Detection of equine herpesviruses in aborted foetuses by consensus PCR

Abstract

20The major role of EHV-1 in equine abortion is widely reported in the literature but the 21 contribution of EHV-2, EHV-3, EHV-4 or EHV-5 remains less well documented. The 22 objective of this study is to evaluate the contribution of these five different EHVs to equine 23 abortion in a variety of biological tissues using a consensus polymerase chain reaction (PCR). 24The test was validated for specificity and sensitivity in horses before screening specimens 25 from 407 foetuses, stillbirths and premature foals collected over a 2½-year interval. Positive 26 results obtained with this assay were compared to other EHV type-specific PCR or by 27 sequencing. EHV-1 was identified as the major cause of abortion in French mares (59/407 28 cases). However, there was evidence to suggest some variation in the potential of EHV-1 29 strains to induce abortion. Indeed, DNA samples from EHV-2 (in three cases) and EHV-5 (in 30 one case) inferred a role of these viruses in abortion. The presence of viral DNA from EHV-3 31 or EHV-4 strains was not detected in the specimens studied. The data obtained suggest that 32 the consensus herpesvirus PCR is an efficient screening tool. In association with a specific 33 PCR, the test provides a rapid identification of the type of herpesvirus involved in abortion 34 and is useful for routine diagnostic tests as it allows the identification of herpesviruses other 35 than the EHV-1 strain. 36 37

Abortion in a Mediterranean miniature donkey (Equus asinus) associated with a gammaherpesvirus similar to Equid herpesvirus 7

“…Although the gammaherpesviruses EHV-2 and EHV-5 have been infrequently isolated from aborted equine fetal tissues (0.75% and 0.25% incidence, respectively), the role of these viruses in the pathogenesis of equid abortion remains unclear. 12 …”

Potential Outbreak in Brazil by Equine Herpesvirus Type 2 (EHV-2): Detection, Clinical and Genetic Analysis of Equine Gammaherpesvirus 2

“…9 EHV-2 presence in South America was previously reported in horses presenting respiratory clinical symptoms in Argentina (11) and only recently in health horses randomly sampled in Brazil (12). Until our data the relation of EHV-2 with horse diseases and abortion was reported only in Italy (17) and the role of EHV-2 in abortion still unclear (18). EHV-2 can immunosuppress foals and allowed other bacterial infection and death.…”

Description of the first recorded major occurrence of equine viral arteritis in France

“…Serological surveys and, more recently, molecular biological surveys showed that EAV infection occurs in France among Equidae. Nevertheless until summer 2007 only few cases were reported, such as the episode of Grosbois in 1986 or Vincennes in 1994 and one isolated case was reported in a retrospective abortion study (Zientara et al 1998;Leon et al 2008). The aim of this paper is to describe the different stages in the development of the 2007 outbreak in France and to show how molecular tools were used for the first time in the detection and management of the crisis.…”

“…Nevertheless until summer 2007 only few cases were reported, such as the episode of Grosbois in 1986 or Vincennes in 1994 and one isolated case was reported in a retrospective abortion study (Zientara et al . 1998; Leon et al . 2008).…”