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1.
Viruses ; 16(4)2024 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-38675847

RESUMO

Ticks are the main arthropod vector of pathogens to humans and livestock in the British Isles. Despite their role as a vector of disease, many aspects of tick biology, ecology, and microbial association are poorly understood. To address this, we investigated the composition of the microbiome of adult and nymphal Ixodes ricinus ticks. The ticks were collected on a dairy farm in Southwest England and RNA extracted for whole genome sequencing. Sequences were detected from a range of microorganisms, particularly tick-associated viruses, bacteria, and nematodes. A majority of the viruses were attributed to phlebo-like and nairo-like virus groups, demonstrating a high degree of homology with the sequences present in I. ricinus from mainland Europe. A virus sharing a high sequence identity with Chimay rhabdovirus, previously identified in ticks from Belgium, was detected. Further investigations of I. ricinus ticks collected from additional sites in England and Wales also identified Chimay rhabdovirus viral RNA with varying prevalence in all tick populations. This suggests that Chimay rhabdovirus has a wide distribution and highlights the need for an extended exploration of the tick microbiome in the United Kingdom (UK).


Assuntos
Ixodes , Filogenia , Rhabdoviridae , Animais , Ixodes/virologia , Ixodes/microbiologia , Inglaterra , País de Gales , Rhabdoviridae/genética , Rhabdoviridae/classificação , Rhabdoviridae/isolamento & purificação , Genoma Viral , RNA Viral/genética , Microbiota , Sequenciamento Completo do Genoma , Ninfa/virologia , Ninfa/microbiologia
2.
JCPP Adv ; 3(2): e12165, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37753158

RESUMO

Given well-established links between socio-economic adversity and mental health, it is unsurprising that young people's mental health is deteriorating amidst economic crises. The World Health Organisation (WHO) recognises mental health as "crucial to personal, community, and socio-economic development" and outlines goals to reshape environments such as schools to protect mental health. Schools offer an ideal setting to promote wellbeing and prevent mental ill-health during a key developmental window. We describe how social inequalities present a challenge to designing school-based interventions for prevention and promotion for mental health and wellbeing, and suggest priorities to aid and evaluate their effectiveness.

3.
Epidemiol Infect ; 151: e163, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37622315

RESUMO

Newcastle disease (ND) is a notifiable disease affecting chickens and other avian species caused by virulent strains of Avian paramyxovirus type 1 (APMV-1). While outbreaks of ND can have devastating consequences, avirulent strains of APMV-1 generally cause subclinical infections or mild disease. However, viruses can cause different levels of disease in different species and virulence can evolve following cross-species transmission events. This report describes the detection of three cases of avirulent APMV-1 infection in Great Britain (GB). Case 1 emerged from the 'testing to exclude' scheme in chickens in Shropshire while cases 2 and 3 were made directly from notifiable avian disease investigations in chicken broilers in Herefordshire and on premises in Wiltshire containing ducks and mixed species, respectively). Class II/genotype I.1.1 APMV-1 from case 1 shared 99.94% identity to the Queensland V4 strain of APMV-1. Class II/genotype II APMV-1 was detected from case 2 while the class II/genotype I.2 virus from case 3 aligned closely with strains isolated from Anseriformes. Exclusion of ND through rapid detection of avirulent APMV-1 is important where clinical signs caused by avirulent or virulent APMV-1s could be ambiguous. Understanding the diversity of APMV-1s circulating in GB is critical to understanding disease threat from these adaptable viruses.


Assuntos
Doenças das Aves , Doença de Newcastle , Animais , Galinhas , Reino Unido/epidemiologia , Vírus da Doença de Newcastle/genética , Doença de Newcastle/epidemiologia , Doença de Newcastle/diagnóstico , Filogenia
5.
Eur Child Adolesc Psychiatry ; 32(6): 1131-1146, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35174418

