Rabies in Callithrix sp. in the urban area of Niterói, Rio de Janeiro, Brazil.

In Brazil, rabies occurs mainly within an urban cycle, in which dogs and bats are reservoirs. This paper aims to report the occurrence of rabies in Callithrix sp. in Niterói, Rio de Janeiro, Brazil. In June 2019 a hybrid specimen was referred for diagnosis. The Direct Fluorescent Antibody, Mouse Inoculation, and Polymerase Chain Reaction tests were positive. A phylogenetic analysis was compatible with antigenic variant 3, characteristic of Desmodus rotundus. New studies should be undertaken to elucidate the real role of callitrichids in the urban rabies cycle.

Rabies in Callithrix sp. in the urban area of Niterói, Rio de Janeiro, Brazil

Abstract In Brazil, rabies occurs mainly within an urban cycle, in which dogs and bats are reservoirs. This paper aims to report the occurrence of rabies in Callithrix sp. in Niterói, Rio de Janeiro, Brazil. In June 2019 a hybrid specimen was referred for diagnosis. The Direct Fluorescent Antibody, Mouse Inoculation, and Polymerase Chain Reaction tests were positive. A phylogenetic analysis was compatible with antigenic variant 3, characteristic of Desmodus rotundus. New studies should be undertaken to elucidate the real role of callitrichids in the urban rabies cycle.

Non-human primates as a reservoir for rabies virus in Brazil.

Rabies virus (RABV) does not persist in the environment as it is a very fragile agent. The primary hosts are mammalian species in the orders Carnivora and Chiroptera. Since the late 1980s, RABV has been isolated from non-human primates, Callithrix jacchus (the white-tufted marmoset), in four coastal states (Rio Grande do Norte, Ceará, Piauí and Pernambuco) in north-eastern Brazil, where this species is indigenous. The original habitat of C. jacchus consisted of two Brazilian biomes, the Atlantic Forest and the Caatinga. However, these marmosets have since adapted to other ecosystems as a result of human activities. Between 1988 and 1989, RABV isolates were obtained from white-tufted marmosets in the state of Rio Grande do Norte, but antigenic and genetic identification studies were not conducted at that time. In the following years, three additional states reported cases (Ceará, Piauí and Pernambuco). In two of these states (Ceará and Piauí), human cases of rabies transmitted by marmosets were reported. According to Brazilian Health Ministry data, at least 19 human cases in which this species was the source of infection were registered in between 1990 and 2016. Recent findings in laboratory tests of 12 rabid samples from humans and marmosets and the regional transmission among these animals for over 20 years, together with the gradual increase in the affected geographic area, support the concept of the emergence of a new RABV reservoir. Regional tourism, the wild animal trade and the cultural practice of maintaining these animals as pets, particularly in coastal regions, appear to be major risk factors for the increase in human cases. Additional epidemiological and ecological studies are required to better understand local disease dynamics and to identify ideal opportunities for prevention and control of this fatal infection.

Non-human primates as a reservoir for rabies virus in Brazil

Rabies virus (RABV) does not persist in the environment as it is a very fragile agent. The primary hosts are mammalian species in the orders Carnivora and Chiroptera. Since the late 1980s, RABV has been isolated from non-human primates, Callithrix jacchus (the white-tufted marmoset), in four coastal states (Rio Grande do Norte, Ceará, Piauí and Pernambuco) in north-eastern Brazil, where this species is indigenous. The original habitat of C. jacchus consisted of two Brazilian biomes, the Atlantic Forest and the Caatinga. However, these marmosets have since adapted to other ecosystems as a result of human activities. Between 1988 and 1989, RABV isolates were obtained from white-tufted marmosets in the state of Rio Grande do Norte, but antigenic and genetic identification studies were not conducted at that time. In the following years, three additional states reported cases (Ceará, Piauí and Pernambuco). In two of these states (Ceará and Piauí), human cases of rabies transmitted by marmosets were reported. According to Brazilian Health Ministry data, at least 19 human cases in which this species was the source of infection were registered in between 1990 and 2016. Recent findings in laboratory tests of 12 rabid samples from humans and marmosets and the regional transmission among these animals for over 20 years, together with the gradual increase in the affected geographic area, support the concept of the emergence of a new RABV reservoir. Regional tourism, the wild animal trade and the cultural practice of maintaining these animals as pets, particularly in coastal regions, appear to be major risk factors for the increase in human cases. Additional epidemiological and ecological studies are required to better understand local disease dynamics and to identify ideal opportunities for prevention and control of this fatal infection.

