Associations between exposure to viruses and bovine respiratory disease in Australian feedlot cattle
Autor: | Tamsin S. Barnes, Timothy J. Mahony, Jennifer L. Gravel, Paul F. Horwood, Rebecca Ambrose, John M. Morton, Archie C. A. Clements, K.E. Hay, Margaret Commins |
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Rok vydání: | 2016 |
Předmět: |
Male
040301 veterinary sciences animal diseases viruses Population Bovine Respiratory Disease Complex Bovine respiratory disease Article Virus 0403 veterinary science Bovine respiratory syncytial virus Food Animals Bovine viral diarrhoea virus 1 Bovine herpesvirus 1 Seroepidemiologic Studies Veterinary virology Prevalence medicine Animals education Seroepidemiology education.field_of_study biology Australia 0402 animal and dairy science 04 agricultural and veterinary sciences biology.organism_classification medicine.disease 040201 dairy & animal science Virology Vaccination Case-Control Studies Viruses Immunology Bovine parainfluenza virus 3 Cattle Female Animal Science and Zoology Blood sampling |
Zdroj: | Preventive Veterinary Medicine |
ISSN: | 0167-5877 |
Popis: | Highlights • Seroepidemiology of BVDV-1, BoHV-1, BRSV and BPIV-3 and risk of BRD was investigated. • For each virus, being seronegative at entry increased risk of BRD in feedlot cattle. • Animals seronegative for more than one virus were at progressively increased risk. • For each virus seroincrease resulted in increased risk of BRD in feedlot cattle. • Seroincrease for more than one virus further increased risk of BRD. Bovine respiratory disease (BRD) is the most important cause of clinical disease and death in feedlot cattle. Respiratory viral infections are key components in predisposing cattle to the development of this disease. To quantify the contribution of four viruses commonly associated with BRD, a case-control study was conducted nested within the National Bovine Respiratory Disease Initiative project population in Australian feedlot cattle. Effects of exposure to Bovine viral diarrhoea virus 1 (BVDV-1), Bovine herpesvirus 1 (BoHV-1), Bovine respiratory syncytial virus (BRSV) and Bovine parainfluenza virus 3 (BPIV-3), and to combinations of these viruses, were investigated. Based on weighted seroprevalences at induction (when animals were enrolled and initial samples collected), the percentages of the project population estimated to be seropositive were 24% for BoHV-1, 69% for BVDV-1, 89% for BRSV and 91% for BPIV-3. For each of the four viruses, seropositivity at induction was associated with reduced risk of BRD (OR: 0.6–0.9), and seroincrease from induction to second blood sampling (35–60 days after induction) was associated with increased risk of BRD (OR: 1.3–1.5). Compared to animals that were seropositive for all four viruses at induction, animals were at progressively increased risk with increasing number of viruses for which they were seronegative; those seronegative for all four viruses were at greatest risk (OR: 2.4). Animals that seroincreased for one or more viruses from induction to second blood sampling were at increased risk (OR: 1.4–2.1) of BRD compared to animals that did not seroincrease for any viruses. Collectively these results confirm that prior exposure to these viruses is protective while exposure at or after feedlot entry increases the risk of development of BRD in feedlots. However, the modest increases in risk associated with seroincrease for each virus separately, and the progressive increases in risk with multiple viral exposures highlights the importance of concurrent infections in the aetiology of the BRD complex. These findings indicate that, while efficacious vaccines could aid in the control of BRD, vaccination against one of these viruses would not have large effects on population BRD incidence but vaccination against multiple viruses would be expected to result in greater reductions in incidence. The findings also confirm the multifactorial nature of BRD development, and indicate that multifaceted approaches in addition to efficacious vaccines against viruses will be required for substantial reductions in BRD incidence. |
Databáze: | OpenAIRE |
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