RESUMO

Relatively little research has focused on children and young people (CYP) whose mental health and wellbeing improved during Covid-19 lockdown measures. We aimed to (1) determine the proportion of CYP who self-reported improvement in their mental wellbeing during the first Covid-19 lockdown and (2) describe the characteristics of this group in relation to their peers. We conducted a descriptive analysis of data from the 2020 OxWell Student Survey, a self-report, cross-sectional survey of English CYP. A total of 16,940 CYP primarily aged 8-18 years reported on change in mental wellbeing during lockdown. We characterised these CYP in terms of school, home, relational, and lifestyle factors as well as feelings about returning to school. One-third (33%) of CYP reported improved mental wellbeing during the first UK national lockdown. Compared with peers who reported no change or deterioration, a higher proportion of CYP with improved mental wellbeing reported improved relationships with friends and family, less loneliness and exclusion, reduced bullying, better management of school tasks, and more sleep and exercise during lockdown. In conclusion, a sizeable minority of CYP reported improved mental wellbeing during lockdown. Determining the reasons why these CYP felt they fared better during lockdown and considering how these beneficial experiences can be maintained beyond the pandemic might provide insights into how to promote the future mental health and wellbeing of school-aged CYP. All those working with CYP now have an opportunity to consider whether a systemic shift is needed in order to understand and realise any learnings from experiences during the pandemic.


Assuntos
COVID-19 , Criança , Humanos , Adolescente , Autorrelato , Estudos Transversais , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Estudantes , Reino Unido/epidemiologia
6.
Transbound Emerg Dis ; 69(6): 3684-3692, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36217722

RESUMO

Usutu virus (USUV) is an emerging zoonotic arbovirus in Europe, where it primarily impacts Eurasian blackbirds (Turdus merula). For mosquito-borne viruses to persist in temperate areas, transovarial transmission in vectors or overwintering in either hosts or diapausing vectors must occur to facilitate autochthonous transmission. We undertook surveillance of hosts and vectors in 2021 to elucidate whether USUV had overwintered in the United Kingdom (UK) following its initial detection there in 2020. From 175 dead bird submissions, we detected 1 case of USUV infection, in a blackbird, from which a full USUV genome was derived. Using a molecular clock analysis, we demonstrate that the 2021 detection shared a most recent common ancestor with the 2020 Greater London, UK, USUV sequence. In addition, we identified USUV-specific neutralizing antibodies in 10 out of 86 serum samples taken from captive birds at the index site, demonstrating in situ cryptic infection and potential sustained transmission. However, from 4966 mosquitoes, we detected no USUV RNA suggesting that prevalence in the vector community was absent or low during sampling. Combined, these results suggest that USUV overwintered in the UK, thus providing empirical evidence for the continued northward expansion of this vector-borne viral disease. Currently, our detection indicates geographically restricted virus persistence. Further detections over time will be required to demonstrate long-term establishment. It remains unclear whether the UK, and by extension other high-latitude regions, can support endemic USUV infection.


Assuntos
Doenças das Aves , Infecções por Flavivirus , Flavivirus , Aves Canoras , Animais , Mosquitos Vetores , Flavivirus/genética , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/veterinária , Reino Unido/epidemiologia
7.
Viruses ; 14(9)2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-36146674

RESUMO

Batai virus (BATV) is a zoonotic orthobunyavirus transmitted by a wide range of mosquito vectors. The virus is distributed throughout Asia and parts of Africa and has been sporadically detected in several European countries. There is increasing evidence that BATV is emerging in Europe as a potential threat to both animal and human health, having been detected in mosquitoes, mammals, birds and humans. In recent years, serological surveillance in cattle, sheep and goats has suggested an antibody prevalence of up to 46% in European livestock, although human serological prevalence remains generally low. However, the recent and continued spread of invasive mosquito species into Europe may facilitate the establishment of competent populations of mosquitoes leading to increased BATV transmission. Migratory birds may also potentially facilitate the emergence of BATV in geographical locations where it was previously undetected. Although BATV has the potential to cause disease in humans and livestock, our understanding of the impact in wild animal populations is extremely limited. Therefore, there is a need for increased surveillance for BATV in mosquitoes, livestock, wild mammals and birds in Europe to understand the true impact of this virus.


Assuntos
Vírus Bunyamwera , Culicidae , Orthobunyavirus , Animais , Bovinos , Europa (Continente)/epidemiologia , Cabras , Humanos , Filogenia , Ovinos
8.
Front Psychiatry ; 13: 881248, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35815012

