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1.
PLoS Negl Trop Dis ; 17(10): e0010803, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37871008

RESUMO

BACKGROUND: Rabies is a zoonotic disease of all warm-blooded animals including humans. There is a paucity of data on the status of rabies in wild animals in Cameroon and the disease is endemic in the country with dogs being the main source of transmission. Bat habitats are widespread in Cameroon, but there is limited information on the prevalence of rabies in bats, and their role of as potential reservoirs of rabies virus. METHODS: A cross sectional study was carried out to estimate the prevalence and to assess risk factors of rabies virus in bats in the North Region of Cameroon. A total of 212 bats belonging to three families (Pteropodidae, Vespertilionidae and Molossidae) and 5 species were sampled in 7 localities in the North Region of Cameroon and were tested for rabies virus antigen using direct Immunofluorescence Test (IFA). RESULTS: Overall, 26.9% (57/212) of the bats collected showed an IFA positive reaction. The prevalence was significantly higher (P<0.05) in adult bats (33.3% (36/108)) compared to young individuals (20.2%; 21/104). The main risk factors identified in the study for human exposure to bats were gender (Male), religion (Christianity), localities (Babla and Lagdo), the practice of bat hunting, bat consumption, unawareness of bat rabies and cohabitation with bats in close proximity. CONCLUSION: The study revealed the first evidence of Lyssavirus in bats in Cameroon. This finding showed that bat rabies are real and represents a potential public health concern in communities with bat habitats in the North Region of Cameroon. Enhancing the level of public awareness and health education on the potential of bats as reservoirs of Lyssavirus in Cameroon as well as the integration of the "One Health" approach for effective management of animal and human rabies should be emphasized.


Assuntos
Quirópteros , Vírus da Raiva , Raiva , Animais , Humanos , Masculino , Camarões/epidemiologia , Quirópteros/virologia , Estudos Transversais , Lyssavirus , Prevalência , Saúde Pública , Raiva/epidemiologia , Raiva/veterinária , Vírus da Raiva/isolamento & purificação , Feminino
2.
Viruses ; 14(2)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35215832

RESUMO

A specialized and fine-tuned immune response of bats upon infection with viruses is believed to provide the basis for a "friendly" coexistence with these pathogens, which are often lethal for humans and other mammals. First insights into the immunity of bats suggest that bats have evolved to possess their own strategies to cope with viral infections. Yet, the molecular details for this innocuous coexistence remain poorly described and bat infection models are the key to unveiling these secrets. In Jamaican fruit bats (Artibeus jamaicensis), a New World bat species, infection experiments with its (putative) natural viral pathogens Tacaribe virus (TCRV), rabies virus (RABV), and the bat influenza A virus (IAV) H18N11, have contributed to an accurate, though still incomplete, representation of the bat-imposed immunity. Surprisingly, though many aspects of their innate and adaptive immune responses differ from that of the human immune response, such as a contraction of the IFN locus and reduction in the number of immunoglobulin subclasses, variations could also be observed between Jamaican fruit bats and other bat species.


Assuntos
Quirópteros/imunologia , Quirópteros/virologia , Viroma , Viroses/veterinária , Imunidade Adaptativa , Animais , Infecções por Arenaviridae/imunologia , Infecções por Arenaviridae/veterinária , Infecções por Arenaviridae/virologia , Arenavirus do Novo Mundo/isolamento & purificação , Imunidade Inata , Vírus da Influenza A/isolamento & purificação , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/veterinária , Raiva/imunologia , Raiva/veterinária , Raiva/virologia , Vírus da Raiva/isolamento & purificação , Viroses/imunologia
3.
Viruses ; 13(12)2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34960742

RESUMO

Rabies is a viral zoonosis that is transmissible to humans via domestic and wild animals. There are two epidemiological cycles for rabies, the urban and the sylvatic cycles. In an attempt to study the epidemiological role of wild canidae in rabies transmission, the present study aimed to analyze the genetic characteristics of virus isolates and confirm prior suggestions that rabies is maintained through a dog reservoir in Tunisia. Virus strains isolated from wild canidae were subject to viral sequencing, and Bayesian phylogenetic analysis was performed using Beast2 software. Essentially, the virus strains isolated from wild canidae belonged to the Africa-1 clade, which clearly diverges from fox-related strains. Our study also demonstrated that genetic characteristics of the virus isolates were not as distinct as could be expected if a wild reservoir had already existed. On the contrary, the geographic landscape is responsible for the genetic diversity of the virus. The landscape itself could have also acted as a natural barrier to the spread of the virus.


