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1.
Viruses ; 13(2)2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-33498685

RESUMO

Nipah virus is a bat-borne paramyxovirus that produces yearly outbreaks of fatal encephalitis in Bangladesh. Understanding the ecological conditions that lead to spillover from bats to humans can assist in designing effective interventions. To investigate the current and historical processes that drive Nipah spillover in Bangladesh, we analyzed the relationship among spillover events and climatic conditions, the spatial distribution and size of Pteropus medius roosts, and patterns of land-use change in Bangladesh over the last 300 years. We found that 53% of annual variation in winter spillovers is explained by winter temperature, which may affect bat behavior, physiology, and human risk behaviors. We infer from changes in forest cover that a progressive shift in bat roosting behavior occurred over hundreds of years, producing the current system where a majority of P. medius populations are small (median of 150 bats), occupy roost sites for 10 years or more, live in areas of high human population density, and opportunistically feed on cultivated food resources-conditions that promote viral spillover. Without interventions, continuing anthropogenic pressure on bat populations similar to what has occurred in Bangladesh could result in more regular spillovers of other bat viruses, including Hendra and Ebola viruses.


Assuntos
Quirópteros/virologia , Comportamento Alimentar , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/veterinária , Vírus Nipah/genética , Animais , Bangladesh/epidemiologia , Quirópteros/fisiologia , Surtos de Doenças , Florestas , Humanos , Modelos Lineares , Estações do Ano , Zoonoses/epidemiologia , Zoonoses/virologia
2.
Nat Commun ; 11(1): 3849, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737300

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr Virus (EBV) establish life-long infections and are associated with malignancies. Striking geographic variation in incidence and the fact that virus alone is insufficient to cause disease, suggests other co-factors are involved. Here we present epidemiological analysis and genome-wide association study (GWAS) in 4365 individuals from an African population cohort, to assess the influence of host genetic and non-genetic factors on virus antibody responses. EBV/KSHV co-infection (OR = 5.71(1.58-7.12)), HIV positivity (OR = 2.22(1.32-3.73)) and living in a more rural area (OR = 1.38(1.01-1.89)) are strongly associated with immunogenicity. GWAS reveals associations with KSHV antibody response in the HLA-B/C region (p = 6.64 × 10-09). For EBV, associations are identified for VCA (rs71542439, p = 1.15 × 10-12). Human leucocyte antigen (HLA) and trans-ancestry fine-mapping substantiate that distinct variants in HLA-DQA1 (p = 5.24 × 10-44) are driving associations for EBNA-1 in Africa. This study highlights complex interactions between KSHV and EBV, in addition to distinct genetic architectures resulting in important differences in pathogenesis and transmission.


Assuntos
Anticorpos Antivirais/biossíntese , Resistência à Doença/genética , Infecções por Vírus Epstein-Barr/genética , Infecções por Henipavirus/genética , Interações Hospedeiro-Patógeno/genética , Sarcoma de Kaposi/genética , Adolescente , Adulto , Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Coinfecção , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/virologia , Antígenos Nucleares do Vírus Epstein-Barr/genética , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Feminino , Expressão Gênica , Estudo de Associação Genômica Ampla , HIV/genética , HIV/imunologia , HIV/patogenicidade , Cadeias alfa de HLA-DQ/genética , Cadeias alfa de HLA-DQ/imunologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/imunologia , Infecções por Henipavirus/virologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/patogenicidade , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/imunologia , Herpesvirus Humano 8/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , População Rural , Sarcoma de Kaposi/epidemiologia , Sarcoma de Kaposi/imunologia , Sarcoma de Kaposi/virologia , Uganda/epidemiologia , População Urbana
3.
Trop Doct ; 50(3): 174-175, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32476600

RESUMO

Without a vaccine or proven therapeutic options in COVID-19, the World Health Organization (WHO) recommends a combination of measures: rapid diagnosis and immediate isolation of cases; rigorous contact tracing; and precautionary self-isolation of close contacts to curb the spread of COVID-19. During a Nipah outbreak in Kerala, India in 2019, it was confined to a single case. The authors were involved in the in-hospital contact tracing. With a single patient producing a contact list of 98 in a healthcare setting, the implications in a community setting during a pandemic of the scale of COVID-19 are huge but it proves that early and rigorous tracing with quarantining is an effective strategy to limit clusters. We believe that if the public is encouraged to maintain their own contact list on a daily basis, it would help in significantly reducing the time and effort invested into contact tracing in the event of a person contracting COVID-19.


