Genetic identification, clinical and epidemiological aspects of an equine infectious anemia outbreak in the Rio Grande do Sul state, Brazil / Identificação genética, aspectos clínicos e epidemiológicos de um foco de anemia infecciosa equina no estado do Rio Grande do Sul, Brasil

The study describes the genetic identification, clinical, and epidemiological characteristics of an outbreak of equine infectious anemia occurring in the state of Rio Grande do Sul, Brazil. Three animals kept in the periurban region of Uruguaiana city tested positive for the AGID test. The serology was performed as a requirement for transit. None of the animals showed clinical signs of infection, one animal was necropsied, and the others were stolen. In the post-mortem examination, no macroscopic changes were observed, and microscopically, discrete hemosiderosis was detected in fragments of the liver and spleen. Amplifying and sequencing a proviral DNA fragment in blood, spleen, and mesenteric lymph node samples confirmed EIAV infection. Phylogenetic analysis of the first sequenced EIAV sample from the Rio Grande do Sul State indicates a high similarity with other Brazilian samples. Results confirmed the viral presence in the state's herds and described epidemiological and virological characteristics of EIA that contribute to the maintenance and dissemination of the virus in herds.

O estudo descreve a identificação genética, as características clínicas e epidemiológicas de um foco de Anemia Infecciosa Equina que ocorreu no Estado do Rio Grande do Sul, Brasil. Três equinos criados na região periurbana da cidade de Uruguaiana testaram positivos pela prova sorológica de IDGA. O exame foi realizado como requerimento para trânsito dos animais. Nenhum animal apresentava sinais clínicos da infecção, um cavalo foi necropsiado e os outros dois foram roubados. Na necropsia não obsevou-se nenhuma alteração e microscopicamente foi constatada hemosiderose discreta em fragmento do fígado e baço. A infecção foi confirmada pela amplificação e sequenciamento de um segmento do genoma pró-viral do EIAV de amostras do sangue, baço e linfonodo mesentérico. A análise filogenética do primeiro EIAV sequenciado no Estado do RS indica similaridade com outras amostras que circulam no Brasil. O resultado confirma a presença do vírus no rebanho equino da região e descreve características clínicas e epidemiológicas que contribuem para a manutenção e disseminação do vírus no rebanho.

Blue tongue virus in dairy cattle in the Southern region of Minas Gerais, Brazil - serological survey

Background: Blue tongue (BT) is a noncontagious viral disease transmitted by hematophagous arthropods, especially of the genus Culicoides. The economic impact of the disease is related not only to deaths in sheep herds but also to the possible correlation of virus infection with the development of other diseases, such as pneumonia, abortion and movement problems. The economic losses caused by Blue Tongue are linked to restrictions on the import and export of animals and their genetic material and to the reproductive disorders associated with this disease. In addition, the fact that cattle take the role of reservoir, combined with the care by other countries with outbreaks of infection and biological contamination of their products, hinders trade in Mercosul, United States and Europe. Cattle are affected by Blue Tongue Virus in endemic areas and in some epidemic areas, but the development of clinical disease is rare. The clinical signs, when evident, range from reproductive losses, such as embryonic death, abortion, fetal malformation, temporary sterility, infertility in bulls, stillbirths and the birth of weak animals. The objective of this study was to determine the epidemiological aspects of Blue Tongue Virus (BTV) infection in dairy cattle in the Lavras region, state of Minas Gerais, Brazil. Materials, Methods & Results: A cross-sectional study was conducted to evaluate the frequency of cattle and herds seropositive for Blue Tongue in the southern region of Minas Gerais. In this study, 54 dairy farms were visited. A total of 586 serum samples were collected from cows of reproductive age. Sampling was random, and serum samples were collected from lactating cows over 24 months of age by puncture of the jugular vein and/or coccidian vein. The samples were transported and stored at the Setor de Patologia Veterinária, at the Universidade Federal de Lavras (SPV-UFLA), where they were centrifuged, and the serum aliquots were obtained, transferred to microtubes and kept at -20°C until the serological tests were performed. The samples were tested with the agarose gel immunodiffusion test (AGID) for anti-blue tongue virus antibodies. The AGID test is more practical and is the main method used to identify Blue Tongue Virus seroprevalence in different ruminant species. They are considered important tools for epidemiological surveillance of the disease. A prevalence of 83.28% was observed among animals that were seropositive for Blue Tongue Virus (488/586; IC 95% = 80.0 - 86.21). In addition, 100% (54/54; IC 95% = 93.4 - 100.0) of the farms had at least 1 positive animal, with rates ranging from 45.45% to 100% within the herds and where 22.22% of the farms had rates of 100% of the animals being positive. Discussion: Blue Tongue is a disease known to affect domestic and wild ruminants in Brazil. However, there is a lack of more precise information about its epidemiology and occurrence in the country and of joint efforts of researchers, producers and the government to understand in detail both the biology of vectors and the viral biology of Blue Tongue Virus in Brazil. This is the first record of detection of anti-blue tongue virus antibodies in cattle in the southern region of Minas Gerais. The results suggest that Blue Tongue Virus is present in cattle in the study area.

Padronização de um ELISA indireto a partir da utilização de uma proteína de superfície do vírus da anemia infecciosa equina como antígeno para o diagnóstico dessa enfermidade / Standardization of an indirect ELISA using a surface protein of the equine infectious anemia virus as an antigen for the diagnosis of this disease

A anemia infecciosa equina é uma importante enfermidade que acomete os equídeos em todo o mundo, se apresentando de forma aguda, crônica e assintomática causando grandes prejuízos para a economia tanto para criadores que vivem do trabalho desses animais quantos aos criadores que investem no melhoramento das raças, impedindo o acesso ao mercado tanto nacional quanto internacional. O Ministério da Agricultura, Pecuária e Abastecimento considera o IDGA como teste oficial para diagnóstico dessa enfermidade, porém essa técnica é demorada e muita vez acaba sendo subjetiva, dependendo da experiencia particular de cada Laboratorista. Além de não conseguir detectar animais no início da infecção. Logo, a necessidade de se buscar novas técnicas como o ELISA indireto que aperfeiçoem o tempo de análise dos resultados, facilita a automação e obtém resultados confiáveis. O estudo realizado teve como objetivo padronizar uma técnica de ELISA indireto utilizando uma proteína de envelope viral GP90 como antígeno para diagnóstico da anemia infecciosa equina. Avaliando o desempenho do teste a partir da sensibilidade, especificidade e valores preditivos positivo e negativo. Os valores obtidos foram: 91,11%, 93,33%, 91,11% e 93,33% respectivamente. Concluiu-se que o teste apresenta bom desempenho, além da possibilidade de detectar amimais positivos no início da infecção.

