Catarrhal Fever Research Articles

Investigation of OvHV-2 virus in small ruminants in Western Turkey

Malignant catarrhal fever (MCF) is a fatal disease of ruminants and has a worldwide distribution. The MCF virus (MCFV) group has currently known to contain 10 members. Ovine gammaherpesvirus 2 (OvHV-2) is one of the members of MCFV group and has economically importance in cattle. Sheep is the reservoir host of OvHV-2 while domestic goat is naturally susceptible species, although infection is generally asymptomatic in goat. In this study, the presence of OvHV-2 was investigated in sheep and goats by hemi-nested PCR in Aegean Region of west Turkey. Total of 138 sheep and goat samples which consist of 73 whole blood, 39 internal organs and 26 aborted fetuses were investigated. Thirty-seven blood samples, four fetal samples, and seven internal organ samples were found to be OvHV-2 positive. While 45.1% of the total sheep samples were found to be positive, only one goat sample was found positive. Similarly, previous studies have showed that prevalence of OvHV-2 in goats lower than sheep.

Detection of bovine gammaherpesvirus 6 in tissues of aborted fetuses from dairy cows concomitantly infected by Histophilus somni

Bovine gammaherpesvirus 6 (BoGHV6), formerly known as bovine lymphotropic virus, is a member of the Macavirus genus, subfamily Gammaherpesvirinae, family Herpesviridae, that was initially associated with proliferative diseases in cattle. While the Macavirus genus contains agents, including alcelaphine gammaherpesvirus 1 (AlGHV1), ovine gammaherpesvirus 2 (OvGHV2), and caprine gammaherpesvirus-2 (CpGHV2), known to cause malignant catarrhal fever (MCF), and are collectively referred to as MCF virus (MCFV) group of organisms, diseases and/or clinical syndromes have not been associated with BoGHV6 and porcine lymphotropic herpesvirus (PLHV). This report investigated the occurrence of BoGHV6 in tissues of aborted dairy fetuses known to be infected by Histophilus somni to identify possible disease patterns associated with infection by this Macavirus. A nested-PCR (nPCR) assay was used to amplify the BoGHV6 polymerase gene from multiple tissues of 13 fetuses and the cow of one of these which were derived from seven dairy herds located in three geographical regions of Brazil. Direct sequencing confirmed the results of the nPCR assays. Additionally, all fetal tissues were previously investigated for the presence of H. somni, Listeria monocytogenes, Neospora caninum, Brucella abortus, Leptospira spp., bovine alphaherpesvirus 1, and bovine viral diarrhea virus (BVDV) by PCR and/or RT-PCR assays. The nPCR assay amplified BoGHV6 DNA from fetuses of most dairy herds (85.7%; 6/7) investigated, resulting in the amplification of BoGHV6 from 76.9% (10/13) of all fetuses evaluated from two geographical and important cattle-producing regions of Brazil. Furthermore, only BoGHV6 was identified in the spleen (n = 3), myocardium, and kidney (n = 2) of five fetuses, and BoGHV6 was the only agent associated with myocarditis in one of these. Nevertheless, dual, triple, and quadruple infections (including BVDV, B. abortus, and N. caninum) were identified in fetuses that were concomitantly infected by H. somni. Phylogenetic analysis revealed that the strain herein identified has 100% nucleotide (nt) sequence identity with wild type strains of BoGHV6 circulating in ruminants from Brazil and 99.8% nt identity with the reference strain of BoGHV6 but was 72.2–73.3% and 67.4–68.2% different from members of the MCFV group and PLHV, respectively. These results demonstrated that 76.9% of the fetuses evaluated were infected by BoGHV6, most likely via vertical infection resulting in transplacental transmission. Considering that most fetuses were concomitantly infected by BoGHV6 and H. somni the real impact of this viral infection cannot be efficiently determined. However, since BoGHV6 was the only pathogen identified in the myocardium of one fetus with myocarditis by histopathology, the possible participation of this Macavirus in the etiopathogenesis of the myocardial disease observed in this fetus cannot be ignored or discarded. However, the mere amplification of BoGHV6 DNA from the myocardium is not enough to establish a definite association between cause and effect, since in situ evaluations and experimental studies would be needed to confirm this agent in the etiopathogenesis of fetal diseases and/or abortions in cattle. Consequently, additional studies are needed to determine the exact role, if any, of BoGHV6 in the development of fetal disease, and possibly fetal mortality.