RESUMO

Background: Little is known about the perceived acceptability and usefulness of supports that adolescents have accessed following self-harm, especially since the onset of the COVID-19 pandemic. Aims: To examine the utilization and acceptability of formal, informal, and online support accessed by adolescents following self-harm before and during the pandemic. Method: Cross-sectional survey (OxWell) of 10,560 secondary school students aged 12-18 years in the south of England. Information on self-harm, support(s) accessed after self-harm, and satisfaction with support received were obtained via a structured, self-report questionnaire. No tests for significance were conducted. Results: 1,457 (12.5%) students reported having ever self-harmed and 789 (6.7%) reported self-harming during the first national lockdown. Informal sources of support were accessed by the greatest proportion of respondents (friends: 35.9%; parents: 25.0%). Formal sources of support were accessed by considerably fewer respondents (Child and Adolescent Mental Health Services: 12.1%; psychologist/ psychiatrist: 10.2%; general practitioner: 7.4%). Online support was accessed by 8.6% of respondents, and 38.3% reported accessing no support at all. Informal sources of support were rated as most helpful, followed by formal sources, and online support. Of the respondents who sought no support, 11.3% reported this as being helpful. Conclusions: More than a third of secondary school students in this sample did not seek any help following self-harm. The majority of those not seeking help did not find this to be a helpful way of coping. Further work needs to determine effective ways of overcoming barriers to help-seeking among adolescents who self-harm and improving perceived helpfulness of the supports accessed.

9.
Parasit Vectors ; 15(1): 210, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710580

RESUMO

BACKGROUND: Japanese encephalitis virus (JEV) is the principal cause of mosquito-borne encephalitis in human populations within Asia. If introduced into new geographic areas, it could have further implications for public and animal health. However, potential mosquito vectors for virus transmission have not been fully investigated. The Asian tiger mosquito, Aedes albopictus, has emerged in Europe and is now expanding its geographical range into more northerly latitudes. Culex quinquefasciatus, although absent from Europe, has been detected in Turkey, a country with territory in Europe, and could act as a vector for JEV in other regions. To assess the risk of these invasive species acting as vectors for JEV and therefore potentially contributing to its geographical expansion, we have investigated the vector competence of Ae. albopictus and Cx. quinquefasciatus. METHODS: Two colonised lines of Ae. albopictus (Italy and Spain) and a line of Cx. quinquefasciatus (Tanzania) were compared for susceptibility to infection by oral feeding with JEV strain SA-14, genotype III at 106 PFU/ml and maintained at 25 °C. Specimens were processed at 7 and 14 days post-inoculation (dpi). Rates of infection, dissemination and transmission were assessed through detection of viral RNA by real-time polymerase chain reaction (RT-PCR) in mosquito body, legs and saliva, respectively, at each time point. Where possible, infection and dissemination were confirmed by immunohistochemical (IHC) detection of the JEV envelope protein. RESULTS: Aedes albopictus from Italy showed no susceptibility to infection with JEV strain SA-14. Conversely, Ae. albopictus colonised in Spain was susceptible and 100% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Culex quinquefasciatus was highly susceptible to infection as early as 7 dpi and 50% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Infection and dissemination were confirmed in Cx. quinquefasciatus by IHC detection of JEV envelope protein in both the mid-gut and salivary glands. CONCLUSIONS: Aedes albopictus from two different locations in Europe range from being susceptible to JEV and capable of transmission through to being resistant. Culex quinquefasciatus also appears highly susceptible; therefore, both species could potentially act as vectors for JEV and facilitate the emergence of JEV into new regions.


Assuntos
Aedes , Culex , Vírus da Encefalite Japonesa (Espécie) , Animais , Suscetibilidade a Doenças , Vírus da Encefalite Japonesa (Espécie)/genética , Mosquitos Vetores , RNA Viral/genética
10.
Artigo em Inglês | MEDLINE | ID: mdl-35627370

RESUMO

Where ticks are found, tick-borne diseases can present a threat to human and animal health. The aetiology of many of these important diseases, including Lyme disease, bovine babesiosis, tick-borne fever and louping ill, have been known for decades whilst others have only recently been documented in the United Kingdom (UK). Further threats such as the importation of exotic ticks through human activity or bird migration, combined with changes to either the habitat or climate could increase the risk of tick-borne disease persistence and transmission. Prevention of tick-borne diseases for the human population and animals (both livestock and companion) is dependent on a thorough understanding of where and when pathogen transmission occurs. This information can only be gained through surveillance that seeks to identify where tick populations are distributed, which pathogens are present within those populations, and the periods of the year when ticks are active. To achieve this, a variety of approaches can be applied to enhance knowledge utilising a diverse range of stakeholders (public health professionals and veterinarians through to citizen scientists). Without this information, the application of mitigation strategies to reduce pathogen transmission and impact is compromised and the ability to monitor the effects of climate change or landscape modification on the risk of tick-borne disease is more challenging. However, as with many public and animal health interventions, there needs to be a cost-benefit assessment on the most appropriate intervention applied. This review will assess the challenges of tick-borne diseases in the UK and argue for a cross-disciplinary approach to their surveillance and control.