Assuntos
Animais Selvagens/virologia , Canidae/virologia , Vírus da Raiva/genética , Raiva/veterinária , Animais , Reservatórios de Doenças/virologia , Cães/virologia , Evolução Molecular , Raposas/virologia , Variação Genética , Chacais/virologia , Epidemiologia Molecular , Filogenia , Raiva/epidemiologia , Raiva/virologia , Vírus da Raiva/classificação , Vírus da Raiva/isolamento & purificação , Tunísia/epidemiologia
4.
Viruses ; 13(12)2021 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-34960753

RESUMO

The rabies virus (RABV) is characterized by a history dominated by host shifts within and among bats and carnivores. One of the main outcomes of long-term RABV maintenance in dogs was the establishment of variants in a wide variety of mesocarnivores. In this study, we present the most comprehensive phylogenetic and phylogeographic analysis, contributing to a better understanding of the origins, diversification, and the role of different host species in the evolution and diffusion of a dog-related variant endemic of South America. A total of 237 complete Nucleoprotein gene sequences were studied, corresponding to wild and domestic species, performing selection analyses, ancestral states reconstructions, and recombination analyses. This variant originated in Brazil and disseminated through Argentina and Paraguay, where a previously unknown lineage was found. A single host shift was identified in the phylogeny, from dog to the crab-eating fox (Cerdocyon thous) in the Northeast of Brazil. Although this process occurred in a background of purifying selection, there is evidence of adaptive evolution -or selection of sub-consensus sequences- in internal branches after the host shift. The interaction of domestic and wild cycles persisted after host switching, as revealed by spillover and putative recombination events.


Assuntos
Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , Raiva/veterinária , Animais , Animais Domésticos/virologia , Animais Selvagens/virologia , Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Cães , Evolução Molecular , Raposas/virologia , Nucleoproteínas/genética , Filogenia , Raiva/epidemiologia , Raiva/virologia , Vírus da Raiva/classificação , Recombinação Genética , América do Sul/epidemiologia
5.
Int J Mol Sci ; 22(21)2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34769416

RESUMO

Rabies is a deadly viral disease caused by the rabies virus (RABV), transmitted through a bite of an infected host, resulting in irreversible neurological symptoms and a 100% fatality rate in humans. Despite many aspects describing rabies neuropathogenesis, numerous hypotheses remain unanswered and concealed. Observations obtained from infected primary neurons or mouse brain samples are more relevant to human clinical rabies than permissive cell lines; however, limitations regarding the ethical issue and sample accessibility become a hurdle for discovering new insights into virus-host interplays. To better understand RABV pathogenesis in humans, we generated human-induced pluripotent stem cell (hiPSC)-derived neurons to offer the opportunity for an inimitable study of RABV infection at a molecular level in a pathologically relevant cell type. This study describes the characteristics and detailed proteomic changes of hiPSC-derived neurons in response to RABV infection using LC-MS/MS quantitative analysis. Gene ontology (GO) enrichment of differentially expressed proteins (DEPs) reveals temporal changes of proteins related to metabolic process, immune response, neurotransmitter transport/synaptic vesicle cycle, cytoskeleton organization, and cell stress response, demonstrating fundamental underlying mechanisms of neuropathogenesis in a time-course dependence. Lastly, we highlighted plausible functions of heat shock cognate protein 70 (HSC70 or HSPA8) that might play a pivotal role in regulating RABV replication and pathogenesis. Our findings acquired from this hiPSC-derived neuron platform help to define novel cellular mechanisms during RABV infection, which could be applicable to further studies to widen views of RABV-host interaction.


Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Proteoma/metabolismo , Vírus da Raiva/metabolismo , Raiva/virologia , Células Cultivadas , Interações Hospedeiro-Patógeno , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/virologia , Neurônios/citologia , Neurônios/virologia , Raiva/metabolismo , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/patogenicidade
6.
Pan Afr Med J ; 39: 129, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34527145

RESUMO

Rabies is a deadly viral disease transmitted through bites of infected animals. Outbreaks continue to escalate in Africa, with fatalities in humans, especially in rural areas, but are rarely reported. About 40% casualties occur among children of < 15 years. A 5-year-old boy on referral from a Primary Health Care Centre to a tertiary hospital presented with anxiety, confusion, agitation, hydrophobia, photo-phobia and aero-phobia, seven weeks after he was bitten by a stray dog in a rural community in Nigeria. The patient did not receive post-exposure prophylaxis and died 48 hours post admission. Confirmatory diagnosis was rabies and the phylogenetic analysis of the partial N-gene sequence of the virus localized it to Africa 2 (genotype 1) Lyssaviruses. There was 95.7-100% and 94.9-99.5% identity between the isolate and other genotype 1 Lyssaviruses and 100% homology with rabies viruses from Mali, Burkina Faso, Senegal and Central African Republic.


Assuntos
Mordeduras e Picadas/complicações , Vírus da Raiva/genética , Raiva/diagnóstico , Animais , Mordeduras e Picadas/virologia , Pré-Escolar , Cães , Evolução Fatal , Genótipo , Humanos , Masculino , Nigéria , Raiva/transmissão , Raiva/virologia , Vírus da Raiva/isolamento & purificação , População Rural
7.
Viruses ; 13(8)2021 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-34452381

RESUMO

The case fatality rate of rabies, nearly 100%, is one of the most unique characteristic of this ancient virus infection. The crucial role rabies virus neutralizing antibody plays in protection is both well established and explanation of why rabies serology is important. Various laboratory methods can and have been used but serum neutralization methods have long been the gold standard due to the ability to measure function (neutralization), however these methods can be difficult to perform for several reasons. Assays such as enzyme linked absorbance assays (ELISA), indirect fluorescence antibody (IFA) and more recently lateral flow methods are in use. Interpretation of results can be problematic, not only between methods but also due to modifications of the same method that can lead to misinterpretations. A common assumption in review of laboratory test results is that different methods for the same component produce comparable results under all conditions or circumstances. Assumptions and misinterpretations provide the potential for detrimental decisions, ranging from regulatory to clinically related, and most importantly what 'level' is protective. Review of the common challenges in performance and interpretation of rabies serology and specific examples illuminate critical issues to consider when reviewing and applying results of rabies serological testing.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Raiva/imunologia , Raiva/diagnóstico , Raiva/imunologia , Testes Sorológicos/normas , Anticorpos Neutralizantes/sangue , Interpretação Estatística de Dados , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Técnica Indireta de Fluorescência para Anticorpo , Testes Hematológicos , Humanos , Testes de Neutralização/métodos , Testes de Neutralização/normas , Vírus da Raiva/isolamento & purificação , Testes Sorológicos/classificação , Testes Sorológicos/métodos
8.
Viruses ; 13(8)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34452492

RESUMO

Rabies is a neglected zoonotic disease which is caused by negative strand RNA-viruses belonging to the genus Lyssavirus. Within this genus, rabies viruses circulate in a diverse set of mammalian reservoir hosts, is present worldwide, and is almost always fatal in non-vaccinated humans. Approximately 59,000 people are still estimated to die from rabies each year, leading to a global initiative to work towards the goal of zero human deaths from dog-mediated rabies by 2030, requiring scientific efforts from different research fields. The past decade has seen a much increased use of phylogeographic and phylodynamic analyses to study the evolution and spread of rabies virus. We here review published studies in these research areas, making a distinction between the geographic resolution associated with the available sequence data. We pay special attention to environmental factors that these studies found to be relevant to the spread of rabies virus. Importantly, we highlight a knowledge gap in terms of applying these methods when all required data were available but not fully exploited. We conclude with an overview of recent methodological developments that have yet to be applied in phylogeographic and phylodynamic analyses of rabies virus.