Equine infectious anemia is an important disease that affects horses all over the world, presenting in an acute, chronic and asymptomatic way, causing great damage to the economy, both for breeders who live off the work of these animals and for breeders who invest in the improvement of breeds, preventing access to both national and international markets. The Ministry of Agriculture, Livestock and Food Supply considers AGID to be the official test for diagnosing this disease, but this technique takes time and often ends up being subjective, depending on the particular experience of each laboratory worker. In addition to not being able to detect animals at the beginning of the infection. Therefore, the need to seek new techniques such as indirect ELISA that improve the time of analysis of results, facilitate automation and obtain reliable results. The aim of this study was to standardize an indirect ELISA technique using a GP90 viral envelope protein as an antigen for the diagnosis of equine infectious anemia. Evaluating test performance based on sensitivity, specificity and positive and negative predictive values. The values obtained were 91.11%, 93.33%, 91.11 and 93.33 respectively. It was concluded that the test performs well, in addition to the possibility of detecting positive animals at the beginning of the infection.

Risk factors and detection of brucella ovis in naturally infected rams and ewes / Fatores de risco e detecção de brucella ovis em carneiros e ovelhas naturalmente infectados

The objective of this study was to verify the occurrence of ovine brucellosis using Agar Gel Immunodiffusion (AGID) and Polymerase Chain Reaction (PCR) techniques, as well as to identify the main risk factors associated with infection in sheep flocks belonging to municipalities in the microregion from Teresina, PI, Brazil. A total of 100 urine and blood samples were collected from sheep aged 6 months or older. The urine samples were submitted to conventional PCR and the blood samples were examined by the AGID technique. Of the 100 blood samples, 17 (17%) were reactive to the AGID test. In conventional PCR of 100 urine samples, six (6%) were positive. Risk factors associated to infection by B. ovis included the rearing system (OR=0.19), feed management (OR=0.05), presence of dystotic births (OR=4.50), miscarriages (OR=3.75) and source of water offered to the animals (OR=0.19). Thus, it was concluded that it is possible to detect the occurrence of animals with ovine brucellosis since PCR is a reliable method to confirm infection. Furthermore, there are risk factors associated to infection by B. ovis in the municipalities studied.

Objetivou-se verificar a ocorrência da brucelose ovina através das técnicas de Imunodifusão em Gel de Ágar (IDGA) e Reação em Cadeia da Polimerase (PCR), bem como identificar os principais fatores de risco associados à infecção nos rebanhos ovinos pertencentes a municípios da microrregião de Teresina, PI, Brasil. Foram colhidas 100 amostras de urina e de sangue de ovinos com idade superior ou igual a seis meses. As amostras de urina foram submetidas a PCR convencional e as amostras de sangue à técnica de IDGA. Das 100 amostras de sangue 17 (17%) foram reagentes ao teste de IDGA. Já na PCR convencional das 100 amostras de urina, seis (6%) foram positivas. Ressalta-se que três animais foram positivos em ambos os testes. Como fatores associados à infecção por B. ovis, observou-se o tipo de sistema de criação (OR=0,19), o manejo alimentar (OR=0,05), presença de partos distócicos (OR=4,50), abortamentos (OR=3,75) e a fonte de água fornecida aos animais (OR=0,19). Assim, conclui-se que foi possível detectar a ocorrência de animais com brucelose ovina, uma vez que a PCR é um método confirmatório. Além disso, há fatores de risco associados à infecção por B. ovis nos municípios estudados.

Risk factors and detection of brucella ovis in naturally infected rams and ewes / Fatores de risco e detecção de brucella ovis em carneiros e ovelhas naturalmente infectados

The objective of this study was to verify the occurrence of ovine brucellosis using Agar Gel Immunodiffusion (AGID) and Polymerase Chain Reaction (PCR) techniques, as well as to identify the main risk factors associated with infection in sheep flocks belonging to municipalities in the microregion from Teresina, PI, Brazil. A total of 100 urine and blood samples were collected from sheep aged 6 months or older. The urine samples were submitted to conventional PCR and the blood samples were examined by the AGID technique. Of the 100 blood samples, 17 (17%) were reactive to the AGID test. In conventional PCR of 100 urine samples, six (6%) were positive. Risk factors associated to infection by B. ovis included the rearing system (OR=0.19), feed management (OR=0.05), presence of dystotic births (OR=4.50), miscarriages (OR=3.75) and source of water offered to the animals (OR=0.19). Thus, it was concluded that it is possible to detect the occurrence of animals with ovine brucellosis since PCR is a reliable method to confirm infection. Furthermore, there are risk factors associated to infection by B. ovis in the municipalities studied.(AU)

Objetivou-se verificar a ocorrência da brucelose ovina através das técnicas de Imunodifusão em Gel de Ágar (IDGA) e Reação em Cadeia da Polimerase (PCR), bem como identificar os principais fatores de risco associados à infecção nos rebanhos ovinos pertencentes a municípios da microrregião de Teresina, PI, Brasil. Foram colhidas 100 amostras de urina e de sangue de ovinos com idade superior ou igual a seis meses. As amostras de urina foram submetidas a PCR convencional e as amostras de sangue à técnica de IDGA. Das 100 amostras de sangue 17 (17%) foram reagentes ao teste de IDGA. Já na PCR convencional das 100 amostras de urina, seis (6%) foram positivas. Ressalta-se que três animais foram positivos em ambos os testes. Como fatores associados à infecção por B. ovis, observou-se o tipo de sistema de criação (OR=0,19), o manejo alimentar (OR=0,05), presença de partos distócicos (OR=4,50), abortamentos (OR=3,75) e a fonte de água fornecida aos animais (OR=0,19). Assim, conclui-se que foi possível detectar a ocorrência de animais com brucelose ovina, uma vez que a PCR é um método confirmatório. Além disso, há fatores de risco associados à infecção por B. ovis nos municípios estudados.(AU)

Risk factors and detection of brucella ovis in naturally infected rams and ewes / Fatores de risco e detecção de brucella ovis em carneiros e ovelhas naturalmente infectados

The objective of this study was to verify the occurrence of ovine brucellosis using Agar Gel Immunodiffusion (AGID) and Polymerase Chain Reaction (PCR) techniques, as well as to identify the main risk factors associated with infection in sheep flocks belonging to municipalities in the microregion from Teresina, PI, Brazil. A total of 100 urine and blood samples were collected from sheep aged 6 months or older. The urine samples were submitted to conventional PCR and the blood samples were examined by the AGID technique. Of the 100 blood samples, 17 (17%) were reactive to the AGID test. In conventional PCR of 100 urine samples, six (6%) were positive. Risk factors associated to infection by B. ovis included the rearing system (OR=0.19), feed management (OR=0.05), presence of dystotic births (OR=4.50), miscarriages (OR=3.75) and source of water offered to the animals (OR=0.19). Thus, it was concluded that it is possible to detect the occurrence of animals with ovine brucellosis since PCR is a reliable method to confirm infection. Furthermore, there are risk factors associated to infection by B. ovis in the municipalities studied.

