Spatial distribution and risk factors for equine infectious anaemia in the state of Mato Grosso, Brazil.

The prevalence of equine infectious anaemia (EIA) in the three biomes of the state of Mato Grosso (Amazon, Cerrado and Pantanal) was estimated. Serum samples were collected from 3,858 equines in 1,067 herds between Septemberand December 2014. The agar gel immunodiffusion (AGID) assay was used to detect EIA virus antibodies, and if a herd contained a seropositive animal itwas classified as a focus. The prevalence rates were 17.2% (95% confidence interval [CI]: 14.9-19.8%) for herds and 6.6% (95% CI: 5.8-7.5%) for animals. The Pantanal region showed the highest prevalence rates: 36.1% (95% CI: 30.8-41.7%) for herds and 17.0% (95% CI: 14.7-19.6%) for animals. The spatial distribution of relative risk was calculated according to the kernel density, which revealed three major clusters with the highest prevalence rates occurring in the north-western(Amazon biome), north-eastern (Cerrado biome) and southern (Pantanal biome)regions. A high spatial correlation was found among ranches, with high intra-herd prevalence rates located in the Amazon and Cerrado biomes, but the highest spatial correlation with EIA foci was found in the Pantanal biome. Variables related to ranch management, reflecting human influence, were associated with positive equines. Based on the results, it can be concluded that EIA is present in all biomes of the state, and that the risk factors are associated with human interference in the transmission process. Given this situation, the EIA control programme should be re-evaluated and more prophylactic measures should be adopted to control the disease.

Les auteurs présentent les résultats d'une estimation de la prévalence de l'anémie infectieuse des équidés (AIE) dans les trois biomes de l'état du Mato Grosso (l'Amazonie, le Cerrado et le Pantanal) réalisée de septembre à décembre2014 à partir d'échantillons de sérum collectés chez 3 858 équidés dans1 067 troupeaux. La méthode d'immunodiffusion sur gélose était utilisée pour détecter les anticorps anti-AIE. En cas de test positif chez un individu, le troupeau était classé comme un foyer. La prévalence par troupeau était de 17,2 % (intervalle de confiance à 95 % [IC 95 %] de 14,9 à 19,8) tandis que la prévalence individuelle était de 6,6 % (IC 95 % de 5,8 à 7,5). La prévalence la plus élevée était enregistrée dans la région du Pantanal : 36,1 % (IC 95 % de 30,8 à 41,7) par troupeaux et17,0 (IC 95 % de 14,7 à 19,6) à l'échelle des individus. La distribution spatiale du risque relatif estimée par noyau montre trois grappes de prévalence élevée dans le nord-ouest (biome de l'Amazonie), le nord-est (biome du Cerrado) et le sud (biome du Pantanal). Si une corrélation spatiale forte est observée dans les élevages des biomes de l'Amazonie et du Cerrado où la prévalence intra-troupeau est élevée, la corrélation spatiale la plus élevée avec les foyers d'AIE se trouve dans le biome du Pantanal. Une association a été constatée entre les équidés testés positifs et les variables descriptives liées aux pratiques d'élevage, ce qui traduit l'importance de l'influence humaine. À partir de ces résultats, on peut conclure que l'AIE est présente dans l'ensemble des biomes de l'état et que les facteurs de risque sont associés à l'interférence humaine dans le processus de transmission. Ainsi, une réévaluation du programme de lutte contre l'AIE serait indiquée avec plus de mesures prophylactiques afin de contrôler la maladie.

