PCR associated with agar gel immunodiffusion assay improve caprine arthritis-encephalitis (CAEV) control

Autor: A.P. Ravazzolo, Roberto Soares de Castro, Bárbara L. S. Leite, Carlos Roberto Padovani, José Rafael Modolo, J. P. Araujo Junior, Anee Valéria Mendonça Stachissini
Rok vydání: 2009
Předmět:
Zdroj: Small Ruminant Research. 81:18-20
ISSN: 0921-4488
DOI: 10.1016/j.smallrumres.2008.10.005
Popis: Caprine arthritis-encephalitis (CAE) is a multi-systemic viral syndrome in goats caused by small ruminant lentivirus (CAEV). The control measures prescribed for CAEV control are based on the identification of infected animals through a suitable serological test. The aim of this work was to improve the CAE control measures through the association of indirect (agar gel immunodiffusion—AGID) and direct (PCR) assays to CAEV diagnosis. Thirty-nine kids born to AGID-seropositive dairy goats were separated from their dams immediately after birth, fed heat-treated colostrum from AGID-seronegative goats and then after pasteurized goat milk. AGID was performed at birth before colostrum, at 9 and 12 months, and the AGID-seropositive animals were segregated. Seronegative goats were also submitted to PCR to detect proviral DNA in blood, and the positives were isolated. A study of accumulated residual negativity was performed using a 95% confidence limit rate. During the 12 month experimental period no clinical signs of CAEV were observed. At the end of that period 34 animals remained AGID-seronegative to CAEV, corresponding to 87% accumulated residual negativity. When submitted to PCR, 4 of the 34 AGID-seronegative animals showed positive results, leading to a 77% final accumulated negativity rate with 64–90% confidence limits. We conclude that the classical management practices recommended for CAEV control are insufficient in CAEV eradication programs and that PCR may be a useful tool for decreasing the risk of breeding AGID false negative animals (CAEV carriers).
Databáze: OpenAIRE
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