Assuntos
Busca de Comunicante , Infecções por Coronavirus/prevenção & controle , Surtos de Doenças/prevenção & controle , Infecções por Henipavirus/prevenção & controle , Vírus Nipah , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Infecções por Coronavirus/epidemiologia , Infecções por Henipavirus/epidemiologia , Humanos , Índia/epidemiologia , Pneumonia Viral/epidemiologia
4.
Am J Trop Med Hyg ; 103(3): 1241-1246, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32588798

RESUMO

In any outbreak situation, a poor stakeholder response can impede the outbreak control and can have high economic and social cost. We conducted a qualitative study to understand stakeholder response in handling of the Nipah deceased persons during the outbreak of Nipah in Kerala, 2018. To understand the responses and to generate knowledge from the data, we used grounded theory approach for the study and conducted in-depth interviews and focus group discussion. Mixed public response and swift state response emerged as the main themes in our study. Under the "mixed public response," three categories emerged, including anxiety and fear, conflicting religious beliefs, and humanitarian concern. Under the "swift state response," the categories emerged were critical resources and robust guidance. A collective effort involving the administration, local and religious groups, and a culturally acceptable scientific protocol proved to be good examples of gaining social acceptance. Kerala puts forth a model of efficient community engagement and communication to gain public support and acceptance in a fatal disease outbreak.


Assuntos
Surtos de Doenças , Infecções por Henipavirus/epidemiologia , Vírus Nipah/isolamento & purificação , Feminino , Grupos Focais , Infecções por Henipavirus/virologia , Humanos , Índia/epidemiologia , Masculino , Pesquisa Qualitativa
5.
Epidemiol Infect ; 148: e90, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32321607

RESUMO

Nipah virus (NiV) outbreak occurred in Kozhikode district, Kerala, India in 2018 with a case fatality rate of 91% (21/23). In 2019, a single case with full recovery occurred in Ernakulam district. We described the response and control measures by the Indian Council of Medical Research and Kerala State Government for the 2019 NiV outbreak. The establishment of Point of Care assays and monoclonal antibodies administration facility for early diagnosis, response and treatment, intensified contact tracing activities, bio-risk management and hospital infection control training of healthcare workers contributed to effective control and containment of NiV outbreak in Ernakulam.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Emergências , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/prevenção & controle , Vírus Nipah , Saúde Pública , Restos Mortais , Surtos de Doenças , Humanos , Índia/epidemiologia , Eliminação de Resíduos de Serviços de Saúde , Equipamento de Proteção Individual
6.
Viruses ; 12(4)2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325930

RESUMO

Viral outbreaks of varying frequencies and severities have caused panic and havoc across the globe throughout history. Influenza, small pox, measles, and yellow fever reverberated for centuries, causing huge burden for economies. The twenty-first century witnessed the most pathogenic and contagious virus outbreaks of zoonotic origin including severe acute respiratory syndrome coronavirus (SARS-CoV), Ebola virus, Middle East respiratory syndrome coronavirus (MERS-CoV) and Nipah virus. Nipah is considered one of the world's deadliest viruses with the heaviest mortality rates in some instances. It is known to cause encephalitis, with cases of acute respiratory distress turning fatal. Various factors contribute to the onset and spread of the virus. All through the infected zone, various strategies to tackle and enhance the surveillance and awareness with greater emphasis on personal hygiene has been formulated. This review discusses the recent outbreaks of Nipah virus in Malaysia, Bangladesh and India, the routes of transmission, prevention and control measures employed along with possible reasons behind the outbreaks, and the precautionary measures to be ensured by private-public undertakings to contain and ensure a lower incidence in the future.


