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Simple Summary: Small ruminant lentiviruses (SRLVs) are responsible for a disease complex that includes a variety of clinical forms with a large degree of severity. The virus is highly variable, and 5 genotypes with 34 subgenotypes have been described so far. However, the application of different protocols for genotyping generated contradictory results with potential misclassification of some strains and/or identification of redundant new subgenotypes. To the best of our knowledge, no systematic review on the molecular characterization of SRLVs in sheep and goats is available. The present systematic review aims to provide an updated, in-depth, comprehensive overview of the phylogenesis of SRLVs. The systematic review was developed according to the PRISMA-P statement. Small ruminant lentiviruses (SRLVs) are responsible for chronic and progressive multisystemic clinical forms, which significantly reduce flocks' productivity and have a considerable economic impact on the small ruminant industry. Due to the increase in genetic analysis studies and the potential for misclassification of certain strains, owing to the high genetic variability of these viruses, a systematic review was deemed necessary. This review explores the types of matrices used for molecular detection and phylogenetic studies, the genomic regions selected as targets, and the software utilized for phylogenetic analysis, assessing the geographical distribution of identified genotypes and subgenotypes over time. A thorough comparison of the diagnostic approaches highlights the strengths and limitations of each method, identifying gaps that need to be addressed. Additionally, recombination events and compartmentalization are examined to provide an updated, detailed, and comprehensive overview of SRLV phylogenesis. [ABSTRACT FROM AUTHOR]

Ovine pulmonary adenocarcinoma (OPA) is an important viral-induced neoplasia in sheep caused by exogenous Jaagsiekte sheep retrovirus (exJSRV). Coinfection of exJSRV and Maedi-Visna virus (MVV) is reported in OPA cases, but its worldwide distribution and significance on lung pathology is not yet completely understood. This study aimed to investigate the MVV coinfection rate in 82 exJSRV-related OPA cases, and their pathological effects on lung parenchyma in slaughtered sheep in Transylvania (Romania). On gross examination, classical form of OPA was identified in 92.7%; no changes consisting with MVV interstitial pneumonia were identified in the included cases. The most common histological type of OPA was acinar (58.5%) and the myxoid growths were found in 18 cases. The exJSRV and MMV coinfection rate in examined sheep was 47.6% (39/82). The assessment of perineoplastic areas from coinfected animals, revealed interstitial lymphoplasmacytic infiltrates in all cases, lymphoid hyperplasia in 60.6% cases (20/33) and fibromuscular hyperplasia in 63.7% (21/33). This is the first report providing new data on distribution of OPA coexisting with MVV infection in slaughtered sheep in Romania. We consider that the OPA and MVV coinfection may play an important role on the severity of ovine chronic pulmonary diseases and further studies are needed to confirm this hypothesis. [ABSTRACT FROM AUTHOR]

Maedi-Visna is a slowly progressive infection of sheep that affects the respiratory and nervous systems and causes significant yield losses worldwide. This study was conducted to assess the seroprevalence of Maedi-Visna infection in sheep across several provinces in the Central Black Sea region of Türkiye, namely Samsun, Sinop, Ordu, Giresun, Amasya and Tokat. A total of 476 sheep serum samples were collected for further analysis. The presence of antibodies in the sera was determined by Ab ELISA. As a result of the study, 263 (55.25%) blood serum samples were positive for the presence of MVV antibodies. Seropositivity rates by province were as follows: Samsun 45%, Sinop 80%, Ordu 58.75%, Giresun 35%, Amasya 38.75%, Tokat 75%. Notably, our findings suggest a significantly high seroprevalence of Maedi-Visna infection in this region compared to other studies conducted in different parts of Türkiye This information is pivotal for understanding the extent of the infection in the sheep population of the Central Black Sea region and can contribute to the development of strategies for disease management and control. [ABSTRACT FROM AUTHOR]

Ovine pulmonary adenocarcinoma (OPA) is an important viral-induced neoplasia in sheep caused by exogenous Jaagsiekte sheep retrovirus (exJSRV). Coinfection of exJSRV and Maedi-Visna virus (MVV) is reported in OPA cases, but its worldwide distribution and significance on lung pathology is not yet completely understood. This study aimed to investigate the MVV coinfection rate in 82 exJSRV-related OPA cases, and their pathological effects on lung parenchyma in slaughtered sheep in Transylvania (Romania). On gross examination, classical form of OPA was identified in 92.7%; no changes consisting with MVV interstitial pneumonia were identified in the included cases. The most common histological type of OPA was acinar (58.5%) and the myxoid growths were found in 18 cases. The exJSRV and MMV coinfection rate in examined sheep was 47.6% (39/82). The assessment of perineoplastic areas from coinfected animals, revealed interstitial lymphoplasmacytic infiltrates in all cases, lymphoid hyperplasia in 60.6% cases (20/33) and fibromuscular hyperplasia in 63.7% (21/33). This is the first report providing new data on distribution of OPA coexisting with MVV infection in slaughtered sheep in Romania. We consider that the OPA and MVV coinfection may play an important role on the severity of ovine chronic pulmonary diseases and further studies are needed to confirm this hypothesis.