Objetivou-se verificar a ocorrência da brucelose ovina através das técnicas de Imunodifusão em Gel de Ágar (IDGA) e Reação em Cadeia da Polimerase (PCR), bem como identificar os principais fatores de risco associados à infecção nos rebanhos ovinos pertencentes a municípios da microrregião de Teresina, PI, Brasil. Foram colhidas 100 amostras de urina e de sangue de ovinos com idade superior ou igual a seis meses. As amostras de urina foram submetidas a PCR convencional e as amostras de sangue à técnica de IDGA. Das 100 amostras de sangue 17 (17%) foram reagentes ao teste de IDGA. Já na PCR convencional das 100 amostras de urina, seis (6%) foram positivas. Ressalta-se que três animais foram positivos em ambos os testes. Como fatores associados à infecção por B. ovis, observou-se o tipo de sistema de criação (OR=0,19), o manejo alimentar (OR=0,05), presença de partos distócicos (OR=4,50), abortamentos (OR=3,75) e a fonte de água fornecida aos animais (OR=0,19). Assim, conclui-se que foi possível detectar a ocorrência de animais com brucelose ovina, uma vez que a PCR é um método confirmatório. Além disso, há fatores de risco associados à infecção por B. ovis nos municípios estudados.

Intercurrence between bovine leukosis virus infection and mastitis in dairy cattle / Intercorrência entre a infecção pelo vírus da leucose bovina e a mastite em bovinos leiteiros

There are several factors affecting global milk production leading to severe economic losses. Mastitis and leukosis are highly prevalent diseases especially in Brazilian cattle herds. The present study aimed to evaluate the correlation between mastitis and the bovine leukemia virus (BLV) infection in naturally infected cows belonging to dairy herds in Minas Gerais State. Additionally, the prevalence of both diseases, pathogens causing mastitis, and their association with BLV infection and persistent lymphocytosis were evaluated. The prevalence of BLV was determined using the agar gel immunodiffusion test (AGID) in 1,392 lactating cows from ten dairy herds. From the AGID results, 240 cows were selected and divided into two experimental groups: A case group composed of 160 BLV-positive cows (BLV-P) and the control group of 80 BLV-negative cows (BLV-N). Based on serological and leucocytic evaluations, the animals were classified into three subgroups: BLV-N, BLV-P without persistent lymphocytosis (BLV-PWPL), and BLV-positive with persistent lymphocytosis (BLV-PPL). The California Mastitis Test (CMT) was performed on days 0 (D0) and 60 (D60) in the subgroups and the milk from CMT-positive glands were analyzed. BLV infection was present in 100% of herds, with an overall prevalence of 80.9% in cows older than 24 months. Among BLV-P animals, 74% were classified as BLV-PWPL and 26% as BLV-PPL. Coagulase-negative Staphylococcus (73.30%), Corynebacterium spp. (12.04%), Streptococcus agalactiae (8.90%), and Staphylococcus aureus (5.76%) were predominant (61.41%). There were no statistical differences among the scores of clinical or subclinical mastitis with the pathogen type (contagious or environmental) in the BLV-PWPL or BLV-PPL subgroups. However, BLV-P animals showed higher CMT scores than BLV-N animals, suggesting a higher predisposition to subclinical mastitis in cows affected by leukosis.(AU)

Tendo em vista a relevância econômica e social da produção de leite e a ampla ocorrência da leucose e mastite em rebanhos brasileiros, foi proposto o presente estudo com o objetivo de avaliar a correlação entre a mastite e a infecção pelo vírus da leucose bovina em vacas leiteiras naturalmente infectadas de 10 rebanhos leiteiros da região sul do estado de Minas Gerais. Além disso, foi avaliada a prevalência de ambas as doenças e dos patógenos causadores de mastite e sua associação com infecção por BLV e linfocitose persistente. A prevalência do VLB foi avaliada pelo teste de imunodifusão em gel de ágar (IDGA) em 1.392 vacas em lactação nos rebanhos estudados. De acordo com os resultados do IDGA, 240 vacas foram selecionadas para compor dois grupos experimentais: 1-caso: composto por 160 vacas BLV positivas (BLV-P) e 2-controle: composto por 80 vacas BLV negativas (BLV-N). De acordo com as avaliações sorológicas e leucocitárias, os animais foram classificados em três subgrupos: BLV-N; BLV-P sem linfocitose persistente (BLV-PWPL) e BLV positivos com linfocitose persistente (BLV-PPL). O California Mastitis Test (CMT) e a cultura do leite das glândulas CMT positivas foram realizados nos dias 0 (D0) e 60 (D60). A leucose foi detectada em 100% dos rebanhos com prevalência média de 80,9%. Entre os animais BLV-P, 74% foram classificados como BLV-PWPL e 26% como BLV-PPL. Staphylococcus coagulase negativos (73,30%), seguido por Corynebacterium spp. (12,04%), Streptococcus agalactiae (8,90%) e Staphylococcus aureus (5,76%) foram os agentes predominantes. Não houve diferença estatística entre os escores de mastite clínica ou subclínica e nem entre o tipo de patógeno (contagioso ou ambiental) nos subgrupos de animais BLV-PWPL ou BLV-PPL relacionados ao BLV-N. No entanto, animais BLV-P apresentaram escores mais elevados no CMT em relação aos animais BLV-N, sugerindo maior predisposição à mastite subclínica em vacas com leucose.(AU)

Western Blot no imunodiagnóstico de lentivírus de pequenos ruminantes / Western Blot in immunodiagnosis of small ruminant lentivirus

Background: Small ruminant lentivirus (SRLV) belong to genus Lentivirus, family Retroviridae. These viruses causecaprine arthritis encephalitis (CAE) and maedi visna (MV), infectious diseases that cause economic, production, and reproductive losses. There are no effective treatments or vaccines for these diseases. Thus, early detection via serology hasgreat importance for control of SRLV. Therefore, the objective of this review is to demonstrate the potential of the westernblot (WB) test as an immunodiagnostic test for SRLV.Review: In general, immunodiagnosis of SRLV is performed via agar gel immunodiffusion (AGID) and indirect enzymelinked immunosorbent assay (ELISA), which can detect antibodies in several different biological samples but is used preferably with serum and blood plasma. However, WB has demonstrated efficacy in the early diagnosis of immunoglobulinsagainst SRLV, presenting higher sensitivity and specificity than the serological tests usually used, because this techniquecan detect antibodies at a dilution as much as 256 times greater than that of AGID and 32 times greater than that of ELISA.SRLV infection and consequent immunological activation result in the induction of cellular and humoral responses. Additionally, around the third week, production of antibodies directed mainly toward viral capsid proteins (p25 and p28)occurs. After the fifth week, production of immunoglobulins directed toward other viral proteins occurs. Because of thepersistence of SRLV infection, serology is considered to be the most practical means to diagnosis. Each serological testhas a percentage specificity and distinct sensitivity, as well as advantages and disadvantages in its applicability. It shouldbe noted that there is no gold standard test for diagnosis of SRLV infection. Moreover, SRLV are characterized by escapemechanisms such as genetic diversity, mutagenic potential, viral intermittence...

