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1.
Proc Natl Acad Sci U S A ; 112(5): 1464-9, 2015 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-25605919

RESUMO

Morbilliviruses cause many diseases of medical and veterinary importance, and although some (e.g., measles and rinderpest) have been controlled successfully, others, such as canine distemper virus (CDV), are a growing concern. A propensity for host-switching has resulted in CDV emergence in new species, including endangered wildlife, posing challenges for controlling disease in multispecies communities. CDV is typically associated with domestic dogs, but little is known about its maintenance and transmission in species-rich areas or about the potential role of domestic dog vaccination as a means of reducing disease threats to wildlife. We address these questions by analyzing a long-term serological dataset of CDV in lions and domestic dogs from Tanzania's Serengeti ecosystem. Using a Bayesian state-space model, we show that dynamics of CDV have changed considerably over the past three decades. Initially, peaks of CDV infection in dogs preceded those in lions, suggesting that spill-over from dogs was the main driver of infection in wildlife. However, despite dog-to-lion transmission dominating cross-species transmission models, infection peaks in lions became more frequent and asynchronous from those in dogs, suggesting that other wildlife species may play a role in a potentially complex maintenance community. Widespread mass vaccination of domestic dogs reduced the probability of infection in dogs and the size of outbreaks but did not prevent transmission to or peaks of infection in lions. This study demonstrates the complexity of CDV dynamics in natural ecosystems and the value of long-term, large-scale datasets for investigating transmission patterns and evaluating disease control strategies.


Assuntos
Animais Domésticos , Animais Selvagens , Vírus da Cinomose Canina/patogenicidade , Morbillivirus/patogenicidade , Animais , Teorema de Bayes , Cinomose/transmissão , Cinomose/virologia , Vírus da Cinomose Canina/fisiologia , Cães , Leões , Morbillivirus/fisiologia
2.
J Gen Virol ; 98(5): 875-887, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28555542

RESUMO

Rift Valley fever virus (RVFV) is a mosquito-borne arbovirus causing severe disease in humans and ruminants. Spread of RVFV out of Africa has raised concerns that it could emerge in Europe or the USA. Virus persistence is dependent on successful infection of, replication in, and transmission to susceptible vertebrate and invertebrate hosts, modulated by virus-host and vector-virus interactions. The principal accepted theory for the long-term maintenance of RVFV involves vertical transmission (VT) of virus to mosquito progeny, with the virus surviving long inter-epizootic periods within the egg. This VT hypothesis, however, is yet to be comprehensively proven. Here, evidence for and against the VT of RVFV is reviewed along with the identification of factors limiting its detection in natural and experimental data. The observations of VT for other arboviruses in the genera Alphavirus, Flavivirus and Orthobunyavirus are discussed within the context of RVFV. The review concludes that VT of RVFV is likely but that current data are insufficient to irrefutably prove this hypothesis.


Assuntos
Interações Hospedeiro-Patógeno , Mosquitos Vetores/virologia , Vírus da Febre do Vale do Rift/crescimento & desenvolvimento , Animais
3.
Lancet ; 384(9951): 1389-99, 2014 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24828901

RESUMO

Rabies is one of the most deadly infectious diseases, with a case-fatality rate approaching 100%. The disease is established on all continents apart from Antarctica; most cases are reported in Africa and Asia, with thousands of deaths recorded annually. However, the estimated annual figure of almost 60,000 human rabies fatalities is probably an underestimate. Almost all cases of human rabies result from bites from infected dogs. Therefore, the most cost-effective approach to elimination of the global burden of human rabies is to control canine rabies rather than expansion of the availability of human prophylaxis. Mass vaccination campaigns with parenteral vaccines, and advances in oral vaccines for wildlife, have allowed the elimination of rabies in terrestrial carnivores in several countries worldwide. The subsequent reduction in cases of human rabies in such regions advocates the multidisciplinary One Health approach to rabies control through the mass vaccination of dogs and control of canine populations.


