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To determine the occurrence of bovine herpesvirus 1 (BoHV-1) related alphaherpesvirus infections in cervids, 1194 serum samples of wild ruminants originating from 59 forest districts of Poland were tested with IBR gB ELISA and virus neutralization test (VNT) against BoHV-1 and cervid herpesvirus 1 (CvHV-1). The seroprevalence differed significantly between free-living and captive cervids (P<0.001) with a total of 89 out of 498 (17.9%) and 268 out of 696 (38.5%) seropositive animals in each type of population. In free-ranging cervids, the highest seroprevalence was found among red deer (25.6%) and in fallow deer (23.1%), while it was the lowest in roe deer (1.7%). The seroprevalence varied at the district level between 0 and 100% with the mean value of 17.4% (95% CI:10.1-24.0). Additionally, seroprevalence was associated with afforestation (χ 2 =7.5; P=0.006) and to some degree with the mean of cattle density in province (χ 2 =7.0; P=0.08). The mean antibody titre against CvHV-1 in VNT (161.8; 95%CI: 146.0-177.6) has been significantly higher (P<0.0001) than the mean titre of BoHV-1 antibodies (10.1; 95%CI: 8.9-11.4). The results showed that BoHV-1 related alphaherpesvirus infections are present in population of free-ranging and farmed cervids in Poland. Based on the VNT results and considering the low susceptibility of red deer to BoHV-1, it seems that the dominant alphaherpesvirus circulating in wild ruminants is most likely CvHV-1 and therefore it is rather unlikely that deer in Poland could play any role as a reservoir of BoHV-1 for cattle., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The infectivity of a recombinant murine norovirus (RecMNV) strain, previously isolated following in vitro coinfections, was evaluated in vivo in comparison with its parental strains (MNV-1-CW1 and WU20) in Balb/cByJ mice via measurement of weight loss and estimation of viral loads in faeces, tissues and organs 48 and 72h post-infection. The presence of infectious virus in all analysed tissues and organs suggests that, similarly to its parental viruses, RecMNV can disseminate beyond organs associated with the digestive tract. Our results also suggest that recombination occurring in vitro between two homologous murine norovirus strains can give rise to a chimeric strain which, despite slight differences, shows similar biological properties to its parental strains. This study provides the first report on in vivo replication of a recombinant norovirus strain isolated following in vitro coinfection. These results have great significance for norovirus genetic evolution and future vaccine development., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Zoonotic transmission of hepatitis E virus (HEV) is of special concern, particularly in high income countries were waterborne infections are less frequent than in developing countries. High HEV seroprevalences can be found in European pig populations. The aims of this study were to obtain prevalence data on HEV infection in swine in Belgium and to phylogenetically compare Belgian human HEV sequences with those obtained from swine. An ELISA screening prevalence of 73% (95% CI 68.8-77.5) was determined in Belgian pigs and a part of the results were re-evaluated by Western blot (WB). A receiver operating characteristic curve analysis was performed and scenarios varying the ELISA specificity relative to WB were analysed. The seroprevalences estimated by the different scenarios ranged between 69 and 81% and are in agreement with the high exposure of the European pig population to HEV. Pig HEV sequences were genetically compared to those detected in humans in Belgium and a predominance of genotype 3 subtype f was shown in both swine and humans. The high HEV seroprevalence in swine and the close phylogenetic relationships between pig and human HEV sequences further support the risk for zoonotic transmission of HEV between humans and pigs., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The emergence of bluetongue disease (BT) among livestock in Europe in 2006 raised many questions including the occurrence and epidemiological significance of foetal infections in cattle. To clarify these aspects, vaccinated and unvaccinated pregnant heifers were sequentially infected twice in an isolation facility (biosafety level 3) with a northern European outbreak strain of Bluetongue virus serotype 8 (BTV-8). The study was terminated 2 months after calving with necropsy of the dams and their offspring. The cattle were monitored throughout the study by clinical scoring and for the presence of circulating neutralising antibodies, and after calving for the presence of infectious virus and viral RNA in blood and milk. Four calves, one born from a vaccinated dam and three from non-vaccinated ones, that were infected at 120 days of gestation had obvious haemorrhage of the pulmonary artery at necropsy. Although haemorrhage of the pulmonary artery is highly characteristic of BT, viral RNA was not detected in any of these calves. Furthermore, although none of the calves born from heifers infected prior to mid-gestation had teratogenic BTV typical brain lesions, some had lesions at birth suggestive of in utero BTV infection. Despite the lack of viral RNA detection, the presence of haemorrhage of the pulmonary artery deserves to be reported as a new observation in the context of the multiple investigations having as main subject the BTV placental crossing in cattle., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The contemporary circulation of multiple bluetongue virus (BTV) serotypes or strains within the same territory can imply the co-infection of the ruminant and/or the vector populations. As a consequence, the clinical and pathological outcomes of co-infections as well as the biological properties of the viral progeny could be influenced and exhibit relevant variation. In this study, two independent co-infection experiments were carried out in calves using European strains of BTV serotypes 1 and 8 (BTV-1 and BTV-8, respectively), with the objective of studying the clinical and virological outcomes in comparison with BTV-1 and BTV-8 single infections. Synchronous co-infections using the same titre for the two viral strains were performed and the clinical signs were quantified using a standardized clinical form. Serotype-specific real-time RT-PCRs and viral isolation were used to monitor the course of viraemia. Neutralizing antibody titres were measured during the experiments, and necropsy with viral detection in the affected organs was performed. In the co-infected calves, a high BTV-8 viraemia was detected, while BTV-1 viraemia was irregular and sporadic. During BTV-1 single infection the development of viraemia and high titres of anti-BTV-1 neutralizing antibodies proved that the inoculum was infectious and the detection protocols were efficient. Several hypotheses could explain the predominant detection of BTV-8 in the co-infected calves, such as the occurrence of a privileged BTV-8 segment 2 reassortment, as recently described during in vitro BTV-1/BTV-8 co-infections; interference between the two viral strains; or a higher BTV-8 tropism for the bovine species., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Herpesviruses of the genus Varicellovirus are known to infect and cause disease in a variety of ruminant species, but the impact of cervid herpesvirus 2 (CvHV2) in reindeer (Rangifer tarandus) is mostly unknown. Reindeer is a circum-polar species with a total estimated number of more than 5 million animals. Mortality may reach high values, as in northern Norway, especially in calves (37%; 2005-2006), and disease can potentially account for some of this mortality. CvHV2 has been isolated during a natural outbreak of infectious keratoconjunctivitis, indicating an etiologal link. Serological screening has shown that CvHV2 infection is prevalent in Northern Norway and experimental infection studies have demonstrated that viremia, latency and vertical transmission occur for CvHV2. The present review aims at summarizing current knowledge on the epidemiology, pathogenesis and molecular virology of CvHV2., (Copyright 2010 Elsevier B.V. All rights reserved.)