Los autores describen el proceso seguido para estimar la prevalencia de anemia infecciosa equina en los tres biomas presentes en el estado de Mato Grosso (Amazonia, Cerrado y Pantanal). Entre septiembre y diciembre de 2014 se extrajeron muestras a 3.858 equinos de 1.067 rebaños, a las que se aplicó la técnica de inmunodifusión en gel de agar para detectar anticuerpos contra el virus de la anemia infecciosa equina: todo rebaño en el que hubiera un animal seropositivo era considerado un foco. La tasa de prevalencia de rebaños infectados resultó del 17,2% (intervalo de confianza [IC] al 95%: 14,9­19,8) y la de individuos infectados del 6,6% (IC 95%: 5,8­7,5). Las tasas más elevadas se observaron en la región de Pantanal: un 36,1% (IC 95%: 30,8­41,7) de prevalencia de rebaño y un 17,0% (IC 95%: 14,7­19,6) de prevalencia individual. La distribución espacial del riesgo relativo se determinó con arreglo a la densidad kernel, proceso que reveló la presencia de tres grandes conglomerados: las mayores tasas de prevalencia se situaban en las regiones del noroeste (en el caso del bioma amazónico), el noreste (biomade Cerrado) y el sur (bioma de Pantanal). Se observó que existía una estrecha correlación espacial entre explotaciones, y aunque en los biomas de la Amazonia y Cerrado había elevadas tasas de prevalencia intrarrebaño, fue en el bioma de Pantanal donde se observó la correlación espacial más estrecha con los focos de anemia infecciosa equina. La presencia de equinos seropositivos venía asociada a variables relacionadas con la gestión de las explotaciones, hecho que pone de relieve la influencia humana en la cuestión. A tenor de los resultados, cabe concluir que la anemia infecciosa equina está presente en todos los biomas del estado y que los factores de riesgo guardan relación con la interferencia humana en el proceso de transmisión. Ante tal situación, convendría evaluar de nuevo el programa de lucha contra la anemia infecciosa y poner mayor acento en las medidas profilácticas para combatir la enfermedad.

Comparison among three different serological methods for the detection of equine influenza virus infection.

The equine influenza virus (EIV) H3N8 subtype is responsible for all EIV outbreaks worldwide while the H7N7 subtype is less pathogenic and is considered extinct as it has not been confirmed in outbreaks since 1980. Although EIV is enzootic in Brazil, few reports describe the actual EIV antibody status in the country. The aims of this study were: - to evaluate the efficiency of different serum treatments described by the World Organisation for Animal Health (OIE) and the World Health Organization (WHO) to remove non-specific haemagglutination inhibitors for the haemagglutination inhibition (HI) assay for EIV - to evaluate the presence of EIV antibodies by HI, enzyme-linked immunosorbent assay and agar gel immunodiffusion in 83 non-vaccinated equines from São Paulo State - to evaluate a strategy to better analyse equine sera for EIV antibodies. Although there was no statistical difference among treatments, receptor-destroying enzyme treatment followed by chicken erythrocyte adsorption showed more consistent results, which corroborate the OIE and WHO recommendation to use this treatment preferentially. The HI results suggest equine H3N8 virus circulation among the animals tested from São Paulo State. The algorithm suggested here could be used to guide antibody detection against equine influenza virus in equines, improving the test specificity by aiming to avoid false positive results.

Tous les foyers de grippe équine dans le monde sont dus au sous-type H3N8 du virus. Le sous-type H7N7, moins pathogène, est considéré comme éteint, sa présence n'ayant été confirmée dans aucun des foyers enregistrés depuis 1980. Au Brésil, la grippe équine est enzootique mais la prévalence d'anticorps dans le pays est peu documentée. La présente étude avait trois objectifs : ­ évaluer l'efficacité de plusieurs traitements de sérums décrits par l'Organisation mondiale de la santé animale (OIE) et l'Organisation mondiale de la santé (OMS) sur la suppression des inhibiteurs d'hémagglutination non spécifiques, afin de pouvoir utiliser l'épreuve d'inhibition de l'hémagglutination pour la détection de la grippe équine, ­ évaluer la présence d'anticorps dirigés contre la grippe équine chez 83 chevaux non vaccinés de l'état de São Paulo en utilisant l'inhibition de l'hémagglutination, l'épreuve immuno-enzymatique (ELISA) et l'épreuve d'immunodiffusion en gélose (IDG) ; ­ évaluer une stratégie visant à améliorer les techniques sérologiques de détection des anticorps dirigés contre la grippe équine. S'il n'y a pas eu de différence statistique significative entre les traitements, celui faisant appel à l'enzyme de destruction du récepteur suivi d'une adsorption sur érythrocytes de poule a permis d'obtenir les résultats les plus cohérents, ce qui corrobore les recommandations de l'OIE et de l'OMS en faveur de ce traitement. Les résultats obtenus au moyen de l'inhibition de l'hémagglutination indiquent que le virus H3N8 est présent parmi les animaux testés de l'état de São Paulo. L'algorithme présenté par les auteurs pourrait servir de modèle pour détecter la présence d'anticorps dirigés contre le virus de la grippe équine chez les chevaux : en effet, il permet d'éviter les résultats faussement positifs, ce qui améliore la spécificité du test utilisé.