Assuntos
Erradicação de Doenças/tendências , Vacina Antirrábica , Raiva/prevenção & controle , Animais , Sistema Nervoso Central/virologia , Vetores de Doenças , Cães , Previsões , Saúde Global , Humanos , Estágios do Ciclo de Vida , Raiva/mortalidade , Raiva/virologia , Vacinação/métodos , Zoonoses/mortalidade , Zoonoses/prevenção & controle , Zoonoses/virologia
4.
BMC Vet Res ; 11: 20, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25880683

RESUMO

BACKGROUND: Avian reoviruses (ARVs) cause a range of disease presentations in domestic, captive and free-living bird species. ARVs have been reported as a cause of significant disease and mortality in free-living corvid species in North America and continental Europe. Until this report, there have been no confirmed cases of ARV-associated disease in British wild birds. CASE PRESENTATION: Sporadic individual magpie (Pica pica) mortality was detected at a single site in Buckinghamshire, England, April-September 2013. An adult female magpie was found moribund and subsequently died. Post-mortem examination identified hepatomegaly and splenomegaly as the most severe macroscopic abnormalities. Histopathological examination revealed extensive hepatic and splenic necrosis. Transmission electron microscopy (TEM) identified virions of a size (circa 78 nm diameter) and morphology consistent with ARV in both the liver and the small intestinal (SI) contents. Nucleic acid extracted from pooled liver and spleen was positive on both a pan-reovirus nested PCR targeting the RNA-dependent RNA polymerase gene and a PCR using primers specific to the ARV sigma C protein gene. Virus isolated from the liver and the SI contents was characterised by a syncytial-type cytopathic effect, a reovirus-like appearance on TEM and sequence identical to that from PCR of tissues. In situ hybridisation confirmed co-localisation of ARV with lesions in the liver and spleen, implicating ARV as the causative agent. Splenic lymphoid atrophy and necrotic stomatitis associated with Aspergillus fumigatus infection were consistent with generalised immunosuppression and resultant opportunistic infection. CONCLUSIONS: The pathology and comprehensive virus investigations in this case indicate ARV as the primary pathogen in this magpie, with concurrent secondary infection subsequent to immunosuppression, as has been observed with reoviral infections in other bird species. ARV should be considered as a differential diagnosis for magpie, and potentially other corvid, disease and mortality incidents. This is the first demonstration of ARV-associated mortality in a wild bird in Britain. The prevalence and significance of ARV infection in British wild birds, and its implications for poultry and captive bird health, are currently unknown.


Assuntos
Doenças das Aves/patologia , Orthoreovirus Aviário/isolamento & purificação , Passeriformes , Infecções por Reoviridae/veterinária , Animais , Evolução Fatal , Feminino , Orthoreovirus Aviário/genética , Filogenia , Infecções por Reoviridae/patologia , Reino Unido
5.
J Gen Virol ; 95(Pt 8): 1647-1653, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24828330

RESUMO

Bokeloh bat lyssavirus (BBLV), a novel lyssavirus, was isolated from a Natterer's bat (Myotis nattererii), a chiropteran species with a widespread and abundant distribution across Europe. As a novel lyssavirus, the risks of BBLV to animal and human health are unknown and as such characterization both in vitro and in vivo was required to assess pathogenicity and vaccine protection. Full genome sequence analysis and antigenic cartography demonstrated that the German BBLV isolates are most closely related to European bat lyssavirus type 2 (EBLV-2) and Khujand virus and can be characterized within phylogroup I. In vivo characterization demonstrated that BBLV was pathogenic in mice when inoculated peripherally causing clinical signs typical for rabies encephalitis, with higher pathogenicity observed in juvenile mice. A limited vaccination-challenge experiment in mice was conducted and suggested that current vaccines would afford some protection against BBLV although further studies are warranted to determine a serological cut-off for protection.


Assuntos
Quirópteros/virologia , Genoma Viral , Lyssavirus/genética , Lyssavirus/imunologia , RNA Viral/genética , Animais , Antígenos Virais/genética , Análise por Conglomerados , Modelos Animais de Doenças , Encefalite Viral/patologia , Encefalite Viral/virologia , Feminino , Lyssavirus/isolamento & purificação , Lyssavirus/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Filogeografia , Raiva/patologia , Raiva/virologia , Vacina Antirrábica/administração & dosagem , Vacina Antirrábica/imunologia
6.
J Gen Virol ; 95(Pt 5): 1025-1032, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24496827

