Prevalence and associated risk factors of peste des petits ruminants in selected districts of the northern border region of Pakistan.

BACKGROUND: Peste des Petits Ruminants (PPR) is a world organization for animal health (WOAH) notifiable and economically important transboundary, highly communicable viral disease of small ruminants. PPR virus (PPRV) belongs to the genus Morbillivirus of the family Paramyxoviridae. AIM: The present cross-sectional epidemiological investigation was accomplished to estimate the apparent prevalence and identify the risk factors linked with peste des petits ruminants (PPR) in the previously neglected northern border regions of Pakistan. METHOD: A total of 1300 samples (serum = 328; swabs = 972) from 150 flocks/herds were compiled from sheep (n = 324), goats (n = 328), cattle (n = 324), and buffaloes (n = 324) during 2020-2021 and tested using ELISA for detection of viral antibody in sera or antigen in swabs. RESULTS: An overall apparent prevalence of 38.7% (504 samples) and an estimated true prevalence (calculated by the Rogan and Gladen estimator) of 41.0% (95% CI, 38.0-44 were recorded in the target regions. The highest apparent prevalence of 53.4% (85 samples) and the true prevalence of 57.0%, 95% Confidence Interval (CI) were documented in the Gilgit district and the lowest apparent prevalence of 53 (25.1%) and the true prevalence of 26.0%, 95% Confidence Interval (CI), 19.0-33.0) was reported in the Swat district. A questionnaire was designed to collect data about associated risk factors that were put into a univariable logistic regression to decrease the non-essential assumed risk dynamics with a P-value of 0.25. ArcGIS, 10.8.1 was used to design hotspot maps and MedCalc's online statistical software was used to calculate Odds Ratio (OR). Some of the risk factors significantly different (P < 0.05) in the multivariable logistic regression were flock/herd size, farming methods, nomadic animal movement, and outbreaks of PPR. The odds of large-sized flocks/herds were 1.7 (OR = 1.79; 95% Confidence Interval (CI) = 0.034-91.80%) times more likely to be positive than small-sized. The odds of transhumance and nomadic systems were 1.1 (OR = 1.15; 95% Confidence Interval (CI) = 0.022-58.64%) and 1.0 (OR = 1.02; 95% Confidence Interval (CI) = 0.020-51.97%) times more associated to be positive than sedentary and mixed farming systems, respectively. The odds of nomadic animal movement in the area was 0.7 (OR = 0.57; 95% Confidence Interval (CI) = 0.014-38.06%) times more associated to be positive than in areas where no nomadic movement was observed. In addition, the odds of an outbreak of PPR in the area were 1.0 (OR = 1.00; 95% Confidence Interval (CI) = 0.018-46.73%) times more associated to be positive than in areas where no outbreak of PPR was observed. CONCLUSIONS: It was concluded that many northern regions considered endemic for PPR, large and small ruminants are kept and reared together making numerous chances for virus transmission dynamic, so a big threats of disease spread exist in the region. The results of the present study would contribute to the global goal of controlling and eradicating PPR by 2030.

Genetic Characterization of Small Ruminant Lentiviruses Isolated from Dairy Sheep in Greece.

The high genetic heterogeneity of small ruminant lentiviruses (SRLV) renders the genetic characterization of the circulating strains crucial for the epidemiological investigation and the designation of effective diagnostic tools. In Greece, research data regarding the genetic diversity of the circulating SRLV strains is scarce, hindering the implementation of efficient surveillance and control programs. The objective of the study was to genetically characterize SRLV strains isolated from intensive dairy sheep farms in Greece and evaluate the variability of the immunodominant regions of the capsid protein. For this reason, a total of 12 SRLV-infected animals from four intensive dairy sheep farms with purebred Chios and Lacaune ewes were used for the amplification and sequencing of an 800 bp gag-pol fragment. The phylogenetic analyses revealed a breed-related circulation of strains; Chios ewes were infected with strains belonging exclusively to a separate group of genotype A, whereas strains belonging to subtype B2 were isolated from Lacaune ewes. Immunodominant epitopes of capsid protein were quite conserved among the strains of the same genotype, except for the Major Homology Region which showed some unique mutations with potential effects on viral evolution. The present study contributes to the extension of the current knowledge regarding the genetic diversity of SRLV strains circulating in sheep in Greece. However, broader genetic characterization studies are warranted for the exploration of possible recombinant events and the more comprehensive classification of the circulating strains.

