• 1.

    Clark EG. Post-weaning multisystemic wasting syndrome, in Proceedings. 28th Annu Meet Am Assoc Swine Pract 1997;499501.

  • 2.

    Segales J, Allan GM, Domingo M. Porcine circovirus diseases. Anim Health Res Rev 2005;6:119142.

  • 3.

    Allan G, McNeilly F, Krakowa S, et al. PCV-2 infection in swine: more than just postweaning multisystemic wasting syndrome. Vet J 2003;166:222223.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Segales J, Alonso F, Rosell C, et al. Changes in peripheral blood leukocyte populations in pigs with natural postweaning multisystemic wasting syndrome (PMWS). Vet Immunol Immunopathol 2001;81:3744.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Nielsen J, Vincent IE, Botner A, et al. Association of lymphopenia with porcine circovirus type 2 induced postweaning multisystemic wasting syndrome (PMWS). Vet Immunol Immunopathol 2003;92:97111.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Segales J, Domingo M, Chianini F, et al. Immunosuppression in postweaning multisystemic wasting syndrome affected pigs. Vet Microbiol 2004;98:151158.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Krakowka S, Ellis JA, McNeilly F, et al. Activation of the immune system is the pivotal event in the production of wasting disease in pigs infected with porcine circovirus-2 (PCV-2). Vet Pathol 2001;38:3142.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Grasland B, Loizel C, Blanchard P, et al. Reproduction of PMWS in immunostimulated SPF piglets transfected with infectious cloned genomic DNA of type 2 porcine circovirus. Vet Res 2005;36:685697.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Ladekjaer-Mikkelsen AS, Nielsen J, Stadejek T, et al. Reproduction of postweaning multisystemic wasting syndrome (PMWS) in immunostimulated and non-immunostimulated 3-week-old piglets experimentally infected with porcine circovirus type 2 (PCV2). Vet Microbiol 2002;89:97114.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Kim J, Chung HK, Jung T, et al. Postweaning multisystemic wasting syndrome of pigs in Korea: prevalence, microscopic lesions and coexisting microorganisms. J Vet Med Sci 2002;64:5762.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Pallares FJ, Halbur PG, Opriessnig T, et al. Porcine circovirus type 2 (PCV-2) coinfections in US field cases of postweaning multisystemic wasting syndrome (PMWS). J Vet Diagn Invest 2002;14:515519.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Chae C. Postweaning multisystemic wasting syndrome: a review of aetiology, diagnosis and pathology. Vet J 2004;168:4149.

  • 13.

    Opriessnig T, Thacker EL, Yu S, et al. Experimental reproduction of postweaning multisystemic wasting syndrome in pigs by dual infection with Mycoplasma hyopneumoniae and porcine circovirus type 2. Vet Pathol 2004;41:624640.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Ha Y, Jung K, Kim J, et al. Outbreak of salmonellosis in pigs with postweaning multisystemic wasting syndrome. Vet Rec 2005;156:583584.

  • 15.

    Harris DL. Multi-site pig production. Ames, Iowa: Iowa State University Press, 2000.

  • 16.

    Davies PR, Bahnson PB, Marsh WE, et al. Prevalence of gross lesions in slaughtered pigs—the PigMON database 1990–1993. Research Investment Report. Minneapolis: University of Minnesota Press, 1995.

    • Search Google Scholar
    • Export Citation
  • 17.

    Ellis J, Clark E, Haines D, et al. Porcine circovirus-2 and concurrent infections in the field. Vet Microbiol 2004;98:159163.

  • 18.

    Harding JCS, Clark EG, Strokappe JH, et al. Postweaning multisystemic wasting syndrome: epidemiology and clinical presentation. Swine Health Prod 1998;6:249254.

    • Search Google Scholar
    • Export Citation
  • 19.

    Sibila M, Calsamiglia M, Vidal D, et al. Dynamics of Mycoplasma hyopneumoniae infection in 12 farms with different production systems. Can J Vet Res 2004;68:1218.

    • Search Google Scholar
    • Export Citation
  • 20.

    Easterday BC. Immunologic considerations in swine influenza. J Am Vet Med Assoc 1972;160:645648.

  • 21.

    Harms PA, Sorden SD, Halbur PG, et al. Experimental reproduction of severe disease in CD/CD pigs concurrently infected with type 2 porcine circovirus and porcine reproductive and respiratory syndrome virus. Vet Pathol 2001;38:528539.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Jung K, Kim J, Ha Y, et al. The effects of transplacental porcine circovirus type 2 infection on porcine epidemic diarrhoea virus-induced enteritis in preweaning piglets. Vet J 2006;171:445450.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23.

    Murakami S, Ogawa A, Kinoshita T, et al. Occurrence of swine salmonellosis in postweaning multisystemic wasting syndrome (PMWS) affected pigs concurrently infected with porcine reproduction and respiratory syndrome virus (PRRSV). J Vet Med Sci 2006;68:387391.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Kim J, Ha Y, Jung K, et al. Enteritis associated with porcine circovirus 2 in pigs. Can J Vet Res 2004;68:218221.