El subtipo H3N8 del virus de la gripe equina (VGE) es el agente etiológico de todos los brotes que se producen en el mundo, mientras que el subtipo H7N7, menos patogénico, se da por extinto, en la medida en que desde 1980 no se ha confirmado su intervención en brote alguno. Aunque en el Brasil el VGE es enzoótico, existen pocos trabajos que den cuenta de la situación real del país en cuanto a la presencia de anticuerpos contra el virus. Los autores describen un estudio que perseguía los siguientes objetivos: ­ evaluar la eficacia de distintos tratamientos séricos descritos por la Organización Mundial de Sanidad Animal (OIE) y la Organización Mundial de la Salud (OMS) para eliminar los inhibidores inespecíficos de la hemaglutinación con objeto de aplicar la técnica de inhibición de la hemaglutinación a la detección del VGE; ­ evaluar la presencia de anticuerpos contra el VGE por inhibición de la hemaglutinación, ensayo inmunoenzimático (ELISA) e inmunodifusión en gel de agar en 83 ejemplares equinos no vacunados del estado de São Paulo; ­ evaluar una estrategia encaminada a analizar más eficazmente sueros equinos para detectar en ellos anticuerpos anti-VGE. Aunque no se observaron diferencias estadísticamente significativas entre los tratamientos, el uso de enzimas destructores de receptores seguido de la técnica de adsorción de eritrocitos de pollo arrojó resultados más coherentes, cosa que avala la recomendación de la OIE y la OMS de privilegiar este tratamiento. Los resultados obtenidos por inhibición de la hemaglutinación parecen indicar que el virus H3N8 equino circula entre los animales analizados del estado de São Paulo. El algoritmo aquí propuesto podría servir de guía para detectar en equinos la presencia de anticuerpos contra el VGE. Puesto que apunta a evitar falsos positivos, su aplicación mejoraría la especificidad de la prueba.

Seroprevalence of infectious bursal disease virus in local chickens in Udu Local Government Area of Delta State, South East Nigeria.

Infectious Bursal Disease Virus (IBDV) poses a great global threat to the poultry industry. Knowledge of the occurrence of the disease is important in the design and implementation of a control program, therefore this study determines the seroprevalence of IBDV in local chickens in Udu Local Government Area of Delta State. 250 chickens were bled by exsanguination and sera obtained were screened using Agar Gel Immunodiffusion (AGID) test. The seropositivity was 51.6%, which is indicates endemicity of the disease. Biosecurity and good sanitary measures are recommended. Molecular characterization of the strains should be carried out for inclusion in generic vaccines.

Equine infectious anemia in 2014: live with it or eradicate it?

In the absence of an effective vaccine, the success of the test and removal approach for the control of equine infectious anemia (EIA) cannot be overstated, at least in those areas where testing has been traditionally routine. This article addresses 4 main aspects: what has been learned about EIA virus, host control of its replication, and inapparent carriers; international status regarding the control of EIA; diagnostic and laboratory investigation; and reducing the spread of blood-borne infections by veterinarians. An attempt is made to put these issues into practical contemporary perspectives for the equine practitioner.

Comparison of 4 agar gel immunodiffusion kits for serologic detection of equine infectious anemia virus antibodies.

Using 85 sera collected from horses that had been experimentally infected with equine infectious anemia virus (EIAV) and 200 field sera collected from racehorses in Japan, we compared 4 agar gel immunodiffusion (AGID) kits for serologic detection of EIAV antibodies from Idexx, VMRD, IDvet, and the National Engineering Research Center of Veterinary Biologics, China (NECVB). The positive control lines were sufficiently clear in all kits for evaluation to be made, with slight differences in sharpness: NECVB was the sharpest, followed by VMRD, IDvet, and Idexx. The test results for all 285 samples agreed among the 4 kits, with 62 positives and 223 negatives. The sensitivities and specificities of VMRD, IDvet, and NECVB compared with the Idexx kit were 100%, and the kappa coefficient values between the kits were 1.0 for all combinations. We concluded that the testing capacity of these 4 kits was virtually identical.

