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Highlights • Small ruminants in the territory of the Suez Canal are at high risk of PPRV infection. • PPRV has been characterized using N and F gene sequences. • Phylogenetic analyses revealed that the identified PPRV may have introduced from Ethiopia into Northeastern Egypt. Abstract Peste des petits ruminants (PPR) is a severe viral disease of small ruminants endemic in Africa, the Middle East and Asia. The aim of this study was to determine the current circulation of PPR virus (PPRV) and the prevalence of PPR disease among sheep and goats in Ismailia and Suez governorates in northeastern Egypt. PPRV infection was confirmed using virus isolation (VI), conventional and real-time RT-PCR. The overall morbidity and mortality were 54.2% and 8.5%, respectively, and clinical disease was significantly higher in goats and young animals in the Suez compared to the Ismailia. Of the 40 samples tested, the real-time PCR showed the highest diagnostic sensitivity (100%) compared to RT-PCR (93%) and VI (83%). Sequence analyses of N and F genes of three field isolates revealed a 97% and 99% nucleotide homology with the Egyptian strains, respectively and 99% identity with 2010 Ethiopian PPRV. Phylogenetically all the Egyptian sequences cluster in lineage IV. This is the first report of PPR in Suez and confirms the (on-going) PPRV circulation in northeastern Egypt and emphasize the need to perpetuate molecular epidemiological surveillance on a large scale to reduce economic loss. [ABSTRACT FROM AUTHOR]

Highlights • Domination of Clostridium perfringens type A as causing agent of enterotoxemia in sheep. • Absence of NetB and TpeL toxins in sheep's isolates. • There is a relationship between cpb2-positive isolates and the outbreak of disease. Abstract Clostridium perfringens (C. perfringens) is a major cause of enteric diseases in sheep, goats, and other animals, since it produces several potent toxins in the intestines of the animal, some of which have proven to be involved in the pathogenesis of the diseases. The purpose of this study was to investigate the presence of major toxin genes along with some of the minor toxins in the isolates obtained from intestinal samples in healthy (non-ENT) and diseased (enterotoxemia = ENT) sheep. Forty intestinal samples from sheep (ENT = 16, non-ENT = 24) were examined to detect C. perfringens. Out of 40 samples, 25 samples were C. perfringens positive in bacteriological investigation and the isolates were typed by multiplex PCR assay. Of the total of 16 ENT isolates, 10 (62.5%) were type A and 6 isolates (37.5%) were type C, while 6 out of 9 (66.6%) isolates taken from non-ENT samples were type A and 3 (33.3%) isolates were type C. Toxin gene cpb2 was found in 9 of 16 (56.2%) isolates of ENT lesions and in 4 of 9 (44.4%) isolates of non-ENT sheep. However, 6 out of 12 isolates (50%), in which cpb2 were negative in multiplex PCR in both groups, were found to be positive using single PCR technique and specific total cpb2 oligonucleotides. The results of this study showed that type A was the dominant type which could threaten the sheep livestock in Iran. [ABSTRACT FROM AUTHOR]

Border disease is a congenital viral disease of sheep and goats and cause significant economic losses worldwide. It may cause abortion in sheep. However, there isn't any report of ovine abortion due to this virus from Iran. The aim of the present study was to investigate the role of this viral infection in sheep abortions in Chaharmahal and Bakhtiari province. To this end, 100 samples of aborted sheep foetuses were tested with RT-PCR. Nine (9%) sheep were determined to be BDV positive. It was concluded that BDV was involved in abortions in sheep population in Chaharmahal and Bakhtiari, Iran. [ABSTRACT FROM AUTHOR]

PPR is an acute, highly contagious and economically important viral disease of small ruminants. A polyclonal based indirect ELISA was developed for detection of antibodies to PPRV in the sheep sera samples using partially purified PPR viral antigen propagated in verocell lines. A cut-off value was set as twice the mean of negative population based on the distribution of known negative serum samples in respect of PPR viral antibodies in the test. The present assay had 100% specificity and 84% sensitivity and can be used as a good alternative to SNT for disease monitoring and serosurveillance. [ABSTRACT FROM AUTHOR]

This study reports the detection by RT-PCR and molecular characterization of partial RdRp gene of picobirnavirus (PBV) dsRNA in fecal samples ( n  = 100) from a meat sheep flock in southern Brazil. The analysis of the results allowed the identification of two important characteristics of PBV infection. The first was the high frequency of infection in the sheep flock evaluated where 62% of the analyzed fecal samples were PBV-positive. The second was the high genetic variability found in field strains of ovine PBV genogroup I circulating in animals of the same sheep flock. [ABSTRACT FROM AUTHOR]

Peste des petits ruminants (PPR) is an acute, highly contagious, and economically important transboundary viral disease of sheep and goats. It is among the major infectious diseases that affect the production and productivity of small ruminants in Ethiopia. Cross-sectional and retrospective studies were undertaken to estimate the sero-prevalence, risk factors, and distribution of PPR in Amhara region. A total of 672 (329 sheep and 343 goats) sera were collected from 30 kebeles in 10 districts. Of the 672 sheep and goat sera samples tested using c-ELISA, 123 were positive for PPR antibodies, with the overall prevalence of 18.30% (95%CI 15.37, 21.24). The sero-prevalence of PPR was 21.57% (95%CI 17.15, 25.86) in goats and 14.89% (95%CI 10.96-18.65) in sheep. The variation of sero-prevalence among study zones was statistically significant (p < 0.05). The highest sero-prevalence was reported in Awi zone (55.34%) followed by South Gondar (15.89%), North Gondar (13.64%), East Gojjam (7.93%), and West Gojjam (6.62%) zones. Among host- and environment-related risk factors, species, sex, agro-ecology, and location of the study were significantly associated with PPR sero-positivity. The analysis of 5-year retrospective data (2010-2014) revealed high occurrence of PPR in the Amhara region with a total occurrence of 63 outbreaks (3978 cases and 919 deaths). In conclusion, the study revealed that PPR is an important and widely distributed disease of small ruminants in Amhara region. Appropriate control strategy including regular surveillance and vaccination is recommended to mitigate the challenge of PPR. [ABSTRACT FROM AUTHOR]