Is bluetongue virus a risk factor for reproductive failure in tropical hair sheep in Brazil?

Background: Bluetongue is a vector-borne viral disease transmitted by midges from the genus Culicoides. The disease caninfect most of the ruminant and camelid species, but the severe disease is most often seen in european wool and muttonsheep breeds. In this sense, there is a gap in the knowledge on BTV infection in hair sheep breeds from tropical zones.Thus, this study aimed at establishing whether exposure to BTV is a risk factor for reproductive failure in Santa Inês ewes,a hair sheep breed, reared under tropical conditions in Brazil.Materials, Methods & Results: A retrospective cross-sectional study was carried out in sheep farms in São Paulo state,Brazil, after the rainy season. Serum samples from 110 Santa Inês ewes with a history of reproductive disorders, in the last6 months, which were included: abortion, premature birth, stillbirth, retention of placenta, infertility, estrus repetition, fetalmalformation, weak lamb birth and neonatal death were collected. The presence of antibodies against BTV was assessedby agar gel immunodiffusion method (AGID). Serology to the infectious agents Brucela ovis, Lepstopira spp., Toxoplasmagondii, Neospora caninum and Campylobacter sp. were also assessed. Bivariate associations between the outcome andindividual explanatory variables were assessed using the Fisher’s exact test. Abortion was the most common reproductive disorder (53%; 74/139) observed, followed by estrus repetition (12%; 17/139) and infertility (11%; 15/139). Otherdisorders related to the conceptus totaled nearly one fourth of the reported disorders. A total of 20% (22/110) of the eweswere seropositive to BTV. A higher frequency of BTV seropositive than BTV seronegative ewes with a history of abortionwas found. Also, abortion with seroreactivity to BTV was tested for prevalence ratio that showed 1.38 [95% CI 1.10-1.74;P = 0.030]. With regards to the abortion involvement of other infectious diseases associated with the seropositive ewes to...

Is bluetongue virus a risk factor for reproductive failure in tropical hair sheep in Brazil?

Background: Bluetongue is a vector-borne viral disease transmitted by midges from the genus Culicoides. The disease caninfect most of the ruminant and camelid species, but the severe disease is most often seen in european wool and muttonsheep breeds. In this sense, there is a gap in the knowledge on BTV infection in hair sheep breeds from tropical zones.Thus, this study aimed at establishing whether exposure to BTV is a risk factor for reproductive failure in Santa Inês ewes,a hair sheep breed, reared under tropical conditions in Brazil.Materials, Methods & Results: A retrospective cross-sectional study was carried out in sheep farms in São Paulo state,Brazil, after the rainy season. Serum samples from 110 Santa Inês ewes with a history of reproductive disorders, in the last6 months, which were included: abortion, premature birth, stillbirth, retention of placenta, infertility, estrus repetition, fetalmalformation, weak lamb birth and neonatal death were collected. The presence of antibodies against BTV was assessedby agar gel immunodiffusion method (AGID). Serology to the infectious agents Brucela ovis, Lepstopira spp., Toxoplasmagondii, Neospora caninum and Campylobacter sp. were also assessed. Bivariate associations between the outcome andindividual explanatory variables were assessed using the Fishers exact test. Abortion was the most common reproductive disorder (53%; 74/139) observed, followed by estrus repetition (12%; 17/139) and infertility (11%; 15/139). Otherdisorders related to the conceptus totaled nearly one fourth of the reported disorders. A total of 20% (22/110) of the eweswere seropositive to BTV. A higher frequency of BTV seropositive than BTV seronegative ewes with a history of abortionwas found. Also, abortion with seroreactivity to BTV was tested for prevalence ratio that showed 1.38 [95% CI 1.10-1.74;P = 0.030]. With regards to the abortion involvement of other infectious diseases associated with the seropositive ewes to...(AU)

Western Blot no imunodiagnóstico de lentivírus de pequenos ruminantes / Western Blot in immunodiagnosis of small ruminant lentivirus

Background: Small ruminant lentivirus (SRLV) belong to genus Lentivirus, family Retroviridae. These viruses causecaprine arthritis encephalitis (CAE) and maedi visna (MV), infectious diseases that cause economic, production, and reproductive losses. There are no effective treatments or vaccines for these diseases. Thus, early detection via serology hasgreat importance for control of SRLV. Therefore, the objective of this review is to demonstrate the potential of the westernblot (WB) test as an immunodiagnostic test for SRLV.Review: In general, immunodiagnosis of SRLV is performed via agar gel immunodiffusion (AGID) and indirect enzymelinked immunosorbent assay (ELISA), which can detect antibodies in several different biological samples but is used preferably with serum and blood plasma. However, WB has demonstrated efficacy in the early diagnosis of immunoglobulinsagainst SRLV, presenting higher sensitivity and specificity than the serological tests usually used, because this techniquecan detect antibodies at a dilution as much as 256 times greater than that of AGID and 32 times greater than that of ELISA.SRLV infection and consequent immunological activation result in the induction of cellular and humoral responses. Additionally, around the third week, production of antibodies directed mainly toward viral capsid proteins (p25 and p28)occurs. After the fifth week, production of immunoglobulins directed toward other viral proteins occurs. Because of thepersistence of SRLV infection, serology is considered to be the most practical means to diagnosis. Each serological testhas a percentage specificity and distinct sensitivity, as well as advantages and disadvantages in its applicability. It shouldbe noted that there is no gold standard test for diagnosis of SRLV infection. Moreover, SRLV are characterized by escapemechanisms such as genetic diversity, mutagenic potential, viral intermittence...(AU)

Economic impact and epidemiological aspects of subclinical mastitis and caprine arthritis-encephalitis in the semiarid northeastern region of Brazil / Impacto econômico e aspectos epidemiológicos da mastite e artrite encefalite caprina na região semiárida do Nordeste Brasileiro

Dairy activity in the semi-arid region has gained prominence due to its profit potential; however, there are still sanitary problems that result in significant economic impact. Thus, this study aimed to assess the economic impact and to conduct an epidemiological study of caprine arthritis-encephalitis (CAE) and subclinical mastitis in dairy goat herds of the semi-arid northeastern region of Brazil. The study proceeded with the collection of blood (n = 351) and milk samples (n = 321) from 15 rural properties with up to 50 animals, risk factor assessment, economic profile analysis, and georeferencing of the properties. The blood serum obtained was subjected to the AGID test. The milk samples were cultured on blood agar, and the reading was performed 24 hours after incubation. Overall, 3.4% of the animals were seropositive for CAE, and 15.8% were diagnosed with subclinical mastitis. 71.95% of the positive animals belonged to properties with a semi-intensive rearing system, weekly cleaning of the facilities, and no pre- or post-dipping. Subclinical mastitis caused by the main agent Staphylococcus spp. was associated with the breed type of the animals, highlighting two risk factors: purebred animals (OR = 12.52) and the milking performed close the soil (OR = 18.07). A reduction of up to 35.34% was observed in the income of dairy properties, constituting a considerable economic impact. Due to these sanitary problems, the economic impact demonstrates the need for a sanitary management program focused on these infirmities.