Assuntos
Encefalite Viral/epidemiologia , Encefalite Viral/transmissão , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Vírus Nipah/classificação , Animais , Bangladesh/epidemiologia , Quirópteros/virologia , Surtos de Doenças , Encefalite Viral/prevenção & controle , Infecções por Henipavirus/prevenção & controle , Humanos , Índia/epidemiologia , Controle de Infecções , Malásia/epidemiologia , Vírus Nipah/genética , Proteínas Estruturais Virais/genética
7.
J Infect Public Health ; 13(5): 674-678, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32265162

RESUMO

Increasing emergence and spread of Nipah, ZIKV and Ebola case and potential outbreaks threats have been reported in several regions around the globe. Yet, emerging Nipah, Ebola and Zika viral diseases outbreaks have been indirectly linked to substantially globalization of trade and travel, climate change and intense urbanization impact, healthcare and socioeconomic inequities as well in affected community settings. Although no case has been documented in Saudi Arabia, there is a great risk of sudden emergence of any of these viruses and others via introducing among pilgrims coming from endemic regions during ritual ceremonies of mass gatherings. Consequently, promoting and investing on new and sensitive proven effective and innovative surveillance and monitoring approaches, including enhanced risk communication, improved integrated vectors surveillance in addition to improved sustainable highly pathogens surveillance control programs to human motility and environmental sanitation strategies all represent 'One Health' approach implementation strategic core. Initiation, development and implementation leaded by Saudi government and international stakeholders' of new partnership, coordinated response leadership and resource mobilization for multidisciplinary and intersectorial advocacy on emerging viral disease outbreaks, accompanied with R&D roadmap and taskforce is crucial. More efforts in epidemiological and laboratory early screening and surveillance of highly pathogenic germs/microbes, and confirmation of asymptomatic and syndromic cases amongst suspected Hajj and Umrah pilgrims, local vulnerable populations and expatriate workers is vital in generating reliable data and data sharing platform for timely risk communication and tourist information update, appropriate immunization campaigns or safe and efficacious care delivery implementation. Moreover, increase Hajj/Umrah mass gathering emergency outbreak preparedness, pilgrims health education and engagement outreach, pre-, during and post programs coverage and effectiveness is needed through One Health approach integration in attaining pilgrims and local population health safety and security, in advancing Saudi sustainable health development goals.


Assuntos
Surtos de Doenças/prevenção & controle , Doença pelo Vírus Ebola/epidemiologia , Infecções por Henipavirus/epidemiologia , Infecção por Zika virus/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Ebolavirus , Emigrantes e Imigrantes/estatística & dados numéricos , Monitoramento Epidemiológico , Humanos , Internacionalidade , Islamismo , Vírus Nipah , Saúde Pública , Arábia Saudita/epidemiologia , Viagem , Zika virus
8.
Transbound Emerg Dis ; 67(1): 121-132, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31408582

RESUMO

Since its first emergence in 1998 in Malaysia, Nipah virus (NiV) has become a great threat to domestic animals and humans. Sporadic outbreaks associated with human-to-human transmission caused hundreds of human fatalities. Here, we collected all available NiV sequences and combined phylogenetics, molecular selection, structural biology and receptor analysis to study the emergence and adaptive evolution of NiV. NiV can be divided into two main lineages including the Bangladesh and Malaysia lineages. We formly confirmed a significant association with geography which is probably the result of long-term evolution of NiV in local bat population. The two NiV lineages differ in many amino acids; one change in the fusion protein might be involved in its activation via binding to the G protein. We also identified adaptive and positively selected sites in many viral proteins. In the receptor-binding G protein, we found that sites 384, 386 and especially 498 of G protein might modulate receptor-binding affinity and thus contribute to the host jump from bats to humans via the adaption to bind the human ephrin-B2 receptor. We also found that site 1645 in the connector domain of L was positive selected and involved in adaptive evolution; this site might add methyl groups to the cap structure present at the 5'-end of the RNA and thus modulate its activity. This study provides insight to assist the design of early detection methods for NiV to assess its epidemic potential in humans.