Assuntos
Doença de Lyme , Saúde Única , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Doença de Lyme/epidemiologia , Doença de Lyme/prevenção & controle , Doenças Transmitidas por Carrapatos/epidemiologia , Reino Unido/epidemiologia
11.
Epidemiol Infect ; 150: e51, 2022 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-35139977

RESUMO

The 2016-17 European outbreak of H5N8 HPAIV (Clade 2.3.4.4b) affected a wider range of avian species than the previous H5N8 outbreak (2014-15), including an incursion of H5N8 HPAIV into gamebirds in England. Natural infection of captive-reared pheasants (Phasianus colchicus) led to variable disease presentation; clinical signs included ruffled feathers, reluctance to move, bright green faeces, and/or sudden mortality. Several birds exhibited neurological signs (nystagmus, torticollis, ataxia). Birds exhibiting even mild clinical signs maintained substantial levels of virus replication and shedding, with preferential shedding via the oropharyngeal route. Gross pathology was consistent with HPAIV, in gallinaceous species but diphtheroid plaques in oropharyngeal mucosa associated with necrotising stomatitis were novel but consistent findings. However, minimal or modest microscopic pathological lesions were detected despite the systemic dissemination of the virus. Serology results indicated differences in the timeframe of exposure for each case (n = 3). This supported epidemiological conclusions confirming that the movement of birds between sites and other standard husbandry practices with limited hygiene involved in pheasant rearing (including several fomite pathways) contributed to virus spread between premises.


Assuntos
Vírus da Influenza A Subtipo H5N8 , Vírus da Influenza A , Influenza Aviária , Animais , Aves , Surtos de Doenças/veterinária , Virulência
12.
Sleep Adv ; 3(1): zpab021, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35128401

RESUMO

STUDY OBJECTIVES: Sleep is essential to young people's wellbeing, yet may be constricted by the adolescent delayed sleep phase coupled with school start times. COVID-19 restrictions caused major disruptions to everyday routines, including partial school closures. We set out to understand changes in students' self-reported sleep quality, and associations with mental wellbeing and interpersonal functioning, during these restrictions. METHODS: The OxWell school survey-a cross-sectional online survey-collected data from 18 642 children and adolescents (aged 8-19 years, 60% female, school year 4-13) from 230 schools in southern England, in June-July 2020. Participants completed self-report measures of the impact of COVID-19 restrictions on sleep quality, happiness, and social relationships. Sleep timing was compared with data collected from 4222 young people in 2019. RESULTS: Females and older adolescents were more likely to report deteriorations in sleep during the national lockdown. Regression analysis revealed that changes in happiness (ß = .34) and how well students were getting on with others in their household (ß = .07) predicted change in sleep quality. Students' bedtimes and wake times were later, and sleep duration was longer in 2020 compared to the 2019 survey. Secondary school students reported the greatest differences, especially later wake times. CONCLUSIONS: During COVID-19 restrictions, sleep patterns consistent with adolescent delayed sleep phase were observed, with longer sleep times for secondary school students in particular. Perceived deteriorations in sleep quality were associated with reductions in happiness and interpersonal functioning, highlighting the importance of including sleep measures in adolescent wellbeing research.