Background: Maedi-visna (MV) is a small ruminant lentiviral (SRLV) disease affecting sheep and goats, and causes pathological alterations in various organs including lungs, pulmonary lymph nodes, mammary glands, joints, and CNS. Aims: Present study was focused to detect the MV virus (MVV) nucleic acid and MVV p28 antigen in different organs of the spontaneously MVV affected sheep and goats. Methods: Total of 657 samples were collected from sheep and goats (169 blood, 136 lungs, 96 pulmonary lymph nodes, 74 brain, 54 mammary gland, 78 joints, and 50 spleen) and screened for MVV nucleic acid using nested PCR assay. Serum samples were screened for SRLV antibodies by cELISA. Immunolocalization of MVV was demonstrated by using the polyclonal antibody against p28 antigen by immunohistochemistry in lungs, lymph nodes, mammary glands, and joint tissues. Results: Out of 657 samples, 10.7% (70) were found positive for MVV. Among different organs, lungs showed highest positivity (25.7%) followed by mammary glands (14.8%), blood (9.5%), joint tissues (7.7%), brain (5.4%), and pulmonary lymph node (1.0%). SRLV antibodies were detected in 29.2% of the serum samples of both sheep and goats by cELISA. MVV p28 antigen immunostaining was observed in lungs, lymph nodes, mammary glands, and joint tissues. However, the presence of MVV p28 antigen could not be demonstrated in the brain tissues. Conclusion: The highest positivity of MVV in lung tissues indicated higher predilection of the virus in the pulmonary tissue. [ABSTRACT FROM AUTHOR]

Small ruminant lentiviruses (SRLVs) pose significant economic challenges to goat farming and have a detrimental impact on animal welfare. The objectives of this study were to deepen our comprehension of SRLV infections and their implications for small ruminant farming. Within the studied herd, the detected seroprevalence of SRLV was notably high at 91.92% (95.0% CI: 86.5%–97.3%). This finding strongly suggests the enduring presence of SRLV infection within the goat farm, spanning multiple years. Antibodies against SRLVs were detected across all selected age categories and breeds, irrespective of the presence or absence of clinical signs. The data gleaned from this study allow significant implications, raising concerns about the potential for future clinical outbreaks resulting from SRLV infections in eastern Romanian goat herds. Given these findings, the imperative for the continuous surveillance of SRLV infections becomes evident. Ongoing vigilance and monitoring are essential to mitigate the risk of disease transmission, minimise economic losses and safeguard the welfare of goats within the region.

Lentiviruses infect small ruminants and cause similar but different two significant diseases: Maedi-Visna in sheep and Caprine Arthritis Encephalitis in goats. In the current study, 91 of 413 adult sheep and goats from the Korça region tested positive for small ruminant lentiviruses. Furthermore, 11 of the 25 small ruminant herds have at least one positive animal for small ruminant lentiviruses. The overall observed herd prevalence was 44.0% (95% Confidence Interval (CI): 29-59) for both diseases, 38.6% (95% CI: 18.6-55.1) for Maedi-Visna in sheep, and 66.7% (95% CI: 43.1-90.2) for Caprine Arthritis Encephalitis in goats. The average observed prevalence rate ranges from 20% to 82.9% (95% CI: 12-89.2) within positive goat's herds, while within sheep-positive herds, it varies from 23.1% to 57.1% (95% CI: 11.7-70.4). There was a positive correlation between seroprevalence rate and animal species; goats seem to have an odd 2.36 (Odds Ratio (OR) 95% CI: 1.48-3.76) higher than sheep to test positive in ELISA. Other risk factors, such as farm size, indoor versus outdoor rearing, and close farm biosecurity, may play a role in disease transmission between and within small ruminant animals' herds. This is the first study on the prevalence of Maedi-Visna infection in sheep and one of the few published Caprine Arthritis Encephalitis studies in Albania. These findings support the presence of Small Ruminant Lentiviruses (SRLV) in the Korça district and emphasize the need for monitoring and controlling SRLV infection in sheep and goats. According to the study's conclusions, a yearly monitoring program is essential and must be developed in the future to keep the disease under control. This initiative aims to help owners understand SRLV and the need to raise seronegative animals. [ABSTRACT FROM AUTHOR]

Small ruminant lentiviruses (SRLVs) pose significant economic challenges to goat farming and have a detrimental impact on animal welfare. The objectives of this study were to deepen our comprehension of SRLV infections and their implications for small ruminant farming. Within the studied herd, the detected seroprevalence of SRLV was notably high at 91.92% (95.0% CI: 86.5%-97.3%). This finding strongly suggests the enduring presence of SRLV infection within the goat farm, spanning multiple years. Antibodies against SRLVs were detected across all selected age categories and breeds, irrespective of the presence or absence of clinical signs. The data gleaned from this study allow significant implications, raising concerns about the potential for future clinical outbreaks resulting from SRLV infections in eastern Romanian goat herds. Given these findings, the imperative for the continuous surveillance of SRLV infections becomes evident. Ongoing vigilance and monitoring are essential to mitigate the risk of disease transmission, minimise economic losses and safeguard the welfare of goats within the region. [ABSTRACT FROM AUTHOR]

