Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Front Public Health ; 11: 1121522, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37383258

RESUMEN

Introduction: The awareness of scientists and policy makers regarding the requirement for an integrated One Health (OH) approach in responding to zoonoses has increased in recent years. However, there remains an overall inertia in relation to the implementation of practical cross-sector collaborations. Foodborne outbreaks of zoonotic diseases continue to affect the European population despite stringent regulations, evidencing the requirement for better 'prevent, detect and response' strategies. Response exercises play an essential role in the improvement of crisis management plans, providing the opportunity to test practical intervention methodologies in a controlled environment. Methods: The One Health European Joint Programme simulation exercise (OHEJP SimEx) aimed at practicing the OH capacity and interoperability across public health, animal health and food safety sectors in a challenging outbreak scenario. The OHEJP SimEx was delivered through a sequence of scripts covering the different stages of a Salmonella outbreak investigation at a national level, involving both the human food chain and the raw pet feed industry. Results: A total of 255 participants from 11 European countries (Belgium, Denmark, Estonia, Finland, France, Italy, Norway, Poland, Portugal, Sweden, the Netherlands) took part in national level two-day exercises during 2022. National evaluations identified common recommendations to countries aiming to improve their OH structure to establish formal communication channels between sectors, implement a common data sharing platform, harmonize laboratory procedures, and reinforce inter-laboratory networks within countries. The large proportion of participants (94%) indicated significant interest in pursuing a OH approach and desire to work more closely with other sectors. Discussion: The OHEJP SimEx outcomes will assist policy makers in implementing a harmonized approach to cross-sector health-related topics, by highlighting the benefits of cooperation, identifying gaps in the current strategies and suggesting actions required to better address foodborne outbreaks. Furthermore, we summarize recommendations for future OH simulation exercises, which are essential to continually test, challenge and improve national OH strategies.


Asunto(s)
Salud Única , Animales , Humanos , Difusión de la Información , Comunicación , Ejercicio Físico , Zoonosis , Brotes de Enfermedades/prevención & control
2.
Adv Virus Res ; 112: 115-173, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35840180

RESUMEN

Rabies infects all mammals; however, transmission cycles are only maintained in certain bat and carnivore species. The high incidence of rabies in Greater Kudu (Tragelaphus strepsiceros) observed in Namibia for over 40 years has led to postulation that independent virus transmission is occurring within this antelope population. We have analysed extensive experimental, epidemiological, phylogeographic and deep sequence data, which collectively refute maintenance of an independent rabies cycle in kudu. As rabies in kudu continues to have a negative impact on the Namibian agricultural sector, measures to protect kudu have been investigated, including the use of a third-generation oral rabies vaccine. Initial results show protection of kudu from rabies infection via the oral route, with an appropriate bait design, different application schedules and vaccination doses further enhancing the immune response. Rabies in kudu is a complex interplay at the wildlife-livestock interface and requires a concerted approach to successfully control.


Asunto(s)
Antílopes , Vacunas Antirrábicas , Virus de la Rabia , Rabia , Animales , Animales Salvajes , Antílopes/fisiología , Rabia/epidemiología , Rabia/prevención & control , Rabia/veterinaria , Virus de la Rabia/genética
3.
Front Vet Sci ; 8: 728271, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34660765