Foot-and-mouth disease seroprevalence is higher in young female crossbred sheep and goats compared to their counterparts in the border area between Pakistan and Afghanistan.

OBJECTIVE: Foot-and-mouth disease (FMD) is a highly contagious disease in ruminants that causes significant economic losses worldwide. However, the prevalence of FMD virus (FMDV) in small ruminants has been overlooked in Pakistan. This study aimed to determine the prevalence of FMD in sheep and goats in the border area between Pakistan and Afghanistan. ANIMALS: 800 sheep and goats belongs to age groups of 6 month to > 2 years. METHODS: A total of 800 serum samples were collected from sheep (n = 424) and goats (n = 376) and subjected to structural protein (SP) and 3ABC non-SP (NSP) ELISAs for the detection of antibodies against SP and NSP of the FMDV. RESULTS: For NSP, 340/800 (42.5%) of samples were positive, while SP analysis revealed that serotype O (44.5%) was the most common in sheep and goats, followed by Asia-1 (42%) and A (32%) serotypes. Sheep (39%; 95% CI, 34 to 44) had a higher (P < .05) prevalence of FMD than goats (46%; 95% CI, 41 to 51). Statistically significant (P < .05) differences in the seroprevalence of FMD-SP and FMD-NSPs were observed between various agencies (areas) of the study area. Risk factors such as age, sex, breed, season, flock size, body condition, animal movement, and production system were significantly (P < .05) associated with FMDV prevalence. CONCLUSIONS: This study showed that FMD is highly prevalent in sheep and goats in the border areas of Pakistan and Afghanistan. Therefore, outbreak investigation teams should be arranged at the border level to develop FMD risk-based surveillance and control plans for small ruminants in order to mitigate infection risks.

Co-infecting viruses of species Bovine rhinitis B virus (Picornaviridae) and Bovine nidovirus 1 (Tobaniviridae) identified for the first time from a post-mortem respiratory sample of a sheep (Ovis aries) in Hungary.

In this study, a picornavirus and a nidovirus were identified from a single available nasopharyngeal swab (NPS) sample of a freshly deceased sheep, as the only vertebrate viruses found with viral metagenomics and next-generation sequencing methods. The sample was originated from a mixed feedlot farm in Hungary where sheep and cattle were held together but in separate stalls. Most of the sheep had respiratory signs (coughing and increased respiratory effort) at the time of sampling. Other NPS were not, but additional enteric samples were collected from sheep (n = 27) and cattle (n = 11) of the same farm at that time. The complete/nearly complete genomes of the identified viruses were determined using RT-PCR and Nanopore (MinION-Flonge) / Dye-terminator sequencing techniques. The results of detailed genomic and phylogenetic analyses indicate that the identified picornavirus most likely belongs to a type 4 genotype of species Bovine rhinitis B virus (BRBV-4, OR885914) of genus Aphthovirus, family Picornaviridae while the ovine nidovirus (OvNV, OR885915) - as a novel variant - could belong to the recently created Bovine nidovirus 1 (BoNV) species of genus Bostovirus, family Tobaniviridae. None of the identified viruses were detectable in the enteric samples using RT-PCR and generic screening primer pairs. Both viruses are well-known respiratory pathogens of cattle, but their presence was not demonstrated before in other animals, like sheep. Furthermore, neither BRBV-4 nor BoNVs were investigated in European cattle and/or sheep flocks, therefore it cannot be determined whether the presence of these viruses in sheep was a result of a single host species switch/spillover event or these viruses are circulating in not just cattle but sheep populations as well. Further studies required to investigate the spread of these viruses in Hungarian and European sheep and cattle populations and to identify their pathogenic potential in sheep.