Seroprevalence and risk factors associated with equine infectious anemia in the state of Goiás, Brazil.

Equine infectious anemia (EIA) is an infectious disease affecting equine in most countries and represents a notifiable disease with compulsory euthanasia of positive animals. The present study aimed to determine the prevalence of EIAV infected equines in herds of the state of Goiás (Central Brazil) and to evaluate the risk factors associated with the occurrence of the disease. Blood samples were collected from 1170 equids from 332 randomly selected farms divided into three different strata according to their herd characteristics. Also, an epidemiological questionnaire was applied during the visit to the farm. Of the 332 farms evaluated, 12 (3.1%; 95% CI: 1.24 - 6.00) had at least one positive equine for EIA, and of the 1170 evaluated equines, 14 (2%; 95% CI: 0.31-3.00) were positive in agar gel immunodiffusion. Multivariate analysis revealed that the use of a vaccination pistol (p < 0.001) and the presence of water bodies inside the farm (p < 0.01) were risk factors associated with the occurrence of EIA. Thus, the present study demonstrated a low but widespread prevalence of EIAV infected animals in the herds of Goiás state and that iatrogenic and environmental risk factors were associated with the occurrence of the disease.

Comparison of 2 ELISAs for detecting exposure to Brucella ovis.

Control of Brucella ovis infection in sheep flocks in the United States depends on early detection of B. ovis antibodies via serologic testing. We used 2,276 sheep sera and various cutoff values to compare seroprevalence and agreement between 2 ELISAs: the National Veterinary Services Laboratories (NVSL) B. ovis indirect ELISA and the IDEXX B. ovis ELISA kit. A subset of 295 sera was used to compare agreement and evaluate relative sensitivity and specificity of the 2 ELISAs with an agar gel immunodiffusion (AGID) test kit. There was no significant difference in B. ovis seroprevalence between the ELISAs; however, there was poor agreement between them. When the AGID test was used as the reference test, the IDEXX ELISA with a moderate cutoff value (S/P ratio = 45%) had the highest relative sensitivity of 38.1% and specificity of 92.0%. The NVSL ELISA with a lax cutoff value (S/P ratio = 0.75) had relative sensitivity of 19.1% and specificity of 94.6%. Receiver operating characteristic analysis revealed that optimal cutoff values for the NVSL and IDEXX ELISAs were 0.091 and 16.5%, respectively. This results in sensitivity and specificity of 85.7% and 31.8% for the NVSL ELISA, and sensitivity and specificity of 81.0% and 53.6% for the IDEXX ELISA, respectively.

Agar Gel Immunodiffusion Assay to Detect Antibodies to Type A Influenza Virus.

The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the nucleoprotein (NP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes. AGID is commonly used to screen poultry flocks for avian influenza virus infection. The AGID is a simple and economical serological test. All serological testing has its advantages and disadvantages, which should be considered before choosing the optimal test for the laboratory needs. Each laboratory must evaluate the laboratory's resources, the volume of testing, the goal of testing, how the test results are used, and what types of samples are being tested in order to select the optimal test.

Comparison of two agar gel immunodiffusion protocols for diagnosing equine infectious anemia.

This study compared agar gel immunodiffusion (AGID) protocols for diagnosing equine infectious anemia. Two commercial testing kits were used: one following the Japanese Act on Domestic Animal Infectious Diseases Control and one following the World Organisation for Animal Health (OIE) manual. From 651 samples tested, both protocols gave identical results for 647 samples (23 samples tested positive; 624 tested negative). Non-specific reactions were observed in 21 samples testing negative by the Japanese protocol, but none were observed with the OIE protocol. The kappa coefficient value was 0.962, indicating almost perfect agreement between the two protocols. This study found no difference in diagnostic agreement between the two protocols, but the OIE protocol produced non-specific reactions less frequently than the Japanese protocol.

Assessment of antibody assay methods in determination of prevalence of infectious bursal disease among local chickens and guinea fowls in Kwara state, North Central Nigeria.