Non-human primates as a reservoir for rabies virus in Brazil

Rabies virus (RABV) does not persist in the environment as it is a very fragile agent. The primary hosts are mammalian species in the orders Carnivora and Chiroptera. Since the late 1980s, RABV has been isolated from non-human primates, Callithrix jacchus (the white-tufted marmoset), in four coastal states (Rio Grande do Norte, Ceará, Piauí and Pernambuco) in north-eastern Brazil, where this species is indigenous. The original habitat of C. jacchus consisted of two Brazilian biomes, the Atlantic Forest and the Caatinga. However, these marmosets have since adapted to other ecosystems as a result of human activities. Between 1988 and 1989, RABV isolates were obtained from white-tufted marmosets in the state of Rio Grande do Norte, but antigenic and genetic identification studies were not conducted at that time. In the following years, three additional states reported cases (Ceará, Piauí and Pernambuco). In two of these states (Ceará and Piauí), human cases of rabies transmitted by marmosets were reported. According to Brazilian Health Ministry data, at least 19 human cases in which this species was the source of infection were registered in between 1990 and 2016. Recent findings in laboratory tests of 12 rabid samples from humans and marmosets and the regional transmission among these animals for over 20 years, together with the gradual increase in the affected geographic area, support the concept of the emergence of a new RABV reservoir. Regional tourism, the wild animal trade and the cultural practice of maintaining these animals as pets, particularly in coastal regions, appear to be major risk factors for the increase in human cases. Additional epidemiological and ecological studies are required to better understand local disease dynamics and to identify ideal opportunities for prevention and control of this fatal infection.

Analysis of rabies diagnosis in dogs and cats in the state of São Paulo, Brazil

The genetic lineage of rabies virus (RABV) associated with dogs has not been found in the state of São Paulo since 1998, and all cases of rabies in domestic animals reported since then have involved the RABV lineage that circulates in bats. As there has been a change in the rabies transmission cycle in cats and dogs, we decided to analyze the tests used to diagnose rabies in these animals in the 15-year period from 2002 to 2016 in the state of São Paulo. During this period, 85,508 central nervous system (CNS) samples from dogs and cats were submitted to the Rabies Diagnosis Section at the Pasteur Institute of São Paulo for testing. All of the samples were tested by the fluorescent antibody test (FAT) and at least one of the following three tests: mouse inoculation test (MIT), rabies tissue culture infection test (RTCIT) and reverse transcription polymerase chain reaction (RT-PCR). Of all the samples tested, twenty were positive in at least one of these assays. Four other positive samples were identified at other institutions in the state of São Paulo. Of the twenty samples that tested positive at the Pasteur Institute of São Paulo, nine were tested by FAT, and the results were subsequently confirmed by other techniques; five gave inconclusive results, and therefore, other techniques had to be used as soon as possible in case the samples were positive; and six were negative by FAT and positive by one or more of the following tests:...