13.
EClinicalMedicine ; 40: 101144, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34608453

RESUMO

BACKGROUND: Vaccine hesitancy has affected COVID-19 adult vaccination programs in many countries. Data on hesitancy amongst child and adolescent populations is largely confined to parent opinion. We investigated the characteristics of vaccine hesitant children and adolescents using results from a large, school-based self-report survey of the willingness to have a COVID-19 vaccination in students aged 9 -18 years in England. METHODS: Data from the OxWell Student Survey on mental health, life experiences and behaviours were used, collected from four counties across England. Local authority partners recruited schools. The vaccine hesitancy question gave six response options and were clustered to inform delivery: eager and willing were categorised as vaccination 'opt-in', don't know and not bothered categorised as 'undecided', and unwilling and anti-vaccination categorised as 'opt-out'. We conducted a multinomial regression to determine associations between vaccine hesitancy and sociodemographic, health behaviour and social connection variables. FINDINGS: 27,910 students from 180 schools answered the vaccine hesitancy question between 14th May and 21st July 2021, of whom 13984 (50.1%) would opt-in to take a vaccination, 10322 (37.0%) were undecided, and 3604 (12.9%) would opt-out. A lower percentage of younger students reported that they would opt-in to vaccination, for example, 35.7% of 9-year-olds and 51.3% of 13-year-olds compared to 77.8% of 17-year-olds would opt-in to take a vaccination. Students who were 'opt-out' or 'undecided' (a combined 'vaccine hesitant' group) were more likely to come from deprived socioeconomic contexts with higher rates of home rental versus home ownership and their school locations were more likely to be in areas of greater deprivation. They were more likely to smoke or vape, spend longer on social media, feel that they did not belong in their school community but had lower levels of anxiety and depression. The vaccine hesitant students- the undecided and opt-out groups- were similar in profile, although the opt-out students had higher reported confirmed or probable previous COVID-19 infection than the opt-in group, whereas those undecided, did not. INTERPRETATION: If government vaccination strategies move towards vaccinating younger school-aged students, efforts to increase vaccination uptake may be necessary. Compared with students who would opt-in, those who were vaccine hesitant had greater indicators of social deprivation and felt a lack of community cohesion by not feeling a sense of belonging at their school. There were indications that those students who would opt-out had higher levels of marginalisation and mistrust. If programmes are rolled out, focus on hesitant younger students will be important, targeting more marginalised and deprived young people with information from trusted sources utilising social media; improving access to vaccination centres with provision both in and outside school; and addressing fears and worries about the effects of the vaccine. The main limitation of this study is that the participant group may not be wholly representative of England or the UK, which may bias population-level estimates of willingness to be vaccinated. FUNDING: The Westminster Foundation, the National Institute for Health Research (NIHR) Applied Research Collaboration Oxford and Thames Valley at Oxford Health NHS Foundation Trust and the NIHR Oxford Health Biomedical Research Centre.

14.
JCPP Adv ; 1(2): e12021, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34514466

RESUMO

BACKGROUND: Understanding adolescents' mental health during lockdown and identifying those most at risk is an urgent public health challenge. This study surveyed school pupils across Southern England during the first COVID-19 school lockdown to investigate situational factors associated with mental health difficulties and how they relate to pupils' access to in-school educational provision. METHODS: A total of 11,765 pupils in years 8-13 completed a survey in June-July 2020, including questions on mental health, risk indicators and access to school provision. Pupils at home were compared to those accessing in-school provision on risk and contextual factors and mental health outcomes. Multilevel logistic regression analyses compared the effect of eight risk and contextual factors, including access to in-school provision, on depression, anxiety and self-reported deterioration in mental wellbeing. RESULTS: Females, pupils who had experienced food poverty and those who had previously accessed mental health support were at greatest risk of depression, anxiety and a deterioration in wellbeing. Pupils whose parents were going out to work and those preparing for national examinations in the subsequent school year were also at increased risk. Pupils accessing in-school provision had poorer mental health, but this was accounted for by the background risk and contextual factors assessed, in line with the allocation of in-school places to more vulnerable pupils. CONCLUSIONS: Although the strongest associations with poor mental health during school closures were established risk factors, further contextual factors of particular relevance during lockdown had negative impacts on wellbeing. Identifying those pupils at greatest risk for poor outcomes is critical for ensuring that appropriate educational and social support can be given to pupils either at home or in-school during subsequent lockdowns.