AIM: This study aimed to assess available assay methods for infectious bursal disease (IBD) diagnosis and seromonitoring in local birds. It also sought to know the prevalence of IBD antibodies among local chickens and guinea fowls in Kwara state, North Central Nigeria. MATERIALS AND METHODS: Sera were obtained from local chickens and guinea fowls and IBD virus (IBDV) antibodies were assayed using enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination (IHA) test, and agar gel immunodiffusion (AGID) test. RESULTS: A total of 265 sera were obtained from local birds during dry and wet seasons. ELISA recorded the highest prevalence of 81.1% (215/265) while IHA and AGID detected IBDV antibodies in 183 (69.1%) and 122 (46%) birds, respectively. Significant differences were established for IBD-positive sera based on the assay method used, bird species, and seasons. CONCLUSION: This study indicated that ELISA is the most sensitive and reliable assay method while AGID is the least. It also showed that there is a high prevalence of IBDV antibodies among local birds which were not vaccinated, and this implies a high IBDV activity among these bird species in the study area. This may have significant epidemiological implications on the spread of the virus to exotic bird reared in the rural areas on a commercial scale. Thus, this study suggests continuous surveillance, awareness campaign, and advocacy for vaccination of indigenous birds against IBD.

Comparative Analysis of Different Serological and Molecular Tests for the Detection of Small Ruminant Lentiviruses (SRLVs) in Belgian Sheep and Goats.

Countries rely on good diagnostic tests and appropriate testing schemes to fight against economically important small ruminant lentivirus (SRLV) infections. We undertook an extensive comparative analysis of seven commercially available serological tests and one in-house real-time PCR (qPCR) detecting genotype A and B strains using a large panel of representative Belgian field samples and samples from experimentally infected sheep and goats. ELISAs generally performed well and detected seroconversion within three weeks post experimental infection. Two enzyme-linked immunosorbent assays (ELISAs) (Elitest and IDscreen® kits) showed the highest sensitivities (>96%) and specificities (>95%) in both species, and their combined use allowed to correctly identify the infection status of all animals. Individual agar gel immunodiffusion (AGIDs) kits lacked sensitivity, but interestingly, the combined use of both kits had a sensitivity and specificity of 100%. qPCRs detected SRLV infection before seroconversion at two weeks post infection and showed a specificity of 100%. Sensitivity however remained suboptimal at 85%. These results allow to propose a faster and cheaper diagnostic testing strategy for Belgium by combining a first ELISA screening, followed by confirmation of positive samples in AGID and/or a second ELISA. Since genotypes A and B strains are predominant in many countries, these results are interesting for other countries implementing SRLV control programs.

Production of pseudorabies virus recombinant glycoprotein B and its use in an agar gel immunodiffusion (AGID) test for detection of antibodies with sensitivity and specificity equal to the virus neutralization assay.

Pseudorabies virus (PrV) causes Aujeszky's disease (AD), which affects mainly swine, but also cattle, sheep, and wild animals, resulting in substantial economic losses due to animal mortality and lost productivity worldwide. To combat PrV, eradication programs using PrV strains lacking the gene encoding glycoprotein E (gE) are ongoing in several countries. These eradication programs have generated a currently unmet demand for affordable, easy-to-use, and sensitive tests that can detect PrV infection in pigs infected with either wild-type virus or vaccine strain (gE-deleted) virus. To meet this demand, we used the baculovirus-insect cell system to produce recombinant glycoprotein B (gB) as antigen for an immune assay. The high GC-content (70% average) of the gB gene from the Argentinian PrV CL15 strain necessitated the use of betaine as a PCR enhancer to amplify the extracellular domain. Recombinant gB was expressed at high levels and reacted strongly with sera from PrV infected pigs. We used the recombinant gB to develop an agar gel immunodiffusion (AGID) test for detection of PrV antibodies. Compared to the gold standard virus neutralization (VN) assay, the AGID sensitivity and specificity were 95% and 96.6% respectively. Thus, recombinant gB produced in the baculovirus-insect cell system is a viable source of antigen for the detection of PrV antibodies in AGID tests. Considering its relatively lower cost, simplicity of use and result interpretation, our AGID is a valuable alternative tool to the VN assay.

Diagnosis of peste des petits ruminants infection in small ruminants through in-house developed Indirect ELISA: Practical considerations.

