African Swine Fever: economics versus pathology

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, Dr. John Deen compares the consequences of African Swine Fever based on its pathogenicity and its economic impact on the swine industry.

Keypoints

  • The disease appears to be relatively easy to identify, control and eradicate in the US
  • Introduction of African Swine Fever (ASF) would result but relatively few infected pigs
  • The immediate loss of export markets would nonetheless result in catastrophic economic losses

The establishment of ASF in pig populations in Eastern Europe and China has significantly increased the likelihood of the introduction into the US pig population. Its ability to survive for long times in a variety of materials, including pork products, makes it a real threat to travel the distance and infect US pigs. Indeed, with the trillions of ASF viral particle already produced, it is not hard to imagine that one or more of them has already found its way to North America, but subsequently did not find its way into a pig.

The multiple effects of Emerging Infectious Diseases (EID’s), especially hemorrhagic diseases such as ASF, have been mostly studied in human populations, but many of the generalities are appropriate in our preparations.Over the past 9 years the University of Minnesota’s College of Veterinary Medicine has led efforts in capacity building in USAID’s Emerging Pandemic Threats program of USAID. This, in turn, was part of the a broader set of efforts called the Global Health Security Agenda, which expends billions of dollars annually to control and prevent diseases such as MERS, Ebola and SARS.

In negotiating, planning and implementing strategies I came to a number of realizations, but a few came up repeatedly.The first is that population or public health is in short supply in many parts of the world. It is a central part of our swine medicine, but those thought processes are often not evident in human medicine, outside agencies such as the CDC.Many countries lack the luxury of such capabilities, both for human and veterinary medicine. Many countries are dependent on international collaboration, and such veterinary collaborations are underfunded.

The other major lesson is that people rarely act rationally in the face of potential epidemics. The combination of fear, rumors, misinformation and ignorance results in damage that goes far beyond the costs of the disease and its control. Economies are often severely affected, with fear driving a restriction in commerce, tourism and even basic policing.The resultant or exacerbated poverty can result in as much of an insult on health as the infectious disease of concern.

A challenge with the introduction of ASF, or any novel reportable disease, into the US swine herd is that we have a good idea on the behavior of the disease. Frankly, there are many diseases in our pigs that are more difficult to control. ASF moves relatively slowly and can be putatively recognized through its and excellent capabilities to isolate, trace and eradicate the disease. We lack, mostly, the major risk factors of feeding food products and backyard herds. The one concern is our extensive feral pig population, but concerted methods to reduce that exposure are available.

Inasmuch as we understand the behavior of the disease, the behavior of farmers, governments, business and farmers are more difficult to predict. With a loss of 25% of the market (plus any exports in transit being returned), those farmers dependent on public price discovery face the prospect of having no market. The devaluation of inventory and farms will result in decreased ability to finance operations.One or more farms will be affected directly by an ASF infection with rapid depopulation. If more farms are close to the infected farms, they too will be depopulated. However, for some time all farms will be severely affected by the elimination of export markets. Transport, especially between states, will often be stopped. Pigs will back up on the farms, with those that go to slaughter being highly devalued. Money for feed, disease control and other inputs will be hard to secure. Payrolls will not be met and employees will look for more promising jobs in other industries.

Much of our planning has been on disease readiness, and rightly so, as the speed and competence in which the disease is brought under control will determine the speed under which markets will be reacquired. Markets are quick to shut down borders and slow to open them. Most scenarios have regaining of all historic markets measured in years, however.Thus, we not only need disease management but supply management. The economics of pig production are brutal, with oversupply resulting in what can be described as death matches, with the survivors also compromised by the times of low prices and the industry stripped of many of its capabilities.

The industry is now completing many simulations of disease management in the face of the identification of pigs infected by ASF in the US.Depopulation to control disease is readily discussed and modelled to regain markets. Beyond this purpose, depopulation and restriction of production is often ignored, but it may be as important to regain market equilibrium and perhaps even price discovery. For the aggregate industry, there is real benefit to create strategies to combine the benefits of both, actively depopulating all potential contacts, not only through location but also through transportation and management networks.

A term in human health management is the “social determinants of disease”. Of these social determinants, none looms larger than poverty.In the same way, we need to recognize that disease affects economics, but economics also affects disease. Competent and invested care is best delivered on farms that are financially healthy. A rapid restabilization of the industry serves not the owners and employees, but also pigs and the public.

ASF threat: 3 swine vets share insights from the frontline

The rapid spread of African swine fever (ASF) throughout China and other regions of the world has raised concerns the disease will ultimately make its way to the US — a development that could cripple the nation’s pork industry if it doesn’t adequately prepare.