Assuntos
Vírus da Raiva/isolamento & purificação , Raiva/veterinária , Raiva/virologia , Animais , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Filogenia , Filogeografia/história , Raiva/epidemiologia , Raiva/história , Vírus da Raiva/classificação , Vírus da Raiva/genética , Zoonoses/epidemiologia , Zoonoses/história , Zoonoses/transmissão , Zoonoses/virologia
9.
PLoS Negl Trop Dis ; 15(7): e0009536, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34264951

RESUMO

Mongooses, a nonnative species, are a known reservoir of rabies virus in the Caribbean region. A cross-sectional study of mongooses at 41 field sites on the US Virgin Islands of St. Croix, St. John, and St. Thomas captured 312 mongooses (32% capture rate). We determined the absence of rabies virus by antigen testing and rabies virus exposure by antibody testing in mongoose populations on all three islands. USVI is the first Caribbean state to determine freedom-from-rabies for its mongoose populations with a scientifically-led robust cross-sectional study. Ongoing surveillance activities will determine if other domestic and wildlife populations in USVI are rabies-free.


Assuntos
Animais Selvagens/virologia , Reservatórios de Doenças/virologia , Herpestidae/virologia , Vírus da Raiva/isolamento & purificação , Animais , Estudos Transversais , Vírus da Raiva/classificação , Vírus da Raiva/genética , Ilhas Virgens Americanas
10.
Mol Biotechnol ; 63(11): 1068-1080, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34228257

RESUMO

Rabies is an ancient zoonotic disease that still causes the death of over 59,000 people worldwide each year. The rabies lyssavirus encodes five proteins, including the envelope glycoprotein and the matrix protein. RVGP is the only protein exposed on the surface of viral particle, and it can induce immune response with neutralizing antibody formation. RVM has the ability to assist with production process of virus-like particles. VLPs were produced in recombinant baculovirus system. In this work, two recombinant baculoviruses carrying the RVGP and RVM genes were constructed. From the infection and coinfection assays, we standardized the best multiplicity of infection and the best harvest time. Cell supernatants were collected, concentrated, and purified by sucrose gradient. Each step was used for protein detection through immunoassays. Sucrose gradient analysis enabled to verify the separation of VLPs from rBV. Through the negative contrast technique, we visualized structures resembling rabies VLPs produced in insect cells and rBV in the different fractions of the sucrose gradient. Using ELISA to measure total RVGP, the recovery efficiency of VLPs at each stage of the purification process was verified. Thus, these results encourage further studies to confirm whether rabies VLPs are a promising candidate for a veterinary rabies vaccine.


Assuntos
Baculoviridae/genética , Insetos/metabolismo , Vacina Antirrábica/biossíntese , Vírus da Raiva/metabolismo , Raiva/virologia , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Animais , Baculoviridae/isolamento & purificação , Baculoviridae/metabolismo , Células Cultivadas , Humanos , Insetos/imunologia , Insetos/virologia , Vacina Antirrábica/genética , Vacina Antirrábica/imunologia , Vacina Antirrábica/isolamento & purificação , Vírus da Raiva/imunologia , Vírus da Raiva/isolamento & purificação , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação
11.
Artigo em Inglês | MEDLINE | ID: mdl-33852711

RESUMO

Currently, the Milwaukee protocol presents healing results in human beings affected by the rabies virus. However, there are many points to clarify on the action of drugs and the immune mechanism involved in the evolution of the disease. One of the drugs used is biopterin, which is an important cofactor for nitric oxide, important for preventing vasospasm. Thus, we describe the effect of biopterin on some inflammatory factors in a rabies virus infection developed in an animal model. The immunological mediators studied in animals infected with rabies virus submitted to doses of sapropterin were Anti-RABV, IL-6, IL-2, IL-17a, INF-gamma and Anti-iNOS. It is suggested that the medication in the context of a RABV infection already installed, had the effect of modulating the inflammatory mechanisms mainly linked to the permeability of the blood-brain barrier and the migration of cytotoxic cells.


Assuntos
/análogos & derivados , Vírus da Raiva/efeitos dos fármacos , Raiva/tratamento farmacológico , Animais , Encéfalo , Sistema Nervoso Central , Modelos Animais de Doenças , Humanos , Camundongos , Vírus da Raiva/isolamento & purificação
12.
PLoS One ; 16(4): e0249176, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33831031