A atividade leiteira na região semiárida vem ganhando expressividade devido seu potencial lucrativo, no entanto, ainda existem problemas sanitários que ocasionam de grande impacto econômico. Assim, objetivou-se dimensionar o impacto econômico e realizar o estudo epidemiológico da artrite encefalite caprina (CAE) e mastite subclínica, nos rebanhos caprinos leiteiros do semiárido nordestino. A pesquisa seguiu-se com a coleta das amostras de sangue (n=351) e leite (n= 321), ava-liação dos fatores de risco, análise do perfil econômico das propriedades e georreferenciamento. O soro sanguíneo obtido foi submetido ao teste de IDGA. As amostras de leite foram semeadas em ágar sangue e a leitura realizada 24 horas após incuba-ção. No total, 3,4%, dos animais foram soropositivos para CAE e 15,8% diagnosticados com mastite subclínica. 71,95% dos animais positivos pertenciam a propriedades com sistema de criação semi-intensivo, limpeza das instalações semanalmente e sem realização de pré e pós dipping. A mastite subclínica causada pelo principal agente Staphylococcus spp. mostrou-se asso-ciada ao padrão racial dos animais, sendo observado dois fatores de risco: padrão racial puro (OR = 12,52) e ordenha no solo (OR = 18,07). A redução nas receitas das propriedades leiteiras foi de até 35,34%, portanto, um relevante impacto econômico. Pode-se constatar a circulação do vírus da CAE nas propriedades rurais visitadas, além da presença de patógenos causadores da mastite com importância na área da saúde pública. O impacto econômico gerado em função da presença desses proble-mas sanitários demonstra a necessidade da implantação de um programa de manejo sanitário com foco nessas enfermidades.

First study of Brucella ovis antibodies in purebred sheep flocks in the State of Parana, Brazil / [Primeiro estudo de anticorpos para Brucella ovis em rebanhos de ovinos puros de Origem, no estado do Paraná, Brasil]

Brucella ovis, a non-zoonotic species, is the etiological agent of ovine brucellosis, an infectious disease of clinical or subclinical occurrence in sheep flocks. Until then, there is no serological study of anti-Brucella ovis antibodies in purebred sheep herds. This study aimed to determine the presence of anti-Brucella ovis antibodies in purebred sheep flocks with breeding purposes from Parana State. Blood samples from 728 animals, of which 563 were females and 165 males, between 8 and 56 months of age from the six major sheep producing mesoregions of Parana, were submitted to detection of anti-Brucella ovis antibodies by the Agar Gel Immunodiffusion technique using an antigen from the bacteria Brucella ovis (Reo 198). The results indicate the presence of this disease in purebred sheep from Parana State in a low occurrence of 0.27% (2/728). The only two positive animals were rams, Santa Inês breed, from the same flock in the East Center region of Parana, without clinical disease. In conclusion, Brucella ovis is present in purebred sheep in Parana State, Brazil, and this low occurrence may have occurred due to rigorous breeding systems that may contribute to reduce the transmission of this disease.(AU)

Brucella ovis, espécie não zoonótica, é o agente etiológico da brucelose ovina, doença infecciosa de ocorrência clínica ou subclínica. Atualmente, não existe estudo sorológico de anticorpos anti-Brucella ovis em rebanhos de ovinos puros de origem. Este estudo teve como objetivo determinar a presença de anticorpos anti-Brucella ovis em rebanhos ovinos de raça pura de origem, com fins reprodutivos do estado do Paraná. Amostras de sangue de 728 animais, sendo 563 fêmeas e 165 machos, entre oito e 56 meses de idade, pertencentes a seis principais mesorregiões produtoras de ovinos no Paraná, foram submetidas à detecção de anticorpos anti-Brucella ovis pela técnica de imunodifusão em ágar gel usando-se um antígeno da bactéria Brucella ovis (Reo 198). Os resultados indicam a presença da doença em ovinos puros de origem do estado do Paraná em baixa ocorrência de 0,27% (2/728). Os dois únicos animais positivos foram reprodutores da raça Santa Inês, do mesmo rebanho da região Centro Leste do Paraná, sem manifestação clínica. Em conclusão, Brucella ovis está presente em ovinos puros de origem no estado do Paraná, e essa baixa ocorrência pode ter ocorrido devido a sistemas rigorosos de criação, que podem contribuir para a redução da transmissão dessa doença.(AU)

True prevalence and spatial distribution of equine infectious anemia virus (EIAV) in horses from northeast region of Brazil

Equine infectious anemia (EIA) is a viral infection, caused by a lentivirus of the Retroviridae family, Orthoretrovirinael subfamily and its occurrence generates significant economic losses due to culling of positive animals as a measure of infection control. The objective of this work was to determine the prevalence of horses positive for equine infectious anemia virus (EIAV) and to identify the occurrence of areas with higher densities of cases in the states of Paraíba (PB), Pernambuco (PE), Rio Grande do Norte (RN) and Ceará (CE), Northeast region of Brazil, during the rainy (May and June) and dry (October and November) periods of 2017 and 2018. Serum samples from 6,566 horses from the states of PB, PE, RN and CE, Brazil, provided by the Laboratório Veterinária Diagnóstico - Ltda., were used. Serological diagnosis of EIA was performed using indirect enzyme-linked immunosorbent assay (ELISA) as a screening test and agar gel immunodiffusion test (AGID) as a confirmatory test. The apparent prevalence was obtained by dividing the number of seroreactive animals by the total number of animals, while the true prevalence was estimated by adjusting the apparent prevalence, considering the sensitivity (100%) and specificity (98.6%) of the diagnostic protocol used. For the construction of Kernel estimates, the Quartic function was used. In the dry season, of the 1,564 animals sampled, 28 were serologically positive, of which 19 belonged to the state of Ceará, 7 to Paraíba and 2 to Rio Grande do Norte. In 2018, it was observed that, during the rainy season, 26 of the 1,635 horses were seroreactive, with 19 cases resulting from Ceará, 4 from Paraíba and 3 from Pernambuco. In the dry season, 32 of the 1,526 animals were seroreactive to EIAV, of which 26 were from Ceará, 3 from Paraíba, 1 from Rio Grande do Norte and 2 from Pernambuco. In the dry period of 2017, the CE had a real prevalence of 1.22% (95% CI = 0.05 - 2.99%). In 2018, during the rainy season, prevalences of 0.03% (95% CI = 0 - 1.18%) were identified in CE and 1.69% (95% CI = 0 - 8.38%) in PE. Regarding the 2018 dry period, a prevalence of 1.32% (95% CI = 0.26 - 2.84%) was found in the state of CE. In both dry and rainy periods of 2017, the presence of spatial clusters of animals positive for EIA was observed, mainly in the border areas among the states of CE, PE, PB and RN. In 2018, there was a variation in the distribution of areas with higher densities of cases between the rainy and dry periods. The state of CE had the highest prevalence of positive animals and the presence of areas with higher densities of EIA cases in both climatic periods, in the years 2017 and 2018. In some municipalities of the CE, important sporting events of agglomeration of animals take place, which can favor the transmission of EIAV by facilitating the contact of infected and susceptible animals. Population density may be a factor associated with the higher prevalence observed in this region, as it has the second largest herd among the states studied. Higher densities indirectly contribute to the occurrence of infectious diseases, as they favor the contact of infected and susceptible animals. The occurrence of higher densities of cases in the border areas of the states of PE, RN, CE, and PB may be related to the greater movement of animals in these regions, favoring the indirect contact of infected horses with susceptible ones. The observed results demonstrate the circulation of the EIAV in four states in the Northeast region of Brazil.(AU)

