No Evidence of Rabies Exposure in Wild Marmosets (Callithrix jacchus) of Northeast Brazil.

Rabies transmitted by wildlife is the main source of human rabies mortality in Latin America and considered an emerging disease. The common marmoset Callithrix jacchus of Brazil is the only known primate reservoir of rabies worldwide. We tested whether alive free-ranging C. jacchus were exposed to rabies in four northeast states that have previously reported rabies-positive dead C. jacchus (Pernambuco and Bahia) or not (Paraíba and Rio Grande do Norte). Our results show no evidence of rabies antibodies or infection in the sampled C. jacchus, suggesting that apparently healthy marmosets are not widely exposed to rabies over their natural range.

Spatio-temporal dynamics of rabies and habitat suitability of the common marmoset Callithrix jacchus in Brazil.

Rabies transmitted by wildlife is now the main source of human rabies in the Americas. The common marmoset, Callithrix jacchus, is considered a reservoir of rabies causing sporadic and unpredictable human deaths in Brazil, but the extent of the spillover risk to humans remains unknown. In this study, we described the spatiotemporal dynamics of rabies affecting C. jacchus reported to Brazil's Ministry of Health passive surveillance system between 2008 and 2020, and combined ecological niche modelling with C. jacchus occurrence data to predict its suitable habitat. Our results show that 67 outbreaks (91 cases) of rabies affecting C. jacchus were reported by 41 municipalities between January 2008 and October 2020, with a mean of 5 outbreaks/year [range: 1-14]. The maximum number of outbreaks and municipalities reporting cases occurred in 2018, coinciding with higher surveillance of primate deaths due to Yellow Fever. A mean of 3 [1-9] new municipalities reported outbreaks yearly, suggesting potential spatial expansions of the C. jacchus variant in northeastern Brazil and emerging rabies spillover from vampire bat Desmodus rotundus to C. jacchus in the north and south. Outbreaks were concentrated in the states of Ceará (72%) and Pernambuco (16%) up to 2012, but are now reported in Piauí since 2013, in Bahia since 2017 (D. rotundus' antigenic variant, AgV3) and in Rio de Janeiro since 2019 (AgV3). Besides confirming suitable habitat for this primate in the northeast and the east coast of Brazil, our Maximum Entropy model also predicted suitable habitat on the north and the west states of the country but predicted low habitat suitability among inland municipalities of the Caatinga biome reporting rabies. Our findings revealed new areas reporting rabies infecting C. jacchus, highlighting the need to implement strategies limiting spillover to humans and to better understand the drivers of C. jacchus rabies dynamics.

Spatio-temporal dynamics of rabies and habitat suitability of the common marmoset Callithrix jacchus in Brazil

Rabies transmitted by wildlife is now the main source of human rabies in the Americas. The common marmoset, Callithrix jacchus, is considered a reservoir of rabies causing sporadic and unpredictable human deaths in Brazil, but the extent of the spillover risk to humans remains unknown. In this study, we described the spatiotemporal dynamics of rabies affecting C. jacchus reported to Brazil’s Ministry of Health passive surveillance system between 2008 and 2020, and combined ecological niche modelling with C. jacchus occurrence data to predict its suitable habitat. Our results show that 67 outbreaks (91 cases) of rabies affecting C. jacchus were reported by 41 municipalities between January 2008 and October 2020, with a mean of 5 outbreaks/year [range: 1–14]. The maximum number of outbreaks and municipalities reporting cases occurred in 2018, coinciding with higher surveillance of primate deaths due to Yellow Fever. A mean of 3 [1–9] new municipalities reported outbreaks yearly, suggesting potential spatial expansions of the C. jacchus variant in northeastern Brazil and emerging rabies spillover from vampire bat Desmodus rotundus to C. jacchus in the north and south. Outbreaks were concentrated in the states of Ceará (72%) and Pernambuco (16%) up to 2012, but are now reported in Piauí since 2013, in Bahia since 2017 (D. rotundus’ antigenic variant, AgV3) and in Rio de Janeiro since 2019 (AgV3). Besides confirming suitable habitat for this primate in the northeast and the east coast of Brazil, our Maximum Entropy model also predicted suitable habitat on the north and the west states of the country but predicted low habitat suitability among inland municipalities of the Caatinga biome reporting rabies. Our findings revealed new areas reporting rabies infecting C. jacchus, highlighting the need to implement strategies limiting spillover to humans and to better understand the drivers of C. jacchus rabies dynamics.

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.

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)

Monoclonal antibodies for characterization of rabies virus isolated from non-hematophagous bats in Brazil.

