dr. rodger main - pedv's emergence in the us: status report, diagnostics, & observations

Veterinary Diagnostic LaboratoryIowa State University

PEDV’s Emergence in US“Status Report, Diagnostics, & Observations”

Iowa Pork Congress1/22/2014

Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Lab, Iowa State University, Ames, IA 50011


Faculty, Staff, & Students of ISU VDL

≈22 Faculty, 100 Technical Staff, & 20 Graduate Students/Residents


Serving Food Animal Agriculture Comprehensive Diagnostic Service, Teaching, and Discovery

(Iowa’s only Full-Service & Fully Accredited Veterinary Diagnostic Laboratory)

Processing 55,000+ cases/year from livestock producersApplying world-class technology to real-world problems


≈ 75% Swine, 10% Bovine, 10% Poultry, + 5% Everything Else


Where the Pigs Are Located in US

≈ 500,000 pigs/week imported to IA to be grown


What is PEDV ?“Porcine Epidemic Diarrhea Virus”

• Corona-virus

• Villous atrophy

• Malabsorptive diarrhea

• Clinically Indistinguishable from TGE– Fecal-Oral Pathogen– ↑ Morality rates approaching 100% in naïve neonate populations– ↓ Mortality and severity of clinical disease in growing-finishing pigs

• Not a Zoonotic Disease or Food Safety Concern


PEDV Historical Distribution

– TGE-like outbreaks England 1971• Multiple European Countries

» Most often in nursery/grow finish pigs» Reportedly of minimal significance today

– More recently a disease of significance in SE Asia» China» South Korea

– Severe epizootic outbreaks– Persists as endemic disease

– Not Confirmed in North America Prior to May 2013


Rapidly spreading across US with more than 2,271 cases in 23 states

0

500

1000

1500

2000

2500

Cumulative Positive PEDv Cases by Farm Type

UnknownGrow-FinishSow

Date by Week

# PE

Dv

Posi

tive

Case

s


15-A

pr22

-Apr

29-A

pr6-

May

13-M

ay20

-May

27-M

ay3-

Jun

10-Ju

n16

-Jun

23-Ju

n30

-Jun

7-Ju

l14

-Jul

21-Ju

l28

-Jul

4-Au

g11

-Aug

18-A

ug25

-Aug

1-Se

p8-

Sep

15-S

ep22

-Sep

29-S

ep6-

Oct

13-O

ct20

-Oct

27-O

ct3-

Nov

10-N

ov17

-Nov

24-N

ov1-

Dec

8-De

c15

-Dec

22-D

ec29

-Dec

5-Ja

n

0

50

100

150

200

250Positive PEDv Cases per Week by Farm Type

UnknownGrow-FinishSow

Date by Week

# PE

Dv

Posi

tive

Case

s

PEDV Positive Swine Cases Ascertained from Multiple VDLs Week

Received @ VDL

Total # of PEDv Positive Diagnostic Case Submissions

(Premises) via PCR or IHC

Farm Type

CA CO IA IL IN KS KY

MI MN MO NC NE NY OH OK PA SC SD TN TX WI WY ? Sow Growing

Pig ? MD4/15/13 2 (1) 0 1 0 1 4/22/13 1 (1) 0 1 0 1 4/29/13 9 (6) 1 5 0 5 1 5/6/13 17 (13) 4 7 3 1 8 3 1 1

5/13/13 10 (9) 5 3 1 1 4 4 5/20/13 44 (43) 7 33 3 5 25 2 7 1 2 1 5/27/13 32 (29) 6 22 1 22 1 1 1 3 1 6/3/13 55 (52) 13 34 5 21 2 3 2 2 17 2 3

6/10/13 48 (42) 11 24 7 17 1 3 2 20 1 36/16/13 47 18 18 14 1 10 1 7 8 1 3 16 6/23/13 37 8 20 9 1 15 1 1 4 2 13 6/30/13 10 4 6 0 3 2 2 3 7/7/13 34 12 20 3 1 6 1 2 4 2 3 2 11 2

7/14/13 33 8 20 6 2 7 4 7 1 3 2 7 7/21/13 24 6 10 9 1 6 1 3 7 4 1 1 7/28/13 31 12 15 7 1 5 1 1 7 3 2 1 10 1 8/4/13 27 18 10 1 1 9 1 1 6 1 2 5 1