RESUMO

Populations are exposed to different types and strains of pathogens across heterogeneous landscapes, where local interactions between host and pathogen may present reciprocal selective forces leading to correlated patterns of spatial genetic structure. Understanding these coevolutionary patterns provides insight into mechanisms of disease spread and maintenance. Arctic rabies (AR) is a lethal disease with viral variants that occupy distinct geographic distributions across North America and Europe. Red fox (Vulpes vulpes) are a highly susceptible AR host, whose range overlaps both geographically distinct AR strains and regions where AR is absent. It is unclear if genetic structure exists among red fox populations relative to the presence/absence of AR or the spatial distribution of AR variants. Acquiring these data may enhance our understanding of the role of red fox in AR maintenance/spread and inform disease control strategies. Using a genotyping-by-sequencing assay targeting 116 genomic regions of immunogenetic relevance, we screened for sequence variation among red fox populations from Alaska and an outgroup from Ontario, including areas with different AR variants, and regions where the disease was absent. Presumed neutral SNP data from the assay found negligible levels of neutral genetic structure among Alaskan populations. The immunogenetically-associated data identified 30 outlier SNPs supporting weak to moderate genetic structure between regions with and without AR in Alaska. The outliers included SNPs with the potential to cause missense mutations within several toll-like receptor genes that have been associated with AR outcome. In contrast, there was a lack of genetic structure between regions with different AR variants. Combined, we interpret these data to suggest red fox populations respond differently to the presence of AR, but not AR variants. This research increases our understanding of AR dynamics in the Arctic, where host/disease patterns are undergoing flux in a rapidly changing Arctic landscape, including the continued northward expansion of red fox into regions previously predominated by the arctic fox (Vulpes lagopus).


Assuntos
Raposas/genética , Polimorfismo de Nucleotídeo Único , Raiva/genética , Alaska , Doenças dos Animais/epidemiologia , Doenças dos Animais/genética , Doenças dos Animais/virologia , Distribuição Animal , Animais , Raposas/virologia , Haplótipos , Mutação de Sentido Incorreto , Ontário , Raiva/epidemiologia , Raiva/virologia , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/patogenicidade , Receptores Toll-Like/genética
13.
Viruses ; 13(2)2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672496

RESUMO

We applied the model-guided fieldwork framework to the Caribbean mongoose rabies system by parametrizing a spatially-explicit, individual-based model, and by performing an uncertainty analysis designed to identify parameters for which additional empirical data are most needed. Our analysis revealed important variation in output variables characterizing rabies dynamics, namely rabies persistence, exposure level, spatiotemporal distribution, and prevalence. Among epidemiological parameters, rabies transmission rate was the most influential, followed by rabies mortality and location, and size of the initial infection. The most influential landscape parameters included habitat-specific carrying capacities, landscape heterogeneity, and the level of resistance to dispersal associated with topography. Movement variables, including juvenile dispersal, adult fine-scale movement distances, and home range size, as well as life history traits such as age of independence, birth seasonality, and age- and sex-specific mortality were other important drivers of rabies dynamics. We discuss results in the context of mongoose ecology and its influence on disease transmission dynamics. Finally, we suggest empirical approaches and study design specificities that would provide optimal contributing data addressing the knowledge gaps identified by our approach, and would increase our potential to use epidemiological models to guide mongoose rabies control and management in the Caribbean.


Assuntos
Herpestidae/virologia , Raiva/veterinária , Distribuição Animal , Animais , Região do Caribe/epidemiologia , Feminino , Herpestidae/fisiologia , Masculino , Modelos Biológicos , Raiva/epidemiologia , Raiva/transmissão , Raiva/virologia , Vírus da Raiva/classificação , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/fisiologia
14.
Biologicals ; 70: 59-63, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33518433

RESUMO

Rabies is a zoonotic disease that can be prevented by vaccination. The confirmation of rabies virus inactivation is a critical step during the vaccine quality test; however, the current protocol conducted in Japan requires a large number of mice. The development and introduction of animal-free alternative assays are essential from the perspective of the 3Rs (reduction, refinement, and replacement) of animal testing. Here, we propose a novel inactivation assay for confirming the complete inactivation of the viable rabies virus using cultured Neuro-2a cells and an enzyme-linked immunosorbent assay (ELISA). The detection ability of ELISA was similar to that of a direct immunofluorescence assay, with the detection limit of ELISA being as low as 0.014 focus forming units/test. These results suggest that the assay could be used as a viral inactivation test. In comparison with a traditional in vivo assay, this assay has a higher detection ability, an objective interpretation, and would shorten the test duration from 25 days to 8 days.