Simple Summary: Maedi-visna is a globally distributed, viral, and incurable chronic disease of small ruminants, challenging the health and welfare of sheep and jeopardizing the sustainability of farms. Currently, the scarcity of representative, updated, and epidemiological data hinders the implementation of successful eradication programs. The objective of our study is to prospectively study the seroepidemiology of maedi-visna in intensively reared dairy sheep. For this reason, a total of 407 purebred Chios and Lacaune ewes from four farms were studied for two successive years, and blood samples were semiannually collected and tested using the ELISA test. Prevalence and incidence rates were found to have increased in all the studied farms, highlighting the importance of horizontal transmission of the virus within the farms. Various serological patterns were observed in the studied animals, namely, constantly seronegative, constantly seropositive, seroconverted, seroreverted, or animals with an intermittent presence of antibodies. The last two categories indicate a special immune response of infected animals which needs to be further investigated and considered for the diagnosis of MV and when designing eradication programs. The objective of this study is to prospectively evaluate the seroepidemiology of maedi-visna (MV) infections in intensively reared dairy sheep. A total of 407 purebred Chios and Lacaune ewes from four farms were surveyed for two consecutive years and were serologically tested semiannually with an indirect ELISA at pre-mating and pre-lambing. The farms' structure and management practices were similar and animal traits (age, breed, and production stage) were recorded. Based on the serological status, morbidity frequency measures were estimated, and ewes were categorized as constantly seronegative, constantly seropositive, seroconverted, seroreverted, or as animals with an intermittent presence of antibodies. During the study, period seroprevalence, incidence rate, and cumulative incidence were 84.8%, 33.6 new cases per 100 sheep-semesters, and 64.2%. Point-seroprevalence ranged from 48.5% to 96.0% among the studied farms and sampling occasions, and they increased by age. Increased morbidity frequency measures indicate the significance of horizontal transmission in intensive dairy sheep farms. A remarkable percentage of infected animals seroreverted (8.1%) or presented an intermittent presence of antibodies (10.3%) during the study, confirming the risk of misdiagnosis in cross-sectional studies and in the currently implemented testing and elimination programs. The serological patterns observed in our study need to be considered when studying MV epidemiology and for the designing of efficient MV elimination programs. [ABSTRACT FROM AUTHOR]

Small ruminant lentiviruses (SRLVs) affect sheep and goats worldwide. The major gene related to SRLV infections is the Transmembrane Protein Gene 154 (TMEM154). We estimated the haplotype frequencies of TMEM154 in the USA (USDA-ARS) and Brazil (Embrapa) Gene Banks by using two different SNP genotyping methodologies, FluidigmTM and KASPTM. We also genotyped the ZNF389_ss748775100 deletion variant in Brazilian flocks. A total of 1040 blood samples and 112 semen samples from 15 Brazilian breeds were genotyped with Fluidigm for the SNP ZNF389_ss748775100 and 12 TMEM154 SNPs. A total of 484 blood samples from the Santa Inês breed and 188 semen samples from 14 North American sheep breeds were genotyped with KASP for 6 TMEM154 SNPs. All the Brazilian samples had the "I/I" genotype for the ZNF389_ss748775100 mutation. There were 25 TMEM154 haplotypes distributed across the Brazilian breeds, and 4 haplotypes in the US breeds. Haplotypes associated with susceptibility were present in almost all breeds, which suggests that genetic testing can help to improve herd health and productivity by selecting non-susceptible animals as founders of the next generations. Fluidigm and KASP are reliable assays when compared with Beadchip arrays. Further studies are necessary to understand the unknown role of TMEM154 mutations, host–pathogen interaction and new genes associated with the clinical condition. [ABSTRACT FROM AUTHOR]

Maedi-visna is a multi-systemic disease of sheep caused by a non-oncogenic, exogenous retrovirus of the Lentiviridae subfamily. It is mainly transmitted through the ingestion of milk from infected sheep, although disease can be spread within flocks through direct contact and transmission can occur also in utero. Maedi usually begins insidiously and leads to a classical interstitial pneumonia. On postmortem examination, the lungs may be 2-4 times heavier than normal, due to decreased elasticity and fibrosis. Regional lymph nodes are enlarged with formation of lymphoid follicles with active germinal centers. Visna - the neurological form of the disease, is characterized by chronic and active meningoencephalomyelitis and chorioiditis with massive infiltrations of mononuclear cells around the blood vessels, microglial nodules formation and astrogliosis. Virus isolation is very specific but of variable sensitivity. The cytopathic effects are characteristic, consisting of the appearance of stellate cells and syncytia. The diagnostic methods currently used are based on the detection of either antibodies or the viral genome. The three most commonly tests used, are the PCR and RT-PCR, agar gel immunodiffusion test (AGID) and the enzyme-linked immunosorbent assay (ELISA). Western blot analysis and radio-immunoprecipitation are also performed, but only in specialized laboratories. No commercial vaccines are available to control infection, and to date, monitoring programs have proved to be the only effective tool in controlling this disease. [ABSTRACT FROM AUTHOR]

