Science Page: Illegal importation of meat derived food products through passenger airline carriers and possibility of disease introduction

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 an article by the MSHMP team regarding the impact of illegal meat product importation on disease introduction.

Key Points:

  • Commercial airplane passengers bring illegal food imports
  • These illegally imported food products are an overlooked but important disease introduction source
  • The illegal importation by commercial travelers happens more frequently then generally assumed

Illegally imported products are a likely source of disease introduction

The recent African Swine Fever (ASF) outbreaks in China have created concern in the US swine industry over the possible introduction of the disease into the US, thus making Foreign Animal Disease (FAD) a primary topic of concern. One of the most pressing concerns about FADs in general, and ASF in particular, is what are the likely sources of entry, and how the associated risks can be mitigated. Illegally imported products, carried by commercial air passengers are often overlooked as a minor introduction source. Several studies around the world show that commercial air passengers do represent a likely source of disease introduction. Outbreaks of ASF, Classical Swine Fever (CSF) and Foot and Mouth Disease (FMD) have been attributed to feeding imported waste meat to domestic pigs (Falk, et al., 2013).

Thousands tons of illegal food products are found at airports

It is difficult to estimate the total amount of illegal food products entering a single country each year. A study conducted in Germany in 2015 at two major airports tracked seizures for three months, including an intensive 10 days of special controls where higher numbers of passenger luggage was searched. Based upon that data they estimated that each year 2,800 tons of illegal food products were brought in via the Frankfurt airport alone. The most commonly imported foods were meat and meat products, including raw, home cooked, preserved, and packaged foods (Beutlich, et al., 2015).

Another study, conducted in Switzerland estimated that the total volume of non-intercepted meat products were 8.6 tons for bush meat, and 1,013 tons for other meat products (Falk, et al., 2013).

Illegal food products contain pathogens; airports are risky ports of entry

A key point to understand the risk of improperly imported foods is knowing how often they contain pathogens and whether these have the capability of remaining infectious. In the German study, out of 474 samples tested, 5% of them contained food borne pathogens (Beutlich, et al., 2015). In a similar study conducted in Spain 67 out of 122 samples tested at an airport contained human noroviruses, and hepatitis E (Rodriguez-Lazaro, et al., 2015).

A modeling study focused on estimating the risk of introduction of ASF and CSF into the US using airport and customs data. The study identified specific airports (i.e.Washington-Dulles, George Bush-Houston, JFK-Queen, Warwick, Sanjuan, West Palm Beach, Charlotte, Ft. Lauderdale, Newark and Cleveland) as ports of entry with the highest risk for both ASF and CSF introduction. This work also identified the months of May through July as the months with the highest risk (Jurado, Paternoster, Martínez-López, Burton, & Mur, 2018).

Only a fraction of illegal imports are intercepted

It is estimated that only between 10-50% of improperly imported products are intercepted at customs (Jurado, Paternoster, Martínez-López, Burton, & Mur, 2018).One study’s sensitivity analysis showed that for both ASF and CSF, the likelihood of detecting illegal products was highly correlated with the final risk of disease introduction.This means that an increase in customs detection of products brought by commercial passengers largely reduces the risk of a CSV or ASF introduction into the US (Jurado, Paternoster, Martínez-López, Burton, & Mur, 2018).

Pork products were seized recently in the USA and Japan

Recently, on October 15th, 2018 a customs and border protection beagle found a whole roasted pig in the luggage of a traveler from Ecuador(Lieu, 2018) at the Hartsfield-Jackson Atlanta airport. Ecuador as any other South American country is ASF negative, but CSF continues to be present in the country. It is unknown whether the smoked pig has been tested for CSF, but the case is a perfect example of the variety of products that are being transported to the US.

On October 1st, Japanese customs officials confiscated a pork sausage from a Beijing traveler. The sausage tested positive for ASF (Reuters). African Swine Fever has also been found at a South Korean airport in pork products brought in a commercial passenger airline from China (Reuters). All of these examples highlight the reality of the risk illegally imported products carried by commercial travelers play in FAD introduction.

It is important for the swine community to be aware of these risks, to be aware of what food products are being brought to their sites by people, and to push for effective prevention methods. It also highlights the need of the swine community to communicate this risk to the non-swine community to raise awareness and thus contribute to protecting the industry. By using research that helps identify where the highest risks lie spatially and temporally, as well as flights from which countries represent risk, better prevention methods can be developed and implemented.

The effect of season on PRRS time-to-stability in the Midwestern United States

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.

Key Points

  • Seasonal conditions may effect the time to stability of a farm
  • Understanding seasonal effects on time to stability can help producers and veterinarians plan herd closures

This week, we are sharing a report by the MSHMP team in collaboration with Dr. Andreia Arruda from the Ohio State University regarding the impact of seasons on PRRS time-to-stability.