Assuntos
Alternativas aos Testes com Animais , Ensaio de Imunoadsorção Enzimática , Vacina Antirrábica , Vírus da Raiva/isolamento & purificação , Raiva , Animais , Anticorpos Antivirais , Camundongos , Raiva/prevenção & controle , Vírus da Raiva/imunologia , Vacinas de Produtos Inativados
15.
Viruses ; 13(2)2021 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-33562073

RESUMO

The contemporary surge in metagenomic sequencing has transformed knowledge of viral diversity in wildlife. However, evaluating which newly discovered viruses pose sufficient risk of infecting humans to merit detailed laboratory characterization and surveillance remains largely speculative. Machine learning algorithms have been developed to address this imbalance by ranking the relative likelihood of human infection based on viral genome sequences, but are not yet routinely applied to viruses at the time of their discovery. Here, we characterized viral genomes detected through metagenomic sequencing of feces and saliva from common vampire bats (Desmodus rotundus) and used these data as a case study in evaluating zoonotic potential using molecular sequencing data. Of 58 detected viral families, including 17 which infect mammals, the only known zoonosis detected was rabies virus; however, additional genomes were detected from the families Hepeviridae, Coronaviridae, Reoviridae, Astroviridae and Picornaviridae, all of which contain human-infecting species. In phylogenetic analyses, novel vampire bat viruses most frequently grouped with other bat viruses that are not currently known to infect humans. In agreement, machine learning models built from only phylogenetic information ranked all novel viruses similarly, yielding little insight into zoonotic potential. In contrast, genome composition-based machine learning models estimated different levels of zoonotic potential, even for closely related viruses, categorizing one out of four detected hepeviruses and two out of three picornaviruses as having high priority for further research. We highlight the value of evaluating zoonotic potential beyond ad hoc consideration of phylogeny and provide surveillance recommendations for novel viruses in a wildlife host which has frequent contact with humans and domestic animals.


Assuntos
Quirópteros/virologia , Vírus/isolamento & purificação , Zoonoses/virologia , Animais , Reservatórios de Doenças/veterinária , Reservatórios de Doenças/virologia , Fezes/virologia , Genoma Viral/genética , Humanos , Aprendizado de Máquina , Metagenômica , Filogenia , Vírus da Raiva/classificação , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , Saliva/virologia , Vírus/classificação , Vírus/genética
16.
Sci Rep ; 11(1): 3131, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542337

RESUMO

Rabies is a generally fatal encephalitis caused by a negative-sense single-stranded RNA lyssavirus transmitted to humans mainly from dog bite. Despite the recommendation by WHO and OIE to use the direct immunofluorescence test as standard method, molecular diagnostic assays like reverse transcription quantitative polymerase chain reaction (RT-qPCR) are increasing as a confirmatory method. However, both technologies are inaccessible in resource-limited settings. Moreover, the available point-of-need molecular assay is of poor detection limit for African strains. Herein, we developed a reverse transcription recombinase polymerase amplification (RT-RPA) assay as potential point-of-need diagnostic tool for rapid detection of various strains of rabies virus including locally isolated African strains. The sensitivity and specificity of the method was evaluated using a molecular RNA standard and different Rabies-related viruses belonging to the Rhabdoviridea family, respectively. The RABV-RPA performances were evaluated on isolates representative of the existing diversity and viral dilutions spiked in non-neural clinical specimen. The results were compared with RT-qPCR as a gold standard. The RABV-RPA detected down to 4 RNA molecules per reaction in 95% of the cases in less than 10 min. The RABV-RPA assay is highly specific as various RABV isolates were identified, but no amplification was observed for other member of the Rhabdoviridea family. The sample background did not affect the performance of the RABV-RPA as down to 11 RNA molecules were identified, which is similar to the RT-qPCR results. Our developed assay is suitable for use in low-resource settings as a promising alternative tool for ante-mortem rabies diagnosis in humans for facilitating timely control decisions.