Peste des petits ruminants (PPR) is a contagious and economically important disease affecting production of small ruminants (i.e., sheep and goats). Taking into consideration the lessons learnt from the Global Rinderpest Eradication Programme (GREP), PPR is now targeted by the international veterinary community as the next animal disease to be eradicated. To support the African continental programme for the control of PPR, the Pan African Veterinary Vaccine Centre of the African Union (AU-PANVAC) is developing diagnostics tools. Here, we describe the development of a blocking enzyme-linked immunosorbent assay (bELISA) that allows testing of a large number of samples for specific detection of antibodies directed against PPR virus in sheep and goat sera. The PPR bELISA uses an anti-haemagglutinin (H) monoclonal antibody (MAb) as a competitor antibody, and tests results are interpreted using the percentage of inhibition (PI) of MAb binding generated by the serum sample. PI values below or equal to 18% (PI ≤ 18%) are negative, PI values greater than or equal to 25% (PI ≥ 25%) are positive, and PI values greater than 18% and below 25% are doubtful. The diagnostic specificity (DSp) and diagnostic sensitivity (DSe) were found to be 100% and 93.74%, respectively. The H-based PPR-bELISA showed good correlation with the virus neutralization test (VNT), the gold standard test, with a kappa value of 0.947. The H-based PPR-bELISA is more specific than the commercial kit ID Screen® PPR Competition (N-based PPR-cELISA) from IDvet (France), but the commercial kit is slightly more sensitive than the H-based PPR-bELISA. The validation process also indicated good repeatability and reproducibility of the H-based PPR-bELISA, making this new test a suitable tool for the surveillance and sero-monitoring of the vaccination campaign. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease (FMD) is an acute, highly contagious viral disease of domestic and wild cloven-hoofed animals, caused by FMD virus (FMDV). An FMD outbreak can cause major production losses and have significant implications for trade. Vaccination can assist in controlling the disease, and emergency vaccination using high antigen payload vaccines (>6 PD50/dose) is considered an important control approach in the event of an outbreak. In recent years there has been a divergence of serotype A viruses in South East Asia (SEA) into several distinct genetic and antigenic clusters. Numerous variants were found to poorly match serotype A vaccines commonly included in international antigen banks. This study examined the ability of single vaccination with high-potency monovalent A22 IRQ vaccine to protect sheep following challenge with the A/VIT/15/2012 strain, just four days following vaccination. The vaccine proved effective at limiting clinical disease but did not prevent infection. [ABSTRACT FROM AUTHOR]

Summary: Blood samples from 65 sheep were tested for the presence of bovine Deltapapillomavirus (δPVs) DNA. The sheep were divided into three groups. Sheep in groups 1 and 2 were from Sardinia and Campania, respectively, and were in contact with cattle and grazed on lands contaminated with bracken fern. Sheep in Group 3 lived in closed pens and had no contact with cattle. These sheep were fed hay that did not contain bracken fern. Bovine δPV E5 DNA was detected in blood from 24 of 27 (89%) sheep in Group 1. A single bovine δPV type was detected in the blood from nine (33%) sheep, including the detection of bovine δPV‐1 DNA in four sheep, bovine δPV‐2 in four and δPV‐13 in one sheep. Two δPV types were detected in 33% of the sheep, and three bovine δPV types were detected in 22% of the sheep. Bovine δPVs were detected in 17 of 20 (85%) sheep from Group 2. The detection rate by a single δPV type was 40% with just δPV‐1 DNA amplified from two, just δPV‐2 DNA from four, and just δPV‐13 DNA from two sheep. Two and three δPVs were detected in 30% and 15%, respectively. All sequenced amplicons showed a 100% identity with papillomaviral E5 DNA deposited in GenBank. Bovine δPV‐14 DNA sequences were not detected from any sheep. No bovine δPV DNA was revealed in blood samples from sheep in Group 3. The detection of bovine δPV DNA in the blood of sheep means that sheep may be able to be infected by these PVs. This suggests that bovine δPVs could potentially be a previously unrecognized cause of disease in sheep. Furthermore, it is possible that sheep could act as a reservoir for these viruses. [ABSTRACT FROM AUTHOR]

Bluetongue virus (BTV), a vector-borne pathogen, is the causative agent of bluetongue disease in ruminants. In view of the recent emergence of BTV in regions previously known to be free from the disease and/or specific serotypes or strains, optimization of the currently available vaccination strategies to control the spread of vector-borne bluetongue is crucial. The main objective of the current study was to develop a subunit vaccine candidate targeting BTV-16, a strain previously isolated in China from sheep with obvious clinical signs. To this end, five polyhistidine-tagged recombinant proteins (BTV-16 VP2, VP3, VP7, NS2 and a truncated version of VP5 (VP5-41amino acids) were expressed using the baculovirus or Escherichia coli expression system for characterization of protective activity. To determine ovine and murine immune responses to the five proteins, sheep and mice were immunized twice at 4- and 2-week intervals, respectively, with one of two different protein combinations in Montanide TM ISA201 VG adjuvant or placebo. Data from the competitive enzyme linked immunosorbent assay revealed significantly higher antibody titers in immunized than control animals. Expressed VP5 and NS2 induced a protein-specific humoral response. Interestingly, a serum neutralization test against the BTV-1 serotype showed promising cross-serotype immune response by the vaccine. Based on the collective data, we suggest that these recombinant purified proteins present promising candidates for the design of effective novel vaccines against BTV. [ABSTRACT FROM AUTHOR]

We report Taenia ovis infection in Danish sheep for the first time. In spring 2016, the metacestode stage of T. ovis was at slaughter observed in heart muscles, diaphragm and skeletal muscles from approx. a third of all sheep from one specific farm localised in South Jutland. The diagnosis was confirmed by molecular typing of the mitochondrial cytochrome c oxidase I (cox1) gene. Three newly imported dogs were suspected but the definitive host was unidentifiable. The finding is not regulated in the meat control procedures. However, infected meat is usually condemned due to aesthetic reasons causing economic losses. Thus, finding of T. ovis is of concern to sheep meat producers in the area, as the infection could have spread further on to other farms. [ABSTRACT FROM AUTHOR]

The study is aimed to develop and evaluate a recombinant P32 protein based ELISA for sero-monitoring and sero-surveillance using known and random/suspected serum samples for capripox infections from sheep and goats. Truncated P32 gene of goatpox virus (with an ORF of 750 bp) was expressed in E. coli BL-21 CodonPlus (DE3)-RIPL cells using pET32a vector and characterized by SDS-PAGE analysis and confirmed by western blotting as 48 kDa polyhistidine-tagged fusion protein. The protein was purified under denaturing conditions using 8M urea and characterized by SDS-PAGE and immunoblotting. The purified protein was used for optimizing ELISA in a chequerboard titration method using anti-GTPV serum as known positive. The optimized conditions were found to be 300 ng of protein/well, 1:10 dilution of antibody, 1:10000 dilution of rabbit anti-goat/sheep conjugate with 3% skim milk powder and 2% gelatin in phosphate buffer saline containing tween-20 as blocking buffer. The expressed protein was specific only for goatpox virus and sheeppox virus but did not react with related viruses of sheep and goats namely orf virus, peste de petits ruminants virus, bluetongue virus and foot and mouth disease virus. The optimized ELISA was evaluated using pre-vaccinated, post-vaccinated and also post-challenge sera. The assay was found to have a diagnostic specificity of 100/98.7% and sensitivity of 97.1/98.1% when compared to whole virus antigen based ELISA/SNT by receiver operating characteristic (ROC) analysis. The optimized ELISA is able to determine the progression of antibody response against GTPV and SPPV following vaccination and challenge in sheep and goats. The rP32 protein based ELISA was evaluated using random field serum samples (n = 1008) suspected for sheeppox and goatpox and it has shown positivity rate as 24.4%. The rP32 protein based ELISA was found to be specific and sensitive for sero-evaluation of sheeppox virus and goatpox virus following vaccination and infection in sheep and goats. [ABSTRACT FROM AUTHOR]

