Low transmission rates of Equine infectious anemia virus (EIAV) in foals born to seropositive feral mares inhabiting the Amazon delta region despite climatic conditions supporting high insect vector populations.

BACKGROUND: Marajó Island, within in the Amazon River Delta, supports numerous bands of feral equids including the genetically distinct Marajoara horses. Approximately 40% of the equids on the island are infected with Equine infectious anemia virus (EIAV). This high seropositivity rate coupled with the need to preserve rare breeds such as the Marajoara horse precludes euthanasia as the primary means for controlling EIAV in this region. In the absence of iatrogenic transmission, spread of this lentivirus is mediated primarily by hematophagous insects, whose year-round prevalence on the island is supported by favorable climatic conditions. In addition, cases of vertical EIAV transmission have been observed suggesting inclusion of seropositive mares in restorative breeding programs could result in their progeny becoming infected with this virus either pre-parturition or post-partum via hematophagous insects. Therefore, the aim of this study was to evaluate EIAV vertical and post-partum insect-mediated transmission rates among foals born to seropositive feral mares until natural weaning. Serum samples from foals born to seropositive feral mares within the Soure municipality, of Marajó Island, were collected to investigate their serological status, using an indirect ELISApgp45, with positive samples confirmed using the classical agar gel immunodiffusion (AGID) assay. RESULTS: The serological status of 28 foals were monitored over a 2-year period with some subjects, depending on their date of birth, being sampled up to six times. All foals remained with their respective mares until fully weaned at approximately 10 months of age. Only 2 foals (7.14%) in the study group became seropositive against EIAV. CONCLUSION: The results demonstrate that in most cases it is possible to obtain seronegative foals born to and eventually weaned by EIA positive mares, even in equatorial regions where substantial rainfall and high temperatures favor the proliferation of insect vectors.

Glanders and brucellosis in equids from the Amazon region, Brazil.

Glanders and brucellosis are zoonotic infectious diseases that affect equids in several countries worldwide. On Marajó Island (Amazon region of Brazil), Marajoara and Puruca horses, which are well adapted to the climatic and territorial adversities of the region, play a fundamental role in the local economy and in the sociocultural lives of the population. However, these animals have undergone a drastic reduction in number, markedly due to precarious veterinary care, unknown causes of morbidity and mortality, and disordered crossing with other breeds introduced to the island. Thus, this study aimed to investigate the occurrence of glanders and brucellosis in equids on a property located in the municipality of Soure, Marajó Island (Brazil). Serum samples were collected from 388 animals (357 horses and 31 mules), maintained in an extensive breeding system, in a property that was also extensively breeding buffaloes, goats, and sheep, with contact among species. The sera were tested for glanders using an indirect ELISA (ELISAi), and the results were confirmed by immunoblotting. The diagnosis of brucellosis was made using the Rose Bengal test (RBT) and confirmed through the Serum Agglutination test (SAT) and 2-mercaptoethanol test. In the case of glanders, 2.31% (9/388) of animals were positive in ELISAi test, of which eight had results confirmed by immunoblotting, representing 2.06% seropositivity in the entire herd. For brucellosis, serum samples from 6.7% (26/388) horses were reactive in the RBT, of which 4.12% (18/388) had a titer ≥50 and 2.06% (8/388) had a titer ≥100 in the SAT. This is the first study to report the occurrence of glanders and equine brucellosis in the municipality of Soure/Marajó Island. Monitoring the occurrence of such diseases is extremely important since they affect the herds economically and zootechnically, in addition to their high zoonotic potential. The number of animals sampled in this study, as well as the way they are raised and managed, is representative of the total equid population of the island. These results, combined with previous studies on buffaloes, indicate that these diseases are endemic in the Marajo Island.

"Which Factors Affect Pregnancy Until Calving and Pregnancy Loss in Buffalo Recipients of in vitro Produced Embryos?"