Non-human primates as a reservoir for rabies virus in Brazil

Rabies virus (RABV) does not persist in the environment as it is a very fragile agent. The primary hosts are mammalian species in the orders Carnivora and Chiroptera. Since the late 1980s, RABV has been isolated from non­human primates, Callithrix jacchus (the white­tufted marmoset), in four coastal states (Rio Grande do Norte, Ceará, Piauí and Pernambuco) in north­eastern Brazil, where this species is indigenous. The original habitat of C. jacchus consisted of two Brazilian biomes, the Atlantic Forest and the Caatinga. However, these marmosets have since adapted to other ecosystems as a result of human activities. Between 1988 and 1989, RABV isolates were obtained from white­tufted marmosets in the state of Rio Grande do Norte, but antigenic and genetic identification studies were not conducted at that time. In the following years, three additional states reported cases (Ceará, Piauí and Pernambuco). In two of these states (Ceará and Piauí), human cases of rabies transmitted by marmosets were reported. According to Brazilian Health Ministry data, at least 19 human cases in which this species was the source of infection were registered in between 1990 and 2016. Recent findings in laboratory tests of 12 rabid samples from humans and marmosets and the regional transmission among these animals for over 20 years, together with the gradual increase in the affected geographic area, support the concept of the emergence of a new RABV reservoir. Regional tourism, the wild animal trade and the cultural practice of maintaining these animals as pets, particularly in coastal regions, appear to be major risk factors for the increase in human cases. Additional epidemiological and ecological studies are required to better understand local disease dynamics and to identify ideal opportunities for prevention and control of this fatal infection. (AU)

Diagnóstico de cinomose canina por RT-PCR em amostras de cães do Estado de São Paulo enviadas para a vigilância laboratorial da raiva

A cinomose canina (CD) é uma das doenças infecciosas mais importantes dos cães domésticos. No Brasil é ainda a principal causa de mortalidade de cães em algumas populações urbanas. Embora sequências de diferentes genes do vírus sejam utilizadas como alvo para detecção do vírus da cinomose canina (CDV), o gene N parece ser o melhor para a amplificação de todas as suas linhagens. Utilizando-se a técnica de RT-PCR direcionada ao gene N do CDV, foram analisadas 190 amostras de sistema nervoso central (SNC) de cães do estado de São Paulo com quadros sugestivos de encefalite e que foram encaminhadas ao Instituto Pasteur para o diagnóstico da raiva, durante o ano de 2014. A positividade foi superior a 50% indicando que a cinomose continua a ser uma importante causa de mortalidade canina.

Identification of Different Species of Mammalians Involved in Zoonoses as Reservoirs or Hosts by Sequencing of the Mitochondrial DNA Cytochrome B Gene

Introduction: The identification of species that act as reservoirs or hosts of zoonotic agents is essential for control and epidemiological surveillance of the important illness in public health. Identification of the reservoirs for zoonoses can help to clarify how the pathogens are maintained in nature, leading to more effective disease control and avoiding indiscriminate extermination of wild animals.Aims: The objective of this study was to describe the genetic identification of 106 samples isolated from different mammalians species.Methodology: This study was conducted using 106 tissue samples from wild and domestic mammals sent to rabies diagnosis in Pasteur Institute, Brazil. Sequencing of the mitochondrial DNA b gene and Basic Local Alignment Search Tool (BLAST) was used to confirm species identity.Results and Conclusion: By sequencing the mtDNA cyt-b gene 10 orders, 20 families, 34 genera and 38 species of mammalians were identified. In conclusion, the method used at this work was efficient for identification of different species of mammalians. Animals identified at this work with same method, belong to high distance order, as marsupials, chiropters and primates.

Genetic identification of species of bats that act as reservoirs or hosts for viral diseases

Introduction: Viruses have been identified as the main etiologic agents of both zoonoses and emerging infectious diseases (EIDs) and various species of wild fauna can be involved in the maintenance of these diseases. The very wide variety of bats, together with their ability to adapt to different environments and fly long distances, means that these animals are currently one of the main reservoirs for zoonoses and EIDs. For these reasons the correct identification of different bat species is essential.Aims: This paper describes the genetic identification of 56 samples isolated from different bat species.Methodology: Sequencing and phylogenetic analysis of the mitochondrial DNA cytochrome b (mtDNA cyt-b) gene. Results: Four families (Molossidae, Vespertilionidae, Noctilionidae and Phyllostomidae), twelve genera and nineteen different species of bats were identified, and the Basic Local Alignment Search Tool (BLAST) was used to confirm species identity. The phylogenetic tree constructed revealed two main clusters (1 and 2), both consist in two subclusters.Conclusions: Our results were concordant with those obtained by morphometric identification and genetic identification carried out by other authors, showing that the method described here can be used as an effective alternative to, or in combination with, morphometric identification of bats