Sheep and goat pox (SGP) with peste des petits ruminants (PPR) are transboundary viral diseases of small ruminants that cause huge economic losses. Recombinant vaccines that can protect from both infections have been reported as a promising solution for the future. SGP was used as a vector to express two structural proteins hemagglutinin or the fusion protein of PPRV. We compared immunity conferred by recombinant capripoxvirus vaccines expressing H or F or both HF. Safety and efficacy were evaluated in goats and sheep. Two vaccine doses were tested in sheep, 10 4.5 TCDI50 in 1 ml dose was retained for the further experiment. Results showed that the recombinant HF confers an earlier and stronger immunity against both SGP and PPR. This recombinant vaccine protect also against the disease in exposed and unexposed sheep. The potential Differentiating Infected from Vaccinated Animals of recombinant vaccines is of great advantage in any eradication program. [ABSTRACT FROM AUTHOR]

Background:Sheep pox and goat pox are contagious viral diseases of sheep and goats, respectively. The diseases result in substantial economic losses due to decreased milk and meat production, damage to hides and wool, and possible trade restriction. A study was undertaken in Amhara region of Ethiopia. A cross-sectional study design was used to estimate the sero-prevalence and identify associated risk factors, while retrospective study design was used to assess the temporal and spatial distribution of the disease. A total of 672 serum samples were collected from 30 Kebeles and tested using virus neutralization test. Results: From a total of 672 sera tested, 104 (15.5%) were positive for sheep and goat pox virus antibody; from which 56 (17%) were sheep and 48 (14%) were goats. The diseases were prevalent in all study zones, the highest sero-prevalence was observed in South Gondar (20.9%) and the lowest in North Gondar and West Gojjam zones (11.9% each). From the potential risk factors considered (species, sex, age, agro-ecology and location); only sex and age were significantly associated (p < 0.05) with the diseases in multivariable logistic regression. Female and young animals were at higher risk than their counterparts. From January 2010 to December 2014, a total of 366 outbreaks, 12,822 cases and 1480 deaths due to SP and 182 outbreaks, 10,066 cases and 997 deaths due to GP were recorded in Amhara National Regional State. Conclusion: Both the serological and the outbreak data revealed that sheep and goat pox is one of the most prevalent and widespread diseases of sheep and goats in the study area. Hence, annual mass vaccination program must be implemented for economic and viable control of sheep and goat pox diseases in the Amhara region in particular and at a national level in general. [ABSTRACT FROM AUTHOR]

Background and Objectives: Sheeppox virus causes systemic disease in sheep that is often associated with high morbidity and mortality. Protection against sheep pox is mainly based on medical prophylaxis, vaccination being the only way. In Morocco, and up to now, there is no available information about local challenge strain to use for controlling the efficiency of vaccines produced against sheep pox. Hence, the objective of the present study was to evaluate and compare the pathogenicity of seven Sheeppox virus (SPVs) isolates from 1993-1995 in Morocco. Materials and Methods: These seven SPV isolates have undergone various tests to evaluate their pathogenicity: Passages and titration on cell culture, Experimental inoculation on sheep, Virus-neutralization, In vivo titration and viral re-isolation by real-time PCR assay. Results: All infected lambs showed severe clinical signs, while most of them have been reproduced on 5 dpi and persisted until 21 dpi. The lambs infected by Oj1P4, Oj2P4 and BerP5 appeared lethargic, reluctant to move compared to those infected by other isolates. The results also revealed that all isolates were able to induce serological response. Virus isolation from infected organs and blood and amplification of the viral DNA by real-time PCR proved the presence of the virus in tissues and blood of infected lambs. These Moroccan SPVs demonstrated that the three isolates Oj1P4, Oj2P4 and BerP5 have a high pathogenicity; especially the BerP5 isolate which has an important infectious titer. Conclusion: These results demonstrate that the Berkane isolate is the most pathogenic of the tested isolates and it can be an excellent challenge strain for the control of the efficiency of vaccines against sheep pox produced in Morocco. [ABSTRACT FROM AUTHOR]

In Poland, no systematic survey of ruminant lentiviruses (SRLVs) infection was performed, neither at the national nor at the regional level and only limited knowledge exists on the prevalence of SRLVs among sheep. The aim of the present study was to establish the true prevalence of SRLVs infection in sheep from Poland at the animal and herd-levels. The blood samples used for this study were the fraction of samples collected by Veterinary Inspection during an official sampling for the national monitoring program for brucellosis. Under this program the animals and herds were randomly selected using the data available from ARMA (Agency for Restructuring and Modernisation of Agriculture). The sampling unit was the herd and the target population included at least 5% of sheep, over 6 months old, from each of 16 voievodships (provinces) of Poland. Two-stage cluster sampling design was performed in this study offering the possibility to determine the prevalence of SRLVs infection, when only a fraction of herds and a fraction of animals in the herds are tested. In total, 8233 sheep serum samples coming from 832 herds were tested by indirect ELISA. 1474 (17.9%) samples were positive and 261 (31.4%) herds with at least one seropositive animals were identified. The overall true prevalence estimated by the Bayesian framework was 9.3% (95% CI 6.8, 11.3) and 33.3% (95% CI 26.5, 38.2) on the animal and herd level, respectively. Large variation in the animal and herd prevalence between the voivodships was observed. True prevalence on the herd level varied from 0.0% (95% CI 0.0, 0.0) to 71.6% (95% CI 67.6, 75.9) whereas true prevalence on the animal level ranged from 0.0% (95% CI 0.0, 0.0) to 55.3% (95% CI 50.0, 61.2). The true prevalence of SRLVs infection at animal and herd level increased according to herd size as was proved by posterior probabilities (POPR). [ABSTRACT FROM AUTHOR]

Peste des petits ruminants virus (PPRV) causes a highly contagious disease, peste des petits ruminants (PPR), in sheep and goats which has been considered as a serious threat to the local economy in Africa and Asia. However, the in-depth evolutionary dynamics of PPRV during an epidemic is not well understood. We conducted phylogenetic analysis on genomic sequences of 25 PPRV strains from China 2013–2014 outbreaks. All these strains clustered into a novel clade in lineage 4. An evolutionary rate of 2.61 × 10 −6 nucleotide substitutions per site per day was estimated, dating the most recent common ancestor of PPRV China 2013–2014 strains to early August 2013. Transmission network analysis revealed that all the virus sequences could be grouped into five clusters of infection, suggesting long-distance animal transmission play an important role in the spread of PPRV in China. These results expanded our knowledge for PPRV evolution to achieve effective control measures. [ABSTRACT FROM AUTHOR]