RESUMO

In 2009, a novel lyssavirus (subsequently named Ikoma lyssavirus, IKOV) was detected in the brain of an African civet (Civettictis civetta) with clinical rabies in the Serengeti National Park of Tanzania. The degree of nucleotide divergence between the genome of IKOV and those of other lyssaviruses predicted antigenic distinction from, and lack of protection provided by, available rabies vaccines. In addition, the index case was considered likely to be an incidental spillover event, and therefore the true reservoir of IKOV remained to be identified. The advent of sensitive molecular techniques has led to a rapid increase in the discovery of novel viruses. Detecting viral sequence alone, however, only allows for prediction of phenotypic characteristics and not their measurement. In the present study we describe the in vitro and in vivo characterization of IKOV, demonstrating that it is (1) pathogenic by peripheral inoculation in an animal model, (2) antigenically distinct from current rabies vaccine strains and (3) poorly neutralized by sera from humans and animals immunized against rabies. In a laboratory mouse model, no protection was elicited by a licensed rabies vaccine. We also investigated the role of bats as reservoirs of IKOV. We found no evidence for infection among 483 individuals of at least 13 bat species sampled across sites in the Serengeti and Southern Kenya.


Assuntos
Antígenos Virais/genética , Antígenos Virais/imunologia , Lyssavirus/genética , Lyssavirus/imunologia , Infecções por Rhabdoviridae/veterinária , Animais , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Quênia , Lyssavirus/classificação , Lyssavirus/isolamento & purificação , Camundongos , Vacina Antirrábica/imunologia , Infecções por Rhabdoviridae/virologia , Tanzânia , Viverridae
7.
Virol J ; 11: 63, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24708671

RESUMO

BACKGROUND: Human rabies infection continues to be a significant public health burden globally, and is occasionally imported to high income settings where the Milwaukee Protocol for intensive care management has recently been employed, with limited success in improving survival. Access to molecular diagnostics, pre- and post-mortem, and documentation of pathophysiological responses while using the Milwaukee protocol, can add useful insights for the future of rabies management. CASE PRESENTATION: A 58-year-old British Asian woman was referred to a regional general hospital in the UK with hydrophobia, anxiety and confusion nine weeks after receiving a dog bite in North West India. Nuchal skin biopsy, saliva, and a skin biopsy from the site of the dog bite wound, taken on the day of admission, all demonstrated the presence of rabies virus RNA. Within 48 hours sequence analysis of viral RNA confirmed the diagnosis and demonstrated that the virus was a strain closely related to canine rabies viruses circulating in South Asia. Her condition deteriorated rapidly with increased agitation and autonomic dysfunction. She was heavily sedated and intubated on the day after admission, treated according to a modified Milwaukee protocol, and remained stable until she developed heart block and profound acidosis and died on the eighth day. Analysis of autopsy samples showed a complete absence of rabies neutralizing antibody in cerebrospinal fluid and serum, and corresponding high levels of virus antigen and nucleic acid in brain and cerebrospinal fluid. Quantitative PCR showed virus was also distributed widely in peripheral tissues despite mild or undetectable histopathological changes. Vagus nerve branches in the heart showed neuritis, a probable Negri body but no demonstrable rabies antigen. CONCLUSION: Rapid molecular diagnosis and strain typing is helpful in the management of human rabies infection. Post-mortem findings such as vagal neuritis highlight clinically important effects on the cardiovascular system which are typical for the clinical course of rabies in humans. Management guided by the Milwaukee protocol is feasible within well-resourced intensive care units, but its role in improving outcome for canine-derived rabies remains theoretical.


Assuntos
Mordeduras e Picadas/complicações , Vírus da Raiva/isolamento & purificação , Raiva/diagnóstico , Raiva/patologia , Animais , Cães , Evolução Fatal , Feminino , Humanos , Índia , Pessoa de Meia-Idade , RNA Viral/isolamento & purificação , Viagem , Reino Unido
8.
J Anim Ecol ; 83(2): 415-28, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24111634

RESUMO

Bats host many viruses that are significant for human and domestic animal health, but the dynamics of these infections in their natural reservoir hosts remain poorly elucidated. In these, and other, systems, there is evidence that seasonal life-cycle events drive infection dynamics, directly impacting the risk of exposure to spillover hosts. Understanding these dynamics improves our ability to predict zoonotic spillover from the reservoir hosts. To this end, we followed henipavirus antibody levels of >100 individual E. helvum in a closed, captive, breeding population over a 30-month period, using a powerful novel antibody quantitation method. We demonstrate the presence of maternal antibodies in this system and accurately determine their longevity. We also present evidence of population-level persistence of viral infection and demonstrate periods of increased horizontal virus transmission associated with the pregnancy/lactation period. The novel findings of infection persistence and the effect of pregnancy on viral transmission, as well as an accurate quantitation of chiropteran maternal antiviral antibody half-life, provide fundamental baseline data for the continued study of viral infections in these important reservoir hosts.