Assuntos
Adaptação Biológica , Quirópteros/virologia , Surtos de Doenças , Infecções por Henipavirus/virologia , Vírus Nipah/genética , Polimorfismo Genético , Animais , Bangladesh/epidemiologia , Evolução Biológica , Biologia Computacional , Geografia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Especificidade de Hospedeiro , Humanos , Malásia/epidemiologia , Modelos Moleculares , Vírus Nipah/isolamento & purificação , Vírus Nipah/patogenicidade , Vírus Nipah/fisiologia , Filogenia , Proteínas Virais/genética
9.
Indian J Public Health ; 63(3): 261-264, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31552860

RESUMO

Asia Pacific region has been witnessing numerous public health emergencies in recent years with the Nipah outbreak in North Kerala (2018), India, needs special mention. Threats posed and experiences gained have compelled health systems to draft frameworks nationally and internationally for preparedness, outbreak response, and recovery. Our failure to obtain comprehensive guiding frameworks for application in the Indian context for Ebola, Severe Acute Respiratory Syndrome, Influenza A (H1N1), and Nipah outbreaks led us to the search outside India for frameworks that have worked in the past. A thorough review of the WHO, Centers for Disease Control and Prevention, and Malaysian framework was done to identify explicit components and replicable objectives to the national context. In the absence of a specific framework, Nipah recovery and response experience that worked in Kerala outbreak (2018) was compared against novel H1N1 (2015) guidelines at national level. This article provides the groundwork and insights as a value addition toward an India-specific framework of action for response and recovery for Nipah outbreaks in future.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Planejamento em Desastres/organização & administração , Infecções por Henipavirus/epidemiologia , Influenza Humana/epidemiologia , Surtos de Doenças , Guias como Assunto , Humanos , Índia/epidemiologia , Vírus da Influenza A Subtipo H1N1
10.
Philos Trans R Soc Lond B Biol Sci ; 374(1782): 20190224, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31401958

RESUMO

Disease emergence events, epidemics and pandemics all underscore the need to predict zoonotic pathogen spillover. Because cross-species transmission is inherently hierarchical, involving processes that occur at varying levels of biological organization, such predictive efforts can be complicated by the many scales and vastness of data potentially required for forecasting. A wide range of approaches are currently used to forecast spillover risk (e.g. macroecology, pathogen discovery, surveillance of human populations, among others), each of which is bound within particular phylogenetic, spatial and temporal scales of prediction. Here, we contextualize these diverse approaches within their forecasting goals and resulting scales of prediction to illustrate critical areas of conceptual and pragmatic overlap. Specifically, we focus on an ecological perspective to envision a research pipeline that connects these different scales of data and predictions from the aims of discovery to intervention. Pathogen discovery and predictions focused at the phylogenetic scale can first provide coarse and pattern-based guidance for which reservoirs, vectors and pathogens are likely to be involved in spillover, thereby narrowing surveillance targets and where such efforts should be conducted. Next, these predictions can be followed with ecologically driven spatio-temporal studies of reservoirs and vectors to quantify spatio-temporal fluctuations in infection and to mechanistically understand how pathogens circulate and are transmitted to humans. This approach can also help identify general regions and periods for which spillover is most likely. We illustrate this point by highlighting several case studies where long-term, ecologically focused studies (e.g. Lyme disease in the northeast USA, Hendra virus in eastern Australia, Plasmodium knowlesi in Southeast Asia) have facilitated predicting spillover in space and time and facilitated the design of possible intervention strategies. Such studies can in turn help narrow human surveillance efforts and help refine and improve future large-scale, phylogenetic predictions. We conclude by discussing how greater integration and exchange between data and predictions generated across these varying scales could ultimately help generate more actionable forecasts and interventions. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.


Assuntos
Doenças Transmissíveis Emergentes , Reservatórios de Doenças , Infecções por Henipavirus , Doença de Lyme , Malária , Zoonoses , Animais , Ásia Sudeste/epidemiologia , Austrália/epidemiologia , Borrelia burgdorferi/fisiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/transmissão , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/parasitologia , Reservatórios de Doenças/virologia , Vírus Hendra/fisiologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Humanos , Doença de Lyme/epidemiologia , Doença de Lyme/transmissão , Malária/epidemiologia , Malária/transmissão , Plasmodium knowlesi/fisiologia , Estados Unidos/epidemiologia , Zoonoses/epidemiologia , Zoonoses/transmissão
11.
Philos Trans R Soc Lond B Biol Sci ; 374(1782): 20190021, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31401962