Phylogenetic analysis of small ruminant lentiviruses in Mongolian sheep supports an ancient east-west split for the genotype A.

The ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) are small ruminant lentiviruses (SRLVs) with striking genetic and structural similarities. The presence of SRLV in Mongolian sheep and goats was serologically demonstrated more than a decade ago; however, the viral genotype remains unknown. In total, 329 blood samples were collected from two sheep breeds (i.e., Khalkha and Sumber) in Tov, Govisumber, Arkhangay, Dornogovi, Zavkhan, and Sukhbaatar provinces, Mongolia. Serological and phylogenetic analyses were performed regardless of any apparent clinical signs, although most of the animals appeared healthy. All sheep in three of the six provinces were seronegative, whereas the seroprevalence in the Tov, Govisumber, and Zavkhan provinces averaged 7.9%. Genomic DNA from seropositive animals was tested using hemi-nested polymerase chain reaction, and sub-genomic SRLV sequences were determined from nine samples. Mongolian SRLV sequences clustered within the divergent subtype A22, which was previously found only in Fertile Crescent regions, including Lebanon, Jordan, and Iran, where the first sheep-domestication (Ovis aries) occurred. According to the phylogenetic analysis, genotype A has two ancestors from the ancient Fertile Crescent: (1) Turkish strains and (2) Iranian, Jordanian, and Lebanese strains. The first ancestor spread westward, whereas the second spread eastward, ultimately reaching Mongolia.

Ovine adenoviruses infecting sheep and goats in Türkiye: detection and molecular characterization of three different types.

Adenoviruses (AdVs) have been detected in a wide variety of animals. To date, eight types of AdVs in sheep and two types in goats have been identified, which belong to two distinct genera, Mastadenovirus and Atadenovirus. Typically, the term pneumo-enteritis is used to describe adenovirus-induced disease in small ruminants, which has been associated with both enteric and respiratory symptoms of varying severity. The aim of this study was to detect and identify AdVs of small ruminants belonging to the genera Mastadenovirus and Atadenovirus. For this purpose, diagnostic samples (47 lung, 27 intestine, and two pooled tissue samples including intestine and lung) from 49 small ruminants (39 sheep and 10 goats) were used. Following the viral DNA extraction, PCR was carried out by using the primers targeting the hexon gene in order to detect both mast- and atadenoviruses. Sequencing the amplified fragments revealed the presence of three types of ovine adenovirus (OAdV): OAdV-3, OAdV-4, and OAdV-8. Specifically, OAdV-3 was detected in two sheep and a goat while OAdV-4 and OAdV-8 were found in only one sheep each. There is still limited data on the interaction between the viruses in different adenovirus genera and the detected disease, as well as the genetic diversity of adenoviruses, especially in small ruminants. In conclusion, the detection of AdVs in lung and intestinal tissues of small ruminants in this study suggests that these viruses may have contributed to the disease and/or predisposed to other agents.

Occurrence of enteric viruses causing clinical diarrhea in small ruminants in northern Indian plains: a reverse transcription PCR based molecular study.

Fowlpox virus (FPV) infects chickens and turkeys giving rise to pock lesions on various body parts like combs, wattles, legs, shanks, eyes, mouth, etc. The birds, affected with FPV, also show anemia and a ruffled appearance which are clinical symptoms of reticuloendotheliosis. Interestingly, the field strains of FPV are integrated with the provirus of reticuloendotheliosis virus (REV). Due to this integration, the infected birds, upon replication of FPV, give rise to free REV virions, causing severe immunosuppression and anemia. Pox scabs, collected from the infected birds, not only show positive PCR results upon performing FPV-specific 4b core protein gene PCR but also show positive results for the PCR of REV-specific env gene and FPV-REV 5'LTR junction. Homogenized suspension of the pock lesions, upon inoculating to the chorio-allantoic membrane (CAM) of 10-day-old specific pathogen-free embryonated chicken eggs, produces characteristic pock lesions in serial passages. However, the lesions also harbor REV mRNA or free virion, which can be identified by performing REV-specific env gene PCR using REV RNA from FPV-infected CAMs. The study suggests successful replication and availability of REV mRNA and free virion alongside the FPV, although the CAM is an ill-suited medium for any retroviral (like REV) growth and replication.