RESUMEN

Background: Thermostable vaccines greatly improved the reach and impact of large-scale programmes to eliminate infectious diseases such as smallpox, polio, and rinderpest. A study from 2015 demonstrated that the potency of the Nobivac® Rabies vaccine was not impacted following experimental storage at 30°C for 3 months. Whether the vaccine would remain efficacious following storage under more natural, fluctuating temperature conditions remains unknown. We carried out a randomised controlled non-inferiority trial to compare serological responses in dogs following vaccination with doses stored under cold chain conditions with those stored within a locally made Passive Cooling Device ("Zeepot") under fluctuating temperature conditions. Materials and Methods: Nobivac® Rabies vaccine was stored under either cold-chain conditions or within the Zeepot for 2 months. Daily ambient temperatures and temperatures within the Zeepot were recorded every 3 h. Following storage, 412 domestic dogs were randomly assigned to receive either cold-chain or Zeepot stored Nobivac® Rabies vaccine. Baseline and day 28-post vaccination blood samples were collected. Serological analysis using the Fluorescent Antibody Virus Neutralisation assay was carried out with a threshold of 0.5 IU/ml to determine seroconversion. In addition, the impact of dog Body Condition Score, sex, and age on seroconversion was examined. Results: The serological response of dogs vaccinated using Nobivac® Rabies vaccine stored within the Zeepot was not inferior to the response of dogs vaccinated using cold-chain stored vaccine (z = 1.1, df = 313, p-value = 0.25). Indeed, the 28-day post-vaccination group geometric mean titre was 1.8 and 2.0 IU/ml for cold-chain vs. non-cold-chain storage, respectively. Moreover, the percentage of dogs that seroconverted in each arm was almost identical (85%). There was a positive linear trend between Body Condition Score (O.R. 2.2, 95% CI: 1.1-5.1) and seroconversion, suggesting dogs of poor condition may not respond as expected to vaccination. Conclusions: Our study demonstrated the potency of Nobivac® Rabies vaccine is not impacted following storage under elevated fluctuating temperatures within a Zeepot. These results have potentially exciting applications for scaling up mass dog vaccination programmes in low-and-middle income countries, particularly for hard-to-reach populations with limited access to power and cold-chain vaccine storage.

4.
Viruses ; 13(10)2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34696409

RESUMEN

Lyssaviruses are an important genus of zoonotic viruses which cause the disease rabies. The United Kingdom is free of classical rabies (RABV). However, bat rabies due to European bat lyssavirus 2 (EBLV-2), has been detected in Daubenton's bats (Myotis daubentonii) in Great Britain since 1996, including a fatal human case in Scotland in 2002. Across Europe, European bat lyssavirus 1 (EBLV-1) is commonly associated with serotine bats (Eptesicus serotinus). Despite the presence of serotine bats across large parts of southern England, EBLV-1 had not previously been detected in this population. However, in 2018, EBLV-1 was detected through passive surveillance in a serotine bat from Dorset, England, using a combination of fluorescent antibody test, reverse transcription-PCR, Sanger sequencing and immunohistochemical analysis. Subsequent EBLV-1 positive serotine bats have been identified in South West England, again through passive surveillance, during 2018, 2019 and 2020. Here, we confirm details of seven cases of EBLV-1 and present similarities in genetic sequence indicating that emergence of EBLV-1 is likely to be recent, potentially associated with the natural movement of bats from the near continent.


Asunto(s)
Quirópteros/virología , Lyssavirus/patogenicidad , Animales , Lyssavirus/genética , Rabia/virología , Infecciones por Rhabdoviridae/epidemiología , Infecciones por Rhabdoviridae/virología , Reino Unido/epidemiología
5.
PLoS Negl Trop Dis ; 15(5): e0009431, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34014930

RESUMEN

Human fatalities caused by rabies are rarely reported in Jordan; however, domestic animals are more likely to fall victim to rabies compared to wild animals, at least this is the case in Jordan due to the presence of canine rabies. In this study, twelve brain samples from domestic and wild animals suspected of being infected with rabies virus from different regions of Jordan were collected during 2019. Seven of them tested positive using the fluorescent antibody test and real-time SYBR RT-PCR assay. Five specimens were from stray dogs and two from foxes. The whole genome sequences were obtained from the positive samples. Sequence analysis showed that one dog virus from Al Quwaysimah city located in Amman governorate, was closely related to an Israeli strain belonging to a Cosmopolitan ME1a clade. The genomes of the remaining six viruses (four from dogs and two from foxes) collected from different areas of Jordan were genetically-related to each other and clustered together with sequences from Iran and Turkey; all belong to Cosmopolitan ME2 clade. These sequences were analyzed with six other Jordanian rabies virus nucleoprotein (N) gene sequences available in the public database, five of them belong to ME1a clade and one belongs to ME1b clade. Rabies virus whole genome data is scarce across the Middle East. This study provides a better understanding of the molecular epidemiology of rabies virus in the region.


