Application of an equine herpesvirus 1 (EHV1) type-specific ELISA to the management of an outbreak of EHV1 abortion

Abstract

Sera from 33 Australian thoroughbred mares were tested during an outbreak of equine herpesvirus 1 (EHV1) abortion with an enzyme-linked immunosorbant assay (ELISA) for the presence of EHV1-specific antibodies. The ELISA used a recombinant EHV1 antigen derived from glycoprotein G (gG) and distinguished antibodies to EHV1 from those of the antigenically related and widespread herpesvirus EHV4. Sera were obtained from most of the mares on three occasions, three, 13 and 67 days after the first abortion. Mares which were negative in the ELISA were kept separate from mares which were positive. A second abortion occurred two days after the first and two more abortions and one perinatal death occurred later. Sera from these last three mares showed a significant increase in EHV1-specific antibody on day 13 indicating a recent infection with EHV1. Ten other mares did not have antibodies to EHV1 on day 13 but had seroconverted to EHV1 by day 67. Despite the EHV1 infection, these mares foaled normally, possibly because the infection had occurred either late in gestation or after foaling. Seven mares that remained negative in the ELISA throughout the testing period did not abort, and neither did 11 mares that were positive in the ELISA when they were first tested.

Equine Herpesvirus type 1 and 4 in Individually Reared Horses in Central and Western Turkey

“…Prevalence studies show that EHV4 is much more prevalent than EHV1, as also our study does. Drummer et al (1995) studied 33 mares during an outbreak of abortions due to EHV1. The researchers collected sera samples 3, 13 and 67 days after the first abortion and tested the samples using ELISA prepared with recombinant EHV1 antigen.…”

“…An ELISA test was developed recently (Crabb and Studdert 1993;Crabb et al 1995;Drummer et al 1995), capable of distinguishing type 1 and 4 and dual infection. In this study, equine herpesvirus type 1 and 4 discriminating ELISA (Enzyme-Linked Immunosorbent Assay) kit (Svanova Biotech AB, Sweden) was used for serological controlling.…”

Equine herpesvirus-4 glycoprotein G is secreted as a disulphide-linked homodimer and is present as two homodimeric species in the virion.

“…Studies of this molecule, and its EHV-1 homologue, have focused on small, highly variable and strongly immunogenic regions which have been used as antigens for detecting type-specific antibodies to these viruses Drummer et al, 1995). The nucleotide and amino acid sequence of EHV-4 gG has been shown to differ from the published sequence (Nagesha et al, 1993).…”

“…Analysis of the primary amino acid sequence of EHV-4 and EHV-1 gG predicted that both molecules are type I integral membrane proteins and that the N-terminal 300 amino acids are relatively conserved (75 % identical). By contrast, the C-terminal 100 amino acids of EHV-4 and EHV-1 gG, adjacent to the predicted C-terminal transmembrane domains, are highly divergent and possess strong type-specific epitopes Drummer et al, 1995).…”

Important viral, bacterial and parasitic agents of the equine reproductive tract and their diagnostic detection

“…Als serologisches Nachweisverfahren wird der Differenzierungs-ELISA zur Unterscheidung von EHV-1-und EHV-4-Antikörpern aus gepaarten Serumproben in der Routinediagnostik erfolgreich eingesetzt , Drummer et al 1995.…”