AIM: The work was conducted to diagnose peste des petits ruminants (PPR) outbreak through an in house developed indirect ELISA (thereafter referred as iELISA) its comparison with other available diagnostic tests and description of practical considerations in its development, utility and limitations. MATERIALS AND METHODS: An outbreak resembled to PPR occurred in two different places of southern Gujarat viz. Vapi and Navsari, affecting 622 animals, including both goat (n = 476) and sheep (n = 146). Animals displayed the typical signs of PPR at Vapi; however diarrhea was the inconsistent feature in animals of Navsari. The affection caused morbidity of 100% and mortality were 73.68% (n = 392/532) and 56.67% (n = 51/90) in Vapi and Navsari outbreaks, respectively. Relevant ante mortem and post mortem samples were collected from representative animals. At the outset of the epidemic no kit was available with us, so agar gel immunodiffusion (AGID) was carried out and a commercial ELISA (cELISA) kit was ordered for making diagnosis through antibody demonstration. Meanwhile, an iELISA was developed in house using PPR vaccine as antigen and protein G conjugated HRPO antibody as detector. Histopathology and results of sandwich ELISA were also used to diagnose PPR virus (PPRV) in the outbreak. RESULTS: The iELISA developed had detected PPRV antibodies in 22/24 samples (91.66%). Significant difference was observed in disease sensitivity pattern of two species by Chi-square test. While AGID failed to detect antibodies in any sample. Results were reconfirmed by comparing with commercially available cELISA kit. CONCLUSION: PPR is an economically important disease and for the rapid diagnosis of PPR the in house developed antibody capture iELISA can be a suitable cost effective alternative.

Production of equine herpesvirus 1 recombinant glycoprotein D and development of an agar gel immunodiffusion test for serological diagnosis.

Equine herpesvirus 1 and 4 (EHV-1 and 4) infect most of the world's horses, causing serious clinical illness. Viral glycoproteins have been identified as the immunodominant antigens that generate the antiviral serological responses to EHV-1 and EHV-4 in infected horses. Here, glycoprotein D of EHV-1 was expressed by a recombinant baculovirus, purified and evaluated by a simple agar gel immunodiffusion test (AGID). Compared with virus neutralization, serological analysis by AGID showed good specificity (100%) and sensitivity (99.5%). The estimated Kappa values for repeatability and reproducibility were satisfactory. Thus, this rapid, inexpensive, simple and highly specific AGID test seems to be a valuable alternative tool for serological detection of antibodies against both EHV-1 and EHV-4.

Infection of California sea lions (Zalophus californianus) with terrestrial Brucella spp.

Infections with Brucella ceti and pinnipedialis are prevalent in marine mammals worldwide. A total of 22 California sea lions (Zalophus californianus) were examined to determine their exposure to Brucella spp. at San Esteban Island in the Gulf of California, Mexico, in June and July 2011. Although samples of blood, vaginal mucus and milk cultured negative for these bacteria, the application of rose Bengal, agar gel immunodiffusion, PCR and modified fluorescence polarization assays found that five animals (22.7%) had evidence of exposure to Brucella strains. The data also suggested that in two of these five sea lions the strains involved were of terrestrial origin, a novel finding in marine mammals. Further work will be required to validate and determine the epidemiological significance of this finding.

Paratuberculosis in different breeds of sheep: A retrospective study of cases.

Spontaneous ovine paratuberculosis in an organized farm was diagnosed based on histopathological lesions, demonstration of acid-fast bacilli in different visceral organs, and detection of antibody levels against Mycobacterium paratuberculosis by agar gel immunodiffusion test (AGID). Out of 190 morbid specimens examined histopathologically, 77% of specimens had pathological lesions, which included predominant epithelioid cell formation, infiltration of lymphocytes, monocytes and macrophages. In acid-fast staining of tissue sections, 74% of intestinal specimens and 53% of mesenteric lymph nodes were positive for the presence of acid-fast bacilli. Hematologically, the animals were showing leucopenia, macrocytic and normochromic anemia. Out of 49 animals tested, 28.5% of animals were positive for antibodies against M. paratuberculosis. Local breeds, namely Nilagiri and Sandyno sheep, were found to be more susceptible than exotic breeds, namely Dorset. Females were more susceptible than males. Mortality was noticed in the age group of 4months to 10years.