Asunto(s)
Enfermedades de los Perros/epidemiología , Virus de la Rabia/genética , Rabia/veterinaria , Animales , Encéfalo/virología , Enfermedades de los Perros/virología , Perros , Zorros/virología , Jordania/epidemiología , Epidemiología Molecular , Filogenia , Rabia/epidemiología , Virus de la Rabia/clasificación , Secuenciación Completa del Genoma
6.
Viruses ; 13(4)2021 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-33917139

RESUMEN

European bat lyssavirus type 1 (EBLV-1) is the causative agent for almost all reported rabies cases found in European bats. In recent years, increasing numbers of available EBLV-1 full genomes and their phylogenetic analyses helped to further elucidate the distribution and genetic characteristics of EBLV-1 and its two subtypes, namely EBLV-1a and EBLV-1b. Nonetheless, the absence of full-genome sequences from regions with known detections of EBLV-1 still limit the understanding of the phylogeographic relations between viruses from different European regions. In this study, a set of 21 archived Danish EBLV-1 samples from the years 1985 to 2009 was processed for the acquisition of full-genome sequences using a high-throughput sequencing approach. Subsequent phylogenetic analysis encompassing all available EBLV-1 full genomes from databases revealed the Danish sequences belong to the EBLV-1a subtype and further highlighted the distinct, close phylogenetic relationship of Danish, Dutch and German isolates in this region. In addition, the formation of five putative groups nearly exclusively formed by Danish isolates and the overall increased resolution of the EBLV-1a branch indicate a higher genetic diversity and spatial segregation for this sublineage than was previously known. These results emphasize the importance of phylogenetic analyses of full-genome sequences of lyssaviruses for genetic geography.


Asunto(s)
Quirópteros/virología , Genoma Viral , Lyssavirus/clasificación , Lyssavirus/genética , Filogenia , Rabia/veterinaria , Animales , Archivos , Mapeo Cromosómico , Segregación Cromosómica , Dinamarca , Secuenciación de Nucleótidos de Alto Rendimiento , Rabia/virología , Secuenciación Completa del Genoma
7.
Viruses ; 12(12)2020 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-33316899

RESUMEN

Emerging infectious diseases are of great concern to public health, as highlighted by the ongoing coronavirus disease 2019 (COVID-19) pandemic. Such diseases are of particular danger during mass gathering and mass influx events, as large crowds of people in close proximity to each other creates optimal opportunities for disease transmission. The Hashemite Kingdom of Jordan and the Kingdom of Saudi Arabia are two countries that have witnessed mass gatherings due to the arrival of Syrian refugees and the annual Hajj season. The mass migration of people not only brings exotic diseases to these regions but also brings new diseases back to their own countries, e.g., the outbreak of MERS in South Korea. Many emerging pathogens originate in bats, and more than 30 bat species have been identified in these two countries. Some of those bat species are known to carry viruses that cause deadly diseases in other parts of the world, such as the rabies virus and coronaviruses. However, little is known about bats and the pathogens they carry in Jordan and Saudi Arabia. Here, the importance of enhanced surveillance of bat-borne infections in Jordan and Saudi Arabia is emphasized, promoting the awareness of bat-borne diseases among the general public and building up infrastructure and capability to fill the gaps in public health preparedness to prevent future pandemics.


Asunto(s)
Quirópteros/virología , Enfermedades Transmisibles Emergentes/epidemiología , Coronavirus/aislamiento & purificación , Salud Pública , Zoonosis/epidemiología , Animales , COVID-19 , Enfermedades Transmisibles Emergentes/virología , Coronavirus/clasificación , Coronavirus/patogenicidad , Brotes de Enfermedades/prevención & control , Humanos , Jordania , Arabia Saudita , Zoonosis/transmisión , Zoonosis/virología
8.
PLoS Negl Trop Dis ; 14(12): e0008898, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33320860