Seroprevalence and Risk Factors Associated with Akabane Virus Infection in Sheep and Goats in Fars Province, Iran.

Akabane disease is an arthropod-borne viral disease that affects ruminants. This teratogenic pathogen causes severe economic losses in ruminants worldwide and in Iran; however, it has not received enough attention in Fars province, Iran. Therefore, this study aimed to determine the influence of age, gender, climate, farming system, and history of abortions on the seroprevalence of the Akabane disease in sheep and goats in Fars province. In the present study, Fars province was divided into three climates, and three cities were randomly selected from each climatic region. In each city, two epidemiologic units were selected, and all sheep and goats in each unit were sampled. Overall, 540 serum samples (391 sheep and 149 goats) were collected and examined with the commercial ELISA kit. The results showed that 83 out of 540 (15.4%) samples were seropositive and had antibodies against the Akabane virus (AKAV). The effect of gender and age on the rate of the AKAV was not significant. Animals in warm climates were 4.218 times more likely to have antibodies against the AKAV than animals in cold climates. Females were 1.32 times more likely to exhibit seropositivity. The odds of AKAV infection were higher in animals with an abortion history than in healthy animals. The findings of the present study indicated that the prevalence of the AKAV was high in small ruminants in Fars province. Therefore, it is necessary to conduct more studies to control the risk factors involved in the spread of this virus.

Field-Reassortment of Bluetongue Virus Illustrates Plasticity of Virus Associated Phenotypic Traits in the Arthropod Vector and Mammalian Host In Vivo.

Segmented RNA viruses are a taxonomically diverse group that can infect plant, wildlife, livestock and human hosts. A shared feature of these viruses is the ability to exchange genome segments during coinfection of a host by a process termed "reassortment." Reassortment enables rapid evolutionary change, but where transmission involves a biological arthropod vector, this change is constrained by the selection pressures imposed by the requirement for replication in two evolutionarily distant hosts. In this study, we use an in vivo, host-arbovirus-vector model to investigate the impact of reassortment on two phenotypic traits, virus infection rate in the vector and virulence in the host. Bluetongue virus (BTV) (Reoviridae) is the causative agent of bluetongue (BT), an economically important disease of domestic and wild ruminants and deer. The genome of BTV comprises 10 linear segments of dsRNA, and the virus is transmitted between ruminants by Culicoides biting midges (Diptera: Ceratopogonidae). Five strains of BTV representing three serotypes (BTV-1, BTV-4, and BTV-8) were isolated from naturally infected ruminants in Europe and ancestral/reassortant lineage status assigned through full genome sequencing. Each strain was then assessed in parallel for the ability to replicate in vector Culicoides and to cause BT in sheep. Our results demonstrate that two reassortment strains, which themselves became established in the field, had obtained high replication ability in C. sonorensis from one of the ancestral virus strains, which allowed inferences of the genome segments conferring this phenotypic trait. IMPORTANCE Reassortment between virus strains can lead to major shifts in the transmission parameters and virulence of segmented RNA viruses, with consequences for spread, persistence, and impact. The ability of these pathogens to adapt rapidly to their environment through this mechanism presents a major challenge in defining the conditions under which emergence can occur. Utilizing a representative mammalian host-insect vector infection and transmission model, we provide direct evidence of this phenomenon in closely related ancestral and reassortant strains of BTV. Our results demonstrate that efficient infection of Culicoides observed for one of three ancestral BTV strains was also evident in two reassortant strains that had subsequently emerged in the same ecosystem.

The complete genome sequence of Indian sheeppox vaccine virus and comparative analysis with other capripoxviruses.

