or imports as relevant to their business. Because these companies need to comply with USDA regulations, along with their interest in delivering high health animals, processes were standard across companies with minimal differences due to having strict biosecurity procedures.
The results of this descriptive study clearly show that breeding-stock imports/exports play an important role in the industry. Export procedures seem to represent low risk as potentially contaminated fomites related to these exports do not return to the US. And US breeding stock companies maintain and follow appropriate biosecurity protocols.
African swine fever (ASF) continues to impact the swine industry worldwide. During the World Organization for Animal Health (OIE) annual meeting last week in Paris, member countries considered and passed a resolution regarding ASF. Within Resolution No. 33 is a framework for addressing this global threat, recognizing the need for collaborative preparedness, prevention, detection, and control measures. Key points from the resolution are included in this article and the full text is here. Of particular note is the recommendation for OIE to develop specific guidelines for implementation of zoning and compartmentalization. An ad hoc working group will meet this year to draft these guidelines, which could help continue international pork marketing even after a contained ASF outbreak.
Contaminated feed has been documented as a risk factor for the transboundary and domestic movement of viral pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV), African swine fever virus (ASFV), and Seneca Virus A (SVA, a surrogate for foot-and-mouth disease virus (FMDV)). A new study, partially funded by the Swine Health Information Center, examines four feed additives, including medium chain fatty acid blends, organic acid mixtures and acid/aldehydes, to determine their ability to negatively affect viral survival. Data from this study suggest that the use of validated additives may reduce the risk of viral infection via contaminated feed.
The test model was designed to represent field conditions, involving large groups of feed and tonnage of feed, and a point-in-time challenge model. In this study, porcine epidemic diarrhea virus (PEDV), PRRSV 174, and SVA were manually dropped into each feed bin to represent contamination of prepared feed on the farm. Under the conditions of the study, feed in all bins was successfully contaminated, resulting in delivery of all three viruses to all rooms.
Transmission of PRRSV, PEDV, and SVA via feed was documented in the positive control group. No product sterilized the feed and there were no significant differences in effectiveness among the feed additives. Based on average daily gain calculations, all products proved to be beneficial to pig health and performance when compared to the positive control group.
Feed additives used in the study:
The project is a collaboration between Pipestone Applied Research, who is testing the mitigants under farm conditions, and Kansas State University, who will use the data to apply mitigant research directly to the ASFV. It will be repeated with five different feed additives during the fall of 2019. And, the complete results of the project will be submitted to a peer-reviewed journal for publication.
The Swine Health Information Center (SHIC) funded a pilot study to determine if a fluorescent powder could be used to study the transfer of contamination from livestock trailers to barns during marketing events. Conducted by staff from Iowa State University (ISU) in collaboration with Iowa Select Farms, the study addresses concerns that livestock trailers are frequently contaminated with PRRSV, PEDV, and other pathogens at swine slaughter plants in the US. Results of this pilot study demonstrated fluorescent powder can be used to track contamination between livestock trailers and barns, offering a needed tool for evaluation and subsequent improvement in transport biosecurity. Complete study results are available on the SHIC website.
In the US, barns of pigs are typically marketed over several weeks, creating the opportunity to bring pathogens from the marketplace back to the farm. If pigs become infected, they are subject to production losses, as well as becoming potential sources of virus for other farms. Contaminated trailers may also become carrying agents to other farms and drivers might pass pathogens on their clothing or boots.
During the study, dry woodchips on the floor of the chute appeared to inhibit the transfer of fluorescent powder, a marker for pathogen contamination, on the boots of the load-out crew but as feces and urine began to accumulate on the chute, the inhibition quickly dissipated. With a fluorescent light, investigators were able to document that fluorescent powder was transferred from the trailer to the load-out chute during the loading procedure at all three study sites. Transfer was confirmed by the detection of fluorescent powder on the bottom of workers’ boots, on their cutting boards for sorting, in the chute, the load-out alleyway, center alleyway of the barn, and the first three pens adjacent to the load-out alleyway on both sides.
In addition to the named objective of the pilot study, several other observations were made relating to transportation biosecurity. Once pigs were on the trailer, they occasionally lost their footing while lunging forward off their back legs. This propelled significant amounts of wood chips from the livestock trailer onto the chute. On several occasions, pigs already on the trailer managed to return to the chute. Additionally, the line of separation between the livestock trailer and chute was often violated by both the driver and farm worker.
