PEDv Update – January 8, 2014

January 8, 2014 — 

1. The New Case Report is delayed and will be posted to the AASV web site on Thursday.
2. PEDv Lateral Spread Study Update and Synopsis
   • 80 total sites have completed questionnaires in combined lateral spread studies
     • 46 positive PEDv sites
     • 34 matched PEDv negative sites
   • 2039 total sites’ data and spatial analysis to identify patterns of spread
   • 639 breeding herds participating in reporting weekly incidence of infection
   
   Synopsis of Preliminary Results
   • Proximity to a PEDv infected farm increases odds of becoming infected. This highlights an opportunity to communicate with neighboring herds in the face of a PEDv outbreak to coordinate transportation and biosecurity as well as alert sites to potential risk of infection.
     • Within 1 mile - 8.4 times higher odds,
     • Within 2 miles - 6.3 times higher odds
     • 3 or more miles away - no greater odds
   • Data support, but don’t confirm aerosol spread of PEDv. This support is based on detecting PCR positive air samples in the air up to 10 miles from positive sow sites as well as the correlation of disease spread with wind direction in spatial analysis of the Oklahoma cluster study. Biofilters or negative pressure filtration systems may decrease risk of infection in a region
   • Sampling at infected farms has indicated potential sources of transmission/reinfection of a site include lagoons and slurry, flies as mechanical vectors, and compost. However, none of these has been confirmed as risk factors for lateral spread in preliminary survey analysis of survey data. With more data collection, these potential sources of transmission may be emphasized and alternative methods of manure and other bio-waste management may be indicated.
   • Site capacity has not been consistently associated with PEDv infection. In one data set sites with sows and growing/finishing pigs had a higher incidence of infection.
   • Analysis of the lateral spread questionnaires to date indicate an increase in the number of visits by trucks picking up trash at sites that have become positive compared to those that were negative and matched to case farms by company, production type, and capacity at the time of data collection. If this remains consistent throughout complete analysis, it shows a need for producers to implement more strict vehicle biosecurity and personnel practices.

Source: UMN Swine Health Monitoring Program