RESUMEN

Rabies is a fatal neurologic disease caused by lyssavirus infection. Bats are important natural reservoir hosts of various lyssaviruses that can be transmitted to people. The epidemiology and pathogenesis of rabies in bats are poorly understood, making it difficult to prevent zoonotic transmission. To further our understanding of lyssavirus pathogenesis in a natural bat host, an experimental model using straw-colored fruit bats (Eidolon helvum) and Lagos bat virus, an endemic lyssavirus in this species, was developed. To determine the lowest viral dose resulting in 100% productive infection, bats in five groups (four bats per group) were inoculated intramuscularly with one of five doses, ranging from 100.1 to 104.1 median tissue culture infectious dose (TCID50). More bats died due to the development of rabies after the middle dose (102.1 TCID50, 4/4 bats) than after lower (101.1, 2/4; 101.1, 2/4) or higher (103.1, 2/4; 104.1, 2/4) doses of virus. In the two highest dose groups, 4/8 bats developed rabies. Of those bats that remained healthy 3/4 bats seroconverted, suggesting that high antigen loads can trigger a strong immune response that abrogates a productive infection. In contrast, in the two lowest dose groups, 3/8 bats developed rabies, 1/8 remained healthy and seroconverted and 4/8 bats remained healthy and did not seroconvert, suggesting these doses are too low to reliably induce infection. The main lesion in all clinically affected bats was meningoencephalitis associated with lyssavirus-positive neurons. Lyssavirus antigen was detected in tongue epithelium (5/11 infected bats) rather than in salivary gland epithelium (0/11), suggesting viral excretion via the tongue. Thus, intramuscular inoculation of 102.1 TCID50 of Lagos bat virus into straw-colored fruit bats is a suitable model for lyssavirus associated bat rabies in a natural reservoir host, and can help with the investigation of lyssavirus infection dynamics in bats.


Asunto(s)
Quirópteros/virología , Lyssavirus , Infecciones por Rhabdoviridae/veterinaria , Animales , Reservorios de Enfermedades , Rabia/veterinaria , Rabia/virología , Infecciones por Rhabdoviridae/virología
9.
PLoS Negl Trop Dis ; 14(10): e0008622, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33090993

RESUMEN

Rabies was first reported in ancient Iraqi civilizations, yet it remains a poorly quantified and important public health threat in the region. Efforts to control rabies in Iraq including dog population control, and vaccination of livestock and dogs, have increased since 2010. Officially reported data on human rabies, dog bites, and animal rabies cases between 2012 and 2017 are analysed here to assess the effect of existing control efforts, to inform future strategies, and to highlight gaps in surveillance and reporting. The results of molecular characterization of 32 viruses from animal cases from throughout Iraq are presented, to improve the understanding of rabies dynamics in the animal reservoir. Although annual numbers of reported human cases were lower in the period between 2012 and 2017 than prior to 2010, human cases continue. There was a distinct gender and age bias among human cases with nine cases in males for every one female and twice as many cases in children than adults. Spatial clustering analysis and phylogenetic evidence suggests rabies is endemic throughout the country, with no regional variation in risk, but better surveillance and reporting is required to underpin control strategies.


Asunto(s)
Mordeduras y Picaduras/epidemiología , Enfermedades de los Perros/epidemiología , Rabia/epidemiología , Rabia/veterinaria , Adolescente , Adulto , Animales , Niño , Enfermedades de los Perros/virología , Perros , Femenino , Humanos , Irak/epidemiología , Ganado , Masculino , Filogenia , Rabia/prevención & control , Vacunas Antirrábicas/administración & dosificación , Virus de la Rabia/clasificación , Virus de la Rabia/aislamiento & purificación , Vacunación/estadística & datos numéricos , Vacunación/veterinaria
10.
Wellcome Open Res ; 5: 3, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32090172