8/11/13 36 26 11 1 6 4 13 5 7 8/18/13 30 14 14 2 1 6 1 5 1 2 14 8/25/13 26 15 8 3 2 1 3 2 4 1 10 3 9/1/13 31 10 18 3 2 6 1 8 1 4 4 5 9/8/13 28 20 8 3 7 6 1 13 1

9/15/13 32 12 15 5 7 1 3 2 12 1 5 1 9/22/13 40 16 17 8 1 3 1 5 1 24 4 19/29/13 42 14 21 8 2 6 2 2 19 6 1 3 110/6/13 43 19 22 2 1 6 6 1 1 21 6 1

10/13/13 56 24 25 7 10 4 1 5 21 13 2 10/20/13 68 41 22 5 1 20 2 1 9 1 2 22 9 1 10/27/13 85 40 44 4 33 4 1 3 1 5 17 1 13 2 1 3 1 11/3/13 90 24 56 12 38 1 1 6 2 7 2 14 5 10 1 1 1 1

11/10/13 92 20 64 12 1 51 1 2 8 1 15 4 5 1 3 11/17/13 116 40 59 21 1 48 5 3 5 17 14 4 11 1 1 6 11/24/13 96 24 38 34 1 25 4 1 1 19 19 9 12 1 3 1 12/1/13 141 40 62 42 2 66 10 10 4 23 8 1 5 6 3 2 112/8/13 132 31 73 29 65 8 6 5 2 18 3 12 3 7 1 1 1

12/15/13 187 46 93 52 1 96 15 9 3 27 5 20 1 3 5 1 112/22/13 118 29 56 36 61 8 3 5 2 17 2 5 1 5 3 2 412/29/13 134 40 59 44 1 54 14 3 4 20 4 18 2 5 2 3 1 1 1 1

1/5/14 188 37 85 70 3 82 10 2 9 1 1 46 15 1 6 4 2 1 4 1Total 2272 715 1119 472 1 38 852 81 69 152 5 1 13 263 18 316 6 2 66 276 28 2 6 6 30 4 1 20


PEDV DiagnosticsDiagnostic Specimens

• Intestine (Fresh & Fixed)• Feces• Fecal Swabs• Oral Fluids • Serum (PEDV Antibody)


Real-Time PCR• PEDV - PCR – Widely available– Same day testing – Highly sensitive… quickly transitioned to majority of testing being surveillance based testing

• Learning Curve on Extraction Techniques • Sample types = Intestine, Feces, Fecal Swabs, & Oral Fluids


PEDV IFA test (Serum = PEDV Antibody)

0 5 7 14 21 28 350

50

100

150

200

250

300

350

400

IFA

antib

ody

titer

Days post inoculation

Development of IFA antibody over time

(Source: Yoon, Sun)


PEDV IFA(Serology / PEDV Antibody Based Assay)

Presently Offered As:

– PEDV IFA as a screening assay = ( + or - @ 1/40 dilution)OR– PEDV IFA as a 4-dilution ( - or + 40, 80, 160, 320)

Drs. Johnson, Yoon, Zhang et al


Other Antibody Test Development

• Multiple ELISA Development Efforts In-Process– Iowa State University – Kansas State University– South Dakota Sate – University of Minnesota– … & likely others

• PEDV ELISA assays commercially available proved to be of very poor quality


Use of PEDV IFA to Complement PEDV PCR Testing

? ‘s = Are these replacement females PEDV negative ?

?’s = What is the actual prevalence of PEDV in a region ?

• Field reports suggest that the clinical presentation of PEDv infection in growing pigs can be variable in its severity and not readily distinguishable from the myriad of other causes of diarrhea in growing pigs.

• Approach antemortem PEDv surveillance with the same rationale more commonly

used in PRRSv surveillance that incorporates the use of both antigen and antibody based diagnostic tools.

PCR on Oral Fluids &/or Fecal Samples ( PEDV shedding and/or presence in the environment)

+ + + PEDV IFA (Antibody-based assay to detect previous exposure / antibody development)

Drs. Johnson, Yoon, Main, et al


Virus Isolation (VI)

P2 (1 dpi)

P1 (4 dpi)

Control cells

P3 (20 hpi)

(Source: Hoang, Chen, Yoon, Zhang)

Research Diagnostic Tool and Vaccine Development Purposes


Sequencing

China (2011-2012)

Belgium (1977)

USA (2013)

Korea (1998)

Korea (2009)

NOTE: The analysis is based on full genome sequences via NGS technique.