Potency tests for commercial oil-adjuvanted foot-and-mouth disease (FMD) vaccines are usually carried out in cattle, using a full dose (2 ml) of vaccine and homologous virus challenge. However, in sheep the recommended vaccine dose is half of the cattle dose (1 ml) and most vaccines have not been potency tested for this species, especially with heterologous viruses. To determine the efficacy of a high potency (>6PD 50 ) FMD virus (FMDV) O1Manisa vaccine in sheep, we carried out a study using a heterologous FMDV (FMDV O/SKR/2010 - Mya-98 strain) challenge. Groups of seven animals each were vaccinated with 2×, 1×, 1/2× or 1/4× dose (2 ml, 1 ml, 0.5 ml or 0.25 ml respectively) and challenged at 7 days post vaccination (dpv). Only 3 of the 7 sheep in the group vaccinated with 2 ml were protected. With 2 additional groups, receiving double or single doses and challenged at 14 dpv, 4 of 7 sheep were protected in each group. None of the sheep had measurable neutralising antibodies against the vaccine or challenge virus at 7 dpv. However, all vaccinated animals challenged at 14 dpv had a homologous neutralising response against FMDV O1 Manisa on the day of challenge and all but one animal also had a heterologous response to FMDV O/SKR/2010. Infectious FMDV and viral RNA could be found in nasal swabs between 1 and 6 days post challenge (dpc) in most vaccinated sheep, but those vaccinated with higher doses or challenged at 14 dpv showed significant decreases in the level of FMDV detection. Intermittent virus shedding was noticed between 1 and 35 dpc in all vaccinated groups, but persistent infection could be demonstrated only in 4 sheep (20%). This study showed that at the recommended dose, a high potency (>6 PD 50 ) FMDV O1Manisa vaccine does not protect sheep against a heterologous challenge at 7 dpv. However, partial protection was observed when a double dose was used at 7 dpv or when double or single dose vaccinated sheep were challenged at 14 dpv. [ABSTRACT FROM AUTHOR]

Middle East respiratory syndrome (MERS) cases continue to be reported, predominantly in Saudi Arabia and occasionally other countries. Although dromedaries are the main reservoir, other animal species might be susceptible to MERS coronavirus (MERS-CoV) infection and potentially serve as reservoirs. To determine whether other animals are potential reservoirs, we inoculated MERS-CoV into llamas, pigs, sheep, and horses and collected nasal and rectal swab samples at various times. The presence of MERS-CoV in the nose of pigs and llamas was confirmed by PCR, titration of infectious virus, immunohistochemistry, and in situ hybridization; seroconversion was detected in animals of both species. Conversely, in sheep and horses, virus-specific antibodies did not develop and no evidence of viral replication in the upper respiratory tract was found. These results prove the susceptibility of llamas and pigs to MERS-CoV infection. Thus, the possibility of MERS-CoV circulation in animals other than dromedaries, such as llamas and pigs, is not negligible. [ABSTRACT FROM AUTHOR]

It is widely known that prion strains can mutate in response to modification of the replication environment and we have recently reported that prion mutations can occur in vitro during amplification of vole-adapted prions by Protein Misfolding Cyclic Amplification on bank vole substrate (bvPMCA). Here we exploited the high efficiency of prion replication by bvPMCA to study the in vitro propagation of natural scrapie isolates. Although in vitro vole-adapted PrPSc conformers were usually similar to the sheep counterpart, we repeatedly isolated a PrPSc mutant exclusively when starting from extremely diluted seeds of a single sheep isolate. The mutant and faithful PrPSc conformers showed to be efficiently autocatalytic in vitro and were characterized by different PrP protease resistant cores, spanning aa ∼155–231 and ∼80–231 respectively, and by different conformational stabilities. The two conformers could thus be seen as different bona fide PrPSc types, putatively accounting for prion populations with different biological properties. Indeed, once inoculated in bank vole the faithful conformer was competent for in vivo replication while the mutant was unable to infect voles, de facto behaving like a defective prion mutant. Overall, our findings confirm that prions can adapt and evolve in the new replication environments and that the starting population size can affect their evolutionary landscape, at least in vitro. Furthermore, we report the first example of “authentic” defective prion mutant, composed of brain-derived PrPC and originating from a natural scrapie isolate. Our results clearly indicate that the defective mutant lacks of some structural characteristics, that presumably involve the central region ∼90–155, critical for infectivity but not for in vitro replication. Finally, we propose a molecular mechanism able to account for the discordant in vitro and in vivo behavior, suggesting possible new paths for investigating the molecular bases of prion infectivity. [ABSTRACT FROM AUTHOR]

Unsettled knowledge as to whether scrapie transmits prenatally in sheep and goats and transmits by semen and preimplantation embryos has a potential to compromise measures for controlling, preventing and eliminating the disease. The remedy may be analysis according to a systematic review, allowing comprehensive and accessible treatment of evidence and reasoning, clarifying the issue and specifying the uncertainties. Systematic reviews have clearly formulated questions, can identify relevant studies and appraise their quality and can summarise evidence and reasoning with an explicit methodology. The present venture lays a foundation for a possible systematic review and applies three lines of evidence and reasoning to two questions. The first question is whether scrapie transmits prenatally in sheep and goats. It leads to the second question, which concerns the sanitary safety of artificial breeding technologies, and is whether scrapie transmits in sheep and goats by means of semen and washed or unwashed in vivo derived embryos. The three lines of evidence derive from epidemiological, field and clinical studies, experimentation, and causal reasoning, where inferences are made from the body of scientific knowledge and an understanding of animal structure and function. Evidence from epidemiological studies allow a conclusion that scrapie transmits prenatally and that semen and embryos are presumptive hazards for the transmission of scrapie. Evidence from experimentation confirms that semen and washed or unwashed in vivo derived embryos are hazards for the transmission of scrapie. Evidence from causal reasoning, including experience from other prion diseases, shows that mechanisms exist for prenatal transmission and transmission by semen and embryos in both sheep and goats. [ABSTRACT FROM AUTHOR]

