Presence of bovine herpesvirus 1 gB‐seropositive but gE‐seronegative Dutch cattle with no apparent virus exposure

Abstract

Two hundred and thirty-seven of 2052 cattle which had not been vaccinated against bovine herpesvirus 1 (BHV-1) were seropositive in a glycoprotein B (gB)-blocking ELISA, but seronegative in a glycoprotein E (gE)-blocking ELISA. In order to detect whether they were latently infected with BHV-1, 10 of them were treated with corticosteroids in an attempt to reactivate putatively latent virus. After successive treatments with dexamethasone and prednisolone, no virus excretion was detected and they showed no increase in antibody titres. In contrast, one gE-seropositive animal re-excreted BHV-1 and had a four-fold increase in antibody titre after the corticosteroid treatments. After slaughter, no BHV-1 DNA could be detected with a sensitive PCR in samples of the trigeminal, cervical and sacral ganglia and spinal cords of the gE-seronegative cattle.

Effects of hypervaccination with bovine herpesvirus type 1 gE‐deleted marker vaccines on the serological response and virological status of calves challenged with wild‐type virus

“…However, no viral reactivation could be detected in any of the hypervaccinated gE‐seronegative animals. Moreover, no anamnestic effect of the bhv ‐1‐specific immune response typically associated with virus reactivation (Thiry and others 1983, Mars and others 2000) was observed in any of the 19 gE‐seronegative calves after their treatment with dexamethasone.…”

Characterization of caprine herpesvirus 1 (CpHV1) glycoprotein E and glycoprotein I ectodomains expressed in mammalian cells

“…This diagnostic tool seems particularly important in Countries in which BoHV1 is under eradication program in presence of vaccination. It is not rare the occurrence of cattle herds that, from a free status, turn to marker vaccinated status (gB+/ gE--) without apparent vaccination (Mars et al, 2000). In this situation a seroconversion against attenuated marker vaccine or BoHV1 strain naturally mutated at the immunodominant epitope level has never been demonstrated.…”

Serological Cross-Reactivity Between Bovine alphaherpesvirus 2 and Bovine alphaherpesvirus 1 in a gB-ELISA: A Case Report in Italy

“…BoHV-2 infections have also been described in Africa, Europe, the United States, and Australia (2-4). Several European countries have reported unexplained cases of gB-positive singleton reactors and they were found to be gE-negative (5,8,13,14). In this report, we have shown that 1 out of 2 commercial competitive gB-ELISAs gave a positive result which was not confirmed by BoHV-1 plaque reduction assay, VN, or competitive gE-ELISA tests.…”