China (1989-2008)

(Source: Yoon, Zhang et al)

To date ≈ Primarily Research Purposes

PEDV Sequencing (S-Gene) is Now Available Epidemiological Purposes


Immunohistochemistry (IHC)

Normal neonatal pig: Healthy, long intestinal villi

Early PEDv infection (~8 hrs PI): Infected cells (brown stain) line the villi

Late PEDv infection (~36 hrs PI): Severe villus atrophy & loss of

absorptive epithelium

Late PEDv infection (~36 hrs PI): Few infected cells remain (brown

stain) & absorptive cells destroyed

1

4

2

3

(Source: Schwartz, Madson, Magstad et al.)


PEDV• Rapidly Spread Across Broad Regions

– Role of Transport Vehicles, Lairage at Collection Points, & Animal Movement– Lowe et al..... PEDV negative trucks returning from plant positive (amplifier)– Turner, Battrell et al…..PEDV positive sow collection stations prior to PEDV in NC

• Ability “Break-Through” Conventional Biosecurity Measures

• Area Spread – Clear & Present Danger– Most apparent in areas of high breeding herd concentration

• Concentrated areas of sow farms in panhandle OK/TX and SE NC...... & now IA, MN, et al


≈ 4 weeks of weaned pigs losses + 1 more week of losses 18 – 20 weeks later≈ 10% of affected sow units annual output…. 2.2 to 2.5+ PSY...... ≈ $150+/Sow

PEDV - Immediate Costs of Disease on Naïve Breeding Herds

Porcine Epidemic Diarrhea Virus (PEDV)

Severity of Disease → Very age / stage of production dependent. • Clinical disease can be readily missed in growing pig populations

Turner, Dufrense, Ackermann, et al


PEDV• Shedding

• Amount of PEDV being shed is extraordinary– Ability to persist in the presence of protective maternal antibody

• Controlled studies up to 35 days (Yoon, Madson, Bower, Magstad et al)• Commercial sow units taking at least 90 days to produce PEDV negative pigs• OF Samples staying PEDV positive for up to 6 – 8 weeks post-exposure

• Mixed Response to TGE-Like Mgt Strategies– ?...≈70% Success rate…. ..≈30% recurring challenges

– “Dose” in farrowing rooms seems to recurring theme

• Endemic Phase of Disease ?– Singular largest & looming concern

• PEDV on Fast-track to Become Endemic US


Key Lessons Being Learned on Broader State of Preparedness

Food

AnimalAgriculture

Consumer

Genetics

Facilities / Environment

Nutrition

Health

Management

Business / Finance

Practicing Veterinarian

VeterinaryDiagnostic

Labs

Production Animal Medicine

SuppliersOf Health Products

Producer

Pathology Virology

Bacteriology Serology

Toxicology

Pharmacology

Epidemiology

Regulatory Agencies

Strategic Alliances in Service, Teaching, & Research


Food Animal Industries → Changed Dramatically ↑ Demand Globally for High Quality Protein Based Diets

↑ Advances in Logistics

Are we keeping pace to support them?

Data courtesy of NPB & Dr. Steve Meyer


Globalization↑ Opportunities & Challenges of Our Time

Opportunities: • ↑ US Animal Agriculture’s Role in High Quality Food to the World• ↑ Global Leaders in Advancing Systems of Food Production

Challenges:• ↑ Risks associated with Transboundary Disease Introductions• ↑ Animal Health Management Infrastructure Needs

– Sustain Market Access & a Competitive Production Environment---------------------------------------------------------------------------------------------------Globalization of the Food Supply Chain Provides a Tremendous Opportunity to Advance Practice of Veterinary Diagnostic and Production Animal Medicine.