In vitro embryo production and embryo transfer (ET) in buffaloes has been developed for decades. However, most studies are focused on the donor or laboratory improvements, and there is a lack of reports regarding the recipients. Therefore, our aim was to investigate factors associated to pregnancy (P/ET), pregnancy loss (PL), and calving rates in buffalo recipients. The studied factors were season, recipient parity, the synchronization protocol, the CL diameter, asynchrony between the embryo and the recipient, the day of the recipient estrous cycle, the embryo (fresh vs. vitrified), the day of embryo development, and the embryo stage. These retrospective data, from a program of in vitro produced embryos, were analyzed by logistic regression, and the odds ratio was also estimated. Two factors were related to P/ET and the calving rate: (1) progesterone associated to estradiol plus eCG protocol for fixed time ET tended to affect positively P/ET on day 30 (41.9 vs. 36.1%, respectively; P = 0.07; AOR = 1.28) and P/ET on day 60 (37.8 vs. 36.1%, respectively; P = 0.09; AOR = 1.08) compared to the Ovsynch protocol; and (2) the CL diameter (≥14.5 mm) at transfer increased P/ET on day 30 (47.4 vs. 32.5%; P < 0.01; AOR = 1.87) and on day 60 (45.3 vs. 27.7%; P < 0.01; AOR = 2.16), and also the calving rate (37.9 vs. 21.7%; P < 0.01; AOR = 2.20). PL was greater when ET was done in the nonbreeding season compared to the breeding season (PL 30-60: 12.8 vs. 0.0%, P = 0.01; AOR > 999.99; PL 60-calving: 26.8 vs. 3.6%, P = 0.03; AOR = 9.90; and PL 30-calving: 36.2 vs. 3.6%, P = 0.01; AOR = 15.30). In conclusion, the data of our study indicated that the synchronization protocol, the CL diameter, and ET during the breeding season impacted the reproductive efficiency of buffalo recipients.

High positivity values for bovine leukemia virus in human breast cancer cases from Minas Gerais, Brazil.

Bovine leukemia virus (BLV) is a retrovirus that causes lymphoma in cattle worldwide and has also been associated with breast cancer in humans. The mechanism of BLV infection in humans and its implication as a primary cause of cancer in women are not known yet. BLV infection in humans may be caused by the consumption of milk and milk-products or meat from infected animals. Breast cancer incidence rates in Brazil are high, corresponding to 29.5% a year of cancer cases among women. In 2020, an estimated 66,280 new cases of breast cancer are expected, whereas in 2018 breast cancer has led to 17,572 deaths, the highest incidence and lethality among cancers in women in this country that year. BLV infection occurrence ranges from 60 to 95% in dairy herds. In addition, there are some regions, such as the Minas Gerais State, southeastern Brazil, where the population traditionally consume unpasteurized dairy products. Taken together, this study aimed to verify if there is a higher association between breast cancer and the presence of BLV genome in breast tissue samples within this population that consumes raw milk from animals with high rates of BLV infection. A molecular study of two BLV genes was carried out in 88 breast parenchyma samples, between tumors and controls. The amplified fragment was subjected to BLV proviral sequencing and its identity was confirmed using GenBank. BLV proviral genes were amplified from tumor breast parenchyma samples and healthy tissue control samples from women, revealing a 95.9% (47/49) and 59% (23/39) positivity, respectively. Our results show the highest correlation of BLV and human breast cancer found in the world to date within the population of Minas Gerais, Brazil.

Genetic material from buffalo and cattle: crucial importance in the formalization of bilateral trade between India and Brazil.

The trade in live animals between India and Brazil dates from the late nineteenth century when European travellers traded animals of Indian origin for display in zoos. Considering the origin of coffee and sugar cane, as well as the expertise related to mineral evaluation, we need to consider that India was involved in important economic cycles of Brazil, even indirectly. This virtuous flow of trade has been maintained and intensified throughout modern history, especially after these two nations gained political independence from their colonisers, thereby becoming independent in mercantile affairs. This paper addresses the main points related to the use of animals of Indian origin in Brazil. We revisit some of the historical aspects of the process of colonisation of Brazil, as well as the importation of animals from India. The restrictions imposed on this process due to the occurrence of diseases in cattle and buffalo in India will be examined. At the end of the text, emphasis will be given to the risks of introducing exotic diseases into Brazil.

