PEDV s Emergence in US Status Report, Diagnostics, & Observations Iowa Pork Congress 1/22/2014

Transcription

1 PEDV s Emergence in US Status Report, Diagnostics, & Observations Iowa Pork Congress 1/22/2014 Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Lab,, Ames, IA 50011

2 Faculty, Staff, & Students of ISU VDL 22 Faculty, 100 Technical Staff, & 20 Graduate Students/Residents

3 Serving Food Animal Agriculture Comprehensive Diagnostic Service, Teaching, and Discovery (Iowa s only Full-Service & Fully Accredited ) Processing 55,000+ cases/year from livestock producers Applying world-class technology to real-world problems

4 75% Swine, 10% Bovine, 10% Poultry, + 5% Everything Else

5 Where the Pigs Are Located in US 500,000 pigs/week imported to IA to be grown

6 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

7 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

8 # PEDv Positive Cases 2500 Cumulative Positive PEDv Cases by Farm Type Unknown Grow-Finish Sow Date by Week Rapidly spreading across US with more than 2,271 cases in 23 states

9 # PEDv Positive Cases 250 Positive PEDv Cases per Week by Farm Type Unknown Grow-Finish Sow Date by Week

10 PEDV Positive Swine Cases Ascertained from Multiple VDLs Week Total # of PEDv Positive Farm Type Received Diagnostic Case Submissions VDL (Premises) via PCR or IHC Sow Pig? CA CO IA IL IN KS KY MD MI MN MO NC NE NY OH OK PA SC SD TN TX WI WY? 4/15/13 2 (1) /22/13 1 (1) /29/13 9 (6) /6/13 17 (13) /13/13 10 (9) /20/13 44 (43) /27/13 32 (29) /3/13 55 (52) /10/13 48 (42) /16/ /23/ /30/ /7/ /14/ /21/ /28/ /4/ /11/ /18/ /25/ /1/ /8/ /15/ /22/ /29/ /6/ /13/ /20/ /27/ /3/ /10/ /17/ /24/ /1/ /8/ /15/ /22/ /29/ /5/ Total

11 PEDV Diagnostics Diagnostic Specimens Intestine (Fresh & Fixed) Feces Fecal Swabs Oral Fluids Serum (PEDV Antibody)

12 PEDV - PCR Real-Time 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

13 IFA antibody titer PEDV IFA test (Serum = PEDV Antibody) 400 Development of IFA antibody over time Days post inoculation (Source: Yoon, Sun)

14 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

15 Other Antibody Test Development Multiple ELISA Development Efforts In-Process Kansas State University South Dakota Sate University of Minnesota & likely others PEDV ELISA assays commercially available proved to be of very poor quality

16 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

17 Virus Isolation (VI) Research Diagnostic Tool and Vaccine Development Purposes Control cells P2 (1 dpi) P1 (4 dpi) P3 (20 hpi) (Source: Hoang, Chen, Yoon, Zhang)

18 Sequencing To date Primarily Research Purposes USA (2013) PEDV Sequencing (S-Gene) is Now Available Epidemiological Purposes China ( ) Belgium (1977) Korea (1998) China ( ) Korea (2009) NOTE: The analysis is based on full genome sequences via NGS technique. (Source: Yoon, Zhang et al)

19 Immunohistochemistry (IHC) 1 3 Normal neonatal pig: Healthy, long intestinal villi 2 Late PEDv infection (~36 hrs PI): Severe villus atrophy & loss of absorptive epithelium 4 Early PEDv infection (~8 hrs PI): Infected cells (brown stain) line the villi (Source: Schwartz, Madson, Magstad et al.) Late PEDv infection (~36 hrs PI): Few infected cells remain (brown stain) & absorptive cells destroyed

20 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

21 Porcine Epidemic Diarrhea Virus (PEDV) PEDV - Immediate Costs of Disease on Naïve Breeding Herds 4 weeks of weaned pigs losses + 1 more week of losses weeks later 10% of affected sow units annual output. 2.2 to 2.5+ PSY... $150+/Sow Severity of Disease Very age / stage of production dependent. Clinical disease can be readily missed in growing pig populations Turner, Dufrense, Ackermann, et al

22 Shedding PEDV 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

23 Key Lessons Being Learned on Broader State of Preparedness Suppliers Of Health Products Producer Genetics Facilities / Environment Production Animal Medicine Practicing Veterinarian Nutrition Health Food Animal Agriculture Consumer Veterinary Diagnostic Labs Management Business / Finance Pathology Virology Bacteriology Serology Toxicology Pharmacology Epidemiology Regulatory Agencies Strategic Alliances in Service, Teaching, & Research

24 Data courtesy of NPB & Dr. Steve Meyer Food Animal Industries Changed Dramatically Demand Globally for High Quality Protein Based Diets Advances in Logistics Are we keeping pace to support them?

25 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.

26 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

27 Integrated Information Management Systems Veterinarians Across U.S. Submitting Cases to their VDL Service Providers in the NAHLN Submission All Dx Results Submission All Dx Results Submission All Dx Results Submission All Dx Results VDL VDL VDL VDL Standardized Messaging / Mechanisms for Information Transfer Centralized Database Tools for Interpretation Seamless, Streamlined, & Active in Private & Public Sectors Area Regional Disease Management Tools Area Regional Disease Management Tools Area Regional Disease Management Tools Permissioned Users Animal Health Officials Permissioned Users

28 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

29 (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

30 Premises ID Barcode Labels on VDL Submissions Working together to enhance preparedness and capabilities Using Premises ID # s Is the Foundation

31 Premises ID Barcode Labels

32 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. spreadsheet to Veterinarian: Clinic Name: Clinic Address: Veterinarian: Clinic Name: Clinic Address: Dr. Smith Smith's Vet Clinic 111 Main Street, Paradise, IA Outcome: ISU VDL has bar-code labels pages printed at remote location and mails back to client Premise ID Official Site Name/Code Owner Premise ID Official Site Name/Code Owner 00ABC12 Bob's Finisher Bob 00ABC13 Bob's Nursery Bob 00ABC14 Bob's Sow Bob 00ABC15 Bob's Farrowing Bob 00ABC16 Bill's Finisher Bob 00ABC17 Bill's Nursery Bob 00ABC18 Bill's Sow Bob 00ABC19 Bill's Farrowing Bob

33 How to Use Premises ID Barcode Labels One sheet of Premises ID barcode labels per site will be designed, printed, and mailed to the address indicated in the 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

34 Premises ID Barcode Labels

35 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)

36 Premises ID & Affiliate Code

37 *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..

38 PEDV s Emergence in US Status Report, Diagnostics, & Observations Iowa Pork Congress 1/22/2014 Thank You Questions? Many acknowledgments to ISU VDL faculty, staff, &clientele