Economic impact and epidemiological aspects of subclinical mastitis and caprine arthritis-encephalitis in the semiarid northeastern region of Brazil / Impacto econômico e aspectos epidemiológicos da mastite e artrite encefalite caprina na região semiárida do Nordeste Brasileiro

Dairy activity in the semi-arid region has gained prominence due to its profit potential; however, there are still sanitary problems that result in significant economic impact. Thus, this study aimed to assess the economic impact and to conduct an epidemiological study of caprine arthritis-encephalitis (CAE) and subclinical mastitis in dairy goat herds of the semi-arid northeastern region of Brazil. The study proceeded with the collection of blood (n = 351) and milk samples (n = 321) from 15 rural properties with up to 50 animals, risk factor assessment, economic profile analysis, and georeferencing of the properties. The blood serum obtained was subjected to the AGID test. The milk samples were cultured on blood agar, and the reading was performed 24 hours after incubation. Overall, 3.4% of the animals were seropositive for CAE, and 15.8% were diagnosed with subclinical mastitis. 71.95% of the positive animals belonged to properties with a semi-intensive rearing system, weekly cleaning of the facilities, and no pre- or post-dipping. Subclinical mastitis caused by the main agent Staphylococcus spp. was associated with the breed type of the animals, highlighting two risk factors: purebred animals (OR = 12.52) and the milking performed close the soil (OR = 18.07). A reduction of up to 35.34% was observed in the income of dairy properties, constituting a considerable economic impact. Due to these sanitary problems, the economic impact demonstrates the need for a sanitary management program focused on these infirmities.(AU)

A atividade leiteira na região semiárida vem ganhando expressividade devido seu potencial lucrativo, no entanto, ainda existem problemas sanitários que ocasionam de grande impacto econômico. Assim, objetivou-se dimensionar o impacto econômico e realizar o estudo epidemiológico da artrite encefalite caprina (CAE) e mastite subclínica, nos rebanhos caprinos leiteiros do semiárido nordestino. A pesquisa seguiu-se com a coleta das amostras de sangue (n=351) e leite (n= 321), ava-liação dos fatores de risco, análise do perfil econômico das propriedades e georreferenciamento. O soro sanguíneo obtido foi submetido ao teste de IDGA. As amostras de leite foram semeadas em ágar sangue e a leitura realizada 24 horas após incuba-ção. No total, 3,4%, dos animais foram soropositivos para CAE e 15,8% diagnosticados com mastite subclínica. 71,95% dos animais positivos pertenciam a propriedades com sistema de criação semi-intensivo, limpeza das instalações semanalmente e sem realização de pré e pós dipping. A mastite subclínica causada pelo principal agente Staphylococcus spp. mostrou-se asso-ciada ao padrão racial dos animais, sendo observado dois fatores de risco: padrão racial puro (OR = 12,52) e ordenha no solo (OR = 18,07). A redução nas receitas das propriedades leiteiras foi de até 35,34%, portanto, um relevante impacto econômico. Pode-se constatar a circulação do vírus da CAE nas propriedades rurais visitadas, além da presença de patógenos causadores da mastite com importância na área da saúde pública. O impacto econômico gerado em função da presença desses proble-mas sanitários demonstra a necessidade da implantação de um programa de manejo sanitário com foco nessas enfermidades.(AU)

Non-specific reactions caused by vaccination in agar gel immunodiffusion for diagnosis of equine infectious anemia / Reações inespecíficas provocadas por vacinação na imunodifusão em gel de ágar para diagnósticodaanemia infecciosa equina

Equine infectious anemia (EIA) is one of the most important diseases from the health and economic point of view for equidae breeding, as it does not have treatment and vaccines. The Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA) instituted mandatory sanitary measures that include the official diagnosis by the agar gel immunodiffusion (AGID) test and sacrifice of seropositive animals to control this disease. Seventy-two seronegative equines, challenged with different vaccines, were used to verify the occurrence of non-specific reactions in the AGID techniques. Five serological controls were performed one week after vaccination, at seven-day intervals. The results indicated that the use of vaccines in equines in a period that precedes the performance of laboratory tests for the diagnosis of EIA does not induce seroconversion. However, 11.11% of the equines vaccinated against influenza, encephalomyelitis, equine rhinopneumonitis, and tetanus, and 15.38% of those vaccinated against leptospirosis had non-specific negative reactions to AGID. In this study, there was a non-specific line in the AGID for EIA described by Ordinance No. 84/1992 by MAPA but already mentioned in the Normative Instruction 55 of 26 November 2018.

Anemia Infecciosa Equina é uma das enfermidades mais importantes sob o ponto de vista sanitário e econômico para a equideocultura, por não possuir tratamento e vacinas. Para controle desta doença, o Ministério da Agricultura, Pecuária e Abastecimento (MAPA) instituiu medidas sanitárias obrigatórias em todo território nacional que incluem o diagnóstico e sacrifício dos animais soropositivos. Para verificar a ocorrência de reações inespecíficas na técnica de IDGA utilizou-se 72 equinos soronegativos, desafiados com diferentes vacinas. Uma semana após a vacinação, realizou-se cinco controles sorológicos, em intervalos de sete dias. Os resultados indicaram que o uso de vacinas em equinos em período que antecede a realização de exames laboratoriais para diagnóstico de AIE, não induz a soroconversão. Entretanto, 11,11% dos equinos vacinados contra influenza, encefalomielite, rinopneumonite equina e tétano, e 15,38% dos que foram vacinados contra leptospirose apresentaram reações negativas inespecíficas ao IDGA. Neste estudo, verificou-se uma linha inespecífica no IDGA para AIE.