RESUMEN

Genomic surveillance is an important aspect of contemporary disease management but has yet to be used routinely to monitor endemic disease transmission and control in low- and middle-income countries. Rabies is an almost invariably fatal viral disease that causes a large public health and economic burden in Asia and Africa, despite being entirely vaccine preventable. With policy efforts now directed towards achieving a global goal of zero dog-mediated human rabies deaths by 2030, establishing effective surveillance tools is critical. Genomic data can provide important and unique insights into rabies spread and persistence that can direct control efforts. However, capacity for genomic research in low- and middle-income countries is held back by limited laboratory infrastructure, cost, supply chains and other logistical challenges. Here we present and validate an end-to-end workflow to facilitate affordable whole genome sequencing for rabies surveillance utilising nanopore technology. We used this workflow in Kenya, Tanzania and the Philippines to generate rabies virus genomes in two to three days, reducing costs to approximately £60 per genome. This is over half the cost of metagenomic sequencing previously conducted for Tanzanian samples, which involved exporting samples to the UK and a three- to six-month lag time. Ongoing optimization of workflows are likely to reduce these costs further. We also present tools to support routine whole genome sequencing and interpretation for genomic surveillance. Moreover, combined with training workshops to empower scientists in-country, we show that local sequencing capacity can be readily established and sustainable, negating the common misperception that cutting-edge genomic research can only be conducted in high resource laboratories. More generally, we argue that the capacity to harness genomic data is a game-changer for endemic disease surveillance and should precipitate a new wave of researchers from low- and middle-income countries.

11.
Viruses ; 12(4)2020 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-32230744

RESUMEN

In South Africa, canid rabies virus (RABV) infection is maintained in domestic and wildlife species. The identification of rabies in African civets raised the question of whether this wildlife carnivore is a potential reservoir host of RABVs of direct and ancestral dog origin (dog-maintained and dog-derived origins) with an independent cycle of transmission. Genetic analyses of African civet nucleoprotein sequences for 23 African civet RABVs and historically published sequences demonstrated that RABVs from African civets have two origins related to dog and mongoose rabies enzootics. The data support observations of the interaction of civets with domestic dogs and wildlife mongooses, mostly in Northern South Africa and North-East Zimbabwe. Within each host species clade, African civet RABVs group exclusively together, implying intra-species virus transfer occurs readily. The canid RABV clade appears to support virus transfer more readily between hosts than mongoose RABVs. Furthermore, these data probably indicate short transmission chains with conspecifics that may be related to transient rabies maintenance in African civets. Hence, it is important to continue monitoring the emergence of lyssaviruses in this host. Observations from this study are supported by ongoing and independent similar cases, in which bat-eared foxes and black-backed jackal species maintain independent rabies cycles of what were once dog-maintained RABVs.


Asunto(s)
Lyssavirus , Rabia/epidemiología , Rabia/virología , Viverridae/virología , Animales , Animales Salvajes/virología , Reservorios de Enfermedades/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Interacciones Huésped-Patógeno , Lyssavirus/clasificación , Lyssavirus/genética , Filogenia , ARN Viral
12.
J Vis Exp ; (149)2019 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-31355796

RESUMEN

Molecular assays are rapid, sensitive and specific, and have become central to diagnosing rabies. PCR based assays have been utilized for decades to confirm rabies diagnosis but have only recently been accepted by the OIE (World Organisation for Animal Health) as a primary method to detect rabies infection. Real-time RT-PCR assays provide real-time data, and are closed-tube systems, minimizing the risk of contamination during setup. DNA intercalating fluorochrome real-time RT-PCR assays do not require expensive probes, minimizing the cost per sample, and when the primers are designed in conserved regions, assays that are specific across virus genera rather than specific to just one virus species are possible. Here we describe a pan-lyssavirus SYBR real-time RT-PCR assay that detects lyssaviruses across the Lyssavirus genus, including the most divergent viruses IKOV, WCBV and LLEBV. In conjunction with dissociation curve analysis, this assay is sensitive and specific, with the advantage of detecting all lyssavirus species. The assay has been adopted in many diagnostic laboratories with quality assured environments, enabling robust, rapid, sensitive diagnosis of animal and human rabies cases.