The time needed between an outbreak and consistently weaning porcine reproductive and respiratory (PRRS) virus PCR negative pigs is referred to as time-to-stability (TTS). In this analysis we describe differences in TTS according to the season when the PRRS outbreak occurred in farms located in the Midwestern United States.

161 PRRS outbreaks in 82 sow farms were classified based on the date of the outbreak:

  • March 21st to June 20th: Spring
  • June 21st to September 20th: Summer
  • September 21st to December 20th: Autumn
  • December 21st to March 20th: Winter

TTS was calculated as the time from the reported PRRS outbreak to the time of the last PRRS PCR negative result in wean-age pigs.

A significant difference was detected in TTS among seasons. The median TTS was higher in spring and summer, compared to autumn and winter.

An explanation for the observed TTS difference among seasons may be found in environmental survivability of the virus as for PRRS outbreaks that occur during spring or summer, the last phase of the stability process coincides with the arrival of winter where the reduced ventilation and decreased temperature within the farm may favor PRRS survival resulting on a lower likelihood of elimination during this time.

PRRS time to stability season

Science Page: Making epidemiological sense out of large datasets of PRRS sequences

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 an epidemiological report regarding a large PRRS sequence dataset from Dr. Igor Paploski in the VanderWaal research group.

Key points:

  • Occurrence of PRRS lineages is not equal in different years, systems or production types
  • Occurrence of specific PRRS lineages is associated with movement of animals
  • Continuous surveillance for PRRS occurrence is important in understanding its determinants and might be able to provide insights that can
    help on its prevention

By utilizing a dataset of 1901 PRRS sequences provided by the Morrison Swine Health Monitoring Project (MSHMP) participants over 3 recent years, the spatiotemporal patterns in the occurrence of different lineages of PRRSV was described and the extent to which the network of pig movement between farms determines the occurrence of PRRS from similar lineages was investigated.

PRRS lineages occurred at different frequencies across geographically overlapping production systems. Preliminary analysis showed that the relative frequency in which specific lineages occur increase while others are decrease over time. The rate at which these changes occur appears to be system-specific. Some lineages were also more common in farms of specific production types (i.e. sow farm or nurseries). As expected, farms that were connected via pig movements were more likely to share the same lineages than expected by chance across all years.

These findings suggest that system-specific characteristics partially drive PRRS occurrence over time and across farms of different production types. Our results also
indicate that animal movement between farms is a driver of PRRS occurrence, strengthening this hypothesis of viral transmission.

Additional research is needed to quantify risks and develop mitigation measures related to animal movement.

Large PRRS sequencing dataset

Science Page: Quarterly review of MSHMP reported PRRSv Restriction Fragment Length Polymorphism (RFLP) patterns

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 report from the MSHMP team regarding reported PRRS RFLP patterns.

Keypoints:

  •  Recording PRRSv RFLP and sequences will provide better insights into the epidemiology of the disease at local, state and national level.
  • Building a RFLP database will allow us to assess which factors could be involved or related with the emergence of a new RFLP.
  • The predominant pattern RFLP in this quarterly review is the 1-7-4.

In the first quarter of the 2018/2019 incidence year, 20 breaks affecting 12 production systems were reported. Out of these, 4 occurred in July, 13 in August and 3 in September.

Of those 20 farms, three had a break while still being status 1, one was status 2 in the process of eliminating the disease (not using any immunization protocol at that point), 6 were using field virus as the acclimatization protocol (2fvi), 8 were using vaccine (2vx), one was provisionally negative (status 3) and one broke from a status 4 after being almost 4 years completely negative (see figure below).

RFLP patterns with status at break

The distribution of the breaks is wide and affects different states. Thus, we had 6, 1, 4, 1, 4, 2, 1 and 1 break in the states of IA, IN, MN, MO, NC, NE, OK and PA, respectively. The closest 2 farms that broke were 1.2 miles apart, belonged to the same company and had the break a week from each other (no sequences was provided).

Eight out of the 20 breaks reported were accompanied by the associated RFLP. The predominant (4 out of 8) RFLP pattern since July is 1-7-4. Iowa was the state with the highest number of 1-7-4 cases.

Science Page: Remembering Professor Mike Murtaugh

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 remembering Professor Mike Murtaugh with Cheryl Dvorak.

Michael MurtaughProfessor Michael Murtaugh, PhD, passed away Tuesday September 18 from complications of pancreatic cancer. He was 67.