Assuntos
Anticorpos Antivirais/sangue , Quirópteros , Infecções por Henipavirus/veterinária , Henipavirus/imunologia , Animais , Feminino , Gana , Infecções por Henipavirus/imunologia , Infecções por Henipavirus/virologia , Lactação , Estudos Longitudinais , Masculino , Gravidez , Estações do Ano
9.
Genome Med ; 16(1): 61, 2024 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-38659008

RESUMO

BACKGROUND: Implementation of clinical metagenomics and pathogen genomic surveillance can be particularly challenging due to the lack of bioinformatics tools and/or expertise. In order to face this challenge, we have previously developed INSaFLU, a free web-based bioinformatics platform for virus next-generation sequencing data analysis. Here, we considerably expanded its genomic surveillance component and developed a new module (TELEVIR) for metagenomic virus identification. RESULTS: The routine genomic surveillance component was strengthened with new workflows and functionalities, including (i) a reference-based genome assembly pipeline for Oxford Nanopore technologies (ONT) data; (ii) automated SARS-CoV-2 lineage classification; (iii) Nextclade analysis; (iv) Nextstrain phylogeographic and temporal analysis (SARS-CoV-2, human and avian influenza, monkeypox, respiratory syncytial virus (RSV A/B), as well as a "generic" build for other viruses); and (v) algn2pheno for screening mutations of interest. Both INSaFLU pipelines for reference-based consensus generation (Illumina and ONT) were benchmarked against commonly used command line bioinformatics workflows for SARS-CoV-2, and an INSaFLU snakemake version was released. In parallel, a new module (TELEVIR) for virus detection was developed, after extensive benchmarking of state-of-the-art metagenomics software and following up-to-date recommendations and practices in the field. TELEVIR allows running complex workflows, covering several combinations of steps (e.g., with/without viral enrichment or host depletion), classification software (e.g., Kaiju, Kraken2, Centrifuge, FastViromeExplorer), and databases (RefSeq viral genome, Virosaurus, etc.), while culminating in user- and diagnosis-oriented reports. Finally, to potentiate real-time virus detection during ONT runs, we developed findONTime, a tool aimed at reducing costs and the time between sample reception and diagnosis. CONCLUSIONS: The accessibility, versatility, and functionality of INSaFLU-TELEVIR are expected to supply public and animal health laboratories and researchers with a user-oriented and pan-viral bioinformatics framework that promotes a strengthened and timely viral metagenomic detection and routine genomics surveillance. INSaFLU-TELEVIR is compatible with Illumina, Ion Torrent, and ONT data and is freely available at https://insaflu.insa.pt/ (online tool) and https://github.com/INSaFLU (code).


Assuntos
COVID-19 , Biologia Computacional , Genoma Viral , Metagenômica , SARS-CoV-2 , Software , Metagenômica/métodos , Humanos , SARS-CoV-2/genética , SARS-CoV-2/classificação , COVID-19/virologia , Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Internet , Genômica/métodos
10.
BMC Genomics ; 14: 444, 2013 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-23822119

RESUMO

BACKGROUND: With the advent of Next Generation Sequencing (NGS) technologies, the ability to generate large amounts of sequence data has revolutionized the genomics field. Most RNA viruses have relatively small genomes in comparison to other organisms and as such, would appear to be an obvious success story for the use of NGS technologies. However, due to the relatively low abundance of viral RNA in relation to host RNA, RNA viruses have proved relatively difficult to sequence using NGS technologies. Here we detail a simple, robust methodology, without the use of ultra-centrifugation, filtration or viral enrichment protocols, to prepare RNA from diagnostic clinical tissue samples, cell monolayers and tissue culture supernatant, for subsequent sequencing on the Roche 454 platform. RESULTS: As representative RNA viruses, full genome sequence was successfully obtained from known lyssaviruses belonging to recognized species and a novel lyssavirus species using these protocols and assembling the reads using de novo algorithms. Furthermore, genome sequences were generated from considerably less than 200 ng RNA, indicating that manufacturers' minimum template guidance is conservative. In addition to obtaining genome consensus sequence, a high proportion of SNPs (Single Nucleotide Polymorphisms) were identified in the majority of samples analyzed. CONCLUSIONS: The approaches reported clearly facilitate successful full genome lyssavirus sequencing and can be universally applied to discovering and obtaining consensus genome sequences of RNA viruses from a variety of sources.