That was the ominous warning of three US swine veterinarians who came together for a roundtable discussion on ASF following their recent trip to China. Among them was Dr. John Deen from the University of Minnesota, coming back from the Leman China conference.

Follow the link to listen to their podcast.

The informative session was organized by the editors of Pig Health Today and sponsored by Zoetis.

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.

What if African Swine Fever came to Minnesota?

The Center for Food Animal Health and Food Safety at the University of Minnesota released a new video on African Swine Fever and what the consequences would be if it ever came to Minnesota. Dr. Marie Culhane from the University of Minnesota and Dr. Beth Thompson, executive director of the Minnesota Board of Animal Health discuss how the state prepared for this eventuality.

Click on the video to listen to their exchange. (14:56 min)

 

The 2018 Allen D. Leman Swine Conference successfully continued its tradition of high-quality content while innovating

The 2018 edition of the Allen D. Leman swine conference held in St. Paul, MN continued to offer a wide range of high-quality, science-driven presentations while innovating on several aspects of its program.

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Megan Bloemer (right) receives the Morrison Swine Innovator Prize from Dr. Perle Boyer (left)

This year marked the second year of the DVM student session at the Leman conference but the first time that a student received the Morrison Swine Innovator Prize. Megan Bloemer, a student from the University of Illinois was truly honored to be the first recipient of this prestigious recognition. Megan received a $7,500 scholarship in addition to participating in an exclusive workshop with the other DVM students-presenters. The quality of the students’ presentations was excellent but the practicality and the innovation with which Megan treated the issue of truck wash biosecurity put her at the top.

Sunday afternoon, the new Beer and Bacon conversation series was launched. The session, during which Dr. Matthew Turner was interviewed by Dr. Marie Culhane, was extremely popular. Seating was limited so do not forget to register early if you would like to attend next year!

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Dr Rebecca Robbins (left), Science in Practice awardee and Dr. Montse Torremorell (right)

We celebrated Dr. Rebecca Robbins for her well-deserved recognition as the Science  in Practice awardee of the year. The reception held in the Science museum in St Paul was sponsored by Boehringer Ingelheim.

 

The spread of African Swine Fever in China and Western Europe prompted us to dedicate two very well-attended sessions on this topic. The first session on Monday afternoon coordinated by Dr. John Deen included a summary of what is known about the disease by Dr. Chris Oura, then a clinical case experienced in Russia by Dr. Gustavo Lopez and a presentation by Patrick Webb on ASF awareness in the industry and beyond. On Tuesday, Dr. Scott Dee presented his latest research on the risk from feed ingredients for the transmission of ASF.

For more information, the University of Minnesota launched two webpages:

The 2018 Allen D. Leman conference continued to propose high quality keynote speakers.
Dr. Brad Freking and Dr. Deb Murray from New Fashion Pork gave the first Morrison lecture and presented their vision of pig farming. They explained how they chose to decrease their antimicrobial usage while reserving the right to treat pigs when needed and why they launched Old Fashion Pork.

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Dr. Maria Pieters presenting

Dr. Maria Pieters reminded us of the issues associated with having a Mycoplasma hyopneumoniae  positive herd and challenged the swine industry to eradicate the diseases that can be eradicated so that we can focus on diseases that are harder to control.

Becca Martin and Randy Spronk gave an update on trade in pigs and the current challenges that we are facing as an exporting nation. Free trade seems to be the best option for our producers in order to maintain the market.

Dr. Michael Rahe presented the Pijoan lecture on behalf of Dr. Michael Murtaugh giving us a overview of the past 30 years dealing with PRRS. Sadly, Dr. Murtaugh passed away that very same day, from his battle with cancer.

As always, we would like to thank all of you for your continuing support. The Allen D. Leman swine conference would not exist without you and we hope to see you next year: September 14-17, 2019.

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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.

 

African Swine Fever information repository web page

The spread of African Swine Fever in China and in Europe has been raising concerns in the US swine industry. To answer the need of updated and relevant information, we created the webpage: z.umn.edu/AfricanSwineFever.

Among other resources you will find recording of the session of the 2018 Allen D. Leman Swine Conference, a link to the Swine Disease Global Surveillance reports, and preparedness checklists from the Pork Checkoff.
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The page is organized to answer the following questions:

  • What do we know about African Swine Fever virus?
  • What is the progression of African Swine Fever worldwide?
  • African Swine Fever in the field
  • What are the available diagnostic tests for African Swine Fever?
  • How to prepare for African Swine Fever
  • Is there a vaccine against African Swine Fever?
  • Is feed a concern?