Evaluation of RT-PCR and hemi-nested RT-PCR in brain samples from dogs with neurologic signs compatible with distemper

Foi comparado o valor diagnóstico das técnicas de RT-PCR e heminested RT-PCR (hnRT-PCR) em amostras de cérebro de cães com sintomatologia nervosa compatível com cinomose. Fragmentos do sistema nervoso central (SNC) colhidos de 68 animais foram testados pela Imunofluorescência direta (IFD) e, independentemente do resultado, foram armazenados a -20°C por pelo menos três anos. Após esse período, foram submetidos a RT-PCR e a hnRT-PCR com oligonucleotídeos iniciadores direcionados ao gene codificador da nucleoproteína N. As proporções de resultados positivos/examinados foram: 59/68 para a IFD, 40/68 para a RT-PCR (Kappa = 0,358) e 54/68 quando associada à heminested PCR (Kappa = 0,740). Houve nove resultados negativos nas três técnicas empregadas. Os resultados do coeficiente Kappa entre a IFD e hnRT-PCR demonstram que apesar das condições de armazenamento, a hnRT-PCR pode ser utilizada em estudos retrospectivos.The diagnostic value of RT-PCR and hemi-nested RT-PCR (hnRT-PCR) was compared in brain samples of dogs presenting neurological signs compatible with canine distemper. Samples of central nervous system (CNS) were collected from 68 dogs and tested by direct immunofluorescence test (RFID) and, independent of the results, they were stored at -20°C for at least three years. They were submitted to the RT-PCR and hnRT-PCR techniques aiming to determine the gene responsible for the viral nucleoprotein decoding. Fifty-nine samples were positive for RIFD, 40 for RT-PCR (Kappa = 0.358) and 54 for hnRT-PCR (Kappa = 0.740). All nine RIFD negative samples were also negative for RT-PCR and hnRT-PCR. In spite of the storage duration and proper sample conditions, the estimated accordance between hnRT-PCR and RIFD demonstrated that hnRT-PCR technique can be applied in retrospective studies

Using surveillance of animal bite patients to decipher potential risks of rabies exposure from domestic animals and wildlife in Brazil

Direct contact with domestic animals and wildlife is linked to zoonotic spillover risk. Patients presenting with animal-bite injuries provide a potentially valuable source of surveillance data on rabies viruses that are transmitted primarily by animal bites. Here, we used passive surveillance data of bite patients to identify areas with high potential risk of rabies transmission to humans across Brazil, a highly diverse and populous country, where rabies circulates in a range of species. We analyzed one decade of bite patient data from the national health information system (SINAN) comprising over 500,000 patients attending public health facilities after being bitten by a domestic or wild animal. Our analyses show that, between 2008 and 2016, patients were mostly bitten by domestic dogs (average annual dog bite patients: 502,043 [436,391–544,564], annual incidence per state: 258 dog bites/100,000 persons) and cats (76,512 [56,588–97,580] cat bites, 41 cat bites/100,000/year), but bites from bats (4,172 [3,351–5,365] bat bites, 2.3/100,000/year), primates (3,320 [3,013–3,710] primate bites, 2.0/100,000/year), herbivores (1,908 [1,492–2,298] herbivore bites, 0.9/100,000/year) and foxes (883 [609–1,086] fox bites, 0.6/100,000/year) were also considerable. Incidence of bites due to dogs and herbivores remained relatively stable over the last decade. In contrast bites by cats and bats increased while bites by primates and foxes decreased. Bites by wild animals occurred in all states but were more frequent in the North and Northeast of Brazil, with over 3-fold differences in incidence between states across all animal groups. Most bites reported from domestic animals and wildlife occurred in urban settings (71%), except for bites from foxes, which were higher in rural settings (57%). Based upon the Ministry of Health guidelines, only half of patients received the correct Post-Exposure Prophylaxis following a bite by a suspect rabid animal. We identified areas and species of high-risk for potential zoonotic transmission of rabies in Brazil and reveal that, despite increasing human encroachment into natural ecosystems, only patients reporting bites by bats increased. Our study calls for future research to identity the socio-ecological factors underlying bites and the preventive measures needed to reduce their incidence and potential risk of rabies transmission

Detecção do antigeno rábico através das provas de imunofluorescência e ímunoperoxidase direta em camundongos, experimentalmente inoculados, sacrificados em fase assintomática e agônica.