Since the first reports of the Schmallenberg disease ( SBD) outbreaks in late 2011, the disease has spread across Europe, affecting cattle and sheep farms. While Schmallenberg virus ( SBV) causes a mild clinical disease in adults, infection of pregnant females may lead to the production of typical congenital malformations ( CMFs) in their offspring. It is speculated that the immunity acquired after a SBV infection is effective in preventing further infections. However, this has not been proven in naturally infected sheep, especially if they are pregnant when reinfected. The aim of this study was to monitor the natural immunity in SBV-infected sheep. Twenty-four ewes from the only Spanish farm with a SBV OIE-notified outbreak were sampled. Subsequently, nine pregnant ewes were inoculated with SBV infectious plasma under controlled conditions. Six of them were euthanized before delivery, and their fetuses were inspected for lesions indicative for the SBV infection. The three remaining ewes were allowed to deliver one lamb each. Inoculation of the lambs was scheduled at approx. 3 months after birth. All samples were analyzed for viral RNA by RT- PCR, and for antibodies by an indirect ELISA and a virus neutralization test ( VNT). The majority of the 24 ewes showed a serological reaction against SBV. The three ewes that were allowed to lamb down demonstrated variable degrees of seroconversion which corresponded to the levels of immune reaction observed in their lambs. Moreover, no viral RNA was detected, no lesions were observed in the fetuses, and no clinical signs were detected in the inoculated animals. These findings suggest that the immunity acquired by sheep following a natural SBV infection could be sufficient to stop SBV reinfection. However, vaccination could be a valuable tool to control SBV infections and associated economic losses as it affords a more uniform and predictable protection at the flock/herd level. [ABSTRACT FROM AUTHOR]

Introduction: Shiga toxin-producing Escherichia coli (STEC) are an important group of emerging zoonotic pathogens carried in the intestinal tracts of ruminants. They can cause mild diarrhea and fatal disease characterized by hemolytic uremic syndrome, especially in children, the elderly, and immune-compromised individuals. Methodology: The aim of this study was to determine if sheep harbor STEC. Sheep feces (n = 40), brisket wool (n = 40), and 150 meat samples were collected from the flank (n = 35), rump (n = 35), brisket (n = 20), shank (n = 25), diaphragm (n = 10), and neck (n = 25) of slaughter-age sheep at a high-throughput abattoir and tested for STEC using a combination of culture and real-time polymerase chain reaction techniques. Results: E. coli O103 (5/40) and O145 (5/40) strains were isolated from the feces and E. coli O157:H7 was isolated from brisket wool (10/40) and flank meat (5/35). The results of this study provide the first report of STEC infections in sheep in Namibia. Conclusions: The results of this study show that sheep, like cattle, can shed STEC strains in their feces, which can contaminate meat and expose humans to infections. [ABSTRACT FROM AUTHOR]

Ovine progressive pneumonia virus (OPPV) is an important virus that causes serious diseases in sheep and goats with a prevalence of 36% in the USA. Although OPPV was discovered more than half of a century ago, little is known about the infection and pathogenesis of this virus. In this report, we used RNA-seq technology to conduct a genome-wide probe for cellular factors that are associated with OPPV infection. A total of approximately 22,000 goat host genes were detected of which 657 were found to have been significantly up-regulated and 889 down-regulated at 12 hours post-infection. In addition to previously known restriction factors from other viral infections, a number of factors which may be specific for OPPV infection were uncovered. The data from this RNA-seq study will be helpful in our understanding of OPPV infection, and also for further study in the prevention and intervention of this viral disease. [ABSTRACT FROM AUTHOR]

Schmallenberg virus ( SBV) is a member of the family Bunyaviridae and mainly affects ruminants. It is transmitted by biting midges, first and foremost Culicoides spp., and causes congenital malformations reflected in arthrogryposis-hydranencephaly ( AH) syndrome. The aim of this study was to collect data on the emergence of SBV as a new arthropod-borne disease introduced into Europe in 2011. Germany was located in the core region of the 2011/2012 epidemic. Following two seroprevalence studies in the north-west of Germany in 2012, this study focused on the epidemiology and distribution of SBV throughout 130 small ruminant flocks in the whole country. Blood samples were obtained of 30 animals per flock and a SBV-specific questionnaire was used to collect operating data of the farms. The median within-herd seroprevalence for all 130 flocks tested was 53.3% with a total range from 0% to 100%. The median within-herd seroprevalence for goats was 30% [interquartile range ( IQR): 40.3%] and 57% for sheep ( IQR: 43.3%). Small ruminant flocks kept permanently indoors or housed overnight had a significantly lower seroprevalence than flocks kept permanently outdoors. In addition, this study revealed a significantly lower seroprevalence in the north-east of Germany. These results show that small ruminants in Germany are still at risk of contracting new SBV infections following incomplete seroconversion of flocks especially in the north-east of Germany. This might contribute to SBV becoming enzootic in central and northern Europe. Furthermore, the survey revealed that housing animals at least during mating and early pregnancy may reduce the risk of new SBV infections and may thus be an option to reduce losses as long as there is no licensed vaccine available on the German market. [ABSTRACT FROM AUTHOR]

Highlights • Wave of abortions in a vaccinated sheep flock. • Detection of C. abortus by real time PCR in vaginal swabs from aborted ewes and in tissues collected from dead fetuses. • Identification of the vaccine strain using the PCR-HRM typing tool. • WGS of one isolate identified the 10 SNP vaccine specific markers. Abstract Chlamydia abortus is responsible for enzootic abortion (known as ovine enzootic abortion (OEA) and enzootic abortion of ewes (EAE)) in both sheep and goats and has major economic implications for the farming industry worldwide. A virulence-attenuated mutant strain of C. abortus (strain 1B) is currently commercially available as a live attenuated vaccine for immunization of sheep and goats in several European countries. Following an abortion storm in a French flock of 200 ewes that occurred two years after vaccination of 36 replacement ewes with the commercial 1B vaccine strain, the vaginal swabs of 3 vaccinated and 7 unvaccinated aborted ewes and 12 of the 13 dead fetuses were found to be positive for C. abortus by real-time PCR. Genotyping of the samples, using vaccine-specific SNP markers, identified all as positive for the vaccine-type strain. The recent vaccination of this flock with the attenuated commercial vaccine strain, the large number of abortion cases observed in ewes irrespective of vaccination status, the high C. abortus load detected in vaginal swabs or abortion tissues and the identification of specific vaccine-type markers in these samples strongly suggest that the 1B strain has been transmitted from vaccinated to naïve animals, thus mimicking a natural wild-type infection. [ABSTRACT FROM AUTHOR]