Assuntos
Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de RNA/métodos , Animais , Sequência de Bases , Encéfalo/virologia , Linhagem Celular , Cricetinae , Heterogeneidade Genética , Lyssavirus/genética , Camundongos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , RNA Viral/genética , Cultura de Vírus
11.
J Gen Virol ; 94(Pt 2): 284-292, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23100360

RESUMO

European bat lyssaviruses type 1 (EBLV-1) and type 2 (EBLV-2) circulate within bat populations throughout Europe and are capable of causing disease indistinguishable from that caused by classical rabies virus (RABV). However, the determinants of viral fitness and pathogenicity are poorly understood. Full-length genome clones based on the highly attenuated, non-neuroinvasive, RABV vaccine strain (SAD-B19) were constructed with the glycoprotein (G) of either SAD-B19 (SN), of EBLV-1 (SN-1) or EBLV-2 (SN-2). In vitro characterization of SN-1 and SN-2 in comparison to wild-type EBLVs demonstrated that the substitution of G affected the final virus titre and antigenicity. In vivo, following peripheral infection with a high viral dose (10(4) f.f.u.), animals infected with SN-1 had reduced survivorship relative to infection with SN, resulting in survivorship similar to animals infected with EBLV-1. The histopathological changes and antigen distribution observed for SN-1 were more representative of those observed with SN than with EBLV-1. EBLV-2 was unable to achieve a titre equivalent to that of the other viruses. Therefore, a reduced-dose experiment (10(3) f.f.u.) was undertaken in vivo to compare EBLV-2 and SN-2, which resulted in 100 % survivorship for all recombinant viruses (SN, SN-1 and SN-2) while clinical disease developed in mice infected with the EBLVs. These data indicate that interspecies replacement of G has an effect on virus titre in vitro, probably as a result of suboptimal G-matrix protein interactions, and influences the survival outcome following a peripheral challenge with a high virus titre in mice.


Assuntos
Glicoproteínas/metabolismo , Lyssavirus/genética , Lyssavirus/patogenicidade , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo , Animais , Antígenos Virais/genética , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Modelos Animais de Doenças , Glicoproteínas/genética , Glicoproteínas/imunologia , Histocitoquímica , Imuno-Histoquímica , Lyssavirus/imunologia , Camundongos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Recombinação Genética , Infecções por Rhabdoviridae/patologia , Infecções por Rhabdoviridae/virologia , Análise de Sobrevida , Carga Viral , Proteínas Virais/genética , Proteínas Virais/imunologia , Fatores de Virulência/genética , Fatores de Virulência/imunologia
12.
J Virol ; 86(18): 10242-3, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22923801

RESUMO

Lyssaviruses (family Rhabdoviridae) constitute one of the most important groups of viral zoonoses globally. All lyssaviruses cause the disease rabies, an acute progressive encephalitis for which, once symptoms occur, there is no effective cure. Currently available vaccines are highly protective against the predominantly circulating lyssavirus species. Using next-generation sequencing technologies, we have obtained the whole-genome sequence for a novel lyssavirus, Ikoma lyssavirus (IKOV), isolated from an African civet in Tanzania displaying clinical signs of rabies. Genetically, this virus is the most divergent within the genus Lyssavirus. Characterization of the genome will help to improve our understanding of lyssavirus diversity and enable investigation into vaccine-induced immunity and protection.