Simple Summary: Local breeds represent a precious reservoir of genetic diversity, crucial to adapting to environmental and climate changes and reacting to evolving diseases. In Sicily, four native dairy breeds, namely Valle del Belìce, Comisana, Barbaresca, and Pinzirita, have adapted to low-input farming systems and semiarid environments, having an essential role in producing high-quality milk and typical dairy products. Maedi-visna (MV) is one of the most important chronic diseases affecting the sheep sector worldwide, causing production losses. Different target genes play an important role in immunity and in genetic resilience to MV, such as TMEM154, TLR9, MYD88, and CCR5. A major host genetic component to sheep MV susceptibility was identified in the ovine TMEM154 gene. Animals with either of TMEM154 haplotypes that encode glutamate at position 35 (E35) of the protein are at higher risk of MV infection than those homozygous with lysine at position 35 (K35). In the tested Sicilian breeds, animals carrying the allele E35 showed a greater risk of being serologically positive. Comisana, Barbaresca, and Pinzirita breeds showed a good frequency of the protective allele K35, whilst a high frequency of risk allele was found in the Valle del Belìce breed, related to the selection strategies addressed to obtain a productive dairy sheep. Our results highlight the importance of the preservation of autochthonous breeds as a reservoir of natural resistance against infectious disease. Maedi-visna (MV) is a disease caused by small ruminant lentiviruses. It is included in the list of notifiable terrestrial animal diseases due to economic losses and animal welfare harm in the sheep sector. To date, control programs remain the onliest approach to avoiding infection. The allelic variant p.Glu35Lys (E35K) of the TMEM154 gene has been strongly associated with host vulnerability to MV illness. The present study aimed to investigate the association of TMEM154 E35K allele frequencies with MV susceptibility in native Sicilian sheep breeds. More than 400 animals from 14 local sheep were serologically tested and genotyped for the TMEM154 E35K polymorphism. The local breeds displayed different values of MV seroprevalence, with the lowest antibody prevalence in Barbaresca and Pinzirita breeds. TMEM154 protective allele (K35) was less frequent than the risk allele (E35) in Valle del Belìce breed, whereas the other three breeds showed a more balanced alleles distribution. A positive association between seroprevalence and genotype was found in the entire sample set. The risk of infection resulted in more than 3-fold times as high in sheep with EK and EE genotype compared to the KK genotype. Our data could be helpful in establishing selection breeding programs aimed at reducing MV infection in Sicilian sheep farming and encouraging the breeding of native breeds. [ABSTRACT FROM AUTHOR]

The results of previous studies of SRLV infections in wild ruminants suggest that wild ruminants may serve as virus reservoirs responsible for the infections of domestic small ruminants. It is possible that SRLVs circulate in free-ranging mouflons in Slovenia, but considering the results of previous studies in which SRLV infections were detected in mouflons, it is very likely that the detected seropositive animal is an accidental spillover host for SRLV. Keywords: small ruminant lentiviruses; SRLV; maedi-visna; caprine arthritis-encephalitis; chamois; mouflon; serology; ELISA; survey EN small ruminant lentiviruses SRLV maedi-visna caprine arthritis-encephalitis chamois mouflon serology ELISA survey N.PAG N.PAG 6 04/26/22 20220415 NES 220415 1. [Extracted from the article]

Aim: In this study, it was aimed to determine the presence of Maedi-Visna Virus (MVV) infection in sheep in Afyonkarahisar province serologically and to analyze the risk factors associated with MVV infection in the region. Materials and Methods: For this purpose, 248 serum samples were randomly collected from 22 sheep flocks considering the epidemiological sample size from the region between May 2016 and April 2018. Collected samples were tested with the ELISA kit for MVV specific antibodies. Potential MVV risk factors were evaluated statistically by univariate logistic regression analysis. Results: The seropositivity in the ensampled animals was found to be 5.65% (14/248), and it was 13.63% on the basis of flock (3/22). Seropositivity was determined to be 3.94% and 13.33% in males and females, respectively. On the basis of animals, there was a statistically significant relationship between the presence of goat in the flock and gender and seropositivity of the disease infection (p Conclusion: Flocks in which sheep with persistent MV infection with a viral disease which is characterized by slow progress followed by a gradual increase in severity and results in death leading to economic losses in the sheep sector are detected, should be monitored periodically for viral factors leading to economic losses. Considering the results of this study, it is thought that analyzing epidemiology of MV infection in flocks through regular monitoring and developing strategies for controlling it would be useful.

The objectives of this cross-sectional study were to detect the presence of small ruminant lentiviral infections in Kosovo and estimate the serological prevalence for the year of 2016 . A total of 5.272 sheep and 435 goats were tested using a commercially available indirect enzymelinked immunosorbent assay (ELISA) for Maedi-Visna/Caprine Arthritis-Encephalitis, giving an overall individual sero-prevalence in sheep of 34.8% (95% confidence interval 31.8% to 38.0%), and a flock prevalence of 85%, and in goats an overall individual sero-prevalence of 15.6% (95% confidence interval 7.2% to 25.6%) and flock prevalence of 35%. Sero-prevalence in sheep was higher in the South and West of Kosovo, whereas in goats was higher in the East and South. There were no statistically significant differences in sero-prevalence between sheep in different age groups

A serological survey was carried out to assess the frequency of leptospirosis, small ruminants lentivirus (SRLV), and brucellosis in small ruminant herds in the Recôncavo Baiano, State of Bahia, Brazil, from February to December 2017. In four goat herds, 125 animals were tested for SRLV and leptospirosis, while in five sheep herds, 378 animals were tested for leptospirosis, brucellosis, and SRLV. Regarding leptospirosis, MAT detected 80% of goats and 15.34% of sheep seroreactive. Reactivity was most frequent to serogroups Autumnalis and Grippotyphosa in goats and sheep, respectively. Regarding SRLV, 8.8% of goats and 0.79% of sheep were reactive. Search for anti-B. ovis antibodies revealed 0.52% reactivity. In sheep, three animals showed simultaneous seroreactivity for SRLV and leptospirosis, while one animal had a serological response for brucellosis and leptospirosis. In goats, simultaneous seroreactivity for SRLV and leptospirosis was observed in only one animal. Leptospirosis was the most frequent of the three infectious diseases in investigated herds.