16.
Parasit Vectors ; 12(1): 204, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053164

RESUMO

BACKGROUND: A number of mosquito-borne viruses such as dengue virus (DENV), Usutu virus (USUV), West Nile virus (WNV) are autochthonously transmitted in Europe and six invasive mosquito species have been detected in this temperate region. This has increased the risk for the emergence of further mosquito-borne diseases. However, there is a paucity of information on whether European populations of invasive mosquito species are competent to transmit arboviruses. In this study, the susceptibility of Aedes albopictus originating from Spain and a laboratory-adapted colony of Aedes aegypti, was assessed for infection with, and transmission of Zika virus (ZIKV). Vertical transmission in both species was also assessed. METHODS: Aedes albopictus colonised from eggs collected in Spain and an existing colony of Ae. aegypti were fed infectious blood meals containing ZIKV (Polynesian strain) at 1.6 × 107 PFU/ml. Blood-fed mosquitoes were separated and maintained at 20 °C or 25 °C. Legs, saliva and bodies were sampled from specimens at 7, 14 and 21 days post-infection (dpi) in order to determine infection, dissemination and transmission rates. All samples were analysed by real-time RT-PCR using primers targeting the ZIKV NS1 gene. RESULTS: At 14 dpi and 21 dpi, ZIKV RNA was detected in the bodies of both species at both temperatures. However, live virus only was detected in the saliva of Ae. aegypti at 25 °C with a transmission rate of 44%. No evidence for virus expectoration was obtained for Ae. albopictus under any condition. Notably, ZIKV RNA was not detectable in the saliva of Ae. aegypti at 20 °C after 21 days. No vertical transmission of ZIKV was detected in this study. CONCLUSIONS: Experimental infection of Ae. albopictus colonized from Spain with ZIKV did not result in expectoration of virus in saliva in contrast to results for Ae. aegypti. No evidence of vertical transmission of virus was observed in this study. This suggests that this strain of Ae. albopictus is not competent for ZIKV transmission under the conditions tested.


Assuntos
Aedes/virologia , Mosquitos Vetores/virologia , Infecção por Zika virus/transmissão , Zika virus/fisiologia , Aedes/crescimento & desenvolvimento , Aedes/fisiologia , Animais , Feminino , Humanos , Masculino , Mosquitos Vetores/crescimento & desenvolvimento , Mosquitos Vetores/fisiologia , Saliva/virologia , Espanha , Temperatura , Zika virus/genética , Zika virus/isolamento & purificação , Infecção por Zika virus/virologia
17.
Vaccine ; 37(33): 4694-4700, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29439871

RESUMO

Over the last 20 years, natural peptides playing a key role in defense mechanisms and innate immunity have been isolated from unicellular organisms. Amphibian skin secretes dermaseptins, 24-34 amino acids in length that have a wide antimicrobial spectrum incorporating yeast, fungi, protozoa, bacteria and enveloped viruses. The anti-rabies virus (RABV) activity of dermaseptins S3 (30aa) and S4 (28aa) from Phyllomedusa sauvagei has been investigated, and further dissected its molecular basis by comparing punctual mutation or deletion of S4 analogues. The results showed that: (1) S4 is more active than S3 against RABV infection, 89% versus 38% inhibition at 7.5 µM; (2) the 5 NH2-aa of S4 are crucial for its inhibitory potential (S46-28 lost any inhibition) but the COOH terminus stabilizes the inhibitory potential (S41-16 showed only 23% inhibition at 7.5 µM); (3) there is a correlation between viral inhibition and dermaseptin cytotoxicity, which remains however moderated for BSR cells (≤12% at 10 µM). A single mutation in position 4 (S4M4K) slightly reduced cytotoxicity while keeping its antiviral activity, 97% at 7.5 µM. S4 and S4M4K showed an antiviral activity in vitro when provided 1 h after infection. In vivo experiments in mice by intramuscular injection of non-toxic doses of dermaseptin S4M4K 1 h post-infection by a lethal dose of RABV at the same site allowed more than 50% improvement in mice survival. This study highlights the potential interest of dermaseptins as non-expansive alternatives to rabies immunoglobulins for the treatment of rabies that continues to claim about 60,000 human lives per year worldwide, almost exclusively in developing countries.


Assuntos
Proteínas de Anfíbios/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Antivirais/uso terapêutico , Raiva/tratamento farmacológico , Proteínas de Anfíbios/administração & dosagem , Proteínas de Anfíbios/efeitos adversos , Proteínas de Anfíbios/genética , Animais , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/efeitos adversos , Peptídeos Catiônicos Antimicrobianos/genética , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Relação Dose-Resposta a Droga , Feminino , Injeções Intramusculares , Camundongos , Mutação/genética , Relação Estrutura-Atividade
18.
Vaccine ; 37(33): 4710-4714, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29274698