Sheeppox virus (SPPV) is responsible for a significant economic loss to sheep husbandry in enzootic regions of Africa, the Middle East, and Asia including the Indian subcontinent. In this study, we present the complete genome sequence of SPPV vaccine strain SPPV-Srin38/00 from India determined by next-generation sequencing (NGS) using Illumina technology. The attenuated Srinagar vaccine strain of SPPV (SPPV-Srin38/00) was developed by serial passaging the virus initially in lamb testes (LT) cells followed by Vero cell line. The SPPV-Srin38/00 virus has a genome size of 150, 103 bp, which encodes for 147 functional putative genes and consists of a central coding region flanked by two identical 2353 bp inverted terminal repeats (ITRs). Comparative phylogenetic analysis based on complete genome sequences of Capripoxviruses formed three distinct groups each for SPPV, GTPV, and LSDV with clustering of SPPV-Srin38/00 strain with SPPV-A strain. Nine ORFs of SPPV-Srin38/00 namely SPPV-Srin_002/SPPV-Srin_155, SPPV-Srin_004/SPPV-Srin_153, SPPV-Srin_009, SPPV-Srin_013, SPPV-Srin_026, SPPV-Srin_132, and SPPV-Srin_136 were found to be fragmented as compared to LSDV, whereas only one ORF (such as SPPV-Srin_136) was found to be fragmented as compared to GTPV. SPPV genomes, including the SPPV-Srin38/00 strain, shared 99.78-99.98% intraspecies nucleotide identity, indicating that SPPV strains have extremely low genetic diversity. The strain shared 96.80-97.08% and 97.11-97.61% nt identity with GTPV and LSDV strains, respectively. Its ORFs 016, 021, 022, 130 and 138 are the least identical ORFs among three species of the genus Capripoxvirus with 72.5-93% aa identity to GTPV and LSDV strains and may be potentially used for differentiation of CaPV species. This study may contribute to a better understanding of the epidemiology and evolution of capripoxviruses as well as the development of specific detection methods, better expression vectors, and vaccines with improved safety and efficacy.

Genomic Epidemiology and Heterogeneity of SRLV in Italy from 1998 to 2019.

Small ruminant lentiviruses (SRLV) are viruses that retro-transcribe RNA to DNA and show high rates of genetic variability. SRLV affect animals with strains specific for each host species (sheep or goats), resulting in a series of clinical manifestations depending on the virulence of the strain, the host's genetic background and farm production system. The aim of this work was to present an up-to-date overview of the genomic epidemiology and genetic diversity of SRLV in Italy over time (1998-2019). In this study, we investigated 219 SRLV samples collected from 17 different Italian regions in 178 geographically distinct herds by CEREL. Our genetic study was based on partial sequencing of the gag-pol gene (800 bp) and phylogenetic analysis. We identified new subtypes with high heterogeneity, new clusters and recombinant forms. The genetic diversity of Italian SRLV strains may have diagnostic and immunological implications that affect the performance of diagnostic tools. Therefore, it is extremely important to increase the control of genomic variants to improve the control measures.

Retrospective Characterization of Initial Peste des petits ruminants Outbreaks (2008-2012) in the Democratic Republic of the Congo.

Peste des petits ruminants (PPR) is an acute, contagious viral disease of small ruminants, goats and sheep. The Democratic Republic of the Congo (DRC) was a PPR-free country until 2007, although in 2006, scare alerts were received from the east and the southwest of the country, reporting repeated mortalities, specifically in goats. In 2008, PPR outbreaks were seen in several villages in the west, leading to structured veterinary field operations. Blood, swabs and pathological specimens consisting of tissues from lungs, spleens, lymph nodes, kidneys, livers and hearts were ethically collected from clinically infected and/or dead animals, as appropriate, in 35 districts. Epidemiological information relating to major risk factors and socio-economic impact was progressively collected, revealing the deaths of 744,527 goats, which converted to a trade value of USD 35,674,600. Samples from infected and dead animals were routinely analyzed by the Central Veterinary Laboratory at Kinshasa for diagnosis, and after official declaration of PPR outbreaks by the FAO in July 2012, selected tissue samples were sent to The Pirbright Institute, United Kingdom, for genotyping. As a result of surveys undertaken between 2008 and 2012, PPR virus (PPRV)-specific antibodies were detected in 25 locations out of 33 tested (75.7%); PPRV nucleic acid was detected in 25 locations out of 35 (71.4%); and a typical clinical picture of PPR was observed in 23 locations out of 35 (65.7%). Analysis of the partial and full genome sequences of PPR viruses (PPRVs) obtained from lymphoid tissues of dead goats collected in Tshela in the DRC in 2012 confirmed the circulation of lineage IV PPRV, showing the highest homology (99.6-100%) with the viruses circulating in the neighboring countries of Gabon, in the Aboumi outbreak in 2011, and Nigeria (99.3% homology) in 2013, although recent outbreaks in 2016 and 2018 in the western part of the DRC that borders with East Africa demonstrated circulation of lineage II and lineage III PPRV.

