Ovine Herpesvirus Type Research Articles

Taxa de infecção pelo Herpesvírus ovino tipo 2 (OvHV-2)em rebanhos de ovinos no Distrito Federal

RESUMO: A febre catarral maligna (FCM) é uma doença causada pela infecção de bovinos pelo herpesvírus ovino tipo 2 (OvHV-2), responsável por perdas econômicas em diferentes regiões do Brasil. Neste trabalho descreve-se a detecção molecular por nested-PCR (nPCR) do OvHV-2 em amostras de secreção/esfoliação nasal e fração celular sanguínea (FCS) de ovinos provenientes de 8 propriedades do Distrito Federal. Das 188 amostras nasais analisadas, 88 (41,5%) foram positivas. Ovelhas prenhes não apresentaram diferenças na taxa de infecção em comparação com fêmeas paridas. Fêmeas recém-paridas apresentaram taxa de infecção pelo OvHV-2 maior que em animais que pariram há mais de 60 dias. Amostras de secreção/esfoliação nasal permitiram a detecção por nPCR de animais infectados com uma eficiência aproximadamente duas vezes maior que em amostras de fração celular sanguínea. No Brasil, informações epidemiológicas sobre a infecção pelo OvHV-2 nos rebanhos ovinos e fatores envolvidos no surgimento de surtos de FCM em bovinos são escassos. Este estudo pode servir de subsídio para elucidar as características da enfermidade e para novos estudos sobre a epidemiologia da doença no Distrito Federal e em outros Estados do Brasil.

Molecular and Serological Survey of Selected Viruses in Free-Ranging Wild Ruminants in Iran.

A molecular and serological survey of selected viruses in free-ranging wild ruminants was conducted in 13 different districts in Iran. Samples were collected from 64 small wild ruminants belonging to four different species including 25 Mouflon (Ovis orientalis), 22 wild goat (Capra aegagrus), nine Indian gazelle (Gazella bennettii) and eight Goitered gazelle (Gazella subgutturosa) during the national survey for wildlife diseases in Iran. Serum samples were evaluated using serologic antibody tests for Peste de petits ruminants virus (PPRV), Pestiviruses [Border Disease virus (BVD) and Bovine Viral Diarrhoea virus (BVDV)], Bluetongue virus (BTV), Bovine herpesvirus type 1 (BHV-1), and Parainfluenza type 3 (PI3). Sera were also ELISA tested for Pestivirus antigen. Tissue samples including spleen, liver, lung, tonsils, mesenteric and mediastinal lymph nodes and white blood cells (WBCs) were tested using polymerase chain reaction (PCR) for PPRV, Foot and Mouth Disease virus (FMDV), Pestivirus, BTV, Ovine herpesvirus type 2 (OvHV-2) and BHV-1. Serologic tests were positive for antibodies against PPRV (17%), Pestiviruses (2%) and BTV (2%). No antibodies were detected for BHV-1 or PI3, and no Pestivirus antigen was detected. PCR results were positive for PPRV (7.8%), FMDV (11%), BTV (3%), OvHV-2 (31%) and BHV-1 (1.5%). None of the samples were positive for Pestiviruses.

Prevalence of Bovine herpesvirus type 4 in aborting dairy cows.

Bovine herpesvirus type 4 (BHV-4) is related to many different conditions: infertility, postpartal metritis, vulvovaginitis, mastitis, encephalitis, calf pneumonia, keratoconjunctivitis, cutaneous lesions, digital dermatitis and abortion. In this study a retrospective PCR examination of 100 extracted DNA samples from aborting cows was performed in order to determine: prevalence of BHV-4 in abortive cattle, whether coinfections BHV-4 with other abortifacient pathogens are present in the same sample and to determine the month of gestation when BHV-4 associated abortions were detected. Out of 100 examined samples, the BHV-4 genome was detected in 21 samples (21%). In two samples we detected coinfection of BHV-4 with bovine viral diarrhea virus (BVDV) and in one with Neospora caninum. Most of the BHV-4-associated abortions were detected during the seventh month of gestation. It was concluded that an active BHV-4 infection was present among cows that aborted on the farms examined. The high prevalence of the BHV-4 genome in abortion material suggests that this virus may have cause the abortions. Further studies and examinations are needed to establish causative connection between presence of BHV-4 and abortion.