INTRODUCTION: In Brazil, various isolates of rabies virus (RABV) show antigenic profiles distinct from those established by the reduced panel of eight monoclonal antibodies (MAbs) determined by the Centers for Disease Control and Prevention (CDC), utilized for the antigenic characterization of RABV in the Americas. The objective of this study was to produce MAbs from RABV isolates from insectivorous bats with an antigenic profile incompatible with the pre-established one. METHODOLOGY: An isolate of RABV from the species Eptesicus furinalis that showed an antigenic profile incompatible with the panel utilized was selected. Hybridomas were produced utilizing the popliteal lymph nodes of mice immunized with ribonucleoproteins purified from the isolate. RESULTS: Two MAbs-producing clones were obtained, BR/IP1-3A7 and BR/IP2-4E10. Fifty-seven isolates of RABV from different species of animals and different regions of Brazil were analyzed utilizing the MAbs obtained. In the analysis of 23 RABV isolates from non-hematophagous bats, the MAbs cross-reacted with ten isolates, of which four were of the species Nyctinomops laticaudatus, one of the species Eptesicus furinalis, and five of the genus Artibeus. Of the nine isolates of non-hematophagous isolates that displayed an incompatible profile analyzed, characteristic of insectivorous bats, BR/IP1-3A7 reacted with five (55.55%) and BR/IP2-4E10 with four (44.44%). CONCLUSIONS: The MAbs obtained were able to recognize epitopes common between the three genera, Artibeus, Eptesicus, and Nyctinomops, thereby allowing the antigenic characterization of RABV isolates in Brazil.

Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil

ABSTRACTRabies virus (RABV) isolated from different mammals seems to have unique characteristics that influence the outcome of infection. RABV circulates in nature and is maintained by reservoirs that are responsible for the persistence of the disease for almost 4000 years. Considering the different pattern of pathogenicity of RABV strains in naturally and experimentally infected animals, the aim of this study was to analyze the characteristics of RABV variants isolated from the main Brazilian reservoirs, being related to a dog (variant 2),Desmodus rotundus (variant 3), crab eating fox, marmoset, and Myotis spp. Viral replication in brain tissue of experimentally infected mouse was evaluated by two laboratory techniques and the results were compared to clinical evolution from five RABV variants. The presence of the RABV was investigated in brain samples by fluorescent antibody test (FAT) and real time polymerase chain reaction (qRT-PCR) for quantification of rabies virus nucleoprotein gene (N gene). Virus replication is not correlated with clinical signs and evolution. The pattern of FAT is associated with RABV replication levels. Virus isolates from crab eating fox and marmoset had a longer evolution period and higher survival rate suggesting that the evolution period may contribute to the outcome. RABV virus variants had independent characteristics that determine the clinical evolution and survival of the infected mice.

Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil.

Rabies virus (RABV) isolated from different mammals seems to have unique characteristics that influence the outcome of infection. RABV circulates in nature and is maintained by reservoirs that are responsible for the persistence of the disease for almost 4000 years. Considering the different pattern of pathogenicity of RABV strains in naturally and experimentally infected animals, the aim of this study was to analyze the characteristics of RABV variants isolated from the main Brazilian reservoirs, being related to a dog (variant 2), Desmodus rotundus (variant 3), crab eating fox, marmoset, and Myotis spp. Viral replication in brain tissue of experimentally infected mouse was evaluated by two laboratory techniques and the results were compared to clinical evolution from five RABV variants. The presence of the RABV was investigated in brain samples by fluorescent antibody test (FAT) and real time polymerase chain reaction (qRT-PCR) for quantification of rabies virus nucleoprotein gene (N gene). Virus replication is not correlated with clinical signs and evolution. The pattern of FAT is associated with RABV replication levels. Virus isolates from crab eating fox and marmoset had a longer evolution period and higher survival rate suggesting that the evolution period may contribute to the outcome. RABV virus variants had independent characteristics that determine the clinical evolution and survival of the infected mice.

Eastern equine encephalitis cases among horses in Brazil between 2005 and 2009.

Eastern equine encephalitis is a viral zoonosis that exhibits complex distribution and epidemiology, and greater importance should be given to this disease by the public-health authorities. In Brazil, although eastern equine encephalitis virus (EEEV) has been identified in vectors and antibodies are sometimes detected in horses and humans, there have been no records of equine encephalitis in horses caused by this virus during the last 24 years. This study describes eighteen cases of eastern equine encephalomyelitis that occurred in six Brazilian states between 2005 and 2009. Viral RNA was identified using semi-nested RT-PCR to detect members of the genus Alphavirus, and by genetic sequencing. The gene encoding NSP1 was partially amplified, and after genetic sequencing, eighteen sequences were generated. All eighteen strains were classified as belonging to lineage III of American EEEV. These findings could be an indication of the importance of this virus in animal and human public health.

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.

Desmodus rotundus and Artibeus spp. bats might present distinct rabies virus lineages

In Brazil, bats have been assigned an increasing importance in public health as they are important rabies reservoirs. Phylogenetic studies have shown that rabies virus (RABV) strains from frugivorous bats Artibeus spp. are closely associated to those from the vampire bat Desmodus rotundus, but little is known about the molecular diversity of RABV in Artibeus spp. The N and G genes of RABV isolated from Artibeus spp. and cattle infected by D. rotundus were sequenced, and phylogenetic trees were constructed. The N gene nucleotides tree showed three clusters: one for D. rotundus and two for Artibeus spp. Regarding putative N amino acid-trees, two clusters were formed, one for D. rotundus and another for Artibeus spp. RABV G gene phylogeny supported the distinction between D. rotundus and Artibeus spp. strains. These results show the intricate host relationship of RABV's evolutionary history, and are invaluable for the determination of RABV infection sources.