Development and Field Testing of a Real-Time PCR Assay for Caprine Arthritis-Encephalitis-Virus (CAEV).

Caprine arthritis/encephalitis (CAE) of goats and occasionally sheep are persistent virus infections caused by a lentivirus (CAEV). This viral infection results in arthritis in adult animals and encephalitis in kids. Prognosis for the encephalitic form is normally poor, with substantial economic loss for the farm. In this context an early/fast laboratory diagnosis for CAEV infection could be useful for effective prophylactic action. In this work we performed a quantitative real time PCR designed on the CAEV env gene to detect/quantify in goat/sheep samples, viral RNA or proviral DNA forms of CAEV. This procedure was validated in 15 sheep, experimentally infected with CAEV or with a highly correlated lentivirus (visna maedi, MVV); in addition, a total of 37 clinical goat specimens recruited in CAEV positive herds were analyzed and compared using serological analysis (Elisa and AGID). All samples infected with MVV resulted negative. In sheep experimentally infected with CAEV, proviral DNA was detectable 15 days post infection, whereas the serological methods revealed an indicative positivity after 40-60 days.This method showed a sensitivity of 10(2) env fragments/PCR) with a linear dynamic range of quantitation from 10(3) to 10(7)env fragments/PCR; the R2 correlation coefficient was 0.98. All subjects with a clinical diagnosis for Caprine Arthritis-Encephalitis (CAE) resulted CAEV DNA positive.

Investigação sorológica das lentiviroses de pequenos ruminantes nas microrregiões homogêneas do Alto Médio Canindé, Picos e Floriano, Piauí, Brasil / Serological investigation of lentiviruses of small ruminants in the microregions of Alto Médio Canindé, Picos and Floriano, Piauí state, Brazil

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.(AU)

Small ruminant lentiviruses (LV) is the generic term for the caprine arthritis-encephalitis and ­­Maedi-Visna viruses, which belong to the Retroviridae family, Orthoretrovirinae subfamily, Lentivirus genus. The virus infects goats and sheep, causing slow course of disease with inflammatory, chronic and degenerative lesions, which can reach several organs, provoking cachexia and death. Infected animals eliminate the virus mainly through secretions and excretions and transmit it especially in close contact situations. There is no treatment to date. The control is based on segregated creation, management and sacrifice of the positive. This infectious agent has been reported in various parts of the world and is responsible for significant economic losses. It was verified in several states of Brazil and there are seroepidemiological data in southeast and southwest mesoregions of Piauí, Brazil. This research aimed to perform serological survey to investigate the occurrence of antibodies to LV in sheep and goats, in the regions of Alto Médio Canindé, Picos and Floriano. So, 1,280 and 1,360 serum goats and sheep samples, respectively, were collected, coming from 20 municipalities, distributed in the 3 microregions. The number of samples was proportional to the actual herd of each municipality. The samples were analyzed using the agar gel immunodiffusion test. None of the surveyed sera reacted positively, though there is a null seroprevalence. It was emphasized the importance of implementing a rigorous control program in order to prevent the introduction and spread of this infectious agent in these microregions.(AU)

Investigação sorológica das lentiviroses de pequenos ruminantes nas microrregiões homogêneas do Alto Médio Canindé, Picos e Floriano, Piauí, Brasil / Serological investigation of lentiviruses of small ruminants in the microregions of Alto Médio Canindé, Picos and Floriano, Piauí state, Brazil

Small ruminant lentiviruses (LV) is the generic term for the caprine arthritis-encephalitis and ­­Maedi-Visna viruses, which belong to the Retroviridae family, Orthoretrovirinae subfamily, Lentivirus genus. The virus infects goats and sheep, causing slow course of disease with inflammatory, chronic and degenerative lesions, which can reach several organs, provoking cachexia and death. Infected animals eliminate the virus mainly through secretions and excretions and transmit it especially in close contact situations. There is no treatment to date. The control is based on segregated creation, management and sacrifice of the positive. This infectious agent has been reported in various parts of the world and is responsible for significant economic losses. It was verified in several states of Brazil and there are seroepidemiological data in southeast and southwest mesoregions of Piauí, Brazil. This research aimed to perform serological survey to investigate the occurrence of antibodies to LV in sheep and goats, in the regions of Alto Médio Canindé, Picos and Floriano. So, 1,280 and 1,360 serum goats and sheep samples, respectively, were collected, coming from 20 municipalities, distributed in the 3 microregions. The number of samples was proportional to the actual herd of each municipality. The samples were analyzed using the agar gel immunodiffusion test. None of the surveyed sera reacted positively, though there is a null seroprevalence. It was emphasized the importance of implementing a rigorous control program in order to prevent the introduction and spread of this infectious agent in these microregions.