Genetic material from buffalo and cattle: crucial importance in the formalization of bilateral trade between India and Brazil

The trade in live animals between India and Brazil dates from the late nineteenth century when European travellers traded animals of Indian origin for display in zoos. Considering the origin of coffee and sugar cane, as well as the expertise related to mineral evaluation, we need to consider that India was involved in important economic cycles of Brazil, even indirectly. This virtuous flow of trade has been maintained and intensified throughout modern history, especially after these two nations gained political independence from their colonisers, thereby becoming independent in mercantile affairs. This paper addresses the main points related to the use of animals of Indian origin in Brazil. We revisit some of the historical aspects of the process of colonisation of Brazil, as well as the importation of animals from India. The restrictions imposed on this process due to the occurrence of diseases in cattle and buffalo in India will be examined. At the end of the text, emphasis will be given to the risks of introducing exotic diseases into Brazil.

Genetic material from buffalo and cattle: crucial importance in the formalization of bilateral trade between India and Brazil

The trade in live animals between India and Brazil dates from the late nineteenth century when European travellers traded animals of Indian origin for display in zoos. Considering the origin of coffee and sugar cane, as well as the expertise related to mineral evaluation, we need to consider that India was involved in important economic cycles of Brazil, even indirectly. This virtuous flow of trade has been maintained and intensified throughout modern history, especially after these two nations gained political independence from their colonisers, thereby becoming independent in mercantile affairs. This paper addresses the main points related to the use of animals of Indian origin in Brazil. We revisit some of the historical aspects of the process of colonisation of Brazil, as well as the importation of animals from India. The restrictions imposed on this process due to the occurrence of diseases in cattle and buffalo in India will be examined. At the end of the text, emphasis will be given to the risks of introducing exotic diseases into Brazil.(AU)

Evaluation of post-mortem diagnostic tests' sensitivity and specificity for bovine tuberculosis using Bayesian latent class analysis.

This study aimed to evaluate the performance of real-time PCR (qPCR), ELISA IDEXX™, and bacterial isolation as post-mortem diagnostic tests in animals with lesions compatible with bovine tuberculosis detected by Brazilian Federal Inspection Service as part of the bovine tuberculosis active surveillance. Bayesian latent class models were used to estimate diagnostic tests' sensitivity, specificity, correlations, predictive values and frequency of infected animals. Samples of tuberculosis-suggestive lesions collected by FIS sanitary inspection routine in slaughterhouses from 11 Brazilian states were analyzed. Isolation was the most sensitive technique, 94.54% (95% Credible Interval (CrI) 90.09%-97.65%), qPCR was 64.69% (95% CrI 54.41%-74.15%) sensitive and ELISA IDEXX™ 26.74% (95% CrI 22.82%-30.97%). Tests' specificities were 98.19% (95% CrI 95.75%-99.45%), 93.49% (95% CrI 79.28%-99.66%), 95.53% (95% CrI 91.71%-98.02%) respectively. Despite its low sensitivity, ELISA IDEXX™ was able to identify positive samples that were not detected by the other techniques. These samples had high probability to be true positives given ELISA's positive predictive value. The correlations between qPCR and isolation were neither biologically nor statistically significant. The low sensitivity of the qPCR is a limiting factor to its use as a post-mortem diagnosis in bovine tuberculosis suggestive lesions. Its use could be recommended in situations of high prevalence, or in parallel association with other tests, such as ELISA IDEXX™. ELISA IDDEX™ should not be used as a unique test, or in substitution of the other tests, for the post-mortem diagnosis of bovine tuberculosis due to its sensitivity.

Comparative study of Mycobacterium bovis primary isolation methods

For the definitive diagnosis of bovine tuberculosis, isolation of the etiologic agent is required. However, there is no consensus on the best methodology for isolation of Mycobacterium bovis in Brazil. This study evaluated the most used decontaminants and culture media in the country, in order to identify the best combination for the Brazilian samples. Three decontaminants - 2% sodium hydroxide (w/v), 0.75% hexadecylpiridinium chloride (w/v) and 5% sulphuric acid (v/v) and four culture media - 7H11 Middlebrook with additives and OADC supplement A (7H11 A), the same media with another supplement trademark (7H11 B), tuberculosis blood agar (B83) and Stonebrink's medium were compared. Regarding the isolation, there were no significant differences between the decontaminants and media combinations, except 7H11A combined to any decontaminant. However, the mean colonies score was significantly greater when the samples were decontaminated with 5% sulphuric acid and inoculated in 7H11 B or SB, without significant difference between them, although colonies appeared earlier on 7H11B than on SB. The trademark of OADC supplement influenced the isolation rate and the number of isolated colonies in Middlebrook 7H11. An incubation time of four weeks was required to detect all positive samples in 7H11 B after decontamination with 5% sulphuric acid but there was an increase in the number of colonies until the sixth week of incubation. Overall, the best strategy for the primary isolation of M. bovis from Brazilian samples was the decontamination with 5% sulphuric acid (final concentration) and inoculation in Middlebrook 7H11 medium formulated with OADC supplement "B".(AU)