A positividade, para raiva, dos materiais cerebrais procedentes de camundongos, foi avaliada comparativamente através das reações de Imunofluorescência Direta (IFD) e Imunoperoxidase Direta (IPD), inoculando-se com vírus rábico de rua, sessenta (60) camundongos jovens pela via intracerebral. Sacrificaram-se trinta (30) dos inoculados em fase assintomática e os demais trinta (30) em fase agônica. No grupo de animais assintomáticos, obteve-se um percentual de 83,3% de positividade com a IPD e 86,6% com a IFD, em materiais cerebrais correspondentes aos mesmos animais. Nos materiais obtidos de animais sacrificados em fase agônica, os resultados foram 100% positivos em ambas as provas. Os resultados demonstraram que a IFD apresentou uma sensibilidade aparentemente superior à da IPD na detecção do antígeno rábico.The positivity of the direct immunoperoxidase and the fluorescent antibody test for rabies virus antigen was comparatively evaluated in sixty young mice inoculated intracerebrally with street rabies virus. Thirty mice were sacrificed in assymptomatic state and the others in their agonizing state. The positive results obtained from impression brain smears of assymptomatic animals by direct immunoperoxidase and fluorescent antibody test were 83.3% and 86.6%, respectively. The results found in impression brain smears of agonizing animals revelead 100% positivity in both techniques. The direct immunoperoxidase test presented a relative sensitivity comparable to thefluorescent antibody test for the detection of rabies virus antigen

Heminested reverse-transcriptase polymerase chain reaction (hnRT-PCR) as a tool for rabies virus detection in stored and decomposed samples

<p>Abstract</p> <p>Background</p> <p>The use of methods, both sensitive and specific, for rabies diagnosis are important tools for the control and prophylaxis of the disease. Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) has been used in rabies diagnosis with good results, even in decomposed materials. Additionally, molecular techniques have been used for epidemiological studies and to gain a better knowledge of viral epidemiology.</p> <p>Findings</p> <p>The aim of this work was to evaluate the RT-PCR and hnRT-PCR for rabies virus detection in original tissues stored at -20°C for different periods considering their use for rabies virus detection in stored and decomposed samples. RT-PCR and hnRT-PCR were evaluated in 151 brain samples from different animal species, thawed and left at room temperature for 72 hours for decomposition.</p> <p>The RT-PCR and hnRT-PCR results were compared with previous results from Direct Fluorescent Antibody Test and Mouse Inoculation Test. From the 50 positive fresh samples, 26 (52%) were positive for RT-PCR and 45 (90%) for hnRT-PCR. From the 48 positive decomposed samples, 17 (34, 3%) were positive for RT-PCR and 36 (75%) for hnRT-PCR. No false-positives results were found in the negatives samples evaluated to the molecular techniques.</p> <p>Conclusion</p> <p>These results show that the hnRT-PCR was more sensitive than RT-PCR, and both techniques presented lower sensibility in decomposed samples. The hnRT-PCR demonstrated efficacy in rabies virus detection in stored and decomposed materials suggesting it's application for rabies virus retrospective epidemiological studies.</p

Avaliação das provas de soroaglutinação rápida, soroaglutinação lenta, antígeno acidificado e 2-mercaptoetanol no diagnóstico da brucelose bovina

Avaliaram-se comparativamente as provas de soroaglutinação rápida, soroaglutinação em tubo, 2-mercaptoetanol e antígeno tamponado acidificado no diagnóstico da brucelose bovina. Todas as provas apresentaram boa concordância quando considerada a interpretação preconizada pelo Ministério da Agricultura do Brasil. As provas do antígeno tamponado acidificado e do 2-mercaptoetanol apresentaram alta concordância. Neste sentido, o presente estudo propõe o uso da prova do antígeno tamponado acidificado como triagem para o diagnóstico da brucelose bovina.Bovine serums were evaluated by the plate agglutination, tube agglutination, buffered plate antigen and 2-Mercaptoethanol tests for bovine brucellosis diagnosis. All presented a good concordance when considering the official Ministry of Agriculture interpretation. High concordance was verified for the buffered plate antigen and 2-Mercapthoetanol tests. This study suggests the use of the buffered plate antigen test as a screening test for bovine brucellosis diagnosis

Caracterização genética do gene da hemaglutinina em vírus da cinomose canina de cães naturalmente infectados no Brasil