Malignant Catarrhal Fever: An Emerging Disease in the African Buffalo (Syncerus caffer)

Within the tribe Bovini in the subfamily Bovinae, the water buffalo (Bubalus Bubalis), American bison (Bison bison), European bison (Bubalus bonasus) and yak (Bos grunniens) are recognized as species highly susceptible to malignant catarrhal fever (MCF). In contrast, the lack of reports describing clinical MCF in the African buffalo (Syncerus caffer) whether free ranging or captive has led to a perception that African buffaloes are resistant to MCF. During the last decade, several cases of MCF in African buffaloes were confirmed in South Africa and experience with seven of these cases is described in this report. Detection of viral nucleic acid in blood or tissues was successful in six African buffaloes that suffered from clinical signs compatible with MCF. Four were positive for infection with ovine herpesvirus type 2 (the causative virus of sheep-associated MCF), and two were positive for alcelaphine herpesvirus type 1 (causative virus of wildebeest-associated MCF). Histopathological examination of tissue samples from all the animals yielded typical lesions that were consistent with those described for MCF in domestic cattle. Developments in the management of African buffaloes translocated from their traditional habitats have likely contributed to the identification of another susceptible host in the subfamily Bovinae.

Diagnóstico de febre catarral maligna em bovinos do Uruguai

Foi realizado um estudo retrospectivo de 14 focos de febre catarral maligna (FCM) em bovinos, detectados nos anos de 1999-2011, a partir dos arquivos da Seção Anatomia Patológica da Divisão de Laboratórios Veterinários (DILAVE) "Miguel C. Rubino" Montevideo. Foram analisados os dados epidemiológicos, apresentação clínica e lesões macroscópicas e histopatológicas. Para a detecção do herpesvírus ovino tipo 2 (OvHV-2) foi utilizada a técnica de PCR sobre as amostras do sistema nervoso central de bovinos de 12 focos. Os surtos ocorreram principalmente nos meses de primavera e verão, na região norte do país. Em 64% (9/14) dos focos ocorreram episódios individuais da enfermidade, enquanto que os casos coletivos foram 5, nos quais a morbidade e mortalidade oscilaram entre 2% e 5%, sendo a letalidade 100% em todos os relatos. Em 50% dos surtos foi confirmado o contato direto entre bovinos e ovinos, enquanto no restante não havia tal informação. Clinicamente predominaram os sinais de opacidade bilateral da córnea, conjuntivite, secreção nasal e ocular mucopurulenta, assim como a síndrome nervosa. Os achados de necropsia mais frequentes foram opacidade bilateral da córnea e lesões inflamatórias nas mucosas. Os achados histopatológicos caracterizaram-se por panvasculite necrótica sistêmica. Foi possível detectar o agente etiológico por PCR em 5 dos 12 casos analisados.

Malignant catarrhal fever in sika deer (Cervus nippon) in the UK

MALIGNANT catarrhal fever (MCF) is a viral disease characterised by lymphoproliferation, vasculitis and erosive-ulcerative mucosal and cutaneous lesions (Brown and others 2007, Russell and others 2009); it is commonly fatal....

Detection of sheep-associated malignant catarrhal fever from clinical cases in Ethiopian cattle.

Mucoid nasal discharge, loss of weight, decreased milk production, diarrhoea, salivation, dyspnoea, fever, lacrimation, bilateral corneal opacity and bloody urine were observed in cattle located in the Arbe Gona district of southern Ethiopia. The disease was associated with a high case fatality rate: diseased cattle died within four to five days after showing clinical signs. The clinical presentation, gross pathological observations, histopathological findings and epidemiological data strongly suggested malignant catarrhal fever. Subsequently, the ovine herpesvirus type 2 (OvHV-2) DNA polymerase (UL30) gene was detected in pathological tissue samples using pan-herpesvirus nested polymerase chain reaction (PCR) and real-time PCR. As far as the authors are aware, this is the first report of a diagnostic investigation resulting in the detection of ovine OvHV-2 in cattle and confirming the existence of sheep-associated malignant catarrhal fever in Ethiopia.