Assuntos
Testes Imediatos/organização & administração , RNA Viral/genética , Vírus da Raiva/genética , Raiva/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Rhabdoviridae/genética , África/epidemiologia , Animais , Primers do DNA/síntese química , Primers do DNA/metabolismo , Cães , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Testes Imediatos/economia , Raiva/epidemiologia , Raiva/transmissão , Raiva/virologia , Vírus da Raiva/isolamento & purificação , Recombinases/genética , Recombinases/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/economia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Rhabdoviridae/classificação
17.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33544071

RESUMO

Nearly 1.7 million cases of dog bites are reported every year in India and many cases of animal rabies are left unattended and undiagnosed. Therefore, a mere diagnosis of rabies is not sufficient to understand the epidemiology and the spread of the rabies virus (RV) in animals. There is a paucity of information about the evolutionary dynamics of RV in dogs and its biodiversity patterns in India. In total, 50 dog-brain samples suspected of rabies were screened by the nucleoprotein- (N) and glycoprotein- (G) gene PCR. The N and G genes were subsequently sequenced to understand the molecular evolution in these genes. The phylogenetic analysis of the N gene revealed that six isolates in the Mumbai region belonged to a single Arctic lineage. Time-scaled phylogeny by Bayesian coalescent analysis of the partial N gene revealed that the time to the most recent common ancestor (TMRCA) for the sequences belonged to the cluster from 2006.68 with a highest posterior density of 95 % betweeen 2005-2008, which is assigned to Indian lineage I. Migration pattern revealed a strong Bayes factor between Mumbai to Delhi, Panji to Hyderabad, Delhi to Chennai, and Chennai to Chandigarh. Phylogenetic analysis of the G gene revealed that the RVs circulating in the Mumbai region are divided into three lineages. Time-scaled phylogeny by the Bayesian coalescent analysis method estimated that the TMRCA for sequences under study was from 1993 and Indian clusters was from 1962. In conclusion, the phylogenetic analysis of the N gene revealed that six isolates belonged to single Arctic lineages along with other Indian isolates and they were clustered into a single lineage but divided into three clades based on the G-gene sequences. The present study highlights and enhances the current molecular epidemiology and evolution of RV and revealed strong location bias and geographical clustering within Indian isolates on the basis of N and G genes.


Assuntos
Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Glicoproteínas/genética , Nucleoproteínas/genética , Vírus da Raiva/genética , Raiva/veterinária , Animais , Teorema de Bayes , Cães , Evolução Molecular , Índia/epidemiologia , Filogenia , Filogeografia , RNA Viral , Vírus da Raiva/isolamento & purificação , Análise de Sequência de DNA
18.
Arch Virol ; 166(4): 1083-1092, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33544254

RESUMO

Rabies, which is caused by rabies virus (RABV), poses an ever-present threat to public health in most countries of the world. Once clinical signs appear, the mortality of rabies approaches 100%. To date, no effective method for early rabies diagnosis has been developed. In this study, an RPA-CRISPR nucleic-acid-based assay was developed for early rabies diagnosis by detecting viral RNA shedding in the cerebrospinal fluid (CSF) of rats. This method can detect a single copy of RABV genomic RNA in 1 µL of liquid. RABV genomic RNA released from viral particles in the CSF could be detected via RPA-CRISPR as early as 3 days postinfection in a rat model. This study provides an RPA-CRISPR technique for early detection of RABV with potential application in the clinical diagnosis of human rabies.


Assuntos
Sistemas CRISPR-Cas , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico , Vírus da Raiva/isolamento & purificação , Raiva/diagnóstico , Animais , Modelos Animais de Doenças , Diagnóstico Precoce , RNA Viral/líquido cefalorraquidiano , RNA Viral/genética , Raiva/líquido cefalorraquidiano , Vírus da Raiva/genética , Ratos , Ratos Sprague-Dawley , Sensibilidade e Especificidade
19.
PLoS Negl Trop Dis ; 15(2): e0009111, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33544702