Malignant Catarrhal Fever (MCF) in the Goat: A Disease Not Quite Identical with MCF in Cattle

Malignant Catarrhal Fever (MCF) in the Goat: A Disease Not Quite Identical with MCF in Cattle

An Outbreak of Malignant Catarrhal Fever in Belgian Red Deer

An Outbreak of Malignant Catarrhal Fever in Belgian Red Deer

A putative PCV3-associated disease in piglets from Southern Brazil.

Porcine circovirus type 3 (PCV3) is widely distributed worldwide, and its association with clinical disease in pigs has been studied in recent years. This study describes a novel PCV3-associated clinical disease in piglets from Brazil. Since September 2020, we received 48 piglets with large caudally rotated ears, weakness, and dyspnea. Most piglets were from gilts and died 1-5days after birth. Two piglets that presented similar clinical signs and survived until 35-60days had a marked decrease in growth rate. At post-mortem examination, the lungs did not collapse due to marked interlobular edema. Microscopically, the main feature was multisystemic vasculitis characterized by lymphocytes and plasma cells infiltrating and disrupting the wall of vessels, lymphohistiocytic interstitial pneumonia, myocarditis, and encephalitis. Viral replication was confirmed in these lesions through in situ hybridization (ISH-RNA). Seventeen cases were positive for PCV3 in PCR analysis, and all samples tested negative for porcine circovirus (PCV1, andPCV2); porcine parvovirus (PPV1, 2, 5, and 6); atypical porcine pestivirus (APPV); porcine reproductive and respiratory syndrome (PRRSV); and ovine herpesvirus-2 (OvHV-2). Phylogenetic analysis of the ORF2 sequence from five different pig farms showed that the PCV3a clade is circulating among Brazil's swineherds and causing neonatal piglet losses. This is the first report of PCV3a-associated disease in neonatal pigs from farms in Brazil.

Gammaherpesvirus Infections in Cattle in Europe

The genus Macavirus, subfamily Gammaherpesvirinae, comprises ungulate viruses that infect domestic and wild ruminants and swine. They cause asymptomatic latent infections in reservoir hosts and malignant catarrhal fever in susceptible species. Lung, spleen, bronchial lymph node, and tongue were collected from 448 cattle (348 necropsied, 100 slaughtered) in Switzerland, United Kingdom, Finland, Belgium, and Germany to determine their infection with bovine herpesvirus-6 (BoHV-6) and gammaherpesviruses of other ruminants, i.e., ovine herpesvirus-1 and -2, caprine herpesvirus-2, and bison lymphotropic herpesvirus, using quantitative PCR. Only BoHV-6 was detected, with an overall frequency of 32%, ranging between 22% and 42% in the different countries. Infection was detected across all ages, from one day after birth, and was positively correlated with age. There was no evidence of an association with specific disease processes. In positive animals, BoHV-6 was detected in all organs with high frequency, consistently in the lungs or spleen. Viral loads varied substantially. In BoHV-6-positive gravid cows, organs of fetuses tested negative for infection, indicating that the virus is not vertically transmitted. Our results confirm previous data indicating that BoHV-6 is a commensal of domestic cattle not associated with disease processes and confirm that infections with other macaviruses are rare and sporadic.

Ovine gammaherpesvirus 2 infections in cattle without typical manifestations of sheep-associated malignant catarrhal fever and concomitantly infected with bovine coronavirus.