Assuntos
Lyssavirus/genética , Animais , Genoma Viral , Lyssavirus/classificação , Lyssavirus/isolamento & purificação , Lyssavirus/patogenicidade , Dados de Sequência Molecular , RNA Viral/genética , Infecções por Rhabdoviridae/veterinária , Infecções por Rhabdoviridae/virologia , Tanzânia , Viverridae/virologia , Zoonoses/virologia
13.
PLoS Negl Trop Dis ; 17(4): e0011204, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37079553

RESUMO

The global 2030 goal set by the World Organization for Animal Health (WOAH), the World Health Organization (WHO), and the Food and Agriculture Organization (FAO), to eliminate dog-mediated human rabies deaths, has undeniably been a catalyst for many countries to re-assess existing dog rabies control programmes. Additionally, the 2030 agenda for Sustainable Development includes a blueprint for global targets which will benefit both people and secure the health of the planet. Rabies is acknowledged as a disease of poverty, but the connections between economic development and rabies control and elimination are poorly quantified yet, critical evidence for planning and prioritisation. We have developed multiple generalised linear models, to model the relationship between health care access, poverty, and death rate as a result of rabies, with separate indicators that can be used at country-level; total Gross Domestic Product (GDP), and current health expenditure as a percentage of the total gross domestic product (% GDP) as an indicator of economic growth; and a metric of poverty assessing the extent and intensity of deprivation experienced at the individual level (Multidimensional Poverty Index, MPI). Notably there was no detectable relationship between GDP or current health expenditure (% GDP) and death rate from rabies. However, MPI showed statistically significant relationships with per capita rabies deaths and the probability of receiving lifesaving post exposure prophylaxis. We highlight that those most at risk of not being treated, and dying due to rabies, live in communities experiencing health care inequalities, readily measured through poverty indicators. These data demonstrate that economic growth alone, may not be enough to meet the 2030 goal. Indeed, other strategies such as targeting vulnerable populations and responsible pet ownership are also needed in addition to economic investment.


Assuntos
Doenças do Cão , Saúde Global , Acessibilidade aos Serviços de Saúde , Raiva , Animais , Cães , Humanos , Doenças do Cão/economia , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Saúde Global/economia , Saúde Global/estatística & dados numéricos , Pobreza/economia , Pobreza/estatística & dados numéricos , Raiva/economia , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Vírus da Raiva , Mortalidade , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Desenvolvimento Econômico/estatística & dados numéricos , Produto Interno Bruto/estatística & dados numéricos , Gastos em Saúde/estatística & dados numéricos , Profilaxia Pós-Exposição/economia , Profilaxia Pós-Exposição/estatística & dados numéricos , Organização Mundial da Saúde
14.
Am J Trop Med Hyg ; 109(1): 205-213, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37188344

RESUMO

The successful prevention, control, and elimination of dog-mediated rabies is challenging due to insufficient resource availability and inadequate placement. An integrated dog bite case management (IBCM) system plus dog vaccination can help address these challenges. Based on data from the IBCM system in Haiti, we conducted a cost-effectiveness evaluation of a newly established IBCM system plus sustained vaccination and compared it with 1) a no bite-case management (NBCM) and 2) a non-risk-based (NRB) program, where bite victims presenting at a health clinic would receive post-exposure prophylaxis regardless of risk assessment. We also provide cost-effectiveness guidance for an ongoing IBCM system and for sub-optimal dog vaccination coverages, considering that not all cost-effective interventions are affordable. Cost-effectiveness outcomes included average cost per human death averted (USD/death averted) and per life-year gained (LYG). The analysis used a governmental perspective. Considering a sustained 5-year implementation with 70% dog vaccination coverage, IBCM had a lower average cost per death averted (IBCM: $7,528, NBCM: $7,797, NRB: $15,244) and cost per LYG (IBCM: $152, NBCM: $158, NRB: $308) than NBCM and NRB programs. As sensitivity analysis, we estimated cost-effectiveness for alternative scenarios with lower dog-vaccination coverages (30%, 55%) and lower implementation costs. Our results suggest that better health and cost-effectiveness outcomes are achieved with the continued implementation of an IBCM program ($118 per life-year saved) compared with a newly established IBCM program ($152 per life-year saved). Our results suggest that IBCM is more cost-effective than non-integrated programs to eliminate dog-mediated human rabies.