Preparedness at the VDL’s• High-Throughput Assays

– PCR (Antigen) and Elisa (Assays) in place

• High-Throughput / Ante-mortem Sample Types– Needs to be in a “Tube”

• Serum / Whole-Blood / Oral Fluid / Swab / Scraping

• Index Case Diagnostic Tools / Protocols– Vitally Important... but limited utility in response-phase in an outbreak situation

High-Throughput Validated Assays & Sample Types


Veterinarians Across U.S. Submitting Cases to their VDL Service Providers in the NAHLN

VDL VDLVDL

Centralized Database Tools for Interpretation

Submission All Dx Results Submission Submission All Dx Results All Dx Results

VDL

Submission All Dx Results

Standardized Messaging / Mechanisms for Information Transfer

Integrated Information Management Systems

Area Regional Disease Management Tools



Permissioned Users Animal Health Officials Permissioned Users

Seamless,Streamlined,

& Active in Private & Public Sectors


Systems of Response Required for Effective Containment(but not eliminate the food supply and industries we are trying to protect)

• Swift, Calculated, Coordinated, and Firm– Built Around Continuity of Business Plans & Compartmentalization– To safely & securely enable movement and continuity within the supply chain)

(e.g., Secure Egg, Milk, Turkey, & Pork Supply Plans)

1. Simple 2. Well Defined 3. Broadly Applicable 4. Active

• Surveillance = Passive Today & Active Tomorrow


(Although Somewhat Daunting)Needs → Very Practical

– Integrated & active information management systems• Submissions → Labs LIMS → Centralized Databases → Area Regional Mgt Tools

– Public and Private Sector Applications• Swine Movement (Interstate, Intrastate, & Slaughter)

– Existing / Validated / High Throughput / Antemortem Diagnostics– Robust / Real-Time Surveillance (Passive Today / Active Tomorrow)– Broadly Applicable Business Continuity &/or Compartmentalization Plans– Self-Serving Reason for Active Participation Throughout the Chain


Premises ID Barcode Labels on VDL Submissions

Working together to enhance preparedness and capabilities

Using Premises ID #’s Is the Foundation


Premises ID Barcode Labels


How to Order Premises ID Barcode Labels

1. Go to the ISU VDL website

2. Click “Premises ID Barcode Label Information”

3. Download “Premises ID Label Spreadsheet”

4. Populate fields

5. Email spreadsheet to [email protected] Veterinarian: Clinic Name:Clinic Address:

Premise ID Official Site Name/Code Owner00ABC12 Bob's Finisher Bob 00ABC13 Bob's Nursery Bob00ABC14 Bob's Sow Bob00ABC15 Bob's Farrowing Bob00ABC16 Bill's Finisher Bob00ABC17 Bill's Nursery Bob00ABC18 Bill's Sow Bob00ABC19 Bill's Farrowing Bob

Dr. SmithSmith's Vet Clinic111 Main Street, Paradise, IA 55555

Veterinarian: Clinic Name:Clinic Address:

Premise ID Official Site Name/Code Owner

Outcome:ISU VDL has bar-code labels pages printed at remote location and mails back to client

mailto:[email protected]


One sheet of Premises ID barcode labels per site will be designed, printed, and mailed to the address indicated in the email

Place premises ID barcode label in the designated area on the submission form

• One premises ID per submission form

• Use premises ID barcodes on VDL submissions

How to Use Premises ID Barcode Labels


Premises ID Barcode Labels


Take Home Message on Prem ID#’s• Premise ID #’s = Foundation for Preparedness

– FAD / Program Disease Response – Continuity of Business Programs– Area Regional Disease Control

• Producer Driven = Region, Practice, Production System

• Premise ID # ≠ Data Sharing• “Affiliates” = Define Diagnostic Data Sharing

• (Beyond Submitting Vet, Clinic, & Bill Party for Non-Reportable Diseases)


Premises ID & Affiliate Code


*Revising paper based submission forms to enhance premise / lot / flow level information as well as currently developing an improved VDL web-submission tool that will incorporate use of Premises ID #’s and improved test selection format, etc..


PEDV’s Emergence in US“Status Report, Diagnostics, & Observations”

Iowa Pork Congress1/22/2014

Thank YouQuestions ?

Many acknowledgments to ISU VDL faculty, staff, &clientele

dr. rodger main - pedv's emergence in the us: status report, diagnostics, & observations

Health & Medicine

pedv pcrreal

pedv positive swine

cumulative positive

diagnostic case submissions

pedv ifa test serum

pedv elisa assays

ifa antibody titer350

disease of significance