The main target of this debate is the revaluation of the biodiversity concept and especially of its significance in the animal husbandry field. The paper analyzes the genetic diversity at the determinant locus of scrapie (PrP) in the sheep breeds from Romania: Palas Merino, Tsigai, Tsurcana, Botosani Karakul, Palas Meat Breed and Palas Milk Breed. The prionic genetic diversity (d) has been quantified by means of informational energy (e). This study highlights the impact of increasing the genetic diversity from the PrP locus level on the health status of ovine species and especially on human food safety. The informational statistics processing shows that the resistance/susceptibility to scrapie is in relation to the degree of prionic genetic diversity. The limitation of genetic diversity by selecting the individuals possessing the ARR allele in both homozygous status and in combination with alleles ARQ, ARH AHQ confers to sheep flocks certain levels of resistance to contamination with scrapie disease. Instead, promoting to reproduction also individuals possessing the VRQ allele in all possible genotypic combinations (including ARR allele) increases genetic diversity but also has as effect increasing the susceptibility of sheep to prion disease onset. From the point of view of morbid phenomenon, the Botosani Karakul breed is clearly advantaged compared to all other indigenous sheep breeds from Romania. For methodological coherency in the interpretative context of this issue, the genetic diversity was analyzed in association with the heterozygosity degree of breeds and their Hardy-Weinberg genetic equilibrium at the PrP locus level. Finally, the paper refers to decisions that the improvers must take to achieve the genetic prophylaxis in the scrapie case taking into account the polymorphism degree of prion protein. [ABSTRACT FROM AUTHOR]

Concerns regarding scrapie in sheep breeding have increased in the last few decades. The present study was carried out in dairy sheep breeds from southern Italy. In order to find breeding animals resistant to scrapie, the PrP genes of 1,205 animals from entire flocks of dairy native Apulian Leccese and Altamurana breeds, and Sicilian Comisana breed, were analysed for polymorphisms at codons 136, 154, and 171 related to scrapie resistance/susceptibility. The Altamurana breed was considered as two populations (Alt-Cav and Alt-Cra-Zoe), based on presumed cross-breeding. A total of five alleles and ten different genotypes were found. The ARQ allele was predominant for all breeds followed by ARR, the most resistant allele to scrapie, which was highly prevalent in Comisana (50%) and in native Alt-Cav (42.4%). The VRQ allele, associated with the highest susceptibility to scrapie, was detected at not negligeable levels in allocthonous Comisana (3.5%), at a low frequency (0.2%) in native Leccese and Alt-Cra-Zoe, while it was absent in Alt-Cav. The frequencies of PrP genotypes with a very low susceptibility risk to scrapie (R1) was higher in Comisana and Alt-Cav. The most susceptible genotype, ARQ/VRQ, was found only in Comisana. Within the Altamurana breed, there were notable differences between Alt-Cav and Alt-Cra-Zoe sheep. The Alt-Cav was characterised by the absence of VRQ and AHQ alleles and by the higher frequency of the ARR/ARR genotype (18.7%). Breeding programs, mainly in endangered breeds such as Altamurana, should be conducted gradually, combining resistance to scrapie, maintenance of genetic variability, and production. [ABSTRACT FROM AUTHOR]

Proteins were described as distinct biological molecules and their significance in cellular processes was recognized as early as the 18th century. At the same time, Spanish shepherds observed a disease that compelled their Merino sheep to pathologically scrape against fences, a defining clinical sign that led to the disease being named scrapie. In the late 19th century, Robert Koch published his postulates for defining causative agents of disease. In the early 20th century, pathologists Creutzfeldt and Jakob described a neurodegenerative disease that would later be included with scrapie into a group of diseases known as transmissible spongiform encephalopathies (TSEs). Later that century, mounting evidence compelled a handful of scientists to betray the prevailing biological dogma governing pathogen replication that Watson and Crick so convincingly explained by cracking the genetic code just two decades earlier. Because TSEs seemed to defy these new rules, J.S. Griffith theorized mechanisms by which a pathogenic protein could encipher its own replication blueprint without a genetic code. Stanley Prusiner called this proteinaceous infectious pathogen a prion. Here we offer a concise account of the discovery of prions, the causative agent of TSEs, in the wider context of protein biochemistry and infectious disease. We highlight the discovery of prions in yeast and discuss the implication of prions as epigenomic carriers of biological and pathological information. We also consider expanding the prion hypothesis to include other proteins whose alternate isoforms confer new biological or pathological properties. [ABSTRACT FROM AUTHOR]

Bluetongue virus (BTV) is an economically important Orbivirus of the Reoviridae family that causes a hemorrhagic disease in ruminants. Its control has been achieved by inactivated-vaccines that have proven to protect against homologous BTV challenge although unable to induce long-term immunity. Therefore, a more efficient control strategy needs to be developed. Recombinant adenovirus vectors are lead vaccine candidates for protection of several diseases, mainly because of their potency to induce potent T cell immunity. Here we report the induction of humoral and T-cell mediated responses able to protect animals against BTV challenge by recombinant replication-defective human adenovirus serotype 5 (Ad5) expressing either VP7, VP2 or NS3 BTV proteins. First we used the IFNAR(-/-) mouse model system to establish a proof of principle, and afterwards we assayed the protective efficacy in sheep, the natural host of BTV. Mice were completely protected against BTV challenge, developing humoral and BTV-specific CD8+- and CD4+-T cell responses by vaccination with the different rAd5. Sheep vaccinated with Ad5-BTV-VP2 and Ad5-BTV-VP7 or only with Ad5-BTV-VP7 and challenged with BTV showed mild disease symptoms and reduced viremia. This partial protection was achieved in the absence of neutralizing antibodies but strong BTV-specific CD8+ T cell responses in those sheep vaccinated with Ad5-BTV-VP7. These data indicate that rAd5 is a suitable vaccine vector to induce T cell immunity during BTV vaccination and provide new data regarding the relevance of T cell responses in protection during BTV infection. [ABSTRACT FROM AUTHOR]

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Bluetongue virus (BTV) is the causative agent of bluetongue (BT), an important sheep disease that caused great economic loss to the sheep industry. There are 26 BTV serotypes based on the outer protein VP2. However, the serotypes BTV-1 and BTV-16 are the two most prevalent serotypes in China. Vaccination is the most effective method of preventing viral infections. Therefore, the need for an effective vaccine against BTV is urgent. In this study, DNA vaccines and recombinant fowlpox virus (rFPV) vaccines expressing VP2 alone or VP2 in combination with VP5 or co-expressing the VP2 and VP5 proteins of BTV-1 were evaluated in both mice and sheep. Several strategies were tested in mice, including DNA vaccine prime and boost, rFPV vaccine prime and boost, and DNA vaccine prime and rFPV vaccine boost. We then determined the best vaccine strategy in sheep. Our results indicated that a strategy combining a DNA vaccine prime (co-expressing VP2 and VP5) followed by an rFPV vaccine boost (co-expressing VP2 and VP5) induced a high titer of neutralizing antibodies in sheep. Therefore, our data suggest that a DNA vaccine consisting of a pCAG-(VP2+VP5) prime and an rFPV-(VP2+VP5) boost is an important candidate for the design of a novel vaccine against BTV-1. [ABSTRACT FROM AUTHOR]