Assuntos
Mordeduras e Picadas , Doenças do Cão , Vacina Antirrábica , Raiva , Humanos , Cães , Animais , Raiva/prevenção & controle , Raiva/veterinária , Análise de Custo-Efetividade , Administração de Caso , Análise Custo-Benefício , Doenças do Cão/prevenção & controle , Vacinação , Vacina Antirrábica/uso terapêutico
15.
mSystems ; 8(1): e0085222, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36629432

RESUMO

Pigs infected with Salmonella may excrete large amounts of Salmonella, increasing the risk of spread of this pathogen in the food chain. Identifying Salmonella high shedder pigs is therefore required to mitigate this risk. We analyzed immune-associated markers and composition of the gut microbiota in specific-pathogen-free pigs presenting different shedding levels after an oral infection with Salmonella. Immune response was studied through total blood cell counts, production of anti-Salmonella antibodies and cytokines, and gene expression quantification. Total Salmonella shedding for each pig was estimated and hierarchical clustering was used to cluster pigs into high, intermediate, and low shedders. Gut microbiota compositions were assessed using 16S rRNA microbial community profiling. Comparisons were made between control and inoculated pigs, then between high and low shedders pigs. Prior to infection, high shedders had similar immunological profiles compared to low shedders. As soon as 1 day postinoculation (dpi), significant differences on the cytokine production level and on the expression level of several host genes related to a proinflammatory response were observed between high and low shedders. Infection with Salmonella induced an early and profound remodeling of the immune response in all pigs, but the intensity of the response was stronger in high shedders. In contrast, low shedders seroconverted earlier than high shedders. Just after induction of the proinflammatory response (at 2 dpi), some taxa of the fecal microbiota were specific to the shedding phenotypes. This was related to the enrichment of several functional pathways related to anaerobic respiration in high shedders. In conclusion, our data show that the immune response to Salmonella modifies the fecal microbiota and subsequently could be responsible for shedding phenotypes. Influencing the gut microbiota and reducing intestinal inflammation could be a strategy for preventing Salmonella high shedding in livestock. IMPORTANCE Salmonellosis remains the most frequent human foodborne zoonosis after campylobacteriosis and pork meat is considered one of the major sources of human foodborne infections. At the farm, host heterogeneity in pig infection is problematic. High Salmonella shedders contribute more significantly to the spread of this foodborne pathogen in the food chain. The identification of predictive biomarkers for high shedders could help to control Salmonella in pigs. The purpose of the present study was to investigate why some pigs become super shedders and others low shedders. We thus investigated the differences in the fecal microbial composition and the immune response in orally infected pigs presenting different Salmonella shedding patterns. Our data show that the proinflammatory response induced by S. Typhimurium at 1 dpi could be responsible for the modification of the fecal microbiota composition and functions observed mainly at 2 and 3 dpi and to the low and super shedder phenotypes.


Assuntos
Microbiota , Salmonella typhimurium , Suínos , Animais , Humanos , Salmonella typhimurium/genética , RNA Ribossômico 16S/genética , Fezes , Fenótipo
17.
Front Mol Biosci ; 10: 1144001, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37842636

RESUMO

Introduction: Accurate and rapid diagnostics paired with effective tracking and tracing systems are key to halting the spread of infectious diseases, limiting the emergence of new variants and to monitor vaccine efficacy. The current gold standard test (RT-qPCR) for COVID-19 is highly accurate and sensitive, but is time-consuming, and requires expensive specialised, lab-based equipment. Methods: Herein, we report on the development of a SARS-CoV-2 (COVID-19) rapid and inexpensive diagnostic platform that relies on a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay and a portable smart diagnostic device. Automated image acquisition and an Artificial Intelligence (AI) deep learning model embedded in the Virus Hunter 6 (VH6) device allow to remove any subjectivity in the interpretation of results. The VH6 device is also linked to a smartphone companion application that registers patients for swab collection and manages the entire process, thus ensuring tests are traced and data securely stored. Results: Our designed AI-implemented diagnostic platform recognises the nucleocapsid protein gene of SARS-CoV-2 with high analytical sensitivity and specificity. A total of 752 NHS patient samples, 367 confirmed positives for coronavirus disease (COVID-19) and 385 negatives, were used for the development and validation of the test and the AI-assisted platform. The smart diagnostic platform was then used to test 150 positive clinical samples covering a dynamic range of clinically meaningful viral loads and 250 negative samples. When compared to RT-qPCR, our AI-assisted diagnostics platform was shown to be reliable, highly specific (100%) and sensitive (98-100% depending on viral load) with a limit of detection of 1.4 copies of RNA per µL in 30 min. Using this data, our CE-IVD and MHRA approved test and associated diagnostic platform has been approved for medical use in the United Kingdom under the UK Health Security Agency's Medical Devices (Coronavirus Test Device Approvals, CTDA) Regulations 2022. Laboratory and in-silico data presented here also indicates that the VIDIIA diagnostic platform is able to detect the main variants of concern in the United Kingdom (September 2023). Discussion: This system could provide an efficient, time and cost-effective platform to diagnose SARS-CoV-2 and other infectious diseases in resource-limited settings.