Mike joined the college in 1985 and spent the entirety of his University of Minnesota career in the Department of Veterinary and Biomedical Sciences. He was a consummate faculty member, excelling in teaching graduate courses and conducting research and
outreach. Mike authored more than 225 peer-reviewed journal articles, was the primary advisor for 30 Master’s and PhD students, and held three U.S. patents. His influence extended throughout the Academic Health Center at the University and throughout the world. At the time of his death, Mike was serving on the editorial boards of more than a dozen academic journals, and had successfully completed nearly 160 sponsored projects as Principal Investigator or Co-Investigator.

Mike was a respected and highly sought after mentor. He always had people coming and going from his office asking for scientific, career, and personal advice. His door was always open and he always stopped what he was doing to help others. He touched many
lives during his career. Besides his numerous graduate student advisees, he also mentored over fifteen veterinary students, thirty-six undergraduate and high school students, twelve post-doctoral researchers, twenty visiting scientists, and numerous others who came to him for advice and support. He cared about everyone not only scientifically, but also personally. He always wanted to do what was in a student’s best interests, even though it may not have been what was in his best interest. His lasting legacy is in the scientific training and education of a generation of swine health specialists and researchers.

Prof. Murtaugh was an international leader in swine immunology, and devoted considerable effort over the past 25 years in battling the Porcine
Reproductive and Respiratory Syndrome virus (PRRSv), a disease that
costs U.S. swine producers alone some $500 million annually. Mike used
molecular biological approaches to first understand the nature of PRRSv
and investigated in detail the immunological response of pigs to this pathogen.

Mike earned the B.S. degree in biology at the University of Notre Dame and
then served as a Peace Corps volunteer in Venezuela. He earned a Ph.D. in entomology at the Ohio State University. The University of Texas Medical School in Houston was his next stop— he spent four years in a post-doctoral position in the Departments of Internal Medicine and Pharmacology— before assuming a faculty position in St. Paul.

He will be remembered for his dry sense of humor and positive outlook on life, character traits that he maintained even as his battle with cancer raged. Mike cared passionately about science and derived some of his greatest personal satisfaction working on the college’s Strategic Plan and the International Conference on One Medicine and One Science (iCOMOS). Mike cared deeply about science informing policy and saw the need for scientists to be more actively involved in communicating about their research.

I am grateful to have known him, and stand in awe of the many contributions he made to our college.

Science Page: Basic Steps for Foreign Animal Disease Preparedness

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 one-page step-by-step reference document for foreign animal disease preparedness, created by the MSHMP team.

Key Points

  • The current African Swine Fever situation in China and Europe makes Foreign Animal Disease preparedness even more crucial.
  • There are steps that can be taken to prepare a site for a Foreign Animal Disease and to improve the probability of continued animal movement.
  • Many producers are already doing these steps in some form and taking the practices to the level of documentation can add benefits when dealing with other diseases such as PRRS and PED.

As African Swine Fever (ASF) has been moving rapidly through China and Europe, the possibility of a Foreign Animal Disease (FAD) event in the United States becomes more of a possibility. In the event of an FAD, state and federal animal health officials will limit movement of animals and animal products to limit disease spread.

Movement permit requirements are decided by regulatory officials from each state’s animal health department, but there are steps producers can take to help them mitigate chances of infection and to increase their likelihood of receiving a movement permit during an FAD. These steps are also outlined on the Secure Pork Supply (SPS) plan website. SPS is a collaboration between USDA APHIS, Pork Checkoff, Iowa State University, and the University of Minnesota.

Basic Steps:

Establishing location and site information:

A site must have a Premises ID Number (PIN) in order to move pigs or pig products. A PIN includes the 911 address and latitude and longitude coordinates of the actual location of the pigs. Having this information allows state and federal animal health officials to determine if a site is within control or quarantine zones based on its location to infected sites. The PIN is also imperative for allowing accurate tracking of pig and supply movement into the farm and identifying any connection to infected sites. It is important to validate that the location information points to the swine location and not an alternative house or building. Additionally, it is good to have information on farm contact such as manager and owner phone numbers and emails, number of animals, and if any other species are present on site.

Proof of biosecurity measures:

secure pork supplyBeing able to demonstrate the biosecurity measures of a production site will greatly improve permitting chances because good biosecurity helps ensure lower infection risk. The SPS supplies a biosecurity self-assessment checklist (http://www.securepork.org/Resources/SPS_Biosecurity_Self-Assessment_Checklist-_-IndoorProduction.pdf) covering the areas that should be included in a biosecurity plan. These areas are staff training, vehicles and equipment, personnel, wildlife and insects, manure management, carcass disposal, animal and semen movement, feed, and establishing protection of the pig herd such as a line of separation, perimeter buffer, disinfection station, and access points, including a map of the site. Being able to track movements in and out of the farm as well as between production sites is highly beneficial. A biosecurity manager should be appointed to write and manage the biosecurity plan.