The present study aimed to estimate the prevalence of antibodies against Brucella ovis-epididymitis, smooth-Brucella, leptospirosis, toxoplasmosis and Maedi-visna in sheep slaughtered in Minas Gerais, Brazil and to study their simultaneous occurrence, including caseous lymphadenitis, at sheep and flock levels. The study was conducted at a sheep slaughterhouse with Federal Inspection Service. Sera from 594 animals from 21 flocks were collected, in 2007. The agar gel immunodiffusion (AGID) was employed to detect anti-B. ovis and anti-Maedi Visna antibodies, whereas Rose Bengal (RB) and the 2-mercaptoethanol test (2ME) were used to test anti-smooth Brucella antibodies. For the detection of anti-Leptospira antibodies, sera were examined by microscopic agglutination test (MAT), while for the detection of IgG antibodies to Toxoplasma gondii ELISA was used. Prevalence of antibodies against smooth Brucella, B. ovis-epididimitis, Leptospira spp., toxoplasmosis and Maedi-Visna found in sheep from Minas Gerais was 0.00%, 24.04%, 25.96%, 10.46% and 3.08%, respectively; whereas the seroprevalence in flocks was 0.00%, 80.95%, 90.48%, 71.43% and 23.81%, respectively. Moreover, when data on antibodies anti-Corynebacterium pseudotuberculosis, previously obtained, were included, about 60% of the flocks showed animals that were exposed to four or more of the studied agents. However, only 25.47% of the sheep exhibited simultaneously antibodies against more than one pathogen. Thus, data from the present study on sheep slaughtered in Minas Gerais, Brazil, showed no antibodies to smooth-Brucella and a low frequency of antibodies anti-Maedi Visna lentivirus, and a high and widespread seroprevalence of B. ovis, Leptospira spp., and T. gondii among animals and flocks.

The production performance of a livestock herd can be compromised by various diseases. In sheep, maedi-visna (MV) infections, which have a chronic nature, are caused by a virus (maedi-visna virus (MVV)) belonging to the genus Lentivirus of the Retroviridae family. The infection can cause significant economic losses and has considerable health impacts on sheep breeding in production systems. Due to the importance of this disease in sheep flocks, the objective was to conduct a serosurvey of MVV in the states of Ceará (CE), Rio Grande do Norte (RN), Paraíba (PB), and Sergipe (SE). A total of, 3332 serum samples were collected in the four states, 1011 in CE, 931 in RN, 459 in PB, and 931 in SE, with the number of samples proportional to the actual herd size of each state. The samples were analyzed using the agar gel microimmunodiffusion test (AGID). Reproducers were revaluated using western blotting (WB). In addition to this serological survey, we administered an investigative questionnaire to identify possible risk factors that facilitate the introduction and spread of diseases (location, category, sex, breed type, creation system, production, herd size, and association with goats). After analysis of the sera using the AGID test, there was zero prevalence. Revaluating breeders by WB revealed a 5.5% prevalence of MV in the four states studied, with prevalences for the states of CE, RN, Paraiba, and SE of 2.3% (2/88), 10.4% (8/77), 3.6% (1/28), and 4.7% (2/42), respectively, corresponding to 13 breeders containing antibodies to the virus. These findings emphasized that the choice of diagnostic tests is extremely important for the early detection of seropositive animals and thus the prevention of the spread of the virus among herds in the region.

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Background: Maedi-Visna (MV) is a progressive lymphoproliferative viral disease that affects multiple organs of small ruminants, including sheep and goats. The disease occurs primarily in the lung tissue and causes interstitial pneumonia. Aims: The aim of present study was to investigate the prevalence of ovine MV infection in Iranian sheep population through macroscopic, histopathological, serological, and molecular assays, as well as transmission electron microscopy (TEM). Methods: Lung and blood samples of one-hundred female sheep (≤ 2 years old) referred to the Kermanshah slaughterhouse with respiratory symptoms were collected for histopathological and molecular evaluations. Corresponding serum samples were also collected for serological examination. Results: Histopathological study showed the Maedi-like pulmonary lesions in 85% of the affected lungs, which included the interstitial pneumonia, smooth muscle hypertrophy of alveolar septa and around the blood vessels, interstitial lymphoplasmacytic infiltration and lymphofollicular hyperplasia. Specific antibodies against MV virus were detected in 7% of serum samples. Long terminal repeat (LTR) region of MV provirus was amplified in three (3%) DNA samples, extracted from the suspected lungs. Sequencing analysis of polymerase chain reaction (PCR)-positive samples confirmed the presence of MV provirus in the genome. No amplification was observed, neither in the DNA samples extracted from the blood samples of suspected sheep nor the control group. Transmission electron microscopy also confirmed the presence of MV virions inside the cytoplasmic membrane of MV-infected macrophages. Conclusion: Although histopathology can provide a preliminary estimation of Maedi in populations, definitive diagnosis of the disease needs to be approved by more sensitive techniques such as serological examinations and molecular analysis. [ABSTRACT FROM AUTHOR]

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Small ruminant lentiviruses (SRLVs), i.e., CAEV and MVV, cause insidious infections with life-long persistence and a slowly progressive disease, impairing both animal welfare and productivity in affected herds. The complex diagnosis of SRLVs currently combines serological methods including whole-virus and peptide-based ELISAs and Immunoblot. To improve the current diagnostic protocol, we analyzed 290 sera of animals originating from different European countries in parallel with three commercial screening ELISAs, Immunoblot as a confirmatory assay and five SU5 peptide ELISAs for genotype differentiation. A newly developed nested real-time PCR was carried out for the detection and genotype differentiation of the virus. Using a heat-map display of the combined results, the drawbacks of the current techniques were graphically visualized and quantified. The immunoblot and the SU5-ELISAs exhibited either unsatisfactory sensitivity or insufficient reliability in the differentiation of the causative viral genotype, respectively. The new truth standard was the concordance of the results of two out of three screening ELISAs and the PCR results for serologically false negative samples along with genotype differentiation. Whole-virus antigen-based ELISA showed the highest sensitivity (92.2%) and specificity (98.9%) among the screening tests, whereas PCR exhibited a sensitivity of 75%.