Canine distemper is one of the major infectious diseases in dogs and wild animals, resulting in high morbidity and mortality. The H gene has the greatest genetic variability among the genes encoded by the canine distemper virus (CDV) genome, and it has been used to characterise field samples, allowing the identification of specific lineages. Variation in the H gene can allow the virus to evade recognition by vaccine-induced antibodies, resulting in vaccine failure. The purpose of this study was to characterise H gene in CDV strains from naturally infected dogs in the state of São Paulo. The phylogenetic analysis revealed that Brazilian CDV strains were genetically related to the circulating CDV strains in Uruguay, Argentina, and Europe. We found no evidence of South America 2 and 3 CDV lineages circulating in Brazilian dogs. The degree of genetic divergence between wild Brazilian CDV strains and vaccine strains may suggest the possibility of vaccine failures and consequently the occurrence of canine distemper outbreaks.A cinomose canina é uma das principais doenças infecciosas em cães e animais selvagens, resultando em alta morbidade e mortalidade. O gene H tem uma das maiores variabilidades genéticas entre os genes codificados pelo vírus da cinomose canina (CDV), e tem sido utilizado para caracterizar as estirpes de CDV, permitindo a identificação de linhagens específicas. A variação no gene H pode permitir que o vírus evite o reconhecimento por anticorpos induzidos pela vacina, resultando em falha vacinal. O objetivo deste estudo foi caracterizar o gene H em estirpes de CDV de cães infectados naturalmente no estado de São Paulo. A análise filogenética revelou que as estirpes de CDV brasileiras estão geneticamente relacionadas as estirpes circulantes no Uruguai, na Argentina e na Europa. Não foi encontrada nenhuma evidência da circulação no estado de São Paulo das linhagens América do Sul 2 e 3. O grau de divergência genética entre linhagens selvagens de CDV brasileiras e as estirpes vacinais podem sugerir a possibilidade de falhas vacinais e consequentemente a ocorrência de surtos de cinomose canina

Salmonelose em cães de experimentação

The occurrence of salmonellosis in dogs maintained in kennels destinated to scientific experiments was described. The isolates were characterized as Salmonella Typhimurium, Salmonella Agona and Salmonella enterica subsp. Enterica. The public health aspect and epidemiology were evaluated.Relata-se um surto de salmonelose em cães de experimentação, com mortalidade de 50% nos animais. Os sorotipos isolados foram Salmonella Typhimurium, Salmonella Agona e Salmonella enterica subsp. Enterica. Discute-se a epidemiologia e sua importância em Saúde Pública

Overview of Q fever in Brazil: an underestimated zoonosis

This review aims to provide current information about Q fever, elucidating the etiological, epidemiological, pathogenic, clinical, diagnostic, therapeutic, and prophylactic aspects of the disease for the medical community. We discuss the main forms of presentation of the agent, its ability to persist in the body, the infinite possibilities of susceptible hosts, the main known forms of transmission, its importance in populations at occupational risk, and the role of arthropods in the natural history of the disease. Focusing on Brazil, we present the cases already described and studies developed since its first report, and how there is still much to unravel. We are aware of the possibilities of the persistence of the agent and the development of severe clinical pictures and the specific treatments currently instituted. We also wish to raise awareness about the future, the new genotypes that are emerging, the need to study the effects of vaccines, and the impact of Q fever on the population. Q fever is a poorly understood disease in Latin America, and recent studies, especially in Brazil, have revealed the importance of developing new studies

Gene Expression Profile Induced by Two Different Variants of Street Rabies Virus in Mice

Pathogenicity and pathology of rabies virus (RABV) varies according to the variant, but the mechanisms are not completely known. In this study, gene expression profile in brains of mice experimentally infected with RABV isolated from a human case of dog rabies (V2) or vampire bat-acquired rabies (V3) were analyzed. In total, 138 array probes associated with 120 genes were expressed differentially between mice inoculated with V2 and sham-inoculated control mice at day 10 post-inoculation. A single probe corresponding to an unannotated gene was identified in V3 versus control mice. Gene ontology (GO) analysis revealed that all of the genes upregulated in mice inoculated with V2 RABV were involved in the biological process of immune defense against pathogens. Although both variants are considered pathogenic, inoculation by the same conditions generated different gene expression results, which is likely due to differences in pathogenesis between the dog and bat RABV variants. This study demonstrated the global gene expression in experimental infection due to V3 wild-type RABV, from the vampire bat Desmodus rotundus, an important source of infection for humans, domestic animals and wildlife in Latin America

Tuberculose canina e sua importância em saúde pública

The present paper describes tuberculosis in a family whose dog also presented the disease. The importance of animal epidemiological investigation in cases of tuberculosis in man is discussed.Relata-se um caso de uma família com diagnóstico de tuberculose, cujo cão também apresentava a enfermidade. Discute-se a importância do rastreamento epidemiológico animal em casos de tuberculose humana