Epidemiologia molecular de surto de raiva bovina na região central do Rio Grande do Sul, 2012 / Molecular epidemiology of an outbreak of bovine rabies in central Rio Grande do Sul, Brazil, 2012

A raiva é uma doença infecciosa do sistema nervoso central de mamíferos causada pelo vírus da raiva (RabV), geralmente, transmitido pela mordedura de animais infectados. No Brasil, os morcegos hematófagos Desmodus rotundus são as principais fontes de infecção do RabV para bovinos e equinos. Este artigo descreve uma investigação epidemiológica e molecular de surtos de raiva ocorridos na região central do Rio Grande do Sul, entre maio e agosto de 2012. Nesse período, 45 casos suspeitos de raiva foram relatados em 22 pequenos rebanhos, localizados dentro de um raio de 4,7km, no município de Pinhal Grande. Desses, 32 amostras foram submetidas para diagnóstico da raiva, sendo que o RabV e/ou antígenos virais foram identificados em 27 amostras. Em um segundo momento, 11 amostras foram submetidas à transcrição reversa/reação em cadeia da polimerase (RT-PCR) para o gene da nucleoproteína (N) do RabV, seguido de sequenciamento nucleotídico e análise filogenética. Sete das 11 amostras apresentaram sequências nucleotídicas idênticas e uma apresentou mutação sinônima, não-codificante, indicando uma provável origem comum dos vírus. Por outro lado, três amostras apresentaram mutações que resultaram em alterações de aminoácidos, sugerindo uma origem diferente do vírus. Esses resultados sugerem que RabV de diferentes origens/linhagens co-circulam na região e foram envolvidos nos surtos descritos. Investigações sobre a circulação de ambos os genótipos em morcegos na região estão em andamento.

Rabies is an infectious disease of the central nervous system of mammals caused by rabies virus (RabV), generally transmitted by the bite of rabid animals. In Brazil, vampire bats Desmodus rotundus are the main reservoirs of RabV for livestock. The present study describes a molecular and epidemiological investigation of outbreaks of bovine rabies occurring in the central region of Rio Grande do Sul state, Brazil, between May and August 2012. In this period, 45 cases suspected of rabies were reported in 22 small herds, located within a 4.7km range, in the county of Pinhal Grande. From these, 32 samples were submitted to rabies diagnosis and RabV and/or viral antigens were identified in 27 samples. Subsequently, 11 brain samples were submitted to reverse transcription/polymerase chain reaction (RT-PCR) for the nucleoprotein gene (N) followed by nucleotide sequencing and phylogenetic analysis. Seven out of 11 samples yielded identical sequences; one presented a synonymous, non-coding mutation, indicating a likely common origin of the virus. However, three other samples presented nucleotide mutations which resulted in amino acid changes, suggesting a different origin of the virus. In summary, these results suggest that RabV strains of different origin/lineages co-circulate in the region and were involved in the outbreaks. Investigations on the circulation of both genotypes in bats in the region are currently underway.

Phylogeographic dispersion and diversification of rabies virus lineages associated with dogs and crab-eating foxes (Cerdocyon thous) in Brazil

Genetic lineages of dog-associated RABV still circulate in some areas of the North and Northeast of Brazil. In parallel, another RABV lineage circulates among wild canids in the Northeast, particularly the crab-eating fox (Cerdocyon thous). Although previous studies and phylogenetic analyses have been carried out, the way in which these lineages are dispersed temporally and spatially remained to be elucidated. In this study, RABV N gene sequences isolated from canids in North and Northeast Brazil were analyzed by the Bayesian Markov Chain Monte Carlo Method, and the results were then used in a phylogeographic study. It was inferred from the findings that the most recent common ancestor became established at the end of the nineteenth century on the border of the Brazilian states of Paraíba and Pernambuco and diversified into the lineages associated with dogs and C. thous. Around 1910, the original C. thous lineage diversified into two main sublineages in the same area, one of which migrated to the south and the other to the north. The dog-associated lineage diversified around 1945 and moved toward the north and south. From the phylogeographic analysis it was possible to infer not only the movement of the virus lineages but also the probable location where dispersion and diversification occurred. The methodology used here enabled the phylogeographic history of RABV in the region to be reconstructed, and the dispersion pattern of the virus can be used to predict its movements, making it easier to stop the advance of a rabies epidemic.