Identification and Genetic Characterization of Viral Pathogens in Ruminant Gestation Abnormalities, Israel, 2015-2019.

Infectious agents including viruses are important abortifacients and can cause fetal abnormalities in livestock animals. Here, samples that had been collected in Israel from aborted or malformed ruminant fetuses between 2015 and 2019 were investigated for the presence of the following viruses: the reoviruses bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), the flaviviruses bovine viral diarrhea virus (BVDV) and border disease virus (BDV), the peribunyaviruses Shuni virus (SHUV) and Akabane virus (AKAV), bovine herpesvirus type 1 (BoHV-1) and bovine ephemeral fever virus (BEFV). Domestic (cattle, sheep, goat) and wild/zoo ruminants were included in the study. The presence of viral nucleic acid or antigen could be confirmed in 21.8 % of abnormal pregnancies (213 out of 976 investigated cases), with peribunyaviruses, reoviruses and pestiviruses being the most prevalent. At least four different BTV serotypes were involved in abnormal courses of pregnancy in Israel. The subtyping of pestiviruses revealed the presence of two BDV and several distinct BVDV type 1 strains. The peribunyaviruses AKAV and SHUV were identified annually throughout the study period, however, variation in the extent of virus circulation could be observed between the years. In 2018, AKAV even represented the most detected pathogen in cases of small domestic ruminant gestation abnormalities. In conclusion, it was shown that various viruses are involved in abnormal courses of pregnancy in ruminants in Israel.

Simbu Viruses' Infection of Livestock in Israel-A Transient Climatic Land.

Important lessons have been learned by the Israeli veterinary community regarding Simbu serogroup viruses infections. This serogroup of viruses might cause the births of neonatal malformation in susceptible ruminant's populations. Until 2012, only Akabane virus was connected with the births of malformed ruminants in Israel. However, serological and genomic detection tests, coupled with viral isolations, revealed that more than a single Simbu serogroup serotype could be present concurrently in the same farm or even in the same animal. From 2012 to date, Aino, Shuni, Shamunda, Satuperi, Peaton, Schmallenberg, and Sango viruses have been found in Israel either by serological or genomic investigation. Israel is located in the Eastern Mediterranean Basin, a terrestrial and climatic bridge between the three old continents. The Eastern Mediterranean shores benefit from both the tropical/subtropical and the continental climatic conditions. Therefore, the Eastern Mediterranean basin might serve as an optimal investigatory compound for several arboviral diseases, acting as a sentinel. This review summarizes updated information related to the presence of Simbu serogroup viruses in Israel.

Virome analysis of three Ixodidae ticks species from Colombia: A potential strategy for discovering and surveying tick-borne viruses.

Ticks are a group of obligate blood-sucking ectoparasites that play a critical role in transmitting several important zoonotic pathogens that can infect animals and humans. Viruses are part of the tick microbiome and are involved in the transmission of important diseases. Furthermore, the little information on these as etiological agents of zoonoses suggests the need to study these microorganisms. For this reason, in this study, we sought to characterize the virome in Rhipicephalus microplus, Dermacentor nitens, and Rhipicephalus sanguineus s.l., which were collected from different domestic animals in Antioquia, Colombia. RNA sequencing was used for virome characterization in these three tick species, using RNA-dependent polymerase as a marker gene. Forty-eight sequences corresponding to 14 different viruses were identified, some of which were previously identified in the tick's virome. Overall, these data indicate that ticks from domestic animals in cattle farms harbor a wide viral diversity at the local scale. Thus, the metatranscriptomic approach provides important baseline information for monitoring the tick virome and to develop future studies on their biology, host-virus interactions, host range, worldwide distribution, and finally, their potential role as emerging vector-borne agents.

