- The New Case Report for the week of 1/12/14 has been posted on the AASV PED web page. 122 new cases were added during the week of 1/12/14. No new states were added during the week so the number of states reporting confirmed cases remains at 23. In addition, the NAHLN slightly modified two previous case counts bringing to 2394 the total number of cases confirmed since the beginning of the outbreak.
- The University of Minnesota’s Swine Health Monitoring Program (SHMP) provided the interim results of the following 2 studies:
- Batch Farrowing PEDv Case Study — A batch farrow-to-wean site that was recently affected by PEDV is offering some unique opportunities to learn more about the virus. Since the active batch was old enough to be weaned (5-15 days of age), the farrowing area was depopulated, cleaned, and closed. Steps were taken to extend the time until the first farrowing of next batch. Fortunately, clinical signs started in the gestation and the next batch to farrow was affected first. Herd wide feedback took place as soon as the last piglets were weaned offsite. The first piglets to potentially see the PEDV challenge will start to be born at just under 14 days post sow exposure. Although the expectation is that there will be piglet losses due to PEDV in the first batch, steps are being taken in the hopes of producing negative pigs by cleaning and delaying farrowing as long as possible while the sows develop immunity. The case highlights some of the advantages that batch farrowing may offer to the health management of this challenge.
- Bio-assay of Positive Lagoon Samples — A previous bio-assay showed viability of PEDv in lagoon slurry during an acute outbreak. Four PCR positive lagoon samples from PED-infected sites were put into bio-assay this week to determine viability of the detected virus in lagoons long after shedding had stopped. One of the four samples was seen to replicate in the bio-assay pigs again showing viability of the virus.
Farm Weeks Post-Infection Weeks Negative Lagoon Ct Clinical signs Intestine Ct 1 16 9 30 Diarrhea 17.43 2 12 0 28 None – 3 16 5 32 None – 4 15 5 32 None – SHMP note – while it is disappointing that the one lagoon sample is still alive, it is surprising and encouraging that 3/4 samples are apparently dead. Given the survival of PED virus in manure and slurry, one must ask what conditions in the 3 lagoons prompted inactivation of the virus?