Malignant catarrhal fever in kune kune pigs in the UK

MALIGNANT catarrhal fever (MCF) is an invariably fatal disease of cattle and other ungulates, including pigs, caused by the gammaherpesviruses alcelaphine herpesvirus type 1 and ovine herpesvirus type 2 (OvHV-2)...

Molecular characterisation of ovine herpesvirus type 2 (OvHV-2) in Turkey

In this study, the physical examination of 22 cattle revealed clinical signs of malignant catarrhal fever (MCF). Peripheral blood leukocyte (PBL) samples of the 22 cattle, and nasal (n = 7) and conjunctival (n = 9) swab samples from 16 sheep from two different farms, were taken for laboratory examination. The clinical diagnosis of MCF in cows was confirmed by the detection of ovine herpesvirus type 2 (OvHV-2) DNA by polymerase chain reaction (PCR). OvHV-2 DNA was detected by nested-PCR in PBL of one cow with clinical signs and nasal (1/7)-conjunctival(1/9) swab samples of two sheep housed in the same barn. According to the sequence analysis, three slightly divergent viruses were detected. The results indicate the need for additional research in different regions of Turkey to gain a better understanding of the incidence of MCF and its implications for the livestock industry.

Ovine herpesvirus type 2 infection in captive bison in India

Veterinary RecordVolume 170, Issue 25 p. 654-654 Letter Ovine herpesvirus type 2 infection in captive bison in India Richa Sood, Richa Sood High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorManoj Kumar, Manoj Kumar High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorS. Bhatia, Corresponding Author S. Bhatia [email protected] High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, Indiae-mail: [email protected]Search for more papers by this authorA. K. Pateriya, A. K. Pateriya High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorR. Khandia, R. Khandia High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorA. Siddiqui, A. Siddiqui High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorD. D. Kulkarni, D. D. Kulkarni High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorSanjeev Kumar, Sanjeev Kumar Institute of Animal Health and Veterinary Biologicals, Southern Regional Disease Diagnostic Laboratory, Hebbal, Bangalore, Karnataka, IndiaSearch for more papers by this authorM. D. Venkatesha, M. D. Venkatesha Institute of Animal Health and Veterinary Biologicals, Southern Regional Disease Diagnostic Laboratory, Hebbal, Bangalore, Karnataka, IndiaSearch for more papers by this author Richa Sood, Richa Sood High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorManoj Kumar, Manoj Kumar High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorS. Bhatia, Corresponding Author S. Bhatia [email protected] High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, Indiae-mail: [email protected]Search for more papers by this authorA. K. Pateriya, A. K. Pateriya High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorR. Khandia, R. Khandia High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorA. Siddiqui, A. Siddiqui High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorD. D. Kulkarni, D. D. Kulkarni High Security Animal Disease Laboratory, Anand Nagar, Bhopal, 462021 Madhya Pradesh, IndiaSearch for more papers by this authorSanjeev Kumar, Sanjeev Kumar Institute of Animal Health and Veterinary Biologicals, Southern Regional Disease Diagnostic Laboratory, Hebbal, Bangalore, Karnataka, IndiaSearch for more papers by this authorM. D. Venkatesha, M. D. Venkatesha Institute of Animal Health and Veterinary Biologicals, Southern Regional Disease Diagnostic Laboratory, Hebbal, Bangalore, Karnataka, IndiaSearch for more papers by this author First published: 23 June 2012 https://doi.org/10.1136/vr.e4291Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume170, Issue25June 2012Pages 654-654 RelatedInformation

Serological Survey to Determine the Occurrence of Blue Tongue Virus, Bovine Leukemia Virus and Herpesvirus Infections in the Japanese Small Ruminant Population from Northern Districts

Ovine sera, collected from the northern prefectures of Hokkaido, Aomori and Iwate in Japan, were examined for the presence of antibodies against Blue tongue virus (BTV), bovine leukemia virus (BLV), bovine Herpesvirus type 1, agent of infectious bovine rhinotracheitis (IBR), ovine Herpesvirus type 2 (OvHV-2), agent of sheep-associated malignant catarrhal fever (SA-MCF), and bovine Herpesvirus type 4 (BoHV-4), using agar immune diffusion, serum neutralisation (SN) and enzyme linked immunosorbent assay (ELISA) tests. No animals were positive to IBR, BoHV- 4 or BLV antigens. Antibodies against BTV have been detected in 3 samples (1.11%) in two flocks from Hokkaido. The seroprevalence of OvHV-2 was observed in twelve flocks from the 3 considered prefectures, in 56 sheep and two goats, with 37.66% of samples giving a positive reaction in the serum neutralization test. The infections did not appear to be related to the reduction in sheep productivity. Immune reaction reported in goats could refer to Caprine Herpesvirus-2 (CpHV-2). These results indicate that sheep are reservoirs for OvHV-2 in the field in Japan.

