Natural progression of Bovine Leukemia Virus infection in Argentinean dairy cattle.
Vet Microbiol
; 151(3-4): 255-63, 2011 Aug 05.
Article
em En
| MEDLINE
| ID: mdl-21550733
We describe the progression of Bovine Leukemia Virus (BLV) infection from birth until the first lactation in 61 animals from a typical large dairy herd of Argentina, with more than 85% of prevalence. The purpose was to identify potential points to effectively break the BLV cycle of transmission in our dairy productive system. We detected early infection in 11.47% of newborn calves by nested PCR. From birth to 12 months, no evidence of new infections was observed. After 12 months of age, the detection of new reactors increased slowly with time, from 15.09% at 15 months to 24% at 27 months. After that, the number of reactors increased rapidly up to 40% and 60.76% at 30 and 36 months, respectively. This last 9-month period coincided with parturition and the entry into the milking herd. Real-time PCR showed that more than 75% of adult animals had low peripheral-blood proviral load. Complementary, all infected animals showed low levels of provirus in milk and colostrum. The most important finding was that even when management procedures to prevent BLV iatrogenic transmission were followed, no significant change was observed in the prevalence after three years, strongly suggesting that other way/s of transmission play a key role under natural conditions. This study showed an interesting baseline to draw an alternative approach based on selective segregation according to the peripheral-blood proviral load as a potential indicator of risk transmission, and as an alternative to classical control measures.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bovinos
/
Leucose Enzoótica Bovina
/
Vírus da Leucemia Bovina
Tipo de estudo:
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
/
Pregnancy
País/Região como assunto:
America do sul
/
Argentina
Idioma:
En
Revista:
Vet Microbiol
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda