Ovine Herpesvirus Type Research Articles

Probable malignant catarrhal fever presented as transient generalised crusting dermatitis in a cow

CASE HISTORY: A 2-year-old crossbred cow developed crusting ulcerative lesions that covered approximately 40% of the body. They were first observed 2 weeks after the cow calved, and were most severe over the caudal aspect of the proximal hindlegs and perineum. CLINICAL FINDINGS AND DIAGNOSIS: Generalised variably confluent 1–2-cm diameter foci of ulceration and crusting were visible. No ocular or oral lesions were visible, and the cow did not have diarrhoea. Skin biopsies revealed lesions consistent with those previously described for malignant catarrhs fever (MCF). Additionally, prominent multinucleate cells were visible. The DNA for ovine herpesvirus type 2 (OHV-2) was amplified from the skin biopsies, using PCR. The cow spontaneously made a complete clinical recovery. CLINICAL RELEVANCE: Malignant catarrhs fever should be considered in cases of ulcerative skin disease in cattle. The disease is difficult to diagnose, and a combination of skin histology as well as PCR is required. Although probably rare, it appears complete recovery from MCF is possible when the disease is confined to the skin.

Outbreak of wildebeest-associated malignant catarrhal fever in Ankole cattle

During an outbreak of malignant catarrhal fever in a herd of Ankole cattle in a zoological collection, two adult cows and one adult bull from a herd of 15 died...

Studies on the aetiology of non-suppurative encephalitis in pigs

Thirty-eight natural cases of aetiologically unclear non-suppurative encephalitis in pigs were studied retrospectively. Brain samples were examined for the presence of porcine circovirus type 2 (PCV-2), porcine respiratory and reproductive...

Molecular epidemiology of ovine herpesvirus type 2 infection in Kashmir, India

The aims of this investigation were to determine the prevalence of ovine herpesvirus type 2 (ovhv-2) (the causative agent of malignant catarrhal fever) infection in cattle, the carrier status of...

Evaluation of ovine herpesvirus type 2 infections, as detected by competitive inhibition ELISA and polymerase chain reaction assay, in dairy cattle without clinical signs of malignant catarrhal fever

To monitor ovine herpesvirus type 2 (OvHV-2) infection status and the association between OvHV-2 infection and development of clinical signs of malignant catarrhal fever (MCF) in cattle. Longitudinal study. 30 mature adult cows and 18 cattle submitted for necropsy. Blood and milk samples were collected at monthly intervals from 30 adult cows for 20 consecutive months. Nasal and ocular swab specimens were also collected during months 9 through 20. Polymerase chain reaction (PCR) assay for detection of OvHV-2 was performed on blood, milk, nasal swab, and ocular swab specimens. Competitive inhibition ELISA (CI-ELISA) for detection of antibodies against MCF viruses was performed on serum samples obtained prior to study initiation and monthly during the last 12 months. Tissues obtained from herdmates without clinical signs of MCF that were submitted for necropsy were analyzed for OvHV-2 DNA via PCR assay for possible sites of latency. Initially, 8 of 30 cows had positive CI-ELISA results. Seroconversion was detected in 4 cows. Ovine herpesvirus type 2 DNA was intermittently detected in blood, milk, nasal secretions, or ocular secretions from 17 of 30 cows. Twenty-one cows had positive CI-ELISA or PCR assay results. No cattle in the study developed clinical signs of MCF. Results of PCR assays performed on tissue samples from 2 of 18 animals submitted for necropsy were positive for OvHV-2. CONCLUSIONS AND CLINICAL RELEVANCE; OvHV-2 infection can occur in cattle without concurrent development of clinical MCF. Ovine herpesvirus type 2 DNA was detected intermittently, suggesting fluctuating viral DNA loads or reinfection in subclinical cattle. A definitive site of latency was not identified from tissues obtained during necropsy.

Persistent Infection of Ovine Herpes virus Type 2 in a Dairy Herd

Malignant catarrhal fever (MCF) is a frequently fatal viral disease of cattle and other ruminants. Sheep-associated MCF is caused by ovine herpesvirus type 2 (OvHV-2). Over 95% of domestic sheep are asymptomatic carriers of OvHV-2 and serve as a source of infection for cattle. Previous studies demonstrated a significant high prevalence of asymptomatic OvHV-2 infection in adult dairy cattle from a herd housed in close proximity to sheep. While sheep are considered to be the primary source of infection in cattle, there are reports of MCF in cattle that are not in direct contact with sheep. The hypothesis for this study is that cattle infected with OvHV-2 can remain asymptomatic for extended periods of time and may transmit the virus to offspring through placenta and/or colostrum. The study's objectives were to monitor a group of adult cattle for evidence of OvHV-2 persistent infection and evaluate possible transmission of OvHV-2 to calves.

Seroprevalence of OHV-2, BVDV, BHV-1, and BRSV in ranch-raised bison (Bison bison).

Serum samples were collected at slaughter from 226 24-30-month-old American bison (Bison bison) bulls from Kansas, Minnesota, North Dakota, and Manitoba and assayed for antibodies to ovine herpesvirus type-2 (OHV-2), bovine viral diarrhea virus (BVDV), bovine herpesvirus type-1 (BHV-1), and bovine respiratory syncytial virus (BRSV). Antibodies were detected by serum neutralization for BVDV, BHV-1, and BRSV, while antibodies to OHV-2 were detected by competitive inhibition-ELISA (CI-ELISA). Detectable antibodies were found against all viruses: 10 of 226 (4.40%) against OHV-2, 125 of 226 (55.3%) against BVDV, 99 of 226 (43.8%) against BHV-1, and 208 of 226 (92.0%) against BRSV. Titers from 93.6% of the BVDV-positive animals, 79.8% of the BHV-1-positive animals, and 98.1% of the BRSV-positive animals were > or = 1.25. These data indicate that a low percentage of clinically normal bison are seropositive for OHV-2 while a high percentage of bison sampled are seropositive for BVDV, BHV-1, and BRSV.

Detection and multigenic characterization of a novel gammaherpesvirus in goats

Evidence for the existence of a caprine gammaherpesvirus was obtained by analysis of peripheral blood leucocytes of goats with PCR assays that target the herpesvirus genes encoding the glycoprotein B (gB), the DNA polymerase (DPOL) and the terminase (TERM) with degenerate and deoxyinosine-substituted primers. A contiguous 3.6 kbp sequence extending from the gB to the DPOL gene was then determined with specific primers. All sequences (gB, DPOL and TERM) showed a close relationship with the corresponding genes of the Gammaherpesvirinae. Alignment of amino acid sequences revealed a particularly high percentage of identity with the ovine herpesvirus type 2 (>83%), followed by the alcelaphine herpesvirus 1 (>76%) and the bovine lymphotropic herpesvirus (>61%). Phylogenetic analyses confirmed these relationships. The putative novel goat herpesvirus from which these sequences originate was tentatively designated caprine herpesvirus 2. This virus is the first gammaherpesvirus recognized in goats.

Detection of two novel porcine herpesviruses with high similarity to gammaherpesviruses.

Evidence for the existence of porcine gammaherpesviruses was obtained by PCR and sequence analysis. Initially, samples of peripheral blood mononuclear cells (PBMC), spleens, lungs, kidneys and livers of pigs from Germany and Spain were tested with a PCR assay which targets conserved regions of the herpesvirus DNA polymerase gene with degenerate and deoxyinosine-substituted primers. Amplicons of identical sequence were obtained from one spleen and two PBMC samples. This sequence showed a high percentage of identity with the DNA polymerase genes of herpesviruses of the oncogenic subfamily Gammaherpesvirinae. Alignment of amino acid sequences showed the highest identity values with bovine gammaherpesviruses, namely alcelaphine herpesvirus type 1 (68%), ovine herpesvirus type 2 (68%) and bovine lymphotropic herpesvirus (67%). Comparison with pseudorabies virus and porcine cytomegalovirus, which are the only porcine herpesvirus species presently known, showed values of only 41%. PCR analysis of PBMC (n = 39) and spleen (n = 19) samples from German pigs, using primers specific for the novel sequence, revealed a prevalence of 87 and 95%, respectively. In this analysis, three out of eight spleen samples from Spanish pigs were also positive. Subsequent sequencing of the amplicons revealed the presence of two closely related gammaherpesvirus sequences, differing from each other by 8% at the amino acid level. The putative novel porcine herpesviruses, from which these sequences originated, were tentatively designated porcine lymphotropic herpesvirus type 1 and type 2 (PLHV-1 and PLHV-2). When using pig organs for xenotransplantation, the presence of these viruses has to be considered.