In vitro and in vivo inhibition of rabies virus replication by RNA interference

Rabies is a zoonotic disease that affects all mammals and leads to more than 55,000 human deaths every year, caused by rabies virus (RABV) (Mononegavirales: Rhabdoviridae: Lyssavirus). Currently, human rabies treatment is based on the Milwaukee Protocol which consists on the induction of coma and massive antiviral therapy. The aim of this study was to assess the decrease in the titer of rabies virus both in vitro and in vivo using short-interfering RNAs. To this end, three siRNAs were used with antisense strands complementary to rabies virus nucleoprotein (N) mRNA. BHK-21 cells monolayers were infected with 1000 to 0.1 TCID50 of PV and after 2 hours the cells were transfected with each of tree RNAs in separate using Lipofectamine-2000. All three siRNAs reduced the titer of PV strain in a least 0.72 logTCID50/mL and no cytotoxic effect was observed in the monolayers treated with Lipofectamine-2000. Swiss albino mice infected with 10.000 to 1 LD of PV strain by the intracerebral route were also transfected after two hours of infection with a pool 3 siRNAs with Lipofectamine-2000 by the intracerebral route, resulting in a survival rate of 30% in mice inoculated with 100 LD50, while the same dose led to 100% mortality in untreated animals. Lipofectamine-2000 showed no toxic effect in control mice. These results suggest that intracerebral administration of siRNAs might be an effective antiviral strategy for rabies.

Antigenic and genetic characterization of rabies virus isolates from Uruguay

After 25 years without any reported cases of rabies in Uruguay, the northern region of the country experienced an epizootic of bovine paralytic rabies in October 2007. The outbreak affected bovines and equines, and the main source of infection was the bat Desmodus rotundus, the only hematophagous species in the country. From October 2007 to July 2008, 42 bovine, 3 equine and 120 chiropteran samples were submitted to the National Veterinary Diagnostic Laboratory for rabies testing. A total of 12 samples (7 bovine, 2 equine and 3 from D. rotundus) were positive by the fluorescent antibody test, and viruses were isolated by the mouse inoculation test. The objective of this study was to compare the antigenic and genetic characteristics of these isolates and three isolates from insectivorous bats from other regions. Antigenic typing using a panel of eight monoclonal antibodies identified all 12 viruses as variant 3 (AgV3), a variant associated with D. rotundus. Two isolates from insectivorous bats (Tadarida brasiliensis and Molossus sp.) were characterized as antigenic variant 4 (AgV4) while the third, from Myotis sp., could not be characterized using this panel as its reactivity pattern did not match that of any of the known antigenic variants. Partial N-gene sequences (nt 149–1420) of these isolates were aligned with homologous sequences derived from GenBank by the CLUSTAL/W method and used to build a neighbor-joining distance tree with the Kimura 2-parameter model. All 12 isolates were genetically grouped into the D. rotundus cluster as they shared 100% identity. In the phylogenetic analysis, the three isolates from insectivorous bats segregated into three clusters: one related to T. brasiliensis, one to Myotis sp. and the other to Lasiurus sp., although the isolate associated with the latter came from a Molossus sp. specimen. These results indicate that AgV3 was associated with the outbreak of bovine paralytic rabies in Uruguay. This is the first report...