Outbreak of Ulcerative Vulvitis in a Sheep Flock Caused by Ovine Herpesvirus Type 2

Outbreak of Ulcerative Vulvitis in a Sheep Flock Caused by Ovine Herpesvirus Type 2

Malignant catarrhal fever in kune kune pigs in the UK

MALIGNANT catarrhal fever (MCF) is an invariably fatal disease of cattle and other ungulates, including pigs, caused by the gammaherpesviruses alcelaphine herpesvirus type 1 and ovine herpesvirus type 2 (OvHV-2)...

An outbreak of porcine malignant catarrhal fever in a farrow-to-finish swine farm in the United States

Malignant catarrhal fever is a sporadic, often fatal viral disease affecting multiple species, including swine. Ovine herpesvirus type 2 (OvHV-2), the cause of sheep-associated malignant catarrhal fever, incites nonspecific clinical signs and occasional death in swine. An outbreak of malignant catarrhal fever in a farrow-to-finish swine farm in the United States was confirmed by identifying OvHV-2 DNA in two clinically affected adult swine previously exposed to sheep. Forty-one swine exhibited clinical signs of lethargy, anorexia, and fever, with recovery or death in 22 and 19 animals, respectively. Abortion was also reported in two clinically affected pregnant females. Ovine herpesvirus type 2 DNA was identified by polymerase chain reaction (PCR) in spleen, brain, and lung tissue. A BLAST homology search of the sequenced PCR amplicon matched the conserved region of the OvHV-2 tegument protein. Porcine malignant catarrhal fever is difficult to diagnose due to the nonspecific clinical signs, rarity of occurrence, and sporadic nature of the disease. Polymerase chain reaction assays and serologic testing are available to assist in an accurate diagnosis. Veterinarians should consider malignant catarrhal fever a potential differential diagnosis in swine with poorly defined clinical signs, intermittent death, and previous exposure to sheep.

Outbreak of malignant catarrhal fever among cattle associated with a state livestock exhibition

Severe disease and death were identified in cattle exhibited at a state fair that were naturally infected with ovine herpesvirus type 2 (OvHV-2). Most affected cattle had anorexia, signs of depression, diarrhea, fever, and respiratory distress ultimately leading to death. Mean duration of clinical signs prior to death was 6 days (range, 1 to 26 days). Mean number of days between apparent exposure and death was 71 days (range, 46 to 139 days). 19 of 132 cattle cohoused in 1 barn died of malignant catarrhal fever (MCF). The diagnosis of sheep-associated MCF was confirmed on the basis of results of an OvHV-2-specific PCR assay performed on tissue samples obtained from affected cattle. The disease was associated but not significantly with distance from the center of the barn and was not associated with distance from the center of the sheep pens. Outbreaks of MCF in cattle are unusual, particularly in association with livestock exhibitions. Because the clinical signs may be similar to those of some transboundary diseases, cases of MCF should be reported and investigated. Findings for this outbreak provided evidence to suggest that fair boards and veterinarians should reexamine biosecurity recommendations for livestock exhibitions.