Desmodus rotundus and Artibeus spp. bats might present distinct rabies virus lineages.

In Brazil, bats have been assigned an increasing importance in public health as they are important rabies reservoirs. Phylogenetic studies have shown that rabies virus (RABV) strains from frugivorous bats Artibeus spp. are closely associated to those from the vampire bat Desmodus rotundus, but little is known about the molecular diversity of RABV in Artibeus spp. The N and G genes of RABV isolated from Artibeus spp. and cattle infected by D. rotundus were sequenced, and phylogenetic trees were constructed. The N gene nucleotides tree showed three clusters: one for D. rotundus and two for Artibeus spp. Regarding putative N amino acid-trees, two clusters were formed, one for D. rotundus and another for Artibeus spp. RABV G gene phylogeny supported the distinction between D. rotundus and Artibeus spp. strains. These results show the intricate host relationship of RABV's evolutionary history, and are invaluable for the determination of RABV infection sources.

Novel monoclonal antibodies that bind to wild and fixed rabies virus strains.

Ten monoclonal antibodies (MAbs) against rabies virus, including IgG3κ, IgG2aκ, IgMκ, and an IgG2bκ isotype, were produced and characterized using neutralization, ELISA, immunodot-blot, and immunofluorescence assays. MAb 8D11, which recognized rabies virus glycoprotein, was found to neutralize rabies virus in vitro. When submitted to an immunofluorescence assay, seven MAbs showed different reactivity against 35 Brazilian rabies virus isolates. Three MAbs (LIA 02, 3E6, and 9C7) only failed to recognize one or two virus isolates, whereas MAb 6H8 was found to be reactive against all virus isolates tested. MAbs were also evaluated for their immunoreactivity against fixed rabies virus strains present in human and veterinary commercial vaccines. MAbs LIA 02, 6H8, and 9C7 reacted against all vaccine strains, while the remaining MAbs recognized at least 76% of vaccine strains tested. This research provides a set of MAbs with potential application for improving existing or developing new diagnostic tests and immunoassays.

Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil.

The Ministry of Health's National Human Rabies Control Program advocates pre-exposure prophylaxis (PEP) for professionals involved with animals that are at risk of contracting rabies. We report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. The antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. The veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. After onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by RT-PCR. Genetic sequencing showed that the infection was caused by variant 3 (Desmodus rotundus), a finding confirmed by tests on the brain sample. It is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. This study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.

Antemortem diagnosis of human rabies in a veterinarian infected when handling a herbivore in Minas Gerais, Brazil / Diagnóstico ante-mortem de raiva humana em médico veterinário infectado por manipulação de herbívoro, Minas Gerais, Brasil

The Ministry of Health's National Human Rabies Control Program advocates pre-exposure prophylaxis (PEP) for professionals involved with animals that are at risk of contracting rabies. We report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. The antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. The veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. After onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by RT-PCR. Genetic sequencing showed that the infection was caused by variant 3 (Desmodus rotundus), a finding confirmed by tests on the brain sample. It is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. This study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.

O Programa Nacional de Controle da Raiva Humana do Ministério da Saúde preconiza o esquema profilático pré-exposição (PEP) para profissionais envolvidos com animais expostos ao risco de contraírem raiva. O presente trabalho relata o diagnóstico de raiva (ante e post-mortem) em veterinário infectado por manipulação de herbívoros raivosos. O diagnóstico laboratorial ante-mortem foi efetuado a partir da saliva e biópsia de folículo piloso, utilizando técnicas de biologia molecular e o post-mortem a partir do tecido cerebral e de técnicas convencionais. O médico veterinário coletou amostras para diagnóstico de raiva em herbívoros (bovinos e caprinos) suspeitos que, posteriormente, foram confirmados positivos em laboratório. Após a apresentação dos sintomas clássicos de raiva e realizadas as provas de diagnóstico ante-mortem com saliva e folículo piloso, ambas as amostras apresentaram resultados positivos pelo nested-RT-PCR. O sequenciamento genético revelou que a infecção se deu pela variante 3 do Desmodus rotundus, resultados estes confirmados com a amostra do cérebro. É indispensável que profissionais expostos ao risco de infecção pelo vírus da raiva realizem a profilaxia pré-exposição. Ressalta-se, também, que as técnicas de biologia molecular apresentaram bons resultados para a realização de diagnóstico ante-mortem, propiciando o desenvolvimento de métodos terapêuticos, e determinando com precisão e rapidez a fonte de infecção dos casos de raiva humana.

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.