Detection of equid herpesvirus 1 DNA by polymerase chain reaction after experimental inoculation of horses with a brazilian A4/72 strain

Abstract

Seven conventional adult horses were inoculated intranasally with a Brazilian A4/72 strain of equid herpesvirus-1 (EHV-1). In the first ten days after the inoculation, they showed signs of a mild, self- limiting upper respiratory tract infection. In spite of the presence of neutralizing antibodies before the trial, seroconversion was observed in some horses. The virus was not isolated from nasal swabs and peripheral blood leukocytes (PBL) of any of the horses. However, the EHV-1 was detected through the polymerase chain reaction (PCR) from PBL of all horses in the experiment within the third to the eighth day after the inoculation that illustrated the viremia. In addition, the PCR assay also detected the virus in bronchoalveolar lavage fluid samples starting on the ninth day after the experimental infection in most of horses. For that reason, as a diagnostic tool, the PCR assay showed higher sensitivity and specificity than the conventional laboratorial methods in detection of EHV-1.