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe, frequently fatal, lymphoproliferative disease that affects a wide variety of ruminants and is caused by ovine gammaherpesvirus 2 (OvHV-2), a member of the MCF virus (MCFV) complex. The typical clinical manifestations of SA-MCF are well known and easily recognized by veterinarians, resulting in clinical diagnosis of MCF when characteristic clinical signs are present. This article describes the findings observed in cattle infected with OvHV-2 but without typical clinical manifestations of SA-MCF. Three calves with episodes of diarrhea before death and a yearling that died suddenly were investigated. Gross alterations were not suggestive of SA-MCF. Histopathology revealed a combination of proliferating vascular lesions (PVLs) and necrotizing vasculitis in three animals (two calves and the yearling); with PVLs being identified only at the carotid rete mirabile of two calves infected with OvHV-2. Additional significant histopathologic lesions included atrophic enteritis, portal lymphocytic hepatitis, interstitial pneumonia, suppurative bacterial bronchopneumonia, and pulmonary hemorrhage. An immunohistochemical assay designed to identify only antigens of MCFV revealed, positive, intralesional, intracytoplasmic immunoreactivity within epithelial cells of multiple tissues of all animals with PVLs. PCR assays amplified OvHV-2 DNA from multiple tissues of the animals that contained MCFV proteins, confirming the MCFV identified as OvHV-2. Additionally, bovine coronavirus (BCoV) nucleic acids were amplified from tissues of all animals, including the animal not infected by OvHV-2. Collectively, these findings confirmed the participation of OvHV-2 in the development of the disease patterns observed in these animals that were concomitantly infected by BCoV and provide additional confirmation that cattle can be subclinically infected with OvHV-2. Consequently, the real occurrence of OvHV-2-related disease may be more elevated than reported, since asymptomatic or subclinically infected animals are not likely to be investigated for OvHV-2. Furthermore, PVLs should be included as possible histologic indicators of OvHV-2-related diseases in ruminants.Supplementary InformationThe online version contains supplementary material available at 10.1007/s42770-021-00653-6.

Development of a recombinant ELISA for ovine herpesvirus 2, suitable for use in sheep

The minor capsid protein of ovine herpesvirus 2, identified as a potential antigen for serological testing, was over-expressed and purified to allow its assessment in ELISA. The corresponding gene sequence (OvHV-2 orf65, Ov65) was modified to incorporate epitope tags and internal restriction enzyme sites in an E. coli codon-optimised version of the gene. This codon-optimised gene was then subject to internal deletions to identify regions of the protein that could be removed while maintaining protein solubility and antigenicity. It was found that a derivative with deletion of the conserved 5’-end of the gene (Ov65delB) expressed a polypeptide that was soluble when over-expressed in bacteria and was detected by OvHV-2 specific sera. Proteomic analysis of the affinity purified Ov65delB showed that it contained multiple predicted Ov65 tryptic peptides but also showed contamination by co-purifying E. coli proteins.An indirect ELISA, based on this affinity-purified OV65delB, was optimised for use with sheep and cattle samples and cut-off values were established based on known negative serum samples. Analysis of groups of samples that were either presumed infected (UK sheep) or tested OvHV-2 positive or negative by PCR (cattle MCF diagnostic samples) showed that the assay had 95 % sensitivity and 96 % specificity for sheep serum; and 80 % sensitivity and 95 % specificity for cattle serum. The lower sensitivity with cattle samples appeared to be due to a lack of serological response in some MCF-affected cattle.This recombinant antigen therefore shows promise as the basis of an inexpensive, simple and reliable test that can be used to detect OvHV-2-specific antibody responses in both MCF-affected animals and in OvHV-2 reservoir hosts.

A Screening for Virus Infections in Eight Herds of Semi-domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Norway, 2013-2018.