Non-specific reactions caused by vaccination in agar gel immunodiffusion for diagnosis of equine infectious anemia / Reações inespecíficas provocadas por vacinação na imunodifusão em gel de ágar para diagnósticodaanemia infecciosa equina

Equine infectious anemia (EIA) is one of the most important diseases from the health and economic point of view for equidae breeding, as it does not have treatment and vaccines. The Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA) instituted mandatory sanitary measures that include the official diagnosis by the agar gel immunodiffusion (AGID) test and sacrifice of seropositive animals to control this disease. Seventy-two seronegative equines, challenged with different vaccines, were used to verify the occurrence of non-specific reactions in the AGID techniques. Five serological controls were performed one week after vaccination, at seven-day intervals. The results indicated that the use of vaccines in equines in a period that precedes the performance of laboratory tests for the diagnosis of EIA does not induce seroconversion. However, 11.11% of the equines vaccinated against influenza, encephalomyelitis, equine rhinopneumonitis, and tetanus, and 15.38% of those vaccinated against leptospirosis had non-specific negative reactions to AGID. In this study, there was a non-specific line in the AGID for EIA described by Ordinance No. 84/1992 by MAPA but already mentioned in the Normative Instruction 55 of 26 November 2018.(AU)

Anemia Infecciosa Equina é uma das enfermidades mais importantes sob o ponto de vista sanitário e econômico para a equideocultura, por não possuir tratamento e vacinas. Para controle desta doença, o Ministério da Agricultura, Pecuária e Abastecimento (MAPA) instituiu medidas sanitárias obrigatórias em todo território nacional que incluem o diagnóstico e sacrifício dos animais soropositivos. Para verificar a ocorrência de reações inespecíficas na técnica de IDGA utilizou-se 72 equinos soronegativos, desafiados com diferentes vacinas. Uma semana após a vacinação, realizou-se cinco controles sorológicos, em intervalos de sete dias. Os resultados indicaram que o uso de vacinas em equinos em período que antecede a realização de exames laboratoriais para diagnóstico de AIE, não induz a soroconversão. Entretanto, 11,11% dos equinos vacinados contra influenza, encefalomielite, rinopneumonite equina e tétano, e 15,38% dos que foram vacinados contra leptospirose apresentaram reações negativas inespecíficas ao IDGA. Neste estudo, verificou-se uma linha inespecífica no IDGA para AIE.(AU)

Detection of bluetongue virus antibodies in sheep from Paraná, Brazil / Detecção de anticorpos para o vírus da língua azul em ovinos do estado do Paraná, Brasil

Bluetongue (BT) is an infectious and non-contagious disease caused by bluetongue virus (BTV) belonging to the genus Orbivirus. It is transmitted by a hematophagous vector, Culicoides sp., to ruminants, particularly to sheep, which are most susceptible to this disease. The main serological tests are agar gel immunodiffusion (AGID), which is recommended by the World Organization for Animal Health (OIE), and the competitive enzyme-linked immunosorbent assay (cELISA), which has the advantage of no cross-reaction with other orbiviruses. The aim was to compare the results of these two tests by conducting them on sera collected from sheep in the state of Paraná, Brazil. From March to October 2017, serum samples were collected from 270 sheep from 10 farms in six mesoregions of Paraná. The samples were subjected to AGID and cELISA to detect antibodies against BTV. Based on the test results, we classified the sheep as low, moderate, and high occurrence. The results demonstrated that 64.81% (175/270) of the sheep were seropositive through the cELISA test, showing a high occurrence, and 41.11% (111/270) were seropositive through the AGID test, indicating a moderate occurrence. The concordance between the tests was moderate (0.51) as determined by the Kappa coefficient. Among the studied farms, 90% (9/10) presented at least one seropositive sheep, and the number of animals tested positive by the cELISA test was higher than those by the AGID test. Favorable climate, which favors the presence and multiplication of the culicoid vector and the occurrence of infection, was the biggest predominant factor responsible for the obtained results. The low occurrence in farms with milder climate suggest that the presence of antibodies also occurs due to the low pathogenicity of circulating serotypes in the different mesoregions studied. It is concluded that BTV infection is present in the sheep herds in Paraná, and the occurrence...

A língua azul (LA) é uma enfermidade infecciosa e não contagiosa causada por um vírus (VLA) do gênero Orbivirus, transmitida por vetores hematófagos Culicoides sp., aos ruminantes sobretudo aos ovinos, espécie mais susceptível. Os principais testes sorológicos utilizados são a Imunodifusão em Gél de Ágar (IDGA), preconizada pela OIE, e o teste Imunoensaio Enzimático Competitivo (ELISAc), sendo que este tem como vantagem não ocorrer reação cruzada contra outros orbivírus. O objetivo do trabalho foi detectar a presença de anticorpos contra o VLA em ovinos no estado do Paraná através dos testes diagnósticos IDGA e ELISAc. Durante os meses de março a outubro de 2017, colheu-se sangue de 270 ovinos, em 10 propriedades localizadas em seis mesorregiões paranaenses. As amostras foram submetidas aos testes de IDGA e ELISAc para detecção de anticorpos contra o VLA. Baseado nos resultados classificaram-se os rebanhos como baixa, moderada ou elevada ocorrência. Os resultados demonstraram elevada ocorrência através do teste de ELISAc, que apresentou 64,81% (175/270) de ovinos positivos, e moderada ocorrência através do IDGA, com 41,11% (111/270) de ovinos soropositivos. A concordância obtida entre os testes foi moderada (0,51) através do coeficiente Kappa. O número de ovinos reagentes no exame de ELISAc foi maior que o teste de IDGA em todas as propriedades positivas, demonstrando ser superior. O clima propício foi um dos fatores favoráveis para as ocorrências observadas, pois favorece a presença e multiplicação do vetor Culicoide e a ocorrência da infecção. A baixa ocorrência nas propriedades com clima mais ameno sugere que a presença de anticorpos provavelmente ocorra também pela baixa patogenicidade dos sorotipos circulantes nas diferentes mesorregiões estudadas. Conclui-se que há infecção de VLA no rebanho ovino paranaense, e a detecção de anticorpos para o VLA foi moderada, através do teste de IDGA, e elevada, através do teste ELISAc.