Next-generation sequencing for the genetic characterization of Maedi/Visna virus isolated from the northwest of China.

BACKGROUND: Maedi/Visna virus (MVV) is a contagious viral pathogen that causes considerable economic losses to the sheep industry worldwide. OBJECTIVES: In China, MVV has been detected in several regions, but its molecular characteristics and genetic variations were not thoroughly investigated. METHODS: Therefore, in this study, we conducted next-generation sequencing on an MVV strain obtained from northwest China to reveal its genetic evolution via phylogenetic analysis. RESULTS: A MVV strain obtained from Inner Mongolia (NM) of China was identified. Sequence analysis indicated that its whole-genome length is 9193 bp. Homology comparison of nucleotides between the NM strain and reference strains showed that the sequence homology of gag and env were 77.1%-86.8% and 67.7%-75.5%, respectively. Phylogenetic analysis revealed that the NM strain was closely related to the reference strains isolated from America, which belong to the A2 type. Notably, there were 5 amino acid insertions in variable region 4 and a highly variable motif at the C-terminal of the surface glycoprotein (SU5). CONCLUSIONS: The present study is the first to show the whole-genome sequence of an MVV obtained from China. The detailed analyses provide essential information for understanding the genetic characteristics of MVV, and the results enrich the MVV library.

Immunization With Bovine Herpesvirus-4-Based Vector Delivering PPRV-H Protein Protects Sheep From PPRV Challenge.

The Morbillivirus peste des petits ruminants virus (PPRV) is the causal agent of a highly contagious disease that mostly affects sheep and goats and produces considerable losses in developing countries. Current PPRV control strategies rely on live-attenuated vaccines, which are not ideal, as they cannot differentiate infected from vaccinated animals (DIVA). Recombinant vector-based vaccines expressing viral subunits can provide an alternative to conventional vaccines, as they can be easily paired with DIVA diagnostic tools. In the present work, we used the bovine herpesvirus-4-based vector (BoHV-4-A) to deliver PPRV hemagglutinin H antigen (BoHV-4-A-PPRV-H-ΔTK). Vaccination with BoHV-4-A-PPRV-H-ΔTK protected sheep from virulent PPRV challenge and prevented virus shedding. Protection correlated with anti-PPRV IgGs, neutralizing antibodies and IFN-γ-producing cells induced by the vaccine. Detection of antibodies exclusively against H-PPRV in animal sera and not against other PPRV viral proteins such as F or N could serve as a DIVA diagnostic test when using BoHV-4-A-PPRV-H-ΔTK as vaccine. Our data indicate that BoHV-4-A-PPRV-H-ΔTK could be a promising new approach for PPRV eradication programs.

Bluetongue virus capsid protein VP5 perforates membranes at low endosomal pH during viral entry.