Asunto(s)
Lyssavirus/genética , Rabia/diagnóstico , Rabia/virología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Animales , Bioensayo , Humanos , Ratones , Filogenia , ARN Viral/genética
13.
Viruses ; 11(2)2019 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-30704076

RESUMEN

The recent discovery of novel alphacoronaviruses (alpha-CoVs) in European and Asian rodents revealed that rodent coronaviruses (CoVs) sampled worldwide formed a discrete phylogenetic group within this genus. To determine the evolutionary history of rodent CoVs in more detail, particularly the relative frequencies of virus-host co-divergence and cross-species transmission, we recovered longer fragments of CoV genomes from previously discovered European rodent alpha-CoVs using a combination of PCR and high-throughput sequencing. Accordingly, the full genome sequence was retrieved from the UK rat coronavirus, along with partial genome sequences from the UK field vole and Poland-resident bank vole CoVs, and a short conserved ORF1b fragment from the French rabbit CoV. Genome and phylogenetic analysis showed that despite their diverse geographic origins, all rodent alpha-CoVs formed a single monophyletic group and shared similar features, such as the same gene constellations, a recombinant beta-CoV spike gene, and similar core transcriptional regulatory sequences (TRS). These data suggest that all rodent alpha CoVs sampled so far originate from a single common ancestor, and that there has likely been a long-term association between alpha CoVs and rodents. Despite this likely antiquity, the phylogenetic pattern of the alpha-CoVs was also suggestive of relatively frequent host-jumping among the different rodent species.


Asunto(s)
Alphacoronavirus/clasificación , Evolución Molecular , Genoma Viral , Roedores/virología , Animales , Arvicolinae/virología , Asia , Coronavirus/genética , Infecciones por Coronavirus/transmisión , Europa (Continente) , Variación Genética , Murinae/virología , Filogenia , Conejos/virología , Ratas/virología , Recombinación Genética , Análisis de Secuencia de ADN
14.
Arch Virol ; 163(8): 2283-2294, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29637429

RESUMEN

In 2018, the order Mononegavirales was expanded by inclusion of 1 new genus and 12 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.


Asunto(s)
Mononegavirales/clasificación , Animales , Humanos , Mononegavirales/genética , Mononegavirales/aislamiento & purificación , Infecciones por Mononegavirales/veterinaria , Infecciones por Mononegavirales/virología , Filogenia
15.
Int J Mol Sci ; 19(1)2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-29303971

RESUMEN

Bat rabies cases in Europe are mainly attributed to two lyssaviruses, namely European Bat Lyssavirus 1 (EBLV-1) and European Bat Lyssavirus 2 (EBLV-2). Prior to the death of a bat worker in Finland in 1985, very few bat rabies cases were reported. Enhanced surveillance in the two subsequent years (1986-1987) identified 263 cases (more than a fifth of all reported cases to date). Between 1977 and 2016, 1183 cases of bat rabies were reported, with the vast majority (>97%) being attributed to EBLV-1. In contrast, there have been only 39 suspected cases of EBLV-2, of which 34 have been confirmed by virus typing and presently restricted to just two bat species; Myotis daubentonii and Myotis dasycneme. The limited number of EBLV-2 cases in Europe prompted the establishment of a network of European reference laboratories to collate all available viruses and data. Despite the relatively low number of EBLV-2 cases, a large amount of anomalous data has been published in the scientific literature, which we have here reviewed and clarified. In this review, 29 EBLV-2 full genome sequences have been analysed to further our understanding of the diversity and molecular evolution of EBLV-2 in Europe. Analysis of the 29 complete EBLV-2 genome sequences clearly corroborated geographical relationships with all EBLV-2 sequences clustering at the country level irrespective of the gene studied. Further geographical clustering was also observed at a local level. There are high levels of homogeneity within the EBLV-2 species with nucleotide identities ranging from 95.5-100% and amino acid identities between 98.7% and 100%, despite the widespread distribution of the isolates both geographically and chronologically. The mean substitution rate for EBLV-2 across the five concatenated genes was 1.65 × 10-5, and evolutionary clock analysis confirms the slow evolution of EBLV-2 both between and within countries in Europe. This is further supported by the first detailed EBLV-2 intra-roost genomic analysis whereby a relatively high sequence homogeneity was found across the genomes of three EBLV-2 isolates obtained several years apart (2007, 2008, and 2014) from M. daubentonii at the same site (Stokesay Castle, Shropshire, UK).


