PEDv Update – November 13, 2013

  1. The new case report from NAHLN was not available in time for this week’s e-Letter. It will be uploaded to the AASV PEDv web page as soon as it becomes available.[NOTE (11/14/13): The new case report for cases submitted during the week of 11/03/2013 has now been posted to the AASV website.]
  2. The latest updates on NPB-sponsored research projects have been posted to the AASV PEDv website.
  3. Environmental stability of PEDV (PI: Sagar Goyal) – Recent update of PEDv environmental stability study.
  4. A summary from Stuart Heller, Division Manager at Preserve International: Synergize and its efficacy v. PEDv: “In partnership with Pipestone Applied Research and South Dakota State University, we recently completed a project designed to validate transport sanitation protocols v. PEDv. The findings of the project indicate that a sanitation protocol utilizing Synergize at 0.8% (1:128 dilution rate) in combination with drying effectively eliminates PEDv from contaminated surfaces. We are also in the process of doing further confirmatory testing at .04% (1:256) dilutions. We are not expecting any issues. Regarding drying, the project used air movement, no heat. Negative PCR’s at 1 hour. (Not sure about bioassay results).”
  5. UMN Swine Health Monitoring Project Update: Please contact Dane Goede (goed0051@umn.edu) with any questions.
    Lateral Spread Study
    Case farms IDed: 30 Case farms agreed: 17
    Case farm questionnaires taken: 7
    Preliminary univariable analysis of lateral spread study biosecurity questionnaires between positive and negative farms have indicated that feed truck visits are more frequent during the two weeks prior to a positive farm outbreak. Less inspection at the truck/trailer washing facility for dryness and organic materials after the wash also seems significant between positive and negative sites for PEDv. Further updates on these trends will be released as the full sampling of farms and questionnaires is obtained.

    North Carolina Cluster
    Out of 2071 sites participating in NC, a cohort of positive case farms and negative control farms has been identified and questionnaire administration for lateral transmission factors has just been started.
    Case farms: 155
    Control farms: 310
    Questionnaires completed: 17
    Spatial analysis:

    • One significant cluster of sites where nearly twice the number of positive farms expected is present (44 km radius)
    • Cases immediately following other infections occur 20 degrees NE on average
    • Farms:
      • 1 mile of a PED positive farm had an 8.4 times higher risk of infection
      • 2 miles of a PED positive farm had a 6.3 times higher risk of infection
      • Greater than 3 miles from a positive farm had no increased risk
    • Risk of infection decreases 27% for every 1 mile away from a positive farm

    Other conclusions:
    • Sites with sows and finishing pigs have the highest incidence of PEDv (48.8%) followed by sow/nursery/finisher sites (31.6%)
    • Site capacity was not significantly associated with PEDv

    PEDv Detected in Flies
    The first PCR positive sample from flies was collected at a sow site positive for PEDv last week. Thirty flies were saturated with 10 ml of media and compressed to extract the sample. Ct-value of the extracted sample was 30.44. There have been 4 previous similar submissions of flies from positive farms which were PEDv PCR negative. Bioassay needs to be conducted to determine if the virus is alive.