  • 25.

    Brown SN, Knowles TG, Wilkins LJ, et al. The response of pigs to being loaded or unloaded onto commercial animal transporters using three systems. Vet J 2005;170:91100.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Apple JK, Kegley EB, Maxwell CV Jr, et al. Effects of dietary magnesium and short-duration transportation on stress response, postmortem muscle metabolism, and meat quality of finishing swine. J Anim Sci 2005;83:16331645.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    Pineiro M, Pineiro C, Carpintero R, et al. Characterisation of the pig acute phase protein response to road transport. Vet J 2006; in press.

    • Search Google Scholar
    • Export Citation
  • 28.

    Kawashima K, Tsunemitsu H, Horino R, et al. Effects of dexamethasone on the pathogenesis of porcine circovirus type 2 infection in piglets. J Comp Pathol 2003;129:294302.

    • Crossref
    • Search Google Scholar
    • Export Citation

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Epidemiologic assessment of porcine circovirus type 2 coinfection with other pathogens in swine

Paul M. DorrDepartment of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.

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Rodney B. BakerDepartment of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.

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Glen W. AlmondDepartment of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.

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Spencer R. WayneDepartment of Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108.

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Wondwossen A. GebreyesDepartment of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.

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Abstract

Objective—To identify important pathogens and characterize their serologic and pathologic effects in porcine circovirus type 2 (PCV2)-infected pigs in relation to pig age and type of swine production system.

Design—Cross-sectional study.

Animals—583 conventionally reared pigs.

Procedures—3- (n = 157), 9- (149), 16- (152), and 24-week-old (125) pigs from 41 different 1-, 2-, and 3-site production systems (5 pigs/age group/farm) were euthanized and necropsied. Pigs with and without PCV2 infection were identified (via PCR assay); infection with and serologic responses to other pathogens and pathologic changes in various tissues (including lungs) were assessed. Logistic regression models were constructed for effects overall and within each age group and type of production system.

Results—Compared with PCV2-negative pigs, PCV2-positive pigs were more likely to have swine influenza virus (SIV) type A and Mycoplasma hyopneumoniae infections and sample-to-positive (S:P) ratios for SIV H1N1 from 0.50 to 0.99; also, PCV2-positive pigs had higher serum anti-porcine reproductive and respiratory syndrome virus (PRRSV) antibody titers and more severe lung tissue damage. Infection with SIV (but lower SIV H1N1 S:P ratio) was more likely in 3-week-old PCV2-positive pigs and evidence of systemic disease was greater in 16-week-old PCV2-positive pigs than in their PCV2-negative counterparts. By site type, associations of coinfections and disease effects between PCV2-positive and -negative pigs were greatest in 3-site production systems.

Conclusions and Clinical Relevance—In PCV2-positive pigs, coinfections with SIV, M hyopneumoniae, and PRRSV are important, having the greatest effect in the early to late nursery phase and in 3-site production systems.

Abstract

Objective—To identify important pathogens and characterize their serologic and pathologic effects in porcine circovirus type 2 (PCV2)-infected pigs in relation to pig age and type of swine production system.

Design—Cross-sectional study.

Animals—583 conventionally reared pigs.

Procedures—3- (n = 157), 9- (149), 16- (152), and 24-week-old (125) pigs from 41 different 1-, 2-, and 3-site production systems (5 pigs/age group/farm) were euthanized and necropsied. Pigs with and without PCV2 infection were identified (via PCR assay); infection with and serologic responses to other pathogens and pathologic changes in various tissues (including lungs) were assessed. Logistic regression models were constructed for effects overall and within each age group and type of production system.

Results—Compared with PCV2-negative pigs, PCV2-positive pigs were more likely to have swine influenza virus (SIV) type A and Mycoplasma hyopneumoniae infections and sample-to-positive (S:P) ratios for SIV H1N1 from 0.50 to 0.99; also, PCV2-positive pigs had higher serum anti-porcine reproductive and respiratory syndrome virus (PRRSV) antibody titers and more severe lung tissue damage. Infection with SIV (but lower SIV H1N1 S:P ratio) was more likely in 3-week-old PCV2-positive pigs and evidence of systemic disease was greater in 16-week-old PCV2-positive pigs than in their PCV2-negative counterparts. By site type, associations of coinfections and disease effects between PCV2-positive and -negative pigs were greatest in 3-site production systems.

Conclusions and Clinical Relevance—In PCV2-positive pigs, coinfections with SIV, M hyopneumoniae, and PRRSV are important, having the greatest effect in the early to late nursery phase and in 3-site production systems.

Contributor Notes

Dr. Baker's present address is Food Supply Veterinary Services, College of Veterinary Medicine, Iowa State University, Ames, IA 50011.

Dr. Dorr was supported by internal funding, private agricultural industry, and Pfizer Animal Health.

Presented in part at the North Carolina Veterinary Conference, Raleigh, NC, November 2005.

Address correspondence to Dr. Dorr.