Background: Previous serological screenings have indicated that Eurasian semi-domesticated tundra reindeer (Rangifer tarandus tarandus) in Finnmark, Northern Norway, are exposed to alphaherpesvirus, gammaherpesvirus and pestivirus. Alphaherpesvirus (i.e., Cervid herpesvirus 2; CvHV2) has been identified as the transmissible component of infectious keratoconjunctivitis (IKC). Limited knowledge exists on the presence and prevalence of virus infections in other herding regions in Norway, which are hosting ~67,000 semi-domesticated reindeer and have contact with other species and populations of wildlife and livestock than those present in Finnmark.Methods: Blood samples (n = 618) were obtained over five winter seasons (2013–2018), from eight different herds representing summer pasture districts in Tana, Lakselv, Tromsø, Lødingen, Hattfjelldal, Fosen, Røros, and Filefjell, distributed from North to South of the reindeer herding regions in Norway. Blood samples were investigated for specific antibodies against five viral pathogen groups, alphaherpesvirus, gammaherpesvirus (viruses in the malignant catarrhal fever group; MCFV), pestivirus, bluetongue virus (BTV), and Schmallenberg virus (SBV), by using commercial multispecies serological tests (ELISA). In addition, swab samples obtained from the nasal mucosal membrane from 486 reindeer were investigated by PCR for parapoxvirus-specific DNA.Results: Antibodies against aphaherpesvirus and MCFV were found in all eight herds, with a total prevalence of 42% (range 21–62%) and 11% (range 2–15%), respectively. Anti-Pestivirus antibodies were detected in five of eight herds, with a total prevalence of 19% (range 0–52%), with two of the herds having a particularly high seroprevalence. Antibodies against BTV or SBV were not detected in any of the animals. Parapoxvirus-specific DNA was detected in two animals representing two different herds in Finnmark.Conclusions: This study confirmed that alphaherpesvirus and MCFV are enzootic throughout the geographical reindeer herding regions in Norway, and that pestivirus is present in most of the herds, with varying seroprevalence. No exposure to BTV and SBV was evident. This study also indicated that semi-domesticated reindeer in Finnmark are exposed to parapoxvirus without disease outbreaks being reported from this region.

Cerebrocortical necrosis causes multiple deaths in Scottish ewes and lambs.

Cerebrocortical necrosis causes multiple deaths in Scottish ewes and lambs.

Pathological findings in African buffaloes (Syncerus caffer) in South Africa.

The African buffalo (Syncerus caffer) is an iconic species of South African megafauna. As the farmed buffalo population expands, the potential impacts on population health and disease transmission warrant investigation. A retrospective study of skin biopsy and necropsy samples from 429 animals was performed to assess the spectrum of conditions seen in buffaloes in South Africa. Determination of the cause of death (or euthanasia) could not be made in 33.1% (136/411) of the necropsy cases submitted due to autolysis or the absence of significant lesions in the samples submitted. Infectious and parasitic diseases accounted for 53.5% (147/275) of adult fatal cases and non-infectious conditions accounted for 34.9% (96/275). Abortions and neonatal deaths made up 11.6% (32/275) of necropsy cases. Rift Valley fever, bovine viral diarrhoea, malignant catarrhal fever, tuberculosis, bacterial pneumonia, anaesthetic deaths, cachexia and hepatotoxic lesions were the most common causes of death. The range of infectious, parasitic and non-infectious diseases to which African buffaloes were susceptible was largely similar to diseases in domestic cattle which supports concerns regarding disease transmission between the two species. The similarity between diseases experienced in both species will assist wildlife veterinarians in the diagnosis and treatment of diseases in captive African buffaloes. The present study likely does not represent accurate disease prevalence data within the source population of buffaloes, and diseases such as anthrax, brucellosis and foot and mouth disease are under-represented in this study. Hepatic ductal plate abnormalities and haemorrhagic septicaemia have not, to our knowledge, been previously reported in African buffaloes.

Predicting uptake of a malignant catarrhal fever vaccine by pastoralists in northern Tanzania: Opportunities for improving livelihoods and ecosystem health

Malignant Catarhal Fever (MCF), caused by a virus transmitted from asymptomatic wildebeest, is a lethal disease in cattle that threatens livestock-based livelihoods and food security in many areas of Africa. Many herd owners reduce transmission risks by moving cattle away from infection hot-spots, but this imposes considerable economic burdens on their households. The advent of a partially-protective vaccine for cattle opens up new options for disease prevention. In a study of pastoral households in northern Tanzania, we use stated preference choice modelling to investigate how pastoralists would likely respond to the availability of such a vaccine. We show a high probability of likely vaccine uptake by herd owners, declining at higher vaccine costs. Acceptance increases with more efficaceous vaccines, in situations where vaccinated cattle are ear-tagged, and where vaccine is delivered through private vets. Through analysis of Normalized Density Vegetation Index (NDVI) data, we show that the reported MCF incidence over 5 years is highest in areas where the mean and interannual varibility in vegetative greeness is relatively low and where herds sizes are smaller. Trends towards lower rainfall and greater landscape-level constraints on cattle movement suggest that MCF avoidance through traditional movement away from wildebeest will become more challenging and that demand for an MCF vaccine will likely increase.