Asunto(s)
Evolución Molecular , Lyssavirus/genética , Infecciones por Rhabdoviridae/virología , Animales , Genoma Viral , Humanos , Lyssavirus/clasificación , Lyssavirus/aislamiento & purificación , Filología , Infecciones por Rhabdoviridae/epidemiología
16.
PLoS Negl Trop Dis ; 12(1): e0006182, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29357361

RESUMEN

Rabies is caused by lyssaviruses, and is one of the oldest known zoonoses. In recent years, more than 21,000 nucleotide sequences of rabies viruses (RABV), from the prototype species rabies lyssavirus, have been deposited in public databases. Subsequent phylogenetic analyses in combination with metadata suggest geographic distributions of RABV. However, these analyses somewhat experience technical difficulties in defining verifiable criteria for cluster allocations in phylogenetic trees inviting for a more rational approach. Therefore, we applied a relatively new mathematical clustering algorythm named 'affinity propagation clustering' (AP) to propose a standardized sub-species classification utilizing full-genome RABV sequences. Because AP has the advantage that it is computationally fast and works for any meaningful measure of similarity between data samples, it has previously been applied successfully in bioinformatics, for analysis of microarray and gene expression data, however, cluster analysis of sequences is still in its infancy. Existing (516) and original (46) full genome RABV sequences were used to demonstrate the application of AP for RABV clustering. On a global scale, AP proposed four clusters, i.e. New World cluster, Arctic/Arctic-like, Cosmopolitan, and Asian as previously assigned by phylogenetic studies. By combining AP with established phylogenetic analyses, it is possible to resolve phylogenetic relationships between verifiably determined clusters and sequences. This workflow will be useful in confirming cluster distributions in a uniform transparent manner, not only for RABV, but also for other comparative sequence analyses.


Asunto(s)
Análisis por Conglomerados , Biología Computacional/métodos , Filogenia , ARN Viral/genética , Virus de la Rabia/clasificación , Virus de la Rabia/genética , Homología de Secuencia de Ácido Nucleico , Algoritmos
17.
Mol Ecol ; 27(3): 773-788, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29274171

RESUMEN

Landscape heterogeneity plays an important role in disease spread and persistence, but quantifying landscape influences and their scale dependence is challenging. Studies have focused on how environmental features or global transport networks influence pathogen invasion and spread, but their influence on local transmission dynamics that underpin the persistence of endemic diseases remains unexplored. Bayesian phylogeographic frameworks that incorporate spatial heterogeneities are promising tools for analysing linked epidemiological, environmental and genetic data. Here, we extend these methodological approaches to decipher the relative contribution and scale-dependent effects of landscape influences on the transmission of endemic rabies virus in Serengeti district, Tanzania (area ~4,900 km2 ). Utilizing detailed epidemiological data and 152 complete viral genomes collected between 2004 and 2013, we show that the localized presence of dogs but not their density is the most important determinant of diffusion, implying that culling will be ineffective for rabies control. Rivers and roads acted as barriers and facilitators to viral spread, respectively, and vaccination impeded diffusion despite variable annual coverage. Notably, we found that landscape effects were scale-dependent: rivers were barriers and roads facilitators on larger scales, whereas the distribution of dogs was important for rabies dispersal across multiple scales. This nuanced understanding of the spatial processes that underpin rabies transmission can be exploited for targeted control at the scale where it will have the greatest impact. Moreover, this research demonstrates how current phylogeographic frameworks can be adapted to improve our understanding of endemic disease dynamics at different spatial scales.