RESUMO

Rabies diagnosis proficiency tests on animal specimens using four techniques (FAT, RTCIT, conventional RT-PCR and real-time RT-PCR) were organised over 10 years (2009-2019). Seventy-three laboratories, of which 59% were from Europe, took part. As the panels were prepared with experimentally-infected samples, the error rate of laboratories on positive and negative samples was accurately estimated. Based on fitted values produced by mixed modelling including the variable "laboratory" as a random variable to take into account the longitudinal design of our dataset, the technique that provided the most concordant results was conventional RT-PCR (99.3%; 95% CI 99.0-99.6), closely followed by FAT (99.1%; 95% CI 98.7-99.4), real-time RT-PCR (98.7%; 95% CI 98.1-99.3) and then RTCIT (96.8%; 95% CI 95.8-97.7). We also found that conventional RT-PCR provided a better diagnostic sensitivity level (99.3% ±4.4%) than FAT (98.7% ±1.6%), real-time RT-PCR (97.9% ±0.8%) and RTCIT (95.3% ±5.1%). Regarding diagnostic specificity, RTCIT was the most specific technique (96.4% ±3.9%) followed closely by FAT (95.6% ±3.8%), real-time RT-PCR (95.0% ±1.8%) and conventional RT-PCR (92.9% ±0.5%). Due to multiple testing of the samples with different techniques, the overall diagnostic conclusion was also evaluated, and found to reach an inter-laboratory concordance level of 99.3%. The concordance for diagnostic sensitivity was 99.6% ±2.0% and for diagnostic specificity, 98.0% ±8.5%. Molecular biology techniques were, however, found to be less specific than expected. The potential reasons for such findings are discussed herein. The regular organisation of performance tests has contributed to an increase in the performance of participating laboratories over time, demonstrating the benefits of such testing. Maintaining a high-quality rabies diagnosis capability on a global scale is key to achieving the goal of eliminating dog-mediated human rabies deaths. The regular organisation of exercises on each continent using selected local strains to be tested according to the local epidemiological situation is one factor that could help increase reliable diagnosis worldwide. Rabies diagnosis capabilities could indeed be enhanced by providing adequate and sustainable proficiency testing on a large scale and in the long term.


Assuntos
Testes Diagnósticos de Rotina/métodos , Técnicas de Diagnóstico Molecular/métodos , Vírus da Raiva/isolamento & purificação , Raiva/diagnóstico , Animais , Cães , Europa (Continente) , Humanos , Laboratórios , RNA Viral , Vírus da Raiva/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Acta Trop ; 216: 105787, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33385361

RESUMO

Despite declaration as a national priority disease, dog rabies remains endemic in Liberia, with surveillance systems and disease control activities still developing. The objective of these initial efforts was to establish animal rabies diagnostics, foster collaboration between all rabies control stakeholders, and develop a short-term action plan with estimated costs for rabies control and elimination in Liberia. Four rabies diagnostic tests, the direct fluorescent antibody (DFA) test, the direct immunohistochemical test (dRIT), the reverse transcriptase polymerase chain reaction (RT-PCR) assay and the rapid immunochromatographic diagnostic test (RIDT), were implemented at the Central Veterinary Laboratory (CVL) in Monrovia between July 2017 and February 2018. Seven samples (n=7) out of eight suspected animals were confirmed positive for rabies lyssavirus, and molecular analyses revealed that all isolates belonged to the Africa 2 lineage, subgroup H. During a comprehensive in-country One Health rabies stakeholder meeting in 2018, a practical workplan, a short-term action plan and an accurately costed mass dog vaccination strategy were developed. Liberia is currently at stage 1.5/5 of the Stepwise Approach towards Rabies Elimination (SARE) tool, which corresponds with countries that are scaling up local-level interventions (e.g. dog vaccination campaigns) to the national level. Overall an estimated 5.3 - 8 million USD invested over 13 years is needed to eliminate rabies in Liberia by 2030. Liberia still has a long road to become free from dog-rabies. However, the dialogue between all relevant stakeholders took place, and disease surveillance considerably improved through implementing rabies diagnosis at the CVL. The joint efforts of diverse national and international stakeholders laid important foundations to achieve the goal of zero dog-mediated human rabies deaths by 2030.


Assuntos
Testes Diagnósticos de Rotina/veterinária , Vacina Antirrábica/administração & dosagem , Raiva/diagnóstico , Raiva/prevenção & controle , Animais , DNA Viral , Testes Diagnósticos de Rotina/métodos , Doenças do Cão/diagnóstico , Doenças do Cão/prevenção & controle , Doenças do Cão/virologia , Cães/virologia , Feminino , Humanos , Libéria/epidemiologia , Masculino , Vacinação em Massa/veterinária , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinária , Filogenia , Reação em Cadeia da Polimerase , Vacina Antirrábica/economia , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação
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