Ultrasonographic features of malignant catarrhal fever induced corneal oedema in cattle

The study was aimed to record the ocular ultrasonographic changes in the confirmed clinical cases of MCF. The cases were confirmed using hemi-nested polymerase chain reaction assay. Ocular ultrasonography was performed using a 10–18 MHz linear transducer (My Lab 40 Vet). Clinical signs observed were corneal oedema, lacrimation, photophobia, corneal oedema and hyperaemia of conjunctiva. In two animals, mild corneal oedema was observed while in four animals each, moderate and severe corneal oedema was recorded. In all the animals, corneal oedema initially appeared at the limbus with subsequent involvement of the entire cornea with varying degree of severity. Hemi-nested polymerase chain reaction was used for confirming the diagnosis. Ocular ultrasonographic examination revealed significant increase in the thickness of the cornea, iris and ciliary body. Anterior uveitis, characterized by thickened iris, exhibiting crust and trough formation covering the major part of the anterior surface of the lens was recorded in nine animals. There was no recovery in any of the case and the animals died within one month of the diagnosis of the MCF. Significant ultrasonographic changes were evident in eyes of animals affected with the malignant catarrhal fever. Ultrasonography may therefore be used for monitoring the ocular changes especially in the anterior segment of the opaque eyes.

The Participation of a Malignant Catarrhal Fever Virus and Mycoplasma bovis in the Development of Single and Mixed Infections in Beef and Dairy Cattle With Bovine Respiratory Disease.

The bovine respiratory disease (BRD) complex is a multietiological and multifactorial disease associated with a wide range of viral and bacterial pathogens. This study evaluated the contribution of specific infectious disease agents in the development of BRD in cattle from Brazil and determined if a virus within the malignant catarrhal fever virus (MCFV) group and Mycoplasma bovis, acting individually or in conjunction, can be associated with the development of BRD. Formalin-fixed paraffin-embedded pulmonary sections were used in immunohistochemical assays to determine the intralesional presence of six antigens associated with BRD: bovine alphaherpesvirus 1 (BoHV-1), bovine parainfluenza virus 3 (BPIV-3), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), MCFV, and M. bovis. Pneumonia was diagnosed in 82.7% (120/145) of all cattle evaluated. Interstitial pneumonia (60%, 72/120) and suppurative bronchopneumonia (25.8%, 31/120) were the most frequent patterns of pneumonia identified. Intralesional antigens of MCFV (53.3%, 64/120) were the most frequently associated with BRD, followed by M. bovis (47.5%, 57/120), BVDV (42.5%, 51/120), BoHV-1 (28.3%, 34/120), BRSV (24.2%, 29/120), and BPIV-3 (8.3%, 10/120). Additionally, antigens of BVDV, MCFV, and M. bovis were the most frequently identified agents associated with singular and concomitant infections. The MCFV identified during this study is more likely to be ovine gammaherpesvirus 2 (OvHV-2), since OvHV-2 is the only MCFV identified within the geographical region of this study. Interstitial pneumonia with proliferative vascular lesions may be a useful histologic feature to differentiate MCFV-induced pneumonia from other viral pneumonias of cattle. These results demonstrate that MCFV and M. bovis, in single or mixed infections, can produce pneumonia in cattle and should therefore be considered as primary agents in the development of BRD.

Schmallenberg virus infection suspected in a calf born to an imported heifer.

Schmallenberg virus infection suspected in a calf born to an imported heifer.