Asunto(s)
Perros/virología , Virus de la Rabia/fisiología , Zoonosis/transmisión , Zoonosis/virología , Animales , Movimiento , Filogeografía , Tanzanía
18.
Curr Opin Virol ; 28: 68-73, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29182939

RESUMEN

Lyssaviruses are a diverse range of viruses which all cause the disease rabies. Of the 16 recognized species, only rabies viruses (RABV) have multiple host reservoirs. Although lyssaviruses are capable of infecting all mammals, onward transmission in a new host population requires adaptation of the virus, in a number of stages with both host and virus factors determining the outcome. Due to an absence of recorded non-RABV host shifts, RABV data is extrapolated to draw conclusions for all lyssaviruses. In this article, we have focused on evidence of host shifts in the same insectivorous bat reservoir species in North America (RABV) and Europe (EBLV-1, EBLV-2 and BBLV). How RABV has successfully crossed species barriers and established infectious cycles in new hosts to be the global multi-host pathogen it is today, whilst other lyssaviruses appear restricted in host species is explored in this review. It hypothesized that RABV is the exception, rather than the rule, in this fascinating genus of viruses.


Asunto(s)
Quirópteros/virología , Reservorios de Enfermedades/virología , Especificidad del Huésped , Lyssavirus/fisiología , Virus de la Rabia/fisiología , Animales , Europa (Continente)/epidemiología , Interacciones Huésped-Patógeno , Humanos , América del Norte/epidemiología , Rabia/epidemiología , Rabia/transmisión , Infecciones por Rhabdoviridae/epidemiología , Infecciones por Rhabdoviridae/transmisión
19.
Virus Evol ; 3(2): vex038, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29255631

RESUMEN

Host shift events play an important role in epizootics as adaptation to new hosts can profoundly affect the spread of the disease and the measures needed to control it. During the late 1990s, an epizootic in Turkey resulted in a sustained maintenance of rabies virus (RABV) within the fox population. We used Bayesian inferences to investigate whole genome sequences from fox and dog brain tissues from Turkey to demonstrate that the epizootic occurred in 1997 (±1 year). Furthermore, these data indicated that the epizootic was most likely due to a host shift from locally infected domestic dogs, rather than an incursion of a novel fox or dog RABV. No evidence was observed for genetic adaptation to foxes at consensus sequence level and dN/dS analysis suggested purifying selection. Therefore, the deep sequence data were analysed to investigate the sub-viral population during a host shift event. Viral heterogeneity was measured in all RABV samples; viruses from the early period after the host shift exhibited greater sequence variation in comparison to those from the later stage, and to those not involved in the host shift event, possibly indicating a role in establishing transmission within a new host. The transient increase in variation observed in the new host species may represent virus replication within a new environment, perhaps due to increased replication within the CNS, resulting in a larger population of viruses, or due to the lack of host constraints present in the new host reservoir.

20.
BMC Vet Res ; 13(1): 216, 2017 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-28693578

RESUMEN

BACKGROUND: In Europe, bat rabies is primarily attributed to European bat lyssavirus type 1 (EBLV-1) and European bat lyssavirus type 2 (EBLV-2) which are both strongly host-specific. Approximately thirty cases of infection with EBLV-2 in Daubenton's bats (Myotis daubentonii) and pond bats (M. dasycneme) have been reported. Two human cases of rabies caused by EBLV-2 have also been confirmed during the last thirty years, while natural spill-over to other non-flying mammals has never been reported. Rabies has never been diagnosed in mainland Norway previously. CASE PRESENTATION: In late September 2015, a subadult male Daubenton's bat was found in a poor condition 800 m above sea level in the southern part of Norway. The bat was brought to the national Bat Care Centre where it eventually displayed signs of neurological disease and died after two days. EBLV-2 was detected in brain tissues by polymerase chain reaction (PCR) followed by sequencing of a part of the nucleoprotein gene, and lyssavirus was isolated in neuroblastoma cells. CONCLUSIONS: The detection of EBLV-2 in a bat in Norway broadens the knowledge on the occurrence of this zoonotic agent. Since Norway is considered free of rabies, adequate information to the general public regarding the possibility of human cases of bat-associated rabies should be given. No extensive surveillance of lyssavirus infections in bats has been conducted in the country, and a passive surveillance network to assess rabies prevalence and bat epidemiology is highly desired.


Asunto(s)
Quirópteros/virología , Lyssavirus/aislamiento & purificación , Rabia/veterinaria , Infecciones por Rhabdoviridae/veterinaria , Animales , Encéfalo/virología , Masculino , Noruega/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Rabia/virología , Infecciones por Rhabdoviridae/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...