Aim: The small ruminant lentiviruses are known to cause maedi-visna (MV) and caprine arthritis - encephalitis in sheep and goats, typically affecting joints, udder, lungs, and the central nervous system. The diagnosis usually involves serology, clinical signs, immunohistochemistry, and polymerase chain reaction (PCR). In the present study, the histopathologically positive pneumonia cases of MV were confirmed by PCR in lung tissue probably for the first time in India. Materials and Methods: A total of 888 lungs of adult sheep, aged between 2 and 5 years, were screened during slaughter, of which 121 were found to have pneumonic lesions. The tissues from each pneumonic lung including associated lymph nodes were collected in 10% neutral buffered formalin for histopathology. The frozen tissues of the same were also collected and stored at -20°C for PCR confirmation. Results: Three of 121 cases of pneumonic lungs of sheep revealed gross and histopathological lesions suggestive of maedi or ovine progressive pneumonia infection. These 3 cases were further confirmed by PCR technique that amplified 291-base pair DNA in the long terminal repeat sequence of MV provirus. Conclusion: This study suggests the low occurrence of MV virus (MVV) infection in India in naturally affected sheep based on pathomorphological lesions and using the molecular tool of PCR detection of the virus in tissues. Further, a combination of pathomorphology or/and PCR testing might be optimal for detecting the animals infected with MVV.

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.

Copyright of Kafkas Universitesi Veteriner Fakultesi Dergisi is the property of University of Kafkas, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Respiratory diseases of sheep produce a relevant economic impact in ovine industry. • In lambs, the principal adverse effects are related to mortality and poor quality of lambs produced. • In adults, financial losses are related to reduced production of affected sheep, need for early culling and death. • These are multi-faceted diseases and prevention is based on management practices. • Appropriate health measures that improve animal immune response also will help control of the diseases. Objectives of the present article are to review the financial significance of respiratory diseases and to indicate their relevance within the health management of sheep. In lambs, the principal adverse effects of the diseases are related to mortality, reduced carcass quality, veterinary expenses, decrease of average daily bodyweight gain and poor quality of lambs produced. In adult animals, financial losses are related to reduced production of affected sheep, need for early culling and death. Given the multi-faceted nature of these diseases, management practices (e.g., housing improvements, implementation of biosecurity provisions) need to be considered for their prevention; as environmental conditions also play a role in development of these diseases, they should be taken into account. Appropriate health measures (e.g., vaccinations) that improve animal immune response also will help control of the diseases. [ABSTRACT FROM AUTHOR]

Small Ruminant Lentiviruses (SRLV) are highly prevalent retroviruses with significant genetic diversity and antigenic heterogeneity that cause a progressive wasting disease of sheep called Maedi-visna. This work provides a systematic review and meta-analysis of the last 40 years (1981–2020) of scientific publications on SRLV individual and flock prevalence. Fifty-eight publications and 314 studies were included. Most articles used a single diagnostic test to estimate prevalence (77.6%), whereas articles using three or more tests were scarce (6.9%). Serological tests are more frequently used than direct methods and ELISA has progressively replaced AGID over the last decades. SRLV infection in sheep is widespread across the world, with Europe showing the highest individual prevalence (40.9%) and being the geographical area in which most studies have been performed. Africa, Asia, and North America show values between 16.7% to 21.8% at the individual level. South and Central America show the lowest individual SRLV prevalence (1.7%). There was a strong positive correlation between individual and flock prevalence (ρ = 0.728; p ≤ 0.001). Despite the global importance of small ruminants, the coverage of knowledge on SRLV prevalence is patchy and inconsistent. There is a lack of a gold standard method and a defined sampling strategy among countries and continents.

Maedi-visna (MV) and Caprine Arthritis-Encephalitis (CAE) are economically important viral diseases that infect sheep and goats. The aim of this study is to determine the seroprevalence of MVV and CAEV on sheep and goats raised in Siirt region by using the ELISA method. Blood samples were collected to non-anticoagulant tubes from the jugular veins of a population of 465 small ruminants consisting of 182 sheep and 283 goats selected from different districts of Siirt Province. The samples were centrifuged for 10 minutes at 3000 rpm and the serum were transferred to Eppendorf tubes, which were stored at -20°C until further analysis. Commercial kits (IDEXX MVV / CAEV p28 Ab screening, IDEXX, USA) were used for the detection of Anti-MVV/CAEV antibodies. All samples were found to be seronegative in terms of Anti-MVV/CAEV antibodies. As a result of this study conducted in the Siirt province, MVV and CAEV infections were not detected in the studied population. Given that the infections exist with varying seroprevalence levels in different regions of Turkey, however, it might be worthwhile to investigate the infection status in Siirt province by including larger herds in future studies. [ABSTRACT FROM AUTHOR]