RESUMO

Pathogen circulation among reservoir hosts is a precondition for zoonotic spillover. Unlike the acute, high morbidity infections typical in spillover hosts, infected reservoir hosts often exhibit low morbidity and mortality. Although it has been proposed that reservoir host infections may be persistent with recurrent episodes of shedding, direct evidence is often lacking. We construct a generalized SEIR (susceptible, exposed, infectious, recovered) framework encompassing 46 sub-models representing the full range of possible transitions among those four states of infection and immunity. We then use likelihood-based methods to fit these models to nine years of longitudinal data on henipavirus serology from a captive colony of Eidolon helvum bats in Ghana. We find that reinfection is necessary to explain observed dynamics; that acute infectious periods may be very short (hours to days); that immunity, if present, lasts about 1-2 years; and that recurring latent infection is likely. Although quantitative inference is sensitive to assumptions about serology, qualitative predictions are robust. Our novel approach helps clarify mechanisms of viral persistence and circulation in wild bats, including estimated ranges for key parameters such as the basic reproduction number and the duration of the infectious period. Our results inform how future field-based and experimental work could differentiate the processes of viral recurrence and reinfection in reservoir hosts. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.


Assuntos
Quirópteros , Reservatórios de Doenças/veterinária , Infecções por Henipavirus/veterinária , Henipavirus/fisiologia , Animais , Animais de Zoológico , Reservatórios de Doenças/virologia , Gana/epidemiologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Infecções por Henipavirus/virologia , Prevalência , Estudos Soroepidemiológicos
12.
Epidemiol Infect ; 147: e240, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-31364577

RESUMO

Hendra virus (HeV) continues to cause fatal infection in horses and threaten infection in close-contact humans in eastern Australia. Species of Pteropus bats (flying-foxes) are the natural reservoir of the virus. We caught and sampled flying-foxes from a multispecies roost in southeast Queensland, Australia on eight occasions between June 2013 and June 2014. The effects of sample date, species, sex, age class, body condition score (BCS), pregnancy and lactation on HeV antibody prevalence, log-transformed median fluorescent intensity (lnMFI) values and HeV RNA status were assessed using unbalanced generalised linear models. A total of 1968 flying-foxes were sampled, comprising 1012 Pteropus alecto, 742 P. poliocephalus and 214 P. scapulatus. Sample date, species and age class were each statistically associated with HeV RNA status, antibody status and lnMFI values; BCS was statistically associated with HeV RNA status and antibody status. The findings support immunologically naïve sub-adult P. alecto playing an important role in maintaining HeV infection at a population level. The biological significance of the association between BCS and HeV RNA status, and BCS and HeV antibody status, is less clear and warrants further investigation. Contrary to previous studies, we found no direct association between HeV infection and pregnancy or lactation. The findings in P. poliocephalus suggest that HeV exposure in this species may not result in systemic infection and virus excretion, or alternatively, may reflect assay cross-reactivity with another (unidentified) henipavirus.


Assuntos
Quirópteros/virologia , Surtos de Doenças/estatística & dados numéricos , Transmissão de Doença Infecciosa/estatística & dados numéricos , Vírus Hendra/isolamento & purificação , Infecções por Henipavirus/epidemiologia , Doenças dos Cavalos/epidemiologia , Fatores Etários , Animais , Anticorpos Antivirais/sangue , Austrália/epidemiologia , Composição Corporal , Feminino , Cavalos , Humanos , Gravidez , Prevalência , Queensland/epidemiologia , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Medição de Risco , Estações do Ano
13.
Public Health ; 173: 97-104, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31261032