Kobuvirus in Domestic Sheep, Hungary

To the Editor: Picornaviruses (family Picornaviridae) are small, nonenveloped viruses with single-stranded, positive-sense genomic RNA. They are divided into 12 genera: Enterovirus, Aphthovirus, Cardiovirus, Hepatovirus, Parechovirus, Erbovirus, Teschovirus, Sapelovirus, Senecavirus, Tremovirus, Avihepatovirus, and Kobuvirus. The genus Kobuvirus consists of 2 officially recognized species, Aichi virus (1) and Bovine kobuvirus (2), and 1 candidate species, porcine kobuvirus (3). The kobuvirus genome is ≈8.2–8.4 kb long and has the typical picornavirus genome organization of leader (L) protein following the structural (viral protein [VP] 0, VP3, and VP1) and nonstructural (2A–2C and 3A–3D) regions (2,4). The genetic identity on the coding region between Aichi (strain A846/88), bovine (U-1), and porcine (S-1-HUN) viruses is between 35% (L protein) and 74% (3D region) (2,4). Aichi virus and bovine kobuvirus were first detected in fecal samples from humans and cattle in Japan, in 1991 and 2003, respectively (1,2). Porcine kobuvirus was identified from domestic pigs in Hungary in 2008 (3,4). Recent studies demonstrated that Aichi virus circulates in Asia (5), Europe (6,7) including Hungary (4), South America (6), and North Africa (8) and can cause gastroenteritis in humans. In addition, bovine and porcine kobuviruses are detected among these farm animals in Europe (4) and Asia (2,9). These data indicate that kobuviruses are widely distributed geographically and raise the possibility of additional animal host species. We detected kobuvirus in sheep. On March 17, 2009, a total of 8 fecal samples were collected from young, healthy, domestic sheep (Ovis aries) <3 weeks of age in a herd of 400 animals in central Hungary. At this farm, merino ewes from Hungary were mated with blackhead meat rams from Germany. At the time of sampling, no clinical signs of diarrhea were reported. Reverse transcription–PCR was performed by using generic kobuvirus screening primers (UNIV-kobu-R/F) reported previously (4). These primers were designed for Aichi virus (GenBank accession no. {type:entrez-nucleotide,attrs:{text:AB040749,term_id:15186718,term_text:AB040749}}AB040749), bovine ({type:entrez-nucleotide,attrs:{text:AB084788,term_id:24817742,term_text:AB084788}}AB084788), and porcine kobuvirus ({type:entrez-nucleotide,attrs:{text:EU787450,term_id:219524015,term_text:EU787450}}EU787450) sequences and amplify a 216-nt region of 3D (RNA-dependent RNA polymerase region). The continuous 3D and 3′ untranslated regions (UTRs) of the kobuvirus genome in sheep were determined by using the 5′/3′ RACE (rapid amplification of cDNA ends) kit, 2nd generation (Roche Diagnostics GmbH, Mannheim, Germany) and primers UNIV-kobu-F and S-1-F-7518/7540 (5′-CACTTCCATCATCAACACCATCA-3′ corresponding to nt 7518–7540 of bovine kobuvirus) (4). PCR products were sequenced directly in both directions by using the BigDye Reaction Kit (Applied Biosystems, Warrington, UK) with the PCR primers and sequenced by an ABI PRISM 310 Genetic Analyzer (Applied Biosystems, Stafford, TX, USA). Phylogenetic analysis was conducted by using MEGA version 4.1 (www.megasoftware.net). The sequence for kobuvirus/sheep/TB3-HUN/2009/Hungary was submitted to GenBank under accession no. {type:entrez-nucleotide,attrs:{text:GU245693,term_id:342240198,term_text:GU245693}}GU245693. Of the 8 sheep fecal samples, 5 (62.5%) were positive for kobuvirus. The partial 3D region (216 nt) was genetically identical for all 5 strains. The 3′ continuous nucleotide sequence of the partial 3D (688 nt) and 3′ UTR (174 nt) regions of strain kobuvirus/sheep/TB3-HUN/2009/Hungary (TB3-HUN; {type:entrez-nucleotide,attrs:{text:GU245693,term_id:342240198,term_text:GU245693}}GU245693) was determined. TB3-HUN had 59%–66% (862) nt and 77%–84% aa identities to Aichi and porcine kobuviruses, respectively. Strain TB3-HUN had 89/97% nt/aa and 86% nt identities to bovine kobuvirus in the 3D/3′ UTR (862 nt) and 3′ UTR (174 nt) regions, respectively. Phylogenetic analysis of the overlapping partial 3D/3′ UTR nucleotide sequence of TB3-HUN from sheep and of reference bovine, porcine, and human kobuviruses confirmed that ovine kobuvirus strain TB3-HUN is related to bovine kobuviruses (Figure). Figure Phylogenetic analysis of kobuvirus in sheep (kobuvirus/sheep/TB3-HUN/2009/Hungary, {type:entrez-nucleotide,attrs:{text:GU245693,term_id:342240198,term_text:GU245693}}GU245693) and kobuvirus lineages in humans, cattle, and swine, according ... The nucleotide sequence of the partial 3D/3′ UTR region of kobuvirus in sheep has high nucleotide identity to bovine kobuviruses and forms the same lineage (but a different sublineage) with the kobuvirus strains in cattle. This result raised the following questions: can a highly similar kobuvirus be present in (and pathogenic for) 2 animal species (cattle and sheep), or is this result a consequence of natural contamination? The concept of sheep as host is supported by the high prevalence of kobuvirus in young healthy sheep; by the sublineage position of the sheep strain on the phylogenetic tree according to the most conserved genetic region; and by the genetic relation between the 2 potential ruminant hosts, cattle and sheep. The existence of 1 pathogen in 2 host species (cattle and sheep) is well known, e.g., for bluetongue virus, adenoviruses, ovine herpesvirus type 2, and foot-and-mouth disease picornaviruses (10). Alternatively, the possibility of natural contamination cannot be excluded. The possibility of passive virus shedding in sheep exists because a cattle farm was located next to the tested sheep herd and would enable fecal–oral transmission of kobuvirus between these farm animals. Both possibilities (host and passive virus reservoir) are preliminary perceptions, regardless which is true. Further molecular and epidemiologic studies are required to determine the relevance, distribution, and diversity of kobuvirus or kobuviruses in sheep.