Molecular detection of Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV) in uterine biopsies of dairy cows with or without reproductive problems / Detecção molecular do Vírus da Língua Azul (BTV) e do Vírus da Leucemia bovina (BLV) em amostras de biópsia uterina de vacas leiteiras com e sem problemas reprodutivos

Reproductive performance of dairy cows has a direct impact on herd productivity. Infectious agents, such as Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV), are associated with reproductive failure. However, it remains unknown if these viruses are present in the uterus and cause gestational loss. This study used molecular methods to assess if BTV and BLV can be detected in the uterus of serologically positive dairy cows with a record of abortions, stillbirths and repeat breeding (n=23) and without a record of reproductive problems (n =23). The cows came from three dairy herds of the state of Minas Gerais, Brazil. BTV was not detected in any of the uterine biopsies. Proviral DNA of BLV was detected in 54.5 % of the seropositive cows, but positivity for BLV in the uterus was not associated with the existence of reproductive problems. In conclusion, this study shows that BLV, but not BTV, is present in the uterus of seropositive cows, regardless of reproductive performance.(AU)

O desempenho reprodutivo das vacas leiteiras tem impacto direto na produtividade dos rebanhos. Agentes infecciosos como o Vírus da Língua Azul (BTV) e o Vírus da Leucemia Bovina (BLV) estãoassociados à ocorrência de falhas reprodutivas. Entretanto, não se sabe se estes vírus poderiam estar presentes no útero resultando nas perdas gestacionais. Este estudo utilizou métodos moleculares para investigar se os vírus BTV e BLV estão presentes no úterio de vacas leiteiras sorologicamente positivas com histórico de abortos, natimortos e repetição de cio (n=23) e em vacas sem histórico de problema reprodutivos (n =23) provenientes de três rebanhos leiteiros localizados no estado de Minas Gerais, Brasil. Não foi detectado BTV em nenhuma amostra de biópsia uterina. Por outro lado, o DNA proviral de BLV foi detectado no útero de 54.5 % das vacas soropositivas, independentemente da ocorrência de problemas reprodutivos. Conclui-se que o vírus BLV, ao contrário do BTV está presente no útero de vacas soropositivas, entretanto, sem associação com o desempenho reprodutivo.(AU)

Molecular detection of Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV) in uterine biopsies of dairy cows with or without reproductive problems / Detecção molecular do Vírus da Língua Azul (BTV) e do Vírus da Leucemia bovina (BLV) em amostras de biópsia uterina de vacas leiteiras com e sem problemas reprodutivos

Reproductive performance of dairy cows has a direct impact on herd productivity. Infectious agents, such as Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV), are associated with reproductive failure. However, it remains unknown if these viruses are present in the uterus and cause gestational loss. This study used molecular methods to assess if BTV and BLV can be detected in the uterus of serologically positive dairy cows with a record of abortions, stillbirths and repeat breeding (n=23) and without a record of reproductive problems (n =23). The cows came from three dairy herds of the state of Minas Gerais, Brazil. BTV was not detected in any of the uterine biopsies. Proviral DNA of BLV was detected in 54.5 % of the seropositive cows, but positivity for BLV in the uterus was not associated with the existence of reproductive problems. In conclusion, this study shows that BLV, but not BTV, is present in the uterus of seropositive cows, regardless of reproductive performance.

O desempenho reprodutivo das vacas leiteiras tem impacto direto na produtividade dos rebanhos. Agentes infecciosos como o Vírus da Língua Azul (BTV) e o Vírus da Leucemia Bovina (BLV) estãoassociados à ocorrência de falhas reprodutivas. Entretanto, não se sabe se estes vírus poderiam estar presentes no útero resultando nas perdas gestacionais. Este estudo utilizou métodos moleculares para investigar se os vírus BTV e BLV estão presentes no úterio de vacas leiteiras sorologicamente positivas com histórico de abortos, natimortos e repetição de cio (n=23) e em vacas sem histórico de problema reprodutivos (n =23) provenientes de três rebanhos leiteiros localizados no estado de Minas Gerais, Brasil. Não foi detectado BTV em nenhuma amostra de biópsia uterina. Por outro lado, o DNA proviral de BLV foi detectado no útero de 54.5 % das vacas soropositivas, independentemente da ocorrência de problemas reprodutivos. Conclui-se que o vírus BLV, ao contrário do BTV está presente no útero de vacas soropositivas, entretanto, sem associação com o desempenho reprodutivo.