Герпесвірусний маміліт великої рогатої худоби

Herpesvirus mamilit in cattle is a viral disease characterized by vesicular, erosive and necrotic lesions of the skin of the nipples and udder. Currently, there are two forms of this disease, PSLD (pseudo-lumpy skin disease) and BHM (bovine herpetic mamilit). The first report on the isolation of herpesvirus from cattle with dermatitis (strain Allerton) dates back to 1957, when in South Africa diseases were observed among cows with lumpy dermatitis with ulcerative damage to the skin of the udder nipples. Later, in the 60s of the last century, there were reports of cases of ulcerative mamilitis of viral etiology among cows in Bulgaria, Australia and in the countries of South Africa - Rwanda and Tanzania. In all cases of herpesvirus mamilitis, the causative agent of the disease was identified as herpesvirus of the 2nd serotype. The herpesvirus etiology of the disease was also laboratory confirmed in the Netherlands, Switzerland, Ireland, Germany and the Czech Republic. In Ukraine, the first report of herpesvirus mamilitis of cattle (ulcerative mamilitis of cows) appeared only in 2003, although diseases with similar clinical signs were known earlier. Infection of dairy cattle can significantly affect productivity (decrease by about 20 %), chronic mastitis arising from this disease leads to a decrease in the number of productive animals. Natural infection caused by BoHV-2 occurs mainly in heifers and first lactation cows. Calving can be a factor in the reactivation of the virus. The natural transmission mechanism of the BoHV-2 virus is not fully understood. Most people talk about mechanical transmission through milking machines, through attendants, through the bites of Stomoxys calcitrans flies. The intact nipple skin is resistant to the penetration of the virus, which proves once again that any nipple injury is preceded by an infection. Serological studies show that the virus is common in livestock throughout the world. According to clinical signs, it is rather difficult to differentiate this disease from other viral diseases (viral diarrhea, malignant catarrhal fever, parapoxviruses, infectious rhinotracheitis in cattle). The specialist literature describes the treatment of BoHV-2 disease in cows. The authors used Intacef for injection (Intas pharma, 3 g i / m), anistamine for injection (10 ml i / m), Melonex (10 ml i / m). Udder ulcers were treated with povidone-iodine ointment twice daily for 5 days. On the 5th day of treatment, the animals recovered. Vaccines for specific prevention of this disease have not been developed. Sick animals are separated (if possible) from the general herd and treated. Clinically affected animals are milked last. The udders and teats should be disinfected to reduce the spread of the virus. It is imperative to disinfect the milking machines and hands after each cow and after milking. The udder skin should be monitored to prevent mastitis. The widespread spread of this disease among productive animals, significant economic losses in the form of reduced milk yield and treatment costs, and the difficult differentiation of this disease from other viral diseases prompts veterinarians to pay special attention to this disease.

Molecular detection and genetic characterization of ovine gammaherpesvirus-2 (OvHV-2) in sheep in the Philippines

Abstract Ovine gammaherpesvirus-2 (OvHV-2) causes sheep-associated malignant catarrhal fever (SA-MCF) and is a fatal disease of some ruminants such as cattle, water buffalo and even-toed ungulates (such as deer, other cervids and some species of pigs). OvHV-2, however, was never reported to be present in the Philippines. Thus, this study is conducted. Out of 89 sheep blood samples from 6 farms, 58 (65.17 %) were positive for OvHV-2 using semi-Polymerase Chain Reaction targeting the tegument gene. Phylogenetic analysis suggests that the OvHV-2 sequences from sheep in the Philippines are nearly identical to the OvHV-2 sequences of animals from Brazil and Germany and 98 % identical to sequences from Turkey, India, Egypt, UK, and Mongolia. To date, this is the first report of OvHV-2 in the Philippines and could provide information in the future for the control and prevention of SA-MCF in the country.