RESUMO

Rabies is a deadly viral disease with an extremely high fatality rate in humans. Previously, it was suggested that an enhancement of the blood-brain barrier (BBB) permeability, which allows immune cells and/or antibodies to enter the central nervous system (CNS) tissue, is critical to clear the infection. In this study, we utilised mannitol to increase BBB permeability in mice infected with highly pathogenic silver-haired bat rabies virus (SHBRV). We found that intraperitoneal injection of mannitol causes a slight, transient increase of BBB permeability in the treated mice. SHBRV-infected mice were treated with intraperitoneally administered mannitol daily from day 3 or day 4 post-infection, but no effect of this treatment on the time of disease onset, clinical signs or survival was observed. This data indicates that the increase of BBB permeability by mannitol is not efficient in promoting CNS virus clearance in SHBRV-infected mice.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Manitol/uso terapêutico , Vírus da Raiva/efeitos dos fármacos , Vírus da Raiva/patogenicidade , Raiva/tratamento farmacológico , Animais , Anticorpos Antivirais/metabolismo , Antígenos Virais/metabolismo , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Raiva/virologia
19.
Vaccine ; 37(33): 4686-4693, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29132993

RESUMO

There is no antiviral treatment available once clinical disease following rabies virus infection has initiated. Considered a neglected tropical disease, >60,000 human rabies deaths are estimated each year despite the availability of pre- and post-exposure prophylaxis for pre-immunisation or administration following a potential exposure before the onset of clinical disease. Such post-exposure treatments include administration of rabies immunoglobulin (RIG) and vaccination at a distant site to prime a humoral immune response. However, current therapeutic options are limited. Regardless there is a need for molecules that target virus infection following the onset of clinical disease where the outcome of infection is invariably fatal. Numerous molecules have been assessed as potential antivirals against rabies virus (RABV) but with little promise. Favipiravir (T-705) is a broad-spectrum RNA polymerase inhibitor, which has been shown to have antiviral activity against a range of RNA viruses including some against RABV. In the present study, the utility of T-705 has been reassessed in vitro as well as in vivo in a murine model using intraperitoneal administration to investigate any immune protective effect of the molecule. In vitro T-705 effectively reduces RABV replication. However, in vivo, following assessment of various applications of the molecule in both pre- and post-exposure scenarios, the effect was limited. T-705 treatment delayed the onset of clinical signs when virus was delivered intramuscularly at a higher dose (106.8 TCID50/ml) and reduced the number of mice that developed clinical signs when virus was delivered at a lower dose (105.8 TCID50/ml) during the observation period. The day at which treatment commenced did not appear to have a statistically significant effect on the results in either experiment. The use of T-705 as a single biological entity may be limited, however, further work is required to assess the synergistic effect of T-705 as a component of a multi-drug therapy for treating human rabies infections.


Assuntos
Amidas/uso terapêutico , Antivirais/uso terapêutico , Pirazinas/uso terapêutico , Vírus da Raiva/efeitos dos fármacos , Vírus da Raiva/patogenicidade , Raiva/tratamento farmacológico , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Testes de Neutralização , Raiva/virologia
20.
J Virol Methods ; 265: 9-14, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30579921

RESUMO

Newcastle disease is a devastating disease of poultry caused by Newcastle disease virus (NDV), a virulent form of avian avulavirus 1 (AAvV-1). A rapid, sensitive and specific means for the detection of NDV is fundamental for the control of this notifiable transboundary virus. Although several real-time RT-PCR assays exist for the detection of AAvV-1, diagnostic sensitivity and specificities can be sub-optimal. In this study, we describe a modification to an existing AAvV-1 l-gene RT-PCR screening assay, where the original probe set was replaced with minor groove binding (MGB) probes, to create the MGB l-gene assay. The diagnostic sensitivity and specificity of this assay was evaluated against a broad panel of both Class I and Class II AAvV-1 viruses of diverse and representative lineages/genotypes in both clinical samples and amplified viruses, and compared with a number of previously published real-time RT-PCR screening assays for AAvV-1. The MGB l-gene assay outperformed all other assays in this assessment, with enhanced sensitivity and specificity, detecting isolates from a broad range of virus lineages/genotypes (including contemporaneously-circulating strains). The assay has also proved its value for screening original clinical samples for the presence of AAvV-1, thus providing an improved screening assay for routine detection of this notifiable disease agent.


Assuntos
Infecções por Avulavirus/veterinária , Avulavirus/isolamento & purificação , Doenças das Aves/diagnóstico , Doenças das Aves/virologia , Primers do DNA/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Avulavirus/classificação , Avulavirus/genética , Infecções por Avulavirus/diagnóstico , Infecções por Avulavirus/virologia , Aves , Genótipo , Sensibilidade e Especificidade
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