Indirect ELISA (iELISA) standardization for the diagnosis of bovine enzootic leukosis / Padronização de um ELISA indireto (iELISA) para diagnóstico da leucose enzoótica bovina

Enzootic bovine leukosis (EBL) is an infectious disease caused by bovine leukemia virus (BLV) that affects cattle worldwide. Agar gel immunodiffusion (AGID) was the reference test for EBL diagnosis for many years, but enzyme-linked immunosorbent assay (ELISA) showed higher sensitivity, was faster to perform, and resulted in an objective reading. However, the importation of ELISA kits is lengthy and expensive, and currently, no AGID kits are available in Brazil. The aim of this work was to standardize an indirect ELISA (iELISA) for EBL diagnosis using BLV antigens produced in Tadarida brasiliensis lung (Tb1Lu) cells, which are Bovine viral diarrhea virus (BVDV) free, unlike fetal lamb kidney (FLK) cells, currently used for this purpose. Following standardization, iELISA results were compared with those obtained by AGID and the commercial Chekit Leucose-Serum ELISA. Compared to AGID, iELISA had 94,44% sensitivity, 75.68% specificity, 79.10% positive predictive value (PPV) and 93.30% negative predictive value (NPV), with 84% concordance and a Kappa index of 0.699. Compared to the Chekit Leucose-Serum ELISA, iELISA showed 92.60% sensitivity, 87.09% specificity, 90.27% PPV and 90,00% NPV, with 90.27% concordance and a Kappa index of 0.801. Taking into account the high agreement with the traditional tests and the absence of non-specific reactions with BVDV, the developed assay could be used as diagnostic method to control EBL in Brazil.(AU)

A leucose enzoótica bovina (LEB) é uma doença infecciosa natural dos bovinos com distribuição mundial causada pelo "bovine leukemia virus" (BLV). A imunodifusão em gel de ágar (IDGA) foi considerada por muitos anos o teste de eleição, porém ensaios imunoenzimáticos (ELISA) apresentam sensibilidade mais elevada e leitura mais rápida e objetiva. No entanto, a importação de kits de ELISA é um processo dispendioso e demorado, e atualmente não há kits de IDGA comercialmente disponíveis no Brasil. Desta forma, o objetivo deste trabalho foi padronizar um ELISA indireto (iELISA) para diagnóstico da LEB utilizando antígenos produzidos a partir do cultivo do BLV em linhagem celular Tadarida brasiliensis "lung" (Tb1Lu) livre de "bovine viral diarrhea virus" (BVDV), diferentemente do que acontece com as linhagens "fetal lamb kidney" (FLK) atualmente utilizadas na produção desses antígenos para uso em ensaios sorológicos. Após a padronização do iELISA, os resultados foram comparados com aqueles obtidos por IDGA e pelo ELISA comercial "Chekit Leucose-Serum". Comparado ao IDGA, o iELISA apresentou 94,44% de sensibilidade, 75,68% de especificidade, valor preditivo positivo (VPP) de 79,1% e valor preditivo negativo (VPN) de 93,3%, com concordância entre os testes de 84% e o índice Kappa 0,699. Quando comparado ao ELISA "Chekit Leucose-Serum", o iELISA apresentou sensibilidade de 92,6%, especificidade de 87,09%, VPP de 90,27% e VPN de 90%, com concordância de 90,27% e o índice Kappa 0,801. Portanto, devido à alta concordância com os testes tradicionais e ausência da ocorrência de reações inespecíficas com BVDV, o ensaio desenvolvido pode ser utilizado como ferramenta diagnóstica para o controle da LEB no Brasil.(AU)

Detection of bluetongue virus antibodies in sheep from Paraná, Brazil / Detecção de anticorpos para o vírus da língua azul em ovinos do estado do Paraná, Brasil

Bluetongue (BT) is an infectious and non-contagious disease caused by bluetongue virus (BTV) belonging to the genus Orbivirus. It is transmitted by a hematophagous vector, Culicoides sp., to ruminants, particularly to sheep, which are most susceptible to this disease. The main serological tests are agar gel immunodiffusion (AGID), which is recommended by the World Organization for Animal Health (OIE), and the competitive enzyme-linked immunosorbent assay (cELISA), which has the advantage of no cross-reaction with other orbiviruses. The aim was to compare the results of these two tests by conducting them on sera collected from sheep in the state of Paraná, Brazil. From March to October 2017, serum samples were collected from 270 sheep from 10 farms in six mesoregions of Paraná. The samples were subjected to AGID and cELISA to detect antibodies against BTV. Based on the test results, we classified the sheep as low, moderate, and high occurrence. The results demonstrated that 64.81% (175/270) of the sheep were seropositive through the cELISA test, showing a high occurrence, and 41.11% (111/270) were seropositive through the AGID test, indicating a moderate occurrence. The concordance between the tests was moderate (0.51) as determined by the Kappa coefficient. Among the studied farms, 90% (9/10) presented at least one seropositive sheep, and the number of animals tested positive by the cELISA test was higher than those by the AGID test. Favorable climate, which favors the presence and multiplication of the culicoid vector and the occurrence of infection, was the biggest predominant factor responsible for the obtained results. The low occurrence in farms with milder climate suggest that the presence of antibodies also occurs due to the low pathogenicity of circulating serotypes in the different mesoregions studied. It is concluded that BTV infection is present in the sheep herds in Paraná, and the occurrence...(AU)

A língua azul (LA) é uma enfermidade infecciosa e não contagiosa causada por um vírus (VLA) do gênero Orbivirus, transmitida por vetores hematófagos Culicoides sp., aos ruminantes sobretudo aos ovinos, espécie mais susceptível. Os principais testes sorológicos utilizados são a Imunodifusão em Gél de Ágar (IDGA), preconizada pela OIE, e o teste Imunoensaio Enzimático Competitivo (ELISAc), sendo que este tem como vantagem não ocorrer reação cruzada contra outros orbivírus. O objetivo do trabalho foi detectar a presença de anticorpos contra o VLA em ovinos no estado do Paraná através dos testes diagnósticos IDGA e ELISAc. Durante os meses de março a outubro de 2017, colheu-se sangue de 270 ovinos, em 10 propriedades localizadas em seis mesorregiões paranaenses. As amostras foram submetidas aos testes de IDGA e ELISAc para detecção de anticorpos contra o VLA. Baseado nos resultados classificaram-se os rebanhos como baixa, moderada ou elevada ocorrência. Os resultados demonstraram elevada ocorrência através do teste de ELISAc, que apresentou 64,81% (175/270) de ovinos positivos, e moderada ocorrência através do IDGA, com 41,11% (111/270) de ovinos soropositivos. A concordância obtida entre os testes foi moderada (0,51) através do coeficiente Kappa. O número de ovinos reagentes no exame de ELISAc foi maior que o teste de IDGA em todas as propriedades positivas, demonstrando ser superior. O clima propício foi um dos fatores favoráveis para as ocorrências observadas, pois favorece a presença e multiplicação do vetor Culicoide e a ocorrência da infecção. A baixa ocorrência nas propriedades com clima mais ameno sugere que a presença de anticorpos provavelmente ocorra também pela baixa patogenicidade dos sorotipos circulantes nas diferentes mesorregiões estudadas. Conclui-se que há infecção de VLA no rebanho ovino paranaense, e a detecção de anticorpos para o VLA foi moderada, através do teste de IDGA, e elevada, através do teste ELISAc.(AU)