Prevalence of equine herpesvirus types 2 and 5 in horse populations by using type-specific PCR assays

Abstract

Equine herpesvirus types 2 and 5 (EHV-2 and EHV-5) have a rather unclear pathogenicity and distribution within the equid population. In order to gain more information on the prevalence of these two viruses, type-specific PCR assays were developed to detect viral DNA in nasal specimens and in peripheral blood leukocytes (PBLs) of adult horses and foals from various regions of Europe, i.e. Sweden, Hungary and the United Kingdom. In adult horses, the prevalence of EHV-2 in PBLs was up to 68% in Sweden and 71% in the United Kingdom. EHV-2 DNA was detected in the PBLs from all the foals tested in all countries and most (93%) of the nasal specimens also yielded positive results. The prevalence of EHV-5 DNA in the PBLs of foals in Hungary was 15 and 24% in adult horses in the United Kingdom. This observation was among the very few reports of the presence of EHV-5 in horses. In summary, the specific PCR assays revealed important data on the occurrence and distribution of EHV-2 and EHV-5 in large horse populations. The findings indicated that infection with EHV-5 occurred later than EHV-2 in foals. This study may contribute to a better understanding of the etiological role of these gammaherpesviruses in equine diseases. equine infections / Gammaherpesvirinae / EHV-2 / EHV-5 / PCR Rsum -Prvalence des herpesvirus quins types 2 et 5 dans les populations de chevaux par l'utilisation de PCR spcifiques du type. Les herpesvirus quins de types 2 et 5 (EHV-2 et EHV-5) ont un pouvoir pathogne et une distribution mal connus parmi la population des quids. Afin de recueillir plus d'informations sur la prvalence de ces deux virus, des tests PCR spcifiques du type ont t dvelopps afin de dtecter l'ADN viral dans les prlvements nasaux et dans les leucocytes du 251