Analysis of immune responses to attenuated alcelaphine herpesvirus 1 formulated with and without adjuvant

The experimental vaccine for bovine malignant catarrhal fever consists of viable attenuated alcelaphine herpesvirus 1 (AlHV-1) derived by extensive culture passage, combined with an oil-in-water adjuvant, delivered intramuscularly. This immunisation strategy was over 80% effective in previous experimental and field trials and protection appeared to be associated with induction of virus-neutralising antibodies. Whether the vaccine virus is required to be viable at the point of immunisation and whether adjuvant is required to induce the appropriate immune responses remains unclear. To address these issues two studies were performed, firstly to analyse immune responses in the presence and absence of adjuvant and secondly, to investigate immune responses to vaccines containing adjuvant plus viable or inactivated AlHV-1.The first study showed that viable attenuated AlHV-1 in the absence of adjuvant induced virus-specific antibodies but the titres of virus-neutralising antibodies were significantly lower than those induced by vaccine containing viable virus and adjuvant, suggesting adjuvant was required for optimal responses. In contrast, the second study found that the vaccine containing inactivated (>99.9%) AlHV-1 induced similar levels of virus-neutralising antibody to the equivalent formulation containing viable AlHV-1.Together these studies suggest that the MCF vaccine acts as an antigen depot for induction of immune responses, requiring adjuvant and a suitable antigen source, which need not be viable virus. These observations may help in directing the development of alternative MCF vaccine formulations for distribution in the absence of an extensive cold chain.

Mode of infection and some diseases caused by Epstein Barr virus: The most ubiquitous, common malignant and characteristic virus

Epstein Barr virus (EBV) was detected for the first time by electron microscopy (EM) in a malignant Burkitt’s lymphoma. EBV has a worldwide distribution and its prevalence is more than 90%. It is a malignant virus, symptoms vary from mild or find no symptoms in some individuals and serious symptoms or cancers in others. EBV is a characteristic one since it has a lot of properties to become latent and modulate the host immune system in a serious manner in some conditions where it has many proteins having sequence and functional homology with many human proteins. EBV could be transmitted through saliva or contact with the air borne, blood transfusion, organ transplantation semen or cervical secretions. EBV Causes a lot of diseases which varies according to some factors. Rediagnosis For COVID-19 is recommended by considering it EBV or ovine herpes virus 2 (OvHV-2) where I think that they are the same virus With two names according to human or veterinary medicine because accurate diagnosis is the first and most important step for controlling COVID-19 and I show that the obtained RNA and considered as corona Virus is mainly one of the messenger RNA (s) of EBV (0vHV-2) to be translated for proteins demanded by this herpesvirus. This false diagnosis may be performed with other RNA viruses named previously. Proper diagnosis will be achieved by electron microscopy for detection of herpes viral particles and sequencing of glycoprotein B complete gene. Another recommendation is taking in consideration that stool is among routes of infection as well as milk and colostrum with special care during management for all animals or birds ( because all species are susceptible ) which also give good chance for experimental application of vaccines, antibodies as well as studying pathogenesis and pathology of the virus.

First Molecular Evidence and Genetic Characterization of Ovine Herpesvirus 2 in Multiple Animal Species in India.

Ovine herpesvirus 2 (OvHV-2) is the causative agent of sheep-associated malignant catarrhal fever (SA-MCF), a highly fatal disease syndrome that predominantly affects susceptible hosts of the order Artiodactyla. In this study, an in-depth clinico-molecular investigation of SA-MCF disease in a morbid 50-days-old cattle calf (Bos taurus indicus) and asymptomatic infection in the in-contact reservoir hosts, sheep (Ovis aries), and goat (Capra hircus) housed on a farm located in the Southern India is reported. An OIE recommended SA-MCF type-specific PCR confirmed the etiological agent as OvHV-2. The genetic characterization and phylogenetic analyses based on the glycoprotein B (gB) gene indicate that three genetic variants of OvHV-2 had infected the animal cluster of this study. As the OvHV-2 infection eventually lead to the death of the cattle calf, and the fact that its gB sequence carried four unique amino acid substitutions (N169S, L594P, I645V, and V730A), an investigation of these substitutions impact on its stability and molecular flexibility was carried out. The mapping of these amino acid substitutions on the three-dimensional structure of gB coupled with supplementary investigations showed that these substitutions conveyed the molecular flexibility to the gB, at the cost of its stability. Future studies would be to investigate whether these gB substitutions have any impact on membrane fusion activity using a virus-free cell-to-cell membrane fusion assay. The study also highlights the importance of adopting stringent biosecurity measures where mixed animal farming is a common practice.