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Pipestone, MN, United States

Dee S.,Pipestone Veterinary Clinic | Dee S.,University of Minnesota | Cano J.P.,Boehringer Ingelheim | Spronk G.,Pipestone Veterinary Clinic | And 4 more authors.
Viruses | Year: 2012

Airborne transmission of porcine reproductive and respiratory syndrome virus (PRRSV) is a risk factor for the infection of susceptible populations. Therefore, a long-term sustainability study of air filtration as a means to reduce this risk was conducted. Participating herds (n = 38) were organized into 4 independent cohorts and the effect of air filtration on the occurrence of new PRRSV infections was analyzed at 3 different levels from September 2008 to January 2012 including the likelihood of infection in contemporary filtered and non-filtered herds, the likelihood of infection before and after implementation of filtration and the time to failure in filtered and non-filtered herds. Results indicated that new PRRSV infections in filtered breeding herds were significantly lower than in contemporary non-filtered control herds (P < 0.01), the odds for a new PRRSV infection in breeding herds before filtration was 7.97 times higher than the odds after filtration was initiated (P < 0.01) and the median time to new PRRSV infections in filtered breeding herds of 30 months was significantly longer than the 11 months observed in non-filtered herds (P < 0.01). In conclusion, across all 3 levels of analysis, the long-term effect of air filtration on reducing the occurrence of new PRRSV infections in the study population was demonstrated. © 2012 by the authors; licensee MDPI, Basel, Switzerland. Source


Alonso C.,University of Minnesota | Murtaugh M.P.,University of Minnesota | Dee S.A.,Pipestone Veterinary Clinic | Davies P.R.,University of Minnesota
Preventive Veterinary Medicine | Year: 2013

Porcine reproductive and respiratory syndrome virus (PRRSV) is the most economically significant pathogen in the US swine industry. Aerosol transmission among herds is a major concern in pig dense regions and filtration of incoming air, in combination with standard biosecurity procedures, has been demonstrated to prevent transmission of PRRSV into susceptible herds. To quantify the impact of air filtration on reducing risk of PRRSV outbreaks, we compared the incidence rate of new PRRSV introductions in 20 filtered and 17 non-filtered control sow herds in a swine dense region of North America during a 7. year study period. Events of novel virus introduction were ascertained by phylogenetic analysis of PRRSV ORF5 gene sequences. Putative new viruses were defined as exogenous (introduced) based on ORF5 nucleotide sequence differences compared to previous farm isolates. The influence of sequence difference cut-off values ranging from 2 to 10% on case definition and relative risk were evaluated. Non-filtered farms incurred about 0.5 outbreaks per year, with a seasonal increase in risk in cooler periods. Baseline risk, prior to filtration, in treatment farms was approximately 0.75 per year, approximately 50% higher than in control farms. Air filtration significantly reduced risk of PRRSV introduction events to 0.06-0.22 outbreaks per year, depending on the cut-off values used to classify a virus isolate as new to the herd. Overall, air filtration led to an approximately 80% reduction in risk of introduction of novel PRRSV, indicating that on large sow farms with good biosecurity in swine-dense regions, approximately four-fifths of PRRSV outbreaks may be attributable to aerosol transmission. © 2013 Elsevier B.V. Source


Goede D.,University of Minnesota | Murtaugh M.P.,University of Minnesota | Nerem J.,Pipestone Veterinary Clinic | Yeske P.,Swine Vet Center | And 2 more authors.
Veterinary Microbiology | Year: 2015

Porcine epidemic diarrhea virus (PEDv) infected approximately 50% of the US swine breeding herds from July 2013 to July 2014 as estimated by the Swine Health Monitoring Project. In the absence of effective vaccines or standard control protocols, there is an urgent need for evidence of cross-protective immune countermeasures. Here, we evaluated the response of 3-day-old piglets born to sows exposed seven months earlier to a mild strain of PEDv to challenge with a virulent PEDv isolate. Piglet survival to one week of age was 100% compared to 67% in piglets born to sows not previously exposed, and morbidity was 43% compared to 100%, respectively. At necropsy at 7 days of age, the PEDv Ct value was 23.6 (range 16.6-30.6) in intestinal contents, compared to 17.2 (range 15.9-18.5) (. p<. 0.06) in litters from sows with no previous exposure to PEDv. The findings indicated that durable lactogenic immunity was present in sows previously exposed to a mild strain of PEDv and this immunity induced cross-protection to representative virulent PEDv. Thus, a naturally attenuated form of PEDv provided significant passive immune protection for seven months against piglet challenge with virulent PEDv. © 2015 Elsevier B.V. Source


Pitkin A.,Swine Disease Eradication Center | Otake S.,Swine Disease Eradication Center | Dee S.,Pipestone Veterinary Clinic
Journal of Swine Health and Production | Year: 2011

This paper summarizes observations recorded over a 4-year (1438-day) period regarding the ability of a l-night period of downtime to prevent mechanical spread of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae between pig populations by personnel and fomites. Source


Mondaca E.,Boehringer Ingelheim | Polson D.,Boehringer Ingelheim | Dee S.A.,Pipestone Veterinary Clinic
Journal of Swine Health and Production | Year: 2012

Objective: To evaluate the ability of a needle-free injection device (NFID) to prevent hematogenous transmission of porcine reproductive and respiratory syndrome virus (PRRSV). Materials and methods: Eighty-eight 5-week-old gilts from a PRRSV-negative source were organized into five groups and individually housed by group in isolation rooms (four replicate trials, 22 pigs per trial). On Day 0, pigs in Group 1 (PRRSV source population) were inoculated with PRRSV isolate MN-184, and pigs in Group 4 (shaminoculated group) were inoculated with virus-free medium. On Days 4, 5, and 6 post inoculation, each pig in Groups 1, 2, and 3 was vaccinated with a Mycoplasma hyopneumoniae bacterin using the needle-syringe and the NFID. First, a needle-syringe and NFID were both used to vaccinate pigs in Group 1, and then the same needle-syringe and NFID were used to vaccinate pigs in Group 2 (needle-syringe) and Group 3 (NFID), respectively. Results: On Day 11, all pigs in Group 2 tested positive for PRRSV RNA, suggesting that transmission of PRRSV had occurred between Groups 1 and 2 by repeated use of the same needle. On Day 21, all pigs in one replicate of Group 3 tested positive for PRRSV RNA, suggesting that transmission of PRRSV had occurred between Groups 1 and 3 by repeated use of the same NFID. Implications: Under the conditions of this study, hematogenous transmission of PRRSV can occur from infected pigs to susceptible pigs via repeated use of the same needle, and use of NFIDs does not prevent hematogenous transmission of PRRSV. Source

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