Studies are planned to use fluorescent powder to evaluate multi-zone loading, where members of the loading crew are restricted to specific zones in the barn, chute and load-out area, as an alternative loading strategy with the intent of reducing the likelihood of transferring pathogens from livestock trailers to the center alleyway and pens inside the barn. While this pilot study was conducted on market pigs, the concept can apply to all sizes of pigs and stages of production.
Keeping African swine fever (ASF) out of the United States requires more than diligence on the farm. International travelers returning home, or those visiting from other countries, present another significant risk. All international travelers entering the United States after visiting a farm or being in contact with animals in a country (or countries) with ASF, or any other foreign animal disease, should declare this information to US Customs and Border Protection (CBP) via written form, airport kiosk, or verbally. The Swine Health Information Center (SHIC), American Association of Swine Veterinarians (AASV), National Pork Board (NPB), and National Pork Producers Council (NPPC) continue to ask international travelers to report if they were not diverted for secondary screening upon arrival in the United States. CBP has responded to the submission of the pork industry’s reports about missed secondary screenings with new processes and enhanced, proactive measures.
CBP has been very appreciative of receiving information from the pork industry. In response, CBP is emphasizing with the Customs agents that all travelers reporting farm contact while abroad should receive a secondary screening. Re-entry kiosks have been reprogrammed to automatically divert travelers for secondary screening if farm contact is reported. CPB continues to develop specific metrics to measure the success and consistency of their screening process and will share those results with the pork industry.
If you are NOT diverted for secondary screening after declaring you have been on a farm or in contact with animals in an ASF or other foreign animal disease positive nation, please email the following to [email protected]:
Dr. Sundberg aggregates this information so SHIC, AASV, NPB, and NPPC can share it with CBP to help identify areas for continued focus.
Continued progress on research, programs, and opportunities highlighted the Swine Health Information Center (SHIC) board of directors meeting on June 6.These projects, continued work on emerging diseases and ongoing industry efforts to prevent foreign animal diseases like African swine fever (ASF) from entering the US, and being prepared in case it does, are the organization’s priorities.
Reports from other industry organizations, including National Pork Board (NPB), National Pork Producers Council (NPPC), and American Association of Swine Veterinarians (AASV), explained the efforts relating to ASF and other swine health issues each organization is working on alone and in collaboration with SHIC.
An update from Dr. Derald Holtkamp, Iowa State University, on the SHIC Rapid Response Program provided the board with information on its effectiveness, improvements made since launching, and definitive guidance on executable plans for on-farm biosecurity. Investigators signed up for the program have been trained and are practicing to assure the best response if they are needed in epidemiological investigations.
SHIC-funded research using Morrison Swine Health Monitoring Program (MSHMP) data has shown learnings on the opportunity to build on its initial information collected. Dr. Kimberly VanderWaal, University of Minnesota, presented these details to the board as an actionable item from SHIC research.
The board continues to meet monthly to assist Dr. Paul Sundberg, SHIC Executive Director, maintain its mission to help protect the US swine herd.
The Swine Health Information Center’s June Domestic Swine Disease Monitoring Report shows PRRSV activity continues to remain in predicted values though the highest number of cases for 2019 were tested in May. PEDV and PDCoV detection by PCR were also within expected values in May with the highest number of cases for the year tested for each virus. Positive cases of TGEV continued to decline. The report notes the overall detection of MHP by PCR is within expected values though there was a substantial increase in positive cases among adult sows from April to May. Diagnoses of respiratory syndromes for spring this year compared to last is similar. There was a 28.47% increase in the number of enteric diagnoses for spring 2019 compared to last year. Details are included in the full report.
In the June Swine Health Information Center (SHIC) Global Swine Disease Monitoring Report, the first African swine fever (ASF) outbreak in Hong Kong is discussed. The first two outbreaks were detected at slaughterhouses in animals imported from mainland China and led to the culling of more than 10,500 pigs. The first ASF outbreak in North Korea was reported in May as well. Authorities said the outbreak occurred at a cooperative farm in Usi county, in the westernmost Changang Province, less than 10 miles from the border with the Chinese province of Liaoning. During the 87th general session World Assembly OIE, a global approach to ASF control was presented. It will be based on an internationally agreed framework intended to harmonize regional and national strategies. This SHIC report also includes information the USDA’s ASF surveillance program, noting USDA will start testing for ASF samples currently included in the classical swine fever (CSF) surveillance program. Finally, in India, an outbreak of nipah virus has been reported.