Prevalence and risk factors for bovine tuberculosis in Minas Gerais State, Brazil.

The aim of the present study was to estimate the prevalence and regional spread of bovine tuberculosis in the state of Minas Gerais, Brazil, to identify herd-level risk factors, and to provide guidance for disease control and mitigation of its impact in public health. The study comprised a large-scale random sample survey of 22,990 animals and 1586 herds, distributed in seven regions. A questionnaire was applied on each farm to collect epidemiological and herd management data. Overall, 5.04 % of herds and 0.81 % of animals were positive for bovine tuberculosis. The highest herd prevalence was found in Alto Paranaíba, an expanding dairy region. The more technologically advanced dairy herds showed a prevalence ratio of 2.83 compared to others and are obvious candidates for risk-based surveillance and herd accreditation schemes. Small farms cannot be left out of disease control efforts because they are the vast majority of herds, albeit with lower individual risk. With regard to public health, there is widespread practice of producing homemade fresh cheese with raw milk and of slaughtering culled cows in places without sanitary inspection. This poses a risk to consumers and limits the efficacy of surveillance at slaughter.

Molecular detection of bovine immunodeficiency virus in water buffaloes (Bubalus bubalis) from the Amazon region, Brazil.

Bovine immunodeficiency is a chronic progressive disease caused by a lentivirus that affects cattle and buffaloes. Although the infection has been described in cattle in some countries, including in Brazil, there are only two reports of infection in buffaloes: one in Pakistan and one in Cambodia. The aim of the present study was to survey the occurrence of bovine immunodeficiency virus (BIV) in water buffaloes from the Amazon region, Pará state, Brazil. BIV proviral DNA was surveyed in 607 whole blood samples of water buffaloes from 10 farms located in the state of Pará using semi-nested polymerase chain reaction (PCR) (PCR-SN) to amplify the pol region of the viral genome. Of the 607 samples tested, 27 (4.4 %) were positive for BIV proviral DNA. The amplified fragments were confirmed by sequence analysis after cloning and nucleotide sequencing. The sequence obtained had 99 % similarity to the reference strain (R-29). The present study provides important epidemiological data because BIV was detected for the first time in water buffaloes in Brazil. Further, the results suggest the possibility of the virus being a risk factor for herd health because it may be a potential causal agent of chronic disease and, also may be associated to other infectious diseases.

Comparison of the tuberculin test, histopathological examination, and bacterial culture for the diagnosis of tuberculosis (Mycobacterium bovis) in buffaloes (Bubalus bubalis) in Brazil.

Tuberculosis is a disease with a great zoonotic potential. It is considered a major obstacle to cattle production and is responsible for severe losses in several production systems. A comparative cervical test (CCT) was performed in 1140 buffaloes from different mesoregions of the state of Pará, Brazil, with the aim of comparing the sensitivity and specificity of CCT with histopathological examination and bacterial culture. Of the animals tested using CCT, 4.65% (53/1140) were positive, 2.98% (34/1140) were inconclusive, and 92.36% (1053/1140) were negative. Among the 168 sacrificed animals, 33 were positive, 18 were inconclusive, and 117 were negative by CCT, and samples from the sacrificed animals were collected for histopathological examination and bacterial culture. A qualitative evaluation of the tuberculin test was performed by comparing the test results with the histopathological and bacteriological results. The latter two tests yielded a prevalence of 4.16%, a sensitivity of 71.43%, and a specificity of 82.61%. Based on these results, we concluded that CCT yielded satisfactory results and can be applied in diagnostic studies in buffaloes. The prevalence rate obtained using three distinct diagnostic methods suggests that Mycobacterium bovis was present in a few animals in the population evaluated.

Bovine herpesvirus 6 in buffaloes (Bubalus bulalis) from the Amazon region, Brazil.