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.

Soroprevalência de Maedi-visna em rebanhos ovinos do estado do Maranhão, Brasil / Seroprevalence of Maedi-Visna in sheep flocks State of Maranhão, Brazil

Apesar de ter sido relatada em vários estados, não há informação sobre o Vírus da Maedi Visna (MVV) no Maranhão, e com o crescimento de sua ovinocultura, aumenta o fluxo de animais de outras regiões. Com isso objetivou-se determinar a soroprevalência do MVV em rebanhos ovinos das três principais mesorregiões produtoras do estado do Maranhão, através da pesquisa das 1.495 amostras sanguíneas de ovinos, com idade superior a seis meses, pertencentes a 83 rebanhos de 23 municípios das mesorregiões Cento, Leste e Norte. O diagnóstico sorológico da infecção pelo vírus MVV foi realizado por meio do teste de imunodifusão em gel de ágar (micro-IDGA). Constatou-se uma prevalência geral de 0,7% (IC95%:0,4-1,3%) de ovinos soropositivos e prevalências nas mesorregiões Centro, Leste e Norte de 0,5% (IC95%:0,1-1,4%), 0,7% (IC95%:0,2-1,8%) e 1% (IC95%:0,3-2,4%) respectivamente. Em relação à variável sexo, não foi observada diferença significativa (P>0,05) entre machos (0,5%, IC95%:0-2,7%) e fêmeas (0,8%, IC95%:0,4-1,4%), assim como quanto a genética comparando-se ovinos de raças puras (1,5%, IC95%: 0,4-8,1%), mestiços (1%, IC95%:0,4-2,0%) e SRD (0,3%, IC95%:0,04-1,1%). A análise quanto à idade não demonstrou diferença significante (P>0,05). Conclui-se que a infecção pelo MVV está presente em ovinos das mesorregiões estudadas, sendo este o primeiro registro desta enfermidade no estado do Maranhão. Considerando a baixa prevalência, é necessário evitar a introdução e a propagação do vírus entre os rebanhos, através da exigência de testes negativos para MVV e descarte dos ovinos positivos.

Although it has been reported in several states, no information about Maedi-Visna (MV) in the state of Maranhão is available. The aim of the present study was to determine the seroprevalence of Maedi Visna Virus (MVV) in sheep flocks of the three most important sheep rearing areas from Maranhão State, Brazil. We surveyed 1.495 blood samples from sheep older than six months, of both sexes and various breeds. The samples were collected from 83 herds of 23 municipalities present in the Central, East and North regions of Maranhão. The immunodifusion agar gel (micro-AGID) performed serological diagnosis of infection MVV. The statistical analysis was performed by Fisher's test, using Epi Info. It was found an overall prevalence of MVV infection of 0,7% (CI95%:0,4-1,3%) the ovines and prevalence of 0,5% (CI95%:0,1-1,4%), 0,7% (CI95%:0,2-1,8%) e 1% (CI95%:0,3-2,4%) in the Central, East and North regions, respectively. In relation to sex, there wasn't a significant difference (P>0.05) between males (0,5,%, CI95%:0-2,7%) and females (0,8%, CI95%:0,4-1,4%), as well as in relation to genetic comparing sheep purebreds (1,5%, CI95%:0,4-8,1%), crossbred (1%, CI95%:0,4-2,0%) and SRD (0,3%, IC95%:0,04-1,1%). In relation to age wasn't observed significant difference. It has concluded that infection with MVV is present in the studied population in low prevalence. This is the first record of MVV in sheep in the State of Maranhão. Considering the low prevalence is necessary to prevent the introduction and spread of the virus between flocks by requiring negative tests for MVV and disposal of positive sheep.