ABSTRACT Because imminent introduction into Vietnam of a vaccine against Rotavirus A is anticipated, baseline information on the whole genome of representative strains is needed to understand changes in circulating strains that may occur after vaccine introduction. In this study, the whole genomes of two G2P[4] strains detected in Nha Trang, Vietnam in 2008 were sequenced, this being the last period during which virtually no rotavirus vaccine was used in this country. The two strains were found to be >99.9% identical in sequence and had a typical DS-1 like G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 genotype constellation. Analysis of the Vietnamese strains with >184 G2P[4] strains retrieved from GenBank/EMBL/DDBJ DNA databases placed the Vietnamese strains in one of the lineages commonly found among contemporary strains, with the exception of the NSP2 and NSP4 genes. The NSP2 genes were found to belong to a previously undescribed lineage that diverged from Chinese sheep and goat rotavirus strains, including a Chinese rotavirus vaccine strain LLR with 95% nucleotide identity; the time of their most recent common ancestor was 1975. The NSP4 genes were found to belong, together with Thai and USA strains, to an emergent lineage (VIII), adding further diversity to ever diversifying NSP4 lineages. Thus, there is a need to enhance surveillance of locally-circulating strains from both children and animals at the whole genome level to address the effect of rotavirus vaccines on changing strain distribution. [ABSTRACT FROM AUTHOR]

In this study, one-step real-time quantitative reverse transcription PCR (qRT- PCR) was developed for the first time and evaluated for detection of peste des petits ruminants virus (PPRV) in field samples obtained from distinct geographical areas of Turkey. Primers and probes targeting four PPRV genes (namely L, M, N and P) were designed based on full genome sequence (AJ849636) of the local isolate (Tu00). The detection limits of the assays were found to be 7 copies/µL RNA for L, 6 copies/µL RNA for P, 10 copies/µL RNA for M and 700 copies/µL RNA for N, respectively. Besides, the detection ratio for PPRV in 45 field samples was 100% (45) for L, 88.9% (40) for M, 77.8% (35) for P and 22.3% (10) for N, respectively. In conclution, onestep real-time quantitative reverse transcription PCR (qRT- PCR) assay reported here for L gene design provides rapid, specific and sensitive detection of PPRV in tissue samples obtained from field cases. [ABSTRACT FROM AUTHOR]

In 2001, border disease virus (BDV) was identified as the cause of a previously unreported disease in Pyrenean chamois (Rupicapra pyrenaica) in Spain. Since then, the disease has caused a dramatic decrease, and in some cases collapse, of chamois populations and has expanded to nearly the entire distribution area in the Pyrenees. Chamois BDV was characterized as BDV-4 genotype and experimental studies confirmed that it was the primary agent of the disease. The infection has become endemic in the Central and Eastern Pyrenees. However, while most Pyrenean chamois populations have been severely affected by the disease, others have not, despite the circulation of BDV in apparently healthy individuals, suggesting the existence of different viral strategies for persisting in the host population. Changes in the interplay of pathogen, host and environmental factors may lead to the formation of different disease patterns. A key factor influencing disease emergence may be pathogen invasiveness through viral mutation. Host factors, such as behavior, immunity at the population level and genetic variability, may also have driven different epidemiological scenarios. Climatic and other ecological factors may have favored secondary infections, such as pneumonia, that under particular circumstances have been major contributing factors in the high mortality observed in some areas. [ABSTRACT FROM PUBLISHER]

The article presents a study focusing on genetic evidence for susceptibility and resistance against scrapie disease in Indian sheep breeds including Karnah, Mandya, Malpura. The findings include the reasons for scrapie resistance in Indian sheep including inherent resistance, polymorphism protecting the animals from prion infections, and management practices of sheep rearing, the association between sheep genotype and the risk of death from scrapie, and several charts related to the same.

Sheep pox is a highly contagious, host specific viral infection and responsible for high morbidity and mortality. Three flocks consisting of 412 Madras Red sheep were examined for the presence of sheep pox at Arasankuppam and Vellakulam village of Thiruvannamalai district, Tamil Nadu. Overall morbidity and mortality of sheep pox was 14.94 and 43.73 %, respectively. The morbidity (53.85%) and mortality(42.85%) rates were higher in lambs than adult and young age groups. Among the sex, the morbidity and mortality rates were higher in females (15.69 and 40.90%) than males (8.00 and 50.00%), respectively. Clinical signs, postmortem lesions and histopathological findings were also reported and discussed. [ABSTRACT FROM AUTHOR]

The relevant information on the occurrence of Blue Tongue (BT) viral disease in sheep was analyzed on the economic losses, and their clinical management were studied. During 2012-13, 2013-14 and 2014-15 there were 10, 34 and 11 cases recorded in Nellore jodipi sheep at Livestock Research Station, Palamaner and the results indicated that the case fatality rate was 20, 23.53 and 18.18 and percent mortality were 0.26, 0.99 and 0.26. The reduction in the growth performance is the main concern and in some of the animals, reduced weights were noticed to a maximum of 7 kgs. The year wise monetary losses were Rs.26954, 103008 and 28232 observed during the respective years. [ABSTRACT FROM AUTHOR]

Prion diseases are a family of fatal neurodegenerative diseases that involve the misfolding of a host protein, PrPC. Measuring prion infectivity is necessary for determining efficacy of a treatment or infectivity of a prion purification procedure; animal bioassays are, however, very expensive and time consuming. The Standard Scrapie Cell Assay (SSCA) provides an alternative approach. The SSCA facilitates quantitative in vitro analysis of prion strains, titres and biological properties. Given its robust nature and potential for high throughput, the SSCA has substantial utility for in vitro characterization of prions and can be deployed in a number of settings. Here we provide an overview on establishing the SSCA, its use in studies of disease dissemination and pathogenesis, potential pitfalls and a number of remaining challenges. [ABSTRACT FROM AUTHOR]

Inbreeding in a small population of Chios sheep undergoing intense selection for the PrP gene was assessed 10 years after the beginning of a scrapie resistance selection programme. Inbreeding in this stock, already under selection for production traits, was analysed by using pedigree records containing 10,492 animals from 1968 to 2008, and also by genotyping 192 individuals with a panel of 15 microsatellites. Genetic markers indicated a loss of heterozygosity (FIS over all loci was 0.059) and allelic diversity (mean effective number of alleles was 3.075±0.275). The annual rate of inbreeding increased significantly after the start of the scrapie resistance programme, ΔF=0.005 compared with ΔF=0.001 before 1999, and was subjected to several genetic bottlenecks, mainly due to the low initial frequency of resistant animals. However, the mean individual inbreeding coefficient estimated from the pedigree - in this closed stock resembling the case of a rare breed - stood at the level of 4.5 per cent, five generations after the implementation of selection for the PrP gene. The inbreeding coefficient estimated by genetic markers was 4.37 per cent, implying that such a marker panel could be a useful and cost-effective tool for estimating inbreeding in unrecorded populations. [ABSTRACT FROM AUTHOR]

The article offers information on the disease surveillance report for July 2014 from SAC Consulting Veterinary Services. It discusses reports about border disease outbreak which led to continuing sheep losses in cattle industry. Other information such as porcine reproductive and respiratory virus and swine influenza virus in pigs as well as transport-associated acetonaemia in dairy heifers is presented. INSET: Review of bovine respiratory disease.