This study presents the first description of Bovine herpesvirus 6 (BoHV-6) that was isolated from buffaloes of Amazon region in Brazil. Phylogenetic analysis showed that the BoHV-6 Brazilian strains clustered with the sequence of BoHV-6 from elsewhere available at the GenBank. It was observed in some buffaloes with lymphoproliferative disease in one herd, thus the animals were also tested for Bovine leukemia virus (BLV), which has been associated to lymphoma in bovines. All animals were negative to BLV. These results indicate that BoHV-6 is present in buffaloes in Brazil, but the importance and impact of this infection and its association with any illness is still undefined.

Efeito da Infecção pelo vírus da leucose bovina na produção de rebanhos leiteiros mestiços e puros no Brasil / Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

O objetivo desse estudo foi avaliar os efeitos da infecção pelo vírus da leucose bovina (VLB) na produção de vacas leiteiras no Brasil. Foram analisadas 158 amostras de sangue de vacas adultas em lactação puras da raça Holandesa e mestiças Holandês X Zebu. As amostras foram testadas pela Imunodifusão em Gel de Ágar (IDGA) e pelo leucograma. De acordo com os resultados da IDGA e do leucograma, os animais estudados foram agrupados em três categorias: soronegativos, soropositivos sem linfocitose persistente e soropositivos com linfocitose persistente. Os dados de produção leiteira foram comparados entre os grupos, de acordo com a raça. Vacas infectadas com o VLB apresentaram produção de leite inferior que de vacas não infectadas, tanto puras como mestiças. Não houve diferença na produção de leite de vacas positivas com e sem linfocitose persistente. Esses resultados indicam a associação da infecção pelo VLB com a queda na produção de leite, e esse é o primeiro estudo a mostrar tais efeitos em vacas mestiças Holandês X Zebu.(AU)

The aim of this study was to evaluate the effects of bovine leukemia virus (BLV) infection on productive performance of dairy cattle in Brazil. A total of 158 blood samples from lactating adult cows, purebred Holstein and crossbred Holstein X Zebu, were analyzed by Agar Gel Immunodifusion Test (AGID) and leukogram. According to AGID and leukogram results, animals were grouped into three categories: seronegative, seropositive without persistent lymphocytosis, and seropositive with persistent lymphocytosis. Milk production data were compared between groups, according to breed. BLV infected females showed lower milk yield than uninfected ones, both purebred and crossbred ones. There was no difference between milk yield of seropositive cows with or without persistent lymphocytosis. These results indicate an association between BLV infection and reduction of milk production, and this study is the first one to show these effects in crossbred Holstein X Zebu cows.(AU)

Inquérito sorológico da infecção pelos vírus da encefalomielite equina no estado de Minas Gerais, Brasil / Serological survey of equine encephalomyelitis virus infection in the state of Minas Gerais, Brazil

Foi investigada a ocorrência da infecção pelos vírus da Encelafalomielite Equina do Leste (EEE), Encefalomielite Equina do Oeste (WEE) e Encefalomielite Equina Venezuelana (VEE) em equídeos não vacinados contra tais agentes, criados em dez delegacias regionais do estado de Minas Gerais (Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí e Viçosa), empregando-se a técnica de soroneutralização em microplacas. Dos 826 animais examinados, 30,2% ((250/826) foram soropositivos para EEE e 1,9% (16/826) para o zuelano de Encefalomielite Equina circulam na população equina do estado de Minas Gerais.

The occurrence of Equine Eastern Encephalomyelitis (EEE), Equine Western Encephalomyelitis (WEE) and Equine Venezuelan Encephalomyelitis (VEE) virus infection was investigated in equids not vaccinated against these viruses. The animals were distributed in ten regional districts of the state of Minas Gerais (Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí e Viçosa). Microplate serum neutralization test was used to detect antibodies against encephalitis virus. Two hundred and fifty animals (30.2%, 250/826) were EEE-seropositive, while 1.9% of them (16/826) were VEE-seropositive. No animals were found to be seropositive for WEE. In conclusion, either EEE or VEE viruses circulate in the equid population of the state of Minas Gerais.