The study was conducted with the objectives of determining the possible causes of pneumonia in the sheep and to characterize the microscopic lesions of concurrent infection of Maedi-Visna with lung worms and other infectious pneumonia. Detailed gross and microscopic examinations were employed on 35 Maedi-Visna seropositive sheep. Out of 35 sheep slaughtered and examined for gross lesions on their lungs, lung worms, fibrinous adhesions, and mottling on the cranioventral lobes were observed with decreasing order of frequency. Histopathologically, the pneumonic lungs (n = 35) revealed Maedi (100%), Maedi-Verminous pneumonia complex (28.57%, n = 10), Maedi bronchopneumonia complex (17.14%, n = 6), and Maedi-pulmonary adenomatosis complex (2.86%, n = 1). The occurrence of high proportion of concurrent infection of Maedi-Visna with lung worms and bacteria strongly suggest synergy of the pathogens and the presence of several stress factors including wind draft, unusually chilly weather and poor management in the area that are known to predispose the improved sheep breeds to respiratory disease complex. On top of culling by slaughter of Maedi-Visna seropositive sheep, regular deworming, redesigning the house, and vaccination of sheep with the available vaccines should be carried out timely at least to reduce the severity of Maedi-Visna induced loss. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Saúde e Produção Animal (RBSPA) is the property of Revista Brasileira de Saude e Producao Animal (RBSPA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

RESUMO: Lentivírus de pequenos ruminantes (LV) é o termo genérico utilizado para designar os vírus da artrite encefalite caprina e Maedi-Visna, os quais pertencem à família Retroviridae, subfamília Orthoretrovirinae, gênero Lentivirus. Tais vírus infectam caprinos e ovinos, causando enfermidades de curso lento com lesões inflamatórias, crônicas e degenerativas que podem atingir vários órgãos, provocando caquexia e morte. Os animais infectados eliminam o vírus sobretudo por meio de secreções e excreções e transmitem-no especialmente em situações de estreito contato. Não há tratamento até o momento. O controle é baseado na criação segregada, no manejo e no sacrifício dos positivos. Esse agente infeccioso já foi relatado em várias partes do mundo, sendo responsável por perdas econômicas significativas. Por o agente ter sido verificado em vários estados do Brasil e por não existirem dados soroepidemiológicos nas mesorregiões sudeste e sudoeste piauiense, esta pesquisa teve por objetivo realizar inquérito sorológico para investigar a ocorrência de anticorpos para o LV em ovinos e caprinos nas microrregiões do Alto Médio Canindé, Picos e Floriano, no Piauí. Para tanto, foram coletadas 1.280 e 1.360 amostras de soro caprino e ovino, respectivamente, oriundos de 20 municípios, distribuídos nas três microrregiões, sendo o número de amostras proporcional ao rebanho efetivo de cada município. As amostras de soro foram analisadas utilizando o teste de imunodifusão em gel de agarose (IDGA). Nenhum dos soros pesquisados reagiu positivamente, constatando-se soroprevalência nula. Ressalta-se a importância da implantação de um rigoroso programa de controle para que se possa evitar a introdução e/ou a disseminação desse agente infeccioso nessas microrregiões.

Small ruminant lentiviruses (SRLVs) cause maedi-visna disease in sheep and are prevalent in Iran and Germany. The association of the transmembrane protein 154 (TMEM154) variants with SRLV infection has been previously identified by a genome-wide association (GWAS) approach and subsequent analyses, and validated in some US, German, and Turkish sheep flocks. We aimed at evaluating these findings for the first time in Iranian, and in some more German sheep flocks/breeds. Also, we aimed at comparing the SRLV susceptibility in Iranian and German sheep based on the frequency of the TMEM154 E35 allele. About 800 blood samples were collected from 21 Iranian and German sheep flocks/breeds for different purposes: (1) The association of TMEM154 E35K with SRLV infection status was tested in four sheep breeds and found to be significant in Kermani, Merinoland, and Brown Hair. (2) The usefulness of the TMEM154 E35 frequency for predicting SRLV susceptibility was evaluated by regression analysis, combining data from this study and some already published data. Results showed a significant association between E35 frequency and SRLV prevalence. (3) SRLV susceptibility was compared based on E35 frequency in Iranian and German sheep. Altogether, findings of this study provide valuable information on SRLV susceptibility, using TMEM154 E35, in Iranian and German sheep.

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the prevalence of small ruminant lentivirus, i.e. Maedi-Visna and caprine arthritis encephalitis virus infections in sheep and goat populations were investigated through epizootiological serosurveillance in the Aegean region located in western Türkiye in 2018. A total of 1,840 serum samples (595 goats, 1,245 sheep) were collected from 92 villages in the region and examined by indirect ELISA. Thirty-nine goat and 304 sheep sera were found positive for small ruminant lentivirus antibodies. The prevalence was 24.42% in sheep and 6.55% in goats. An average of 18.64% was found in small ruminants in the Aegean region. The prevalence of small ruminant lentiviruses was found to be higher in Pirlak and Pirlak hybrid sheep and in Saanen and Saanen hybrid goats (P < 0.05). The prevalence was found to increase with age, as it was higher in animals older than 48 months than in the age groups of 0–24 or 25–48 months (P < 0.05). Moreover, the small ruminant lentivirus prevalence was higher in sheep than in goats (P < 0.0001). With the epizootiological approach, this study is expected to contribute to the control and prevention of small ruminant lentivirus infections. [ABSTRACT FROM AUTHOR]

Multisystemic disease caused by Small Ruminant Lentiviruses (SRLV) in sheep and goats leads to production losses, to the detriment of animal health and welfare. This, together with the lack of treatments, has triggered interest in exploring different strategies of immunization to control the widely spread SRLV infection and, also, to provide a useful model for HIV vaccines. These strategies involve inactivated whole virus, subunit vaccines, DNA encoding viral proteins in the presence or absence of plasmids encoding immunological adjuvants and naturally or artificially attenuated viruses. In this review, we revisit, comprehensively, the immunization strategies against SRLV and analyze this double edged tool individually, as it may contribute to either controlling or enhancing virus replication and/or disease.

