Development of a predictive model for bovine leukemia virus proviral load.
J Vet Intern Med
; 36(5): 1827-1836, 2022 Sep.
Article
em En
| MEDLINE
| ID: mdl-35950569
ABSTRACT
BACKGROUND:
There is currently no commercially available method in Canada to identify bovine leukemia virus (BLV)-positive cows with high proviral load (PVL).OBJECTIVES:
First, develop a model to predict PVL using common, commercially available, cost-effective diagnostic tests. Second, investigate the relationship between lymphocyte count and PVL in BLV-positive cows. ANIMALS A total of 339 BLV-positive and 62 BLV-seronegative cows on 15 dairy farms.METHODS:
Cross-sectional study. Blood and milk samples were collected from all lactating BLV-positive cows on each farm and 5 to 10 BLV-seronegative cows depending on herd size. Blood and milk samples were tested for anti-BLV antibodies using enzyme-linked immunosorbent assay (ELISA). Complete blood counts were performed on blood samples, and standard components analyses were obtained for milk samples. Proviral load was determined by quantitative polymerase chain reaction for each cow.RESULTS:
The inverse of lymphocyte count, the square of the inverse of lymphocyte count, and milk ELISA percent positivity were positively associated with increasing PVL in BLV-positive cows. For BLV-positive cows, lymphocyte count >5.2 × 109 /L predicted a high PVL (BLVBovine DNA of >1 in blood) with a sensitivity of 92.4% and a specificity of 79.8%. For BLV-positive cows, white blood cell count >10.8 × 109 /L predicted a high PVL, with a sensitivity of 85.5% and a specificity of 83.6%. CONCLUSIONS AND CLINICAL IMPORTANCE Based on these results, producers can implement commonly available diagnostic tests to identify cows with high probability of having high PVL, which may help in designing effective disease control strategies for BLV-positive herds.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças dos Bovinos
/
Leucose Enzoótica Bovina
/
Vírus da Leucemia Bovina
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
J Vet Intern Med
Assunto da revista:
MEDICINA INTERNA
/
MEDICINA VETERINARIA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Canadá