Efeito da Infecção pelo vírus da leucose bovina na produção de rebanhos leiteiros mestiços e puros no Brasil / Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

O objetivo desse estudo foi avaliar os efeitos da infecção pelo vírus da leucose bovina (VLB) na produção de vacas leiteiras no Brasil. Foram analisadas 158 amostras de sangue de vacas adultas em lactação puras da raça Holandesa e mestiças Holandês X Zebu. As amostras foram testadas pela Imunodifusão em Gel de Ágar (IDGA) e pelo leucograma. De acordo com os resultados da IDGA e do leucograma, os animais estudados foram agrupados em três categorias: soronegativos, soropositivos sem linfocitose persistente e soropositivos com linfocitose persistente. Os dados de produção leiteira foram comparados entre os grupos, de acordo com a raça. Vacas infectadas com o VLB apresentaram produção de leite inferior que de vacas não infectadas, tanto puras como mestiças. Não houve diferença na produção de leite de vacas positivas com e sem linfocitose persistente. Esses resultados indicam a associação da infecção pelo VLB com a queda na produção de leite, e esse é o primeiro estudo a mostrar tais efeitos em vacas mestiças Holandês X Zebu.

The aim of this study was to evaluate the effects of bovine leukemia virus (BLV) infection on productive performance of dairy cattle in Brazil. A total of 158 blood samples from lactating adult cows, purebred Holstein and crossbred Holstein X Zebu, were analyzed by Agar Gel Immunodifusion Test (AGID) and leukogram. According to AGID and leukogram results, animals were grouped into three categories: seronegative, seropositive without persistent lymphocytosis, and seropositive with persistent lymphocytosis. Milk production data were compared between groups, according to breed. BLV infected females showed lower milk yield than uninfected ones, both purebred and crossbred ones. There was no difference between milk yield of seropositive cows with or without persistent lymphocytosis. These results indicate an association between BLV infection and reduction of milk production, and this study is the first one to show these effects in crossbred Holstein X Zebu cows.

Inquérito sorológico da infecção pelos vírus da encefalomielite equina no estado de Minas Gerais, Brasil / Serological survey of equine encephalomyelitis virus infection in the state of Minas Gerais, Brazil

Foi investigada a ocorrência da infecção pelos vírus da Encelafalomielite Equina do Leste (EEE), Encefalomielite Equina do Oeste (WEE) e Encefalomielite Equina Venezuelana (VEE) em equídeos não vacinados contra tais agentes, criados em dez delegacias regionais do estado de Minas Gerais (Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí e Viçosa), empregando-se a técnica de soroneutralização em microplacas. Dos 826 animais examinados, 30,2% ((250/826) foram soropositivos para EEE e 1,9% (16/826) para o zuelano de Encefalomielite Equina circulam na população equina do estado de Minas Gerais.(AU)}

The occurrence of Equine Eastern Encephalomyelitis (EEE), Equine Western Encephalomyelitis (WEE) and Equine Venezuelan Encephalomyelitis (VEE) virus infection was investigated in equids not vaccinated against these viruses. The animals were distributed in ten regional districts of the state of Minas Gerais (Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí e Viçosa). Microplate serum neutralization test was used to detect antibodies against encephalitis virus. Two hundred and fifty animals (30.2%, 250/826) were EEE-seropositive, while 1.9% of them (16/826) were VEE-seropositive. No animals were found to be seropositive for WEE. In conclusion, either EEE or VEE viruses circulate in the equid population of the state of Minas Gerais.(AU)

Quill mites in Brazilian psittacine birds (Aves: Psittaciformes).

The primary and secondary feathers of 170 Brazilian psittacine birds (Aves: Psittaciformes) were examined in order to identify feather quill mite fauna. Birds were held captive in two locations in the state of Minas Gerais (MG), and two in the state of Espirito Santo (ES). The quills were cut longitudinally and were examined under optical microscopy. The genus of quill mites most frequently found was Paralgopsis (Astigmata: Pyrogliphidae), followed by Cystoidosoma (Astigmata: Syringobiidae). Astigmata: Syringophilidae mites were sporadically observed. After analyzing the data using logistic regression models, it was determined that there was higher infestation risk for psittacines in ES state, as compared with those in MG, and a significant increase in risk depending on the psittacine host species. However, the location of captivity did not have a significant effect. Lesions were observed in infested feathers. Cystoidosoma sp. and Paralgopsis sp. were always observed together, with parts of Paralgopsis found inside Cystoidosoma sp., suggesting thanatochresis or predation.