Método de diagnóstico antemortem da raiva humana por meio de técnicas de biologia molecular, utilizando saliva e biópsia de pele da região da nuca / An antemortem method for diagnosis of human rabies by molecular techniques using saliva and neck-skin biopsy

Por meio das técnicas de RT-PCR com primers direcionados para o gene da

glicoproteína e RT-PCR e hemi-nested RT-PCR com primers direcionados para o gene da nucleoproteína, o RNA do vírus da raiva foi identificado em 95,2% de 21 amostras, 18 de saliva e três de biópsia de pele da região da nuca, coletadas entre a hospitalização e a morte de um paciente com sinais clínicos da raiva. O tratamento administrado ao paciente incluiu a indução de coma e terapia antiviral. Cada técnica, isoladamente, detectou RNA viral em 90,5%; 57,1% e 85,7% das amostras, respectivamente. Nossos resultados sugerem que a amplificação em paralelo de diferentes regiões do genoma do vírus da raiva pode fornecer maior confiabilidade ao diagnóstico antemortem da doença, auxiliando a decisão médica quanto à aplicação do protocolo de tratamento com antivirais.

Antigenic and genetic characterization of rabies virus isolates from Uruguay.

After 25 years without any reported cases of rabies in Uruguay, the northern region of the country experienced an epizootic of bovine paralytic rabies in October 2007. The outbreak affected bovines and equines, and the main source of infection was the bat Desmodus rotundus, the only hematophagous species in the country. From October 2007 to July 2008, 42 bovine, 3 equine and 120 chiropteran samples were submitted to the National Veterinary Diagnostic Laboratory for rabies testing. A total of 12 samples (7 bovine, 2 equine and 3 from D. rotundus) were positive by the fluorescent antibody test, and viruses were isolated by the mouse inoculation test. The objective of this study was to compare the antigenic and genetic characteristics of these isolates and three isolates from insectivorous bats from other regions. Antigenic typing using a panel of eight monoclonal antibodies identified all 12 viruses as variant 3 (AgV3), a variant associated with D. rotundus. Two isolates from insectivorous bats (Tadarida brasiliensis and Molossus sp.) were characterized as antigenic variant 4 (AgV4) while the third, from Myotis sp., could not be characterized using this panel as its reactivity pattern did not match that of any of the known antigenic variants. Partial N-gene sequences (nt 149-1420) of these isolates were aligned with homologous sequences derived from GenBank by the CLUSTAL/W method and used to build a neighbor-joining distance tree with the Kimura 2-parameter model. All 12 isolates were genetically grouped into the D. rotundus cluster as they shared 100% identity. In the phylogenetic analysis, the three isolates from insectivorous bats segregated into three clusters: one related to T. brasiliensis, one to Myotis sp. and the other to Lasiurus sp., although the isolate associated with the latter came from a Molossus sp. specimen. These results indicate that AgV3 was associated with the outbreak of bovine paralytic rabies in Uruguay. This is the first report of rabies virus having been detected in non-hematophagous bats in this country.

Análise da mudança da cobertura e uso da terra dos municípios de Jacarei e Santa Branca-SP como subsídio ao estudo das ocorrências de raiva transmitida por morcegos / Analysis of cover and land use change in the municipalities of Santa Branca and Jacarei-SP to the study of the occurrence of rabies transmitted by bats

Neste trabalho avaliou-se a influência do uso e cobertura da terra nas ocorrências de raiva animal nos municípios de Jacareí e Santa Branca, Vale do Paraíba, Estado de São Paulo. Combinou-se o mapeamento a partir de imagens TM/Landsat-5 com os dados de ocorrência da enfermidade, entre 2002 e 2009. Animais silvestres atropelados em rodovias, morcegos urbanos e Desmodus rotundus de áreas rurais e animais de fazenda de interesse econômico foram considerados. Dez amostras foram positivas para raiva, três de morcegos insetívoros da área urbana de Jacareí e sete animais de fazenda de interesse econômico, sendo dois de Jacareí e cinco de Santa Branca. Nenhum dos animais silvestres avaliados foram raiva-positivos. A análise da dinâmica da cobertura e uso da terra não evidenciou alteração significante. Embora a enfermidade ocorresse sem uma aparente mudança na região, provavelmente devido à escala de análise utilizada, concluiu-se que a classe reflorestamento e agropecuária foram relacionadas à enfermidade, por ocorrerem com maior freqüência na área analisada.