Diagnostic Exercise

An 18-month-old cross-bred goat was presented with generalized erythema and thinning of the hair coat, as well as localized moderate scaling. Histopathological evaluation of skin biopsies showed hyperplasia and marked disruption of the infundibular epithelium owing to a predominant infiltrate of macrophages with multinucleated histiocytic giant cells and some lymphocytes, plasma cells, and eosinophils. Examination of peripheral blood and skin by polymerase chain reaction gave positive results for ovine herpesvirus type 2 consistent with a diagnosis of malignant catarrhal fever.

Unusual cases of illthrift associated with PGE in Scottish cattle

Illthrift related to parasitic gastroenteritis in cattlePlant poisoning due to Pieris species in sheepPenile and vulval lesions in sheep associated with ovine herpesvirus type 2Necrotising epidermitis in pigs due to...

Ulcerative vulvitis and balanitis in sheep flocks

Outbreaks of ulcerative vulvitis and balanitis occurred in three commercial sheep flocks in England and Wales. Between 29 and 44 per cent of the ewes were affected; most of the...

Gammaherpesvirus carrier status of black wildebeest (Connochaetes gnou) in South Africa

Malignant catarrhal fever (MCF) is an economically important disease primarily of domestic cattle with a high case fatality rate. It is caused by either alcelaphine herpesvirus type 1 (AlHV-1) or ovine herpesvirus type 2 (OvHV-2). The major reservoir host of AlHV-1 is the blue wildebeest (Connochaetes taurinus), but it is generally accepted that the black wildebeest (Connochaetes gnou) is also a reservoir host. No viral studies in the black wildebeest have been reported and the carrier status of black wildebeest has not been documented. Specimens were collected from several game farms and conservation areas in central South Africa representing the geographical area historically linked to the natural habitat of the black wildebeest. Specimens were obtained from 304 black wildebeest of different ages and sex, as well as 51 black wildebeest foetuses at different stages of gestation. Virus was isolated from a black wildebeest calf. Morphological features and antigenic characteristics suggested it to be a gammaherpesvirus closely related to AlHV-1. All serum samples tested positive with a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) for group-specific malignant catarrhal fever virus antibody. A SYBR Green real-time PCR assay was developed for the detection of gammaherpesviral DNA. Only 15.8 % of the animals tested positive with the real-time PCR assay whereas 90 % of the foetuses tested positive. This finding suggests that, unlike OvHV-2 infection in lambs in which the infection takes place after weaning, the virus in black wildebeest is mainly transmitted in utero or soon after birth. The results suggest that black wildebeest are latent carriers of a gammaherpesvirus similar or closely related to AlHV-1 present in blue wildebeest and that it is likely that all black wildebeest are persistently infected.