Cost of PRRS in Netherlands.

Nieuwenhuis N, Duinhof T F, van Nes A. Economic analysis of outbreaks of porcine reproductive and respiratory syndrome virus in nine sow herds. Veterinary record 2012 [in press].


Abstract

The economic losses due to porcine reproductive and respiratory syndrome virus (PRRSv) outbreaks are reported in the literature to be substantially high, but recent figures are not available. The aim of this study was to quantify the economic effects of epidemic PRRSv outbreaks in Dutch sow herds. Nine sow herds were selected based on a confirmed PRRSv outbreak within those populations. The economic impact during the first 18 weeks after the outbreak was estimated by comparing the overall costs between pre- and postoutbreak periods, using different factors (production data, medication, diagnostics, labour, etc.). An outbreak of PRRSv resulted in a reduced number of sold pigs per sow of 1.7. The economic loss varied between €59 and €379 for one sow per 18-week period outbreak. The mean loss per sow per outbreak was €126. The costs after the outbreak varied significantly from €3 to 160 per sow, due to the different methods used by farmers to tackle PRRSv outbreaks. The calculated costs in this study correlate with the costs of the initial outbreak in The Netherlands of 98 per sow.

Epidemiological investigations in regard to porcine reproductive and respiratory syndrome (PRRS) in Quebec, Canada. Part 1: Biosecurity practices and their geographical distribution in two areas of different swine density.

Lambert M, Poljak Z, Arsenault J, D S. Epidemiological investigations in regard to porcine reproductive and respiratory syndrome (PRRS) in Quebec, Canada. Part 1: Biosecurity practices and their geographical distribution in two areas of different swine density. Preventive veterinary medicine 2012;

Porcine reproductive and respiratory syndrome virus (PRRSV) is a considerable threat to the swine industry and implementing biosecurity measures is essential for the control of its transmission. The aims of this study were: (1) to describe biosecurity practices in production sites located in a moderate density (MD) and a high density (HD) pig area according to pro- duction type; (2) to group sites in different patterns according to their biosecurity practices; and (3) to determine the geographical distribution of sites according to biosecurity patterns. Biosecurity practices were selected based on PRRS epidemiology. A questionnaire was com- pleted on 125 breeding sites (MD = 54; HD = 71) and 120 growing (HD) sites, between 2005 and 2008. Depending on area and production type, the frequency of biosecurity practices used ranged from 0 to 2% for barrier at site entrance, 0 to 19% for use of shower, 25 to 35% for washing truck between loads of pigs, 51 to 57% for absence of rendering or rendering without access to the site, and 26 to 51% for absence of gilt purchase or purchase with quarantine. Better practices pertaining to entrance protocol (i.e. “no-entry” sign, shower, ≥24 h downtime) were reported more frequently on breeding sites in the MD than the HD area (P < 0.05). In the HD area, growing sites had in general a lower level of biosecu- rity than breeding sites. Using a two-step clustering procedure performed separately for breeding and growing sites, two different patterns were obtained for each production type, which corresponded to a high and low level of biosecurity. For breeding sites, a higher biosecurity level was observed at sites located away from other pig sites, set at more than 300 m from the public road, having higher sow inventory, or being part of an integrated production (P < 0.05). Spatial clusters of sites for each biosecurity pattern were detected. This study identified some shortcomings regarding biosecurity that should be addressed before implementing any PRRSV regional control. Vicinity of sites with different biosecurity levels also suggests difficulties in planning priorities of intervention based on geographical distribution of sites.

© 2011 Elsevier B.V. All rights reserved.

Efficient surveillance of pig populations using oral fluids

Abstract

Currently virus surveillance in swine herds is constrained by the cost-effectiveness and efficiency of sampling methods. The objective of this study was to assess the value of using oral fluids collected by barn personnel as a method of surveillance based on PCR testing. Approximately 12,150 pigs in 10 wean-to-finish barns on 10 farms were monitored for the presence of porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and Torque teno virus genogroups 1 (TTV1) and 2 (TTV2) by sampling oral fluid specimens. Oral fluid samples were collected from 6 pens at each site starting at the time of pig placement (∼3 weeks of age) and continuing thereafter at 2-week intervals for a period of 18 weeks. Data were analyzed both on a pen basis and barn basis. Overall, 508 (85%) samples were positive for PCV2, 73 (12%) for PRRSV, 46 (8%) for IAV, 483 (81%) for TTV2, and 155 (26%) for TTV1 during the study period. The estimated arithmetic means of the quantitative PCR-positive oral fluids for PCV2, PRRSV, and IAV were 1×10(4.62), 1×10(4.97), and 1×10(5.49)per ml. With a single exception, all barns were positive for PCV2 and TTV2 at every sampling point in the study. Virus detection varied among barns, particularly for IAV and PRRSV. The pen level, cumulative distribution of agent combinations between all 10 barns were statistically different. The most commonly observed patterns were PCV2+TTV2 (239 pen samples, 40%), PCV2+TTV1+TTV2 (88 pen samples, 15%), and PCV2 alone (66 pen samples, 11%). This "proof-of-concept" project showed that a variety of viruses could be detected either intermittently or continuously in pig populations and demonstrated that barn herd virus status is highly variable, even among barns in the same production system. Oral fluid sampling is a promising approach for increasing the efficiency and cost effectiveness of virus surveillance in swine herds.

Copyright © 2011 Elsevier B.V. All rights reserved.