In this paper, the influence of land cover and land use on the rabies in Jacareí and Santa Branca municipalities, Paraíba's Valley of the State of Sao Paulo was evaluated by combining the Landsat satellite images mapping with data of rabies occurrence, in 2002-2009. Wildlife roadkills, urban bats, Desmodus rotundus bats from rural areas and livestock were considered. Ten samples were rabies-positive, being three insectivorous bats from the urban Jacareí, and seven livestock, being two from Jacarei and five from Santa Branca. None of the wildlife examined was rabies-positive. The landscape and land use analysis found that no significant changes occurred. Although the disease has occurred even without apparent changes in the region, probably due to the scale used in this study, it was concluded that the reforestation and agriculture areas were associated to the disease to show major frequency in the analyzed areas.

Rabies virus in insectivorous bats: implications of the diversity of the nucleoprotein and glycoprotein genes for molecular epidemiology.

Insectivorous bats are the main reservoirs of rabies virus (RABV) in various regions of the world. The aims of this study were to (a) establish genealogies for RABV strains from different species of Brazilian insectivorous bats based on the nucleoprotein (N) and glycoprotein (G) genes, (b) investigate specific RABV lineages associated with certain genera of bats and (c) identify molecular markers that can distinguish between these lineages. The genealogic analysis of N and G from 57 RABV strains revealed seven genus-specific clusters related to the insectivorous bats Myotis, Eptesicus, Nyctinomops, Molossus, Tadarida, Histiotus and Lasiurus. Molecular markers in the amino acid sequences were identified which were specific to the seven clusters. These results, which constitute a novel finding for this pathogen, show that there are at least seven independent epidemiological rabies cycles maintained by seven genera of insectivorous bats in Brazil.

Human rabies transmitted by vampire bats: antigenic and genetic characterization of rabies virus isolates from the Amazon region (Brazil and Ecuador).

Since 2004, the main transmitter of human rabies in Latin America has been the vampire bat (Desmodus rotundus). Based on the nucleoprotein of the rabies virus (RV), we analyzed antigenic and genetic profiles of isolates from 29 samples taken from humans living in different areas of the Amazon region. Two isolates were from Ecuador and 27 from the Northern and Northeastern regions of Brazil, which were obtained during outbreaks in various municipalities in the states of Pará and Maranhão in the years 2004 and 2005. The partial N gene (nt 104-1477) of the 29 isolates was sequenced, and the sequences were used to build a neighbor-joining tree with the Kimura-2 parameter model. All 29 human RV isolates were identified as belonging to antigenic variant 3 (AgV3) and were genetically grouped into the D. rotundus cluster, which was divided into two subclusters (A and B), subcluster A in turn being divided into four genetic groups (A1, A2, A3 and A4). Genetic and molecular markers characterizing these genetic lineages were also identified. The results of this study show that the isolates belong to the same rabies cycle as that of the vampire bat D. rotundus. However, the division of clusters within the lineage associated with D. rotundus shows that different genetic sublineages of the virus were circulating in the Amazon region during the study period. Our findings suggest that there are phylogeographic differences between isolates obtained over a short period.

Genetic characterization of rabies virus isolated from bovines and equines between 2007 and 2008, in the States of São Paulo and Minas Gerais.

INTRODUCTION: Rabies is an acute disease of the central nervous system and is responsible for the deaths of thousands of humans, wild animals and livestock, particularly cattle, as well as causing major economic losses. This study describes the genetic characterization of rabies virus variants that circulate in Desmodus rotundus populations and are transmitted to herbivores. METHODS: Fifty rabies virus isolates from bovines and equines in the States of São Paulo and Minas Gerais, Brazil, were genetically characterized and compared with sequences retrieved from GenBank. RESULTS: Two clusters (I and II) with mean nucleotide identities of 99.1 and 97.6% were found. The first of these contained nearly all the samples analyzed. Lineages from other Brazilian states grouped in cluster II. CONCLUSIONS: Analysis of the amino acid sequences of the N proteins revealed the existence of genetic markers that may indicate possible variations between geographic regions, although the biologically active regions are conserved within the species over space and time.