Bluetongue virus (BTV) is a non-enveloped virus and causes substantial morbidity and mortality in ruminants such as sheep. Fashioning a receptor-binding protein (VP2) and a membrane penetration protein (VP5) on the surface, BTV releases its genome-containing core (VP3 and VP7) into the host cell cytosol after perforation of the endosomal membrane. Unlike enveloped ones, the entry mechanisms of non-enveloped viruses into host cells remain poorly understood. Here we applied single-particle cryo-electron microscopy, cryo-electron tomography and structure-guided functional assays to characterize intermediate states of BTV cell entry in endosomes. Four structures of BTV at the resolution range of 3.4-3.9 Å show the different stages of structural rearrangement of capsid proteins on exposure to low pH, including conformational changes of VP5, stepwise detachment of VP2 and a small shift of VP7. In detail, sensing of the low-pH condition by the VP5 anchor domain triggers three major VP5 actions: projecting the hidden dagger domain, converting a surface loop to a protonated ß-hairpin that anchors VP5 to the core and stepwise refolding of the unfurling domains into a six-helix stalk. Cryo-electron tomography structures of BTV interacting with liposomes show a length decrease of the VP5 stalk from 19.5 to 15.5 nm after its insertion into the membrane. Our structures, functional assays and structure-guided mutagenesis experiments combined indicate that this stalk, along with dagger domain and the WHXL motif, creates a single pore through the endosomal membrane that enables the viral core to enter the cytosol. Our study unveils the detailed mechanisms of BTV membrane penetration and showcases general methods to study cell entry of other non-enveloped viruses.

Serological, Molecular and Culture-Based Diagnosis of Lentiviral Infections in Small Ruminants.

Small ruminant lentiviruses (SRLVs) infections lead to chronic diseases and remarkable economic losses undermining health and welfare of animals and the sustainability of farms. Early and definite diagnosis of SRLVs infections is the cornerstone for any control and eradication efforts; however, a "gold standard" test and/or diagnostic protocols with extensive applicability have yet to be developed. The main challenges preventing the development of a universally accepted diagnostic tool with sufficient sensitivity, specificity, and accuracy to be integrated in SRLVs control programs are the genetic variability of SRLVs associated with mutations, recombination, and cross-species transmission and the peculiarities of small ruminants' humoral immune response regarding late seroconversion, as well as intermittent and epitope-specific antibody production. The objectives of this review paper were to summarize the available serological and molecular assays for the diagnosis of SRLVs, to highlight their diagnostic performance emphasizing on advantages and drawbacks of their application, and to discuss current and future perspectives, challenges, limitations and impacts regarding the development of reliable and efficient tools for the diagnosis of SRLVs infections.

Household and animal factors associated with sheeppox and goatpox sero-prevalence and identification of high-risk areas in selected States of northern Nigeria.

Sheeppox and goatpox (SGP) are transboundary, highly contagious diseases affecting sheep and goats with characteristic clinical signs. SGP affect populations of small ruminants in Africa, Asia and the Middle East and, as a result, threaten farmers' livelihoods. Despite their importance, studies looking at factors that increase the risk of sheeppox-virus (SPPV) and goatpox-virus (GTPV) exposure and infection are limited. A cross-sectional study was conducted in three states of Northern Nigeria (Bauchi, Kaduna and Plateau) to determine the sero-prevalence and spatial patterns of SGP, and identify risk factors for SPPV/GTPV exposure at animal and household level. Sera samples were collected from 1,800 small ruminants from 300 households. Data on putative risk factors were collected using a standardised questionnaire. Twenty-nine small ruminants were sero-positive to SGP - apparent weighted sero-prevalence 2.0 %; 95 % C.I. 1.1-.3.0 %. Sero-positive animals came from 19 (6.3 %) households. Analysis of the questionnaire showed that a fifth (20.3 %) of farmers claimed to have experienced SGP outbreaks previously in their flocks, with 33 (1.8 %) of the individual animals sampled in this study reported to have had clinical signs. At animal level, the odds of being sero-positive were higher in older animals (>24months; OR = 8.0, p = 0.008 vs ≤24 months) and small ruminants with a history of clinical SGP (OR = 16.9, p = 0.01). Bringing new small ruminants into the household and having a history of SGP in the flock were the main factors identified at household level. Households were less likely to be sero-positive if the time between bringing animals into the household and sampling was over a year (PR = 0.31, p = 0.05), while households with a history of SGP were more likely to be sero-positive regardless of the timeframe. Important spatial heterogeneity was found. The Bayes smooth rate ranged from 0.06 to 4.10 % across local government areas (LGA), with LGA in the north-east or north-west of the study area identified as hot-spots for SGP exposure. Results from this study shed new light on the understanding of SGP epidemiology and provide key inputs to design risk-based surveillance and intervention programmes in the area.