Alphaherpesviruses infect a wide range of animal species and cause diseases. Cervid herpesvirus 2 (CvHV-2) was originally isolated from reindeer in Finland but the impact of CvHV-2 infections on reindeer remains unclear. CvHV-2 infection could be partly responsible for calf losses as there are indications that it is associated with abortions and neonatal diseases. Previous serosurveys of reindeer (Rangifer tarandus tarandus) have shown that an alphaherpesvirus is circulating among reindeer in Norway. The aim of the present study was to determine the prevalence of CvHV-2 infection among reindeer in various herding districts in Finnmark, the largest reindeer area in Norway, and to identify factors associated with becoming infected with CvHV-2. A total of 3062 serum samples were tested using an ELISA and a sub-set of samples was further tested using a seroneutralization test. The ELISA revealed that 49% of samples were positive. Extrapolation of the results to the total population (111,350 animals; 66% of the Finnmark reindeer population) showed that the seroprevalence in the population was 48%. Seroprevalence varied from 7.6% to 90.7% between districts and was affected by age, weight and population density. ELISA-positive samples neutralized CvHV-2 at serum dilutions greater than those required for neutralization of bovine herpesvirus type 1. It is concluded that CvHV-2 is endemic throughout the reindeer herding districts of northern Norway.

The objectives of this study were to estimate the prevalence and the potential role of equine herpesviruses (EHVs) detection in both bronchoalveolar lavage (BAL) and tracheal wash (TW). The population included a control group (CTL; 37 TW and 25 BAL) and a pathological group (PAT; 259 TW and 387 BAL), including horses either suffering from respiratory diseases including syndrome of tracheal inflammation, inflammatory airway disease, recurrent airway obstruction, or submitted to respiratory investigation because of exercise intolerance or poor performance. Each respiratory liquid was submitted to a standardised cytological analysis, mentioning the morphological abnormalities of exfoliated epithelial cells (ECAb) and ciliocytophthoria (CCPh) as markers of potential viral infection, as well as PCR assays including a consensus PCR and virus-specific PCR for both equine alphaherpesviruses (EHV-1; EHV-4) and gammaherpesviruses (EHV-2; EHV-5). The EHV infections were more prevalent in the TW of PAT group (P=0.004), with the highest prevalence being for EHV-2 (P=0.006). The EHV detection in BALs was not significantly different between groups. The EHVs detection in TW was correlated to the polymorphonuclear neutrophil (PMN) counts in the respiratory liquid but not with CCPh or ECAb. CCPh or ECAb were associated with both consensus PCR and EHV-2 and EHV-5 virus-type PCR in the BAL only. The significant detection of EHVs in the TW of PAT group in association with the PMN increased counts could lead to further investigations about their putative role in equine syndrome of tracheal inflammation.