Bluetongue virus (BTV) is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0) or a leporipoxvirus (SG33-VP7), to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity. [ABSTRACT FROM AUTHOR]

After the decline of the Bovine Spongiform Encephalopathy (BSE) epidemic in Great Britain (GB), scrapie remains the most prevalent animal Transmissible Spongiform Encephalopathy (TSE) present in GB. A number of control measures have been implemented for classical scrapie, and since 2005 there has been a large reduction in the number of observed cases. The objective of this study is to estimate two measures of disease frequency using up to date surveillance data collected during and after the implementation of different control measures established since 2004, and breeding for resistance schemes that ran from 2001 until 2009. This would enable an assessment of the effectiveness of both the breeding for resistance programme and the compulsory eradication measures in reducing the prevalence of scrapie in GB. Evaluation of the sensitivity of the rapid post-mortem test for scrapie indicated that it detected scrapie in the last 25% of the incubation period. A back-calculation model was developed to estimate the prevalence of infection at animal and flock-level. The results of the model indicated a mean drop of infection prevalence of 31% each year, leading to a 90% drop in infection prevalence between 2005, with an estimate of 5737 infected sheep in GB in 2012. The risks of classical scrapie infection in animals with genotypes of National Scrapie Plan Types I–IV (all other genotypes), relative to Type V (all genotypes containing V 136 R 154 Q 171 and not A 136 R 154 R 171 ), were estimated to be: 0, 0.0008, 0.07, and 0.21 respectively. The model estimated a very low rate of reporting of clinical suspects and a large decline from 2007 of the probability of a sheep being reported as a clinical suspect. The model also estimated that the expected number of sheep holdings with classical scrapie in 2012 was 215 (95% confidence interval: 33–437), out of a total of approximately 72,000 sheep holdings in GB. Model estimates indicate that the prevalence in 2012 has dropped to 10% of that in 2005, showing the effectiveness of the control measures. It also shows a bias in the destination of infected animals, with the majority of infected animals being detected in the fallen stock surveillance stream, and an extremely low proportion of animals detected as clinical suspects; this is very important in terms of the design of surveillance schemes for classical scrapie. [ABSTRACT FROM AUTHOR]

AIMS: To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN) from non-infected and infected sheep of different PrP genotypes. METHODS: Using published data on the distribution of PrP genotypes within the New Zealand sheep flock and the prevalence of cases of scrapie in these genotypes in the United Kingdom, the annual expected number of cases of scrapie per genotype was estimated, should scrapie become established in New Zealand, assuming a total population of 28 million sheep. A non-infected panel of RLN was collected from 737 sheep from New Zealand that had been culled, foundin extremisor died. Brain stem samples were also collected from 131 of these sheep. A second panel of infected samples comprised 218 and 117 RLN from confirmed scrapie cases that had originated in Europe and the United States of America, respectively. All samples were screened using two commercial, rapid, transmissible spongiform encephalopathy ELISA kits: Bio-Rad TeSeE ELISA (ELISA-BR), and IDEXX HerdChek BSE-Scrapie AG Test (ELISA-ID). RESULTS: If scrapie became established in New Zealand, an estimated 596 cases would occur per year; of these 234 (39%) and 271 (46%) would be in sheep carrying ARQ/ARQ and ARQ/VRQ PrP genotypes, respectively. For the non-infected samples from New Zealand the diagnostic specificity of both ELISA kits was 100%. When considering all infected samples, the diagnostic sensitivity was 70.4 (95% CI=65.3–75.3)% for ELISA-BR and 91.6 (95% CI=88.2–94.4)% for ELISA-ID. For the ARQ/ARQ genotype (n=195), sensitivity was 66.2% for ELISA-BR and 90.8% for ELISA-ID, and for the ARQ/VRQ genotype (n=107), sensitivity was 81.3% for ELISA-BR and 98.1% for ELISA-ID. CONCLUSIONS: In this study, the ELISA-ID kit demonstrated a higher diagnostic sensitivity for detecting scrapie in samples of RLN from sheep carrying scrapie-susceptible PrP genotypes than the ELISA-BR kit at comparable diagnostic specificity. CLINICAL RELEVANCE: The diagnostic performance of the ELISA-ID kit using ovine RLN merits the consideration of including this assay in the national scrapie surveillance programme in New Zealand. [ABSTRACT FROM PUBLISHER]

Sixteen sheep and 18 cattle were followed up during 1 year to estimate the duration of immunity induced by inactivated bluetongue virus serotype 8 ( BTV-8) vaccines (sheep and cattle) and a bluetongue virus serotype 1 ( BTV-1) vaccine (cattle) under field conditions using cELISA and seroneutralization test ( SNT). Four sheep never seroconverted. Those that seroconverted were all seronegative by BTV-8 SNT at the date of last sampling [378 days post-vaccination (dpv)]. Eight sheep were still positive by competitive ELISA ( cELISA) 378 dpv. All the cattle seroconverted. At the end of the study, eight and 11 cattle were still positive by BTV-8 SNT and cELISA, respectively (335 dpv); and nine were still positive by BTV-1 SNT (301 dpv). [ABSTRACT FROM AUTHOR]

A serological survey to detect Schmallenberg virus ( SBV)-specific antibodies by ELISA was organized in the Belgian sheep population to study the seroprevalence at the end of the epidemic. One thousand eighty-two sheep samples which were collected from 83 herds all over Belgium between November 2011 and April 2012 were tested. The overall within-herd seroprevalence and the intraclass correlation coefficient were estimated at 84.31% (95% CI: 84.19-84.43) and 0.34, respectively. The overall between-herd seroprevalence was 98.03% (95% CI: 97.86-98.18). A spatial cluster analysis identified a cluster of six farms with significantly lower within-herd seroprevalence in the south of Belgium compared with the rest of the population ( P = 0.04). It was shown that seroprevalence was associated to flock density and that the latter explained the presence of the spatial cluster. Additionally, 142 goat samples from eight different herds were tested for SBV-specific antibodies. The within-herd seroprevalence in goats was estimated at 40.68% (95% CI: 23.57-60.4%). The results of the current study provided evidence that almost every Belgian sheep herd has been in contact with SBV during 2011 and should be taken into consideration as part of comprehensive SBV surveillance and control strategies. [ABSTRACT FROM AUTHOR]