Disease Monitoring and Epidemiological Information

In the event of an FAD, producers will be asked to provide epidemiological information and confirmation based on monitoring that there is no evidence of infection. Much of the epidemiological information that may be requested overlaps with the SPS biosecurity plan outline, such as knowing movement of equipment, incoming animals, products, and feed, and inter-site movement of personnel. Regular recorded monitoring of the animals allows a producer to provide confirmation that no clinical signs of an FAD have been observed. To make this effective, staff performing the monitoring must know how to identify the diseases and records must be consistent. Additionally, samplescan be stored and used to prove that the herd has been and remains negative. The SPS provides resources in both Spanish and English detailing disease identification for FAD’s, an example questionnaire of epidemiological information that may be requested, and resources for disease monitoring and emergency response.These resources can be found at http://www.securepork.org/pork-producers/disease-monitoring/ and http://www.securepork.org/Resources/SecurePorkSupply-Questionnaire.pdf .

These steps can be labor intensive with no clear immediate return, particularly the development of a biosecurity plan and regular monitoring records. This understandably can make them a low priority as producers deal with many resource decisions and demands on a daily basis.In light of this, it is important to remember that having these steps prepared will be invaluable for maintaining animal movement and continuity of business in the case of an FAD. Many of the steps or questions being used in these tools, like awareness of movement into and out of the farm, regular monitoring for clinical signs, and good biosecurity measures are things producers often do already. These steps simply put them into finalized and recordable forms. The process can also benefit the farm by showing biosecurity gaps and improving monitoring practices and records that are relevant to diseases such as PRRS, PED, and influenza.

Find more info about SPS at: http://www.securepork.org/

Science Page: African swine fever experience in a large commercial system in the Russian Federation

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 the experience Dr. Gustavo Lopez, a PhD candidate at the University of Minnesota, had dealing with African Swine Fever in Russia.

Key points:

  • Infected pigs can be asymptomatic carriers of African swine fever virus (ASFv)
  • Timely detection with diagnostic testing, strict biosecurity measures and rapid removal of the source of infection are key to limit the transmission of the virus within and between sites.

In December 2014, ASFv was detected in a finishing site of a multiplier herd from a large commercial pig company located in the Russian Federation. The region had multiple reports of ASFv in backyard pigs before the outbreak. The affected company consisted of 80,000 sows in 15 farms organized as a three-site production system with each sow farm having a dedicated nursery and two finishers. The multiplier herd supplied gilts from the finisher to the gilt development unit (GDUs) for each farm. Each sow farm had a quarantine within the farm to receive the gilts from the GDU .

A 3% mortality increase was reported in one room of the finishing site. A few pens in one of the rooms had pigs affected with fever, purple ear and mild scouring. The site was being monitored for ASFv on a weekly basis before gilt shipment, following local regulations and results always came back negative.

Samples collected from the affected pigs were negative for ASFv, Classical Swine Fever, PRRSv, and Salmonella so the decision was made to resume shipment of gilts from a room with no clinical signs to the GDU.

As the days progressed, the clinical signs in the affected room worsened and affected more pens. The GDU that had just received gilts reported similar clinical signs and diagnostics on samples collected then from the multiplier finisher and the GDU confirmed the presence of ASFv at both sites.

At that time, all pig movements were stopped and a 5km quarantine area was imposed around the two affected sites. Gilts that had been sent from the GDU to five commercial sow farms, and were in quarantine tested negative to ASFv. Nevertheless as a precaution, the decision was taken to sacrifice all the gilts in the quarantines.

Protocols mandated by the government were implemented in the ASFv positive multiplier finisher and GDU which consisted of euthanasia of all pigs within a 5km radius, destruction with burial and burning of all carcasses, strict movement restrictions for vehicles and people and exhaustive disinfection protocols inside the farm and its territory.

Transportation of infected non-symptomatic animals from the multiplier finisher was the most likely route of infection to the GDU. The source of infection to the multiplier finisher is unknown, although people are thought to have played a role given the presence of ASFv in backyard farms in the area. Events such as introduction of infected pork meat, lack of proper disinfection of 3rd party trucks or non-compliance with the shower-in policy of the farm could not be ruled out. The outbreak occurred in December when temperatures were below zero Celsius and wild pig-tick-domestic pig interaction was unlikely.

It is important to point out that 12 of the 16 rooms in the multiplier finisher remained negative to ASFv until the moment of euthanasia. The sow farm and nursery multiplier were monitored for ASFv during the quarantine period and until the moment of euthanasia 6 months later. During this time, they remained negative to ASFv, even though they were within close proximity to the affected farm. Our experience indicates that a timely detection of ASFv with testing, strict biosecurity measures and removal of the source of infection as soon as possible can limit the transmission of the virus between sites.