Noroviruses, belonging to the family Caliciviridae, have been identified in human beings and in several animal species including cattle. The distribution of bovine norovirus infections was investigated by both RT-PCR to detect norovirus genomes and a virus-like particles-based ELISA to detect genotype 2 bovine norovirus antibodies. During a 1-year systematic study, a virus prevalence of 7.5% (CI 95%: [3.7; 13.4%]) (10 out of 133 samples) was found in stool samples from diarrhoeic calves screened by RT-PCR. Nucleotide sequencing performed on the polymerase region classified all the norovirus amplicons in the bovine norovirus genotype 2. Rather surprisingly, some rotavirus sequences were also detected. On the basis of the polymerase region, genotype 1 bovine norovirus was not identified. Other enteropathogens were found in all samples. By ELISA, a genotype 2 seroprevalence of 93.2% (CI 95%: [90.4; 95.3%]) was found from calves and adult cattle. Antibody levels against genotype 2 bovine noroviruses rose in the first 6 months of life and were maintained in adults. Together the results of virus prevalence and seroprevalence studies suggest that bovine norovirus infection occurs early in life and that re-infection with serologically related bovine noroviruses strains could occur in adult cattle as reported for rotaviruses. The antibody rise against genotype 2 bovine noroviruses in the adult cattle also suggests a short lived and/or strain specific immunity as already shown in human noroviruses. Genotype 2 bovine noroviruses are endemic in the region investigated.

Caprine herpesvirus 1 (CpHV-1) is responsible of a systemic disease in kids and genital diseases inducing abortions in adult goats. In Europe, CpHV-1 is widespread in Mediterranean countries such as Greece, Italy and Spain. As France is geographically close to these countries, a survey was conducted to investigate the presence of CpHV-1 in goats in a Mediterranean department (Corse-du-Sud) and in continental departments (Dordogne and Vendée) of this country. Taking into account the close antigenic and genetic relationships between bovine herpesvirus 1 (BoHV-1) and CpHV-1, the serological detection was performed by using BoHV-1 glycoproteins B (gB) and E (gE) blocking ELISAs. The analysis of 2548 serum samples in a BoHV-1 gB blocking ELISA revealed that a ruminant alphaherpesvirus infection related to BoHV-1 was widespread in Corse-du-Sud whereas no positive animals was detected in Dordogne and Vendée. Furthermore, the specificity and the sensitivity of the BoHV-1 gB blocking ELISA to detect a BoHV-1 related infection in goats were evaluated. A subsequent analysis by a BoHV-1 gE blocking ELISA demonstrated that 22.6% of gB-positive serum samples were also gE-positive. Cross-seroneutralisation assays afforded the unambiguous identification of antibodies against CpHV-1 in gB-positive goats. The likely presence of CpHV-1 in Corse-du-Sud supported by a high seroprevalence (61.9%) in all investigated flocks extends the number of countries infected with CpHV-1. Moreover, the difference observed between Corse-du-Sud and Dordogne and Vendée suggests that CpHV-1 is more prevalent in Mediterranean countries or regions than in central and northern Europe.

Intramolecular recombination is a frequent event during the replication cycle of bovine herpesvirus 1 (BoHV-1). Recombinant viruses frequently arise and survive in cattle after concomitant nasal infections with two BoHV-1 mutants. The consequences of this process, related to herpesvirus evolution, have to be assessed in the context of large use of live marker vaccines based on glycoprotein E (gE) gene deletion. In natural conditions, double nasal infections by vaccine and wild-type strains are likely to occur. This situation might generate virulent recombinant viruses inducing a serological response indistinguishable from the vaccine one. This question was addressed by generating in vitro BoHV-1 recombinants deleted in the gE gene from seven wild-type BoHV-1 strains and one mutant strain deleted in the genes encoding gC and gE. In vitro growth properties were assessed by virus production, one step growth kinetics and plaque size assay. Heterogeneity in the biological properties was shown among the investigated recombinant viruses. The results demonstrated that some recombinants, in spite of their gE minus phenotype, have biological characteristics close to wild-type BoHV-1.

Taking into account the close antigenic relationship between bovine herpesvirus 1 (BoHV-1) and caprine herpesvirus 1 (CpHV-1), a live attenuated glycoprotein E (gE) negative BoHV-1 vaccine was assessed in goats with the aim to protect against CpHV-1 infection. Vaccine safety was evaluated by intranasal inoculation of two groups of goats with either a gE-negative BoHV-1 vaccine or a virulent BoHV-1. The length of viral excretion and the peak viral titre were reduced with the gE-negative vaccine. To assess the efficacy, two goats were inoculated intranasally twice 2 weeks apart with a gE-negative BoHV-1 vaccine. Four weeks later, immunised and control goats were challenged with CpHV-1. A 2 log(10) reduction in the peak viral titre was observed and the challenge virus excretion lasted 2 days more in immunised than in control goats. These data indicate the safety and the partial efficacy of a live attenuated gE-negative BoHV-1 vaccine intranasally administrated in goats.

The current situation of infectious bovine rhinotracheitis/infectious pustular vulvovaginitis infection in various European countries is reviewed. Whilst some have a high serological prevalence and use live virus vaccines to control the disease, others have a low prevalence and two countries (Denmark and Switzerland) have national eradication schemes which are almost complete. Serology remains important for diagnosis although other tests such as delayed cutaneous hypersensitivity may have a role to play. New tests such as polymerase chain reaction may find increasing application where high sensitivity is required, such as the detection of virus in semen.