18.
Int Health ; 15(2): 216-223, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35896028

RESUMO

BACKGROUND: Neglected tropical diseases (NTDs) disproportionately affect populations living in resource-limited settings. In the Amazon basin, substantial numbers of NTDs are zoonotic, transmitted by vertebrate (dogs, bats, snakes) and invertebrate species (sand flies and triatomine insects). However, no dedicated consortia exist to find commonalities in the risk factors for or mitigations against bite-associated NTDs such as rabies, snake envenoming, Chagas disease and leishmaniasis in the region. The rapid expansion of COVID-19 has further reduced resources for NTDs, exacerbated health inequality and reiterated the need to raise awareness of NTDs related to bites. METHODS: The nine countries that make up the Amazon basin have been considered (Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Surinam and Venezuela) in the formation of a new network. RESULTS: The Amazonian Tropical Bites Research Initiative (ATBRI) has been created, with the aim of creating transdisciplinary solutions to the problem of animal bites leading to disease in Amazonian communities. The ATBRI seeks to unify the currently disjointed approach to the control of bite-related neglected zoonoses across Latin America. CONCLUSIONS: The coordination of different sectors and inclusion of all stakeholders will advance this field and generate evidence for policy-making, promoting governance and linkage across a One Health arena.


Assuntos
COVID-19 , Saúde Única , Mordeduras de Serpentes , Medicina Tropical , Humanos , Animais , Cães , Antivenenos , Disparidades nos Níveis de Saúde , Venenos de Serpentes , Doenças Negligenciadas
19.
Emerg Infect Dis ; 18(4): 664-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22469151

RESUMO

Evidence in support of a novel lyssavirus was obtained from brain samples of an African civet in Tanzania. Results of phylogenetic analysis of nucleoprotein gene sequences from representative Lyssavirus species and this novel lyssavirus provided strong empirical evidence that this is a new lyssavirus species, designated Ikoma lyssavirus.


Assuntos
Lyssavirus/isolamento & purificação , Raiva/veterinária , Raiva/virologia , Viverridae/virologia , Animais , Teorema de Bayes , Humanos , Lyssavirus/classificação , Lyssavirus/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Tanzânia
20.
Nat Microbiol ; 7(8): 1180-1188, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35836002

RESUMO

SARS-CoV-2 variants may threaten the effectiveness of vaccines and antivirals to mitigate serious COVID-19 disease. This is of most concern in clinically vulnerable groups such as older adults. We analysed 72 sera samples from 37 individuals, aged 70-89 years, vaccinated with two doses of BNT162b2 (Pfizer-BioNTech) 3 weeks apart, for neutralizing antibody responses to wildtype SARS-CoV-2. Between 3 and 20 weeks after the second vaccine dose, neutralizing antibody titres fell 4.9-fold to a median titre of 21.3 (neutralization dose 80%), with 21.6% of individuals having no detectable neutralizing antibodies at the later time point. Next, we examined neutralization of 21 distinct SARS-CoV-2 variant spike proteins with these sera, and confirmed substantial antigenic escape, especially for the Omicron (B.1.1.529, BA.1/BA.2), Beta (B.1.351), Delta (B.1.617.2), Theta (P.3), C.1.2 and B.1.638 spike variants. By combining pseudotype neutralization with specific receptor-binding domain (RBD) enzyme-linked immunosorbent assays, we showed that changes to position 484 in the spike RBD were mainly responsible for SARS-CoV-2 neutralizing antibody escape. Nineteen sera from the same individuals boosted with a third dose of BNT162b2 contained higher neutralizing antibody titres, providing cross-protection against Omicron BA.1 and BA.2. Despite SARS-CoV-2 immunity waning over time in older adults, booster vaccines can elicit broad neutralizing antibodies against a large number of SARS-CoV-2 variants in this clinically vulnerable cohort.


Assuntos
COVID-19 , SARS-CoV-2 , Idoso , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Humanos , Glicoproteínas de Membrana/química , Testes de Neutralização , SARS-CoV-2/genética , Proteínas do Envelope Viral/química
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