RESUMO: Maedi-Visna (MV) é uma enfermidade causada por lentivírus de pequenos ruminantes com evolução crônica e em grande parte dos casos sinais clínicos inaparentes. O diagnóstico da doença é baseado em sinais clínicos e dados epidemiológicos, sendo a imunodifusão em gel de ágar (IDGA) o método padrão para a detecção sorológica de anticorpos contra o lentivírus. Sabendo que o estado do Tocantins possui potencial para o desenvolvimento da ovinocultura e que grande parte dos produtores de Colinas do Tocantins, no referido estado, possui interesse em estabelecer criação racional, esta pesquisa teve por objetivo a realização de um estudo acerca da soroprevalência da doença. Foram coletadas 369 amostras de sangue de ovinos, independentemente de raça, sexo e idade, de diferentes propriedades rurais do município para diagnóstico de MV utilizando a técnica de IDGA. Após as análises laboratoriais, para avaliação dos resultados no tocante às categorias, foi utilizado o teste exato de Fisher e também foi calculado o odds ratio , com intervalo de confiança de 95% para verificação da idade como possível fator de risco ou de proteção. Constatou-se que 6 animais (1,62%) se apresentaram positivos no IDGA. Diante desses resultados, foi possível concluir que a frequência de ovinos soropositivos no município é baixa.

RESUMO: A soroprevalência da infecção por lentivírus de pequenos ruminantes (LVPR) foi determinada em amostras de soros sanguíneos de caprinos e ovinos de aptidão cárnea provenientes de abatedouros de dez municípios do estado de Pernambuco, Brasil. O diagnóstico sorológico ocorreu por meio da imunodifusão em gel de agarose (micro-IDGA) com antígenos dos vírus artrite encefalite caprina (CAE)/Maedi-Visna. Entre as 369 amostras de caprinos, 7(1,89%) (0,8-3,9%) eram soropositivas, e, entre as 383 de ovinos, 1 (0,26%) (0,0-1,4%) estava infectada. Os 7 caprinos soropositivos procederam dos abatedouros públicos dos municípios de Gravatá (n=2), Sertânia (n=4) e Timbaúba (n=1), e o ovino soropositivo veio do abatedouro público de Serra Talhada. A soroprevalência da infecção por LVPR em pequenos ruminantes oriundos de abatedouros do estado de Pernambuco, de 1,06% (8/752), é considerada baixa.

Maedi-Visna in sheep and CAEV in goats are diseases caused by lentiviruses with very similar antigenic characteristics. This diseases are very important for the animal husbandry because of the economical losses they cause (reduced milk yield, lower body weight, deaths, therapy expenses). The results in this article, represents the first serological confirmation for the existence of this diseases in Macedonia. Investigations showed high percent of seroprevalence in the examined herds. The seroprevalence ranges from 60.3% for Maedi-Visna to 55.8% for CAEV. Despite the presence of clinical signs of the disease, the mortality is low, witch is related to the presence of the causal agent in the field i.e. the endemic character of this diseases.

Maedi-Visna (MV) and Caprine Arthritis Encephalitis (CAE) are diseases of sheep and goats. They are caused by lentiviruses which belong to Retroviridae family. The usual way of contamination is the cohabitation of animals. Diseases are widespread in many countries as: Norway, France, Italy, Spain, USA, Panama, Cyprus, Greece, and Japan. The present paper aimed to present the MVV and CAEV antibodies seroprevalence in samples collected in different sheep and goats farms from Romania. There were collected blood samples from the following counties: ClujNapoca, Ilfov, Constanta, Galati, Giurgiu, Braila, Arges, Bacau, Dâmbovita, Ialomita, Suceava, Calarasi, Buzau, Vrancea, and Vaslui. In order to determine the presence of antibodies, the samples were analysed by indirect ELISA, using commercial kits. There were registered negative results in only four counties and the possible existence of viruses in farms cannot be excluded. In order to confirm and strengthen the preliminary results, we recommend to analyses the samples by molecular biology techniques. Also, national authorities could establish a program of surveillance and diagnosis at national level, able to provide a more complete picture of the SRLVs prevalence in each county. [ABSTRACT FROM AUTHOR]

Maedi-visna virus (MVV) is an ovine lentivirus that is widespread in many countries worldwide. Both clinical and subclinical MVV infections cause substantial economic losses. MVV infection in live sheep is usually diagnosed serologically, with antibody-positive sheep being regarded as infected. There have been few reports of maedi-visna in China, with no detailed epidemic analysis of MVV infection in ovine herds. In order to investigate the seroprevalence and spatial distribution of maedi-visna among ovine flocks in China, a total of 672 serum samples were collected from different ovine flocks in 12 regions (provinces, autonomous regions or municipalities) of China in 2011, and serum antibody levels were determined using a commercial ELISA Kit. This study represents the first investigation of the seroepidemiology of maedi-visna in China, indicating a circulation of MMV among sheep.