Ramirez A, Wang C, Prickett J R, Pogranichniy R, Yoon K, Main R, Johnson J K, Rademacher C, Hoogland M, Hoffmann P, Kurtz A, Kurtz E, Zimmerman J. Efficient surveillance of pig populations using oral fluids. Preventive veterinary medicine 2011 [in press].

Downtime for PRRSv+Myco

Pitkin A, Otake S, Dee S. A one-night downtime period prevents the spread of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae by personnel and fomites (boots and coveralls). J Swine Health Prod. 2011;19(6):345–348.

Summary

This paper summarizes observations recorded over a 4-year (1438-day) period regarding the ability of a 1-night period of downtime [+ shower and cloth-change] to prevent mechanical spread of porcine repro- ductive and respiratory syndrome virus and Mycoplasma hyopneumoniae between pig populations by personnel and fomites.

Keywords: swine, porcine reproductive and respiratory syndrome, downtime, personnel, fomites

Effect of PRRSv vaccine on the shedding of wild-type virus from an infected population of growing pigs

Linhares D C, Cano J P, Wetzell T, Nerem J, Torremorell M, Dee S A. Effect of modified-live porcine reproductive and respiratory syndrome virus (PRRSv) vaccine on the shedding of wild-type virus from an infected population of growing pigs. Vaccine 2011 [in press]

Abstract

There are ongoing efforts to eliminate porcine reproductive and respiratory syndrome virus (PRRSv) from regions in the United States swine industry. However, an important challenge for the accomplishment of those efforts is the re-infection of pig units due to the area spread of PRRSv. The objective of this study was to evaluate the effect of PRRS modified-live virus vaccine (MLV) on viral shedding and on dynamics of PRRSv infection in pig populations raised under commercial conditions. The study composed of two rooms of 1000 pigs each. Ten percent of pigs of each room were inoculated with a field isolate of PRRSv. Rooms had separate air spaces and strict scientifically validated biosecurity protocols were adopted to avoid movement of pathogens between rooms. At 8 and 36dpi (days post inoculation), all pigs of the challenge-vaccine group were inoculated with a MLV vaccine. Pigs of the challenge-control group were placebo-inoculated. Blood and oral fluid samples were collected from each room at 0, 8, 36, 70, 96 and 118dpi for PRRSv RNA detection using PCR. PRRSv-antibodies were also screened from blood serum samples with a commercially available ELISA test. Additionally, tonsil scraping samples were collected from both groups at 70, 96 and 118dpi. Moreover, air samples were collected 6 times per week from 0 to 118dpi and were tested for PRRSv RNA using qPCR assay. There was no difference in the PRRSv infection dynamics measured as duration and magnitude of viremia and seroconversion. Also, there was no difference in the frequency of tonsil scraping samples PRRSv-positive by PCR. However, the challenge-vaccine group had significantly less PRRSv shed compared to the challenge-control group. The challenge-vaccine group had significant less PRRSv-positive oral fluids at 36dpi. Moreover, the challenge-vaccine group had significant reduction in the cumulative PRRSv shed in the air.

Copyright © 2011. Published by Elsevier Ltd.

PMID:

 

22063389

 

[PubMed]

Can we vaccinate pigs via their feed?

Maybe in the near future... see abstract below.

Planta. 2011 Oct 5. [Epub ahead of print]

Expression of the nucleocapsid protein of Porcine Reproductive and Respiratory Syndrome Virus in soybean seed yields an immunogenic antigenic protein.

Vimolmangkang S, Gasic K, Soria-Guerra R, Rosales-Mendoza S, Moreno-Fierros L, Korban SS.

Source

Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, IL, 61801, USA.

Abstract

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is a serious disease of swine and contributes to severe worldwide economic losses in swine production. Current vaccines against PRRS rely on the use of an attenuated-live virus; however, these are unreliable. Thus, alternative effective vaccines against PRRS are needed. Plant-based subunit vaccines offer viable, safe, and environmentally friendly alternatives to conventional vaccines. In this study, efforts have been undertaken to develop a soybean-based vaccine against PRRSV. A construct carrying a synthesized PRRSV-ORF7 antigen, nucleocapsid N protein of PRRSV, has been introduced into soybean, Glycine max (L.) Merrill. cvs. Jack and Kunitz, using Agrobacterium-mediated transformation. Transgenic plants carrying the sORF7 transgene have been successfully generated. Molecular analyses of T(0) plants confirmed integration of the transgene and transcription of the PRRSV-ORF7. Presence of a 15-kDa protein in seeds of T(1) transgenic lines was confirmed by Western blot analysis using PRRSV-ORF7 antisera. The amount of the antigenic protein accumulating in seeds of these transgenic lines was up to 0.65% of the total soluble protein (TSP). A significant induction of a specific immune response, both humoral and mucosal, against PRRSV-ORF7 was observed following intragastric immunization of BALB/c female mice with transgenic soybean seeds. These findings provide a 'proof of concept', and serve as a critical step in the development of a subunit plant-based vaccine against PRRS.

A four-year summary of air filtration system efficacy for preventing airborne spread of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae

Summary
A 4-year study evaluated the ability of commercial air filters to protect susceptible populations against airborne transmission
of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneu- moniae. All filter types*, equally reduced the risk of airborne transmission of both pathogens, compared to non-filtered controls, supporting further application in the field.
Keywords: swine, porcine reproductive and respiratory syndrome virus, airborne, trans- mission, filtration



Dee S, Pitkin A, Otake S, et al. A four-year summary of air filtration system efficacy for preventing airborne spread of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae. J Swine Health Prod. 2011;19(5):292–294. 




* types of filters evaluated:
     - mechanical: MERV14 and MERV 16
     - electrostatic
     - chemical