RESUMO

OBJECTIVES: The objectives of this article are to highlight the properties of the Nipah virus (NiV) and discuss its epidemiological determinants. STUDY DESIGN: A review of conjectures, epidemiological and clinically related studies, and identification and discussion of preventive approaches is conducted. METHODS: A review of the current literature is performed going through online search engines: PubMed and Google Scholar. The search strategy was focused on two main components, first on the NiV ('Nipah' OR 'Nipah Virus') and subsequently on its epidemiology, including determinants and preventive measures ('Epidemiology/determinants' OR 'Epidemiology/prevention'). RESULTS: NiV infection is an emerging zoonotic infectious disease causing sporadic outbursts in many developing countries within Asia, Africa, and South America. Pteroid bats are the natural reservoirs, but human-to-human transmission is possible. Clinical course ranges from non-specific influenza-like symptoms to rapidly progressive respiratory and neurologic complications. Vector control has been challenging because of its widely distributed ecological niche. Currently, no definitive treatment protocols are available in humans, but profound breakthrough in vaccine technology and successful equine vaccines has shown the way for the development of NiV vaccine and immunization in the near future. CONCLUSIONS: The NiV poses a significant public health risk because of its intricate transmission cycle, unpredictable viral course, murky management protocol, and unavailability of vaccine. Complicated by emergence and subsequent reemergence, prevention and containment are the two most important public health promotion strategies. Early anticipation, intergovernmental preparedness and cooperation, and surveillance of zoonotic infections still remain the key to mitigate the risk.


Assuntos
Surtos de Doenças , Infecções por Henipavirus/epidemiologia , Vírus Nipah , Animais , Surtos de Doenças/prevenção & controle , Infecções por Henipavirus/prevenção & controle , Humanos , Vacinas Virais , Zoonoses/epidemiologia , Zoonoses/prevenção & controle
14.
PLoS Negl Trop Dis ; 13(6): e0007393, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31246966

RESUMO

The 2018 outbreak of Nipah virus in Kerala, India, highlights the need for global surveillance of henipaviruses in bats, which are the reservoir hosts for this and other viruses. Nipah virus, an emerging paramyxovirus in the genus Henipavirus, causes severe disease and stuttering chains of transmission in humans and is considered a potential pandemic threat. In May 2018, an outbreak of Nipah virus began in Kerala, > 1800 km from the sites of previous outbreaks in eastern India in 2001 and 2007. Twenty-three people were infected and 21 people died (16 deaths and 18 cases were laboratory confirmed). Initial surveillance focused on insectivorous bats (Megaderma spasma), whereas follow-up surveys within Kerala found evidence of Nipah virus in fruit bats (Pteropus medius). P. medius is the confirmed host in Bangladesh and is now a confirmed host in India. However, other bat species may also serve as reservoir hosts of henipaviruses. To inform surveillance of Nipah virus in bats, we reviewed and analyzed the published records of Nipah virus surveillance globally. We applied a trait-based machine learning approach to a subset of species that occur in Asia, Australia, and Oceana. In addition to seven species in Kerala that were previously identified as Nipah virus seropositive, we identified at least four bat species that, on the basis of trait similarity with known Nipah virus-seropositive species, have a relatively high likelihood of exposure to Nipah or Nipah-like viruses in India. These machine-learning approaches provide the first step in the sequence of studies required to assess the risk of Nipah virus spillover in India. Nipah virus surveillance not only within Kerala but also elsewhere in India would benefit from a research pipeline that included surveys of known and predicted reservoirs for serological evidence of past infection with Nipah virus (or cross reacting henipaviruses). Serosurveys should then be followed by longitudinal spatial and temporal studies to detect shedding and isolate virus from species with evidence of infection. Ecological studies will then be required to understand the dynamics governing prevalence and shedding in bats and the contacts that could pose a risk to public health.


Assuntos
Quirópteros/virologia , Controle de Doenças Transmissíveis/organização & administração , Transmissão de Doença Infecciosa , Monitoramento Epidemiológico , Infecções por Henipavirus/epidemiologia , Vírus Nipah/crescimento & desenvolvimento , Zoonoses/epidemiologia , Animais , Reservatórios de Doenças/virologia , Infecções por Henipavirus/transmissão , Infecções por Henipavirus/veterinária , Humanos , Índia/epidemiologia , Vírus Nipah/imunologia , Vírus Nipah/isolamento & purificação , Medição de Risco , Estudos Soroepidemiológicos , Zoonoses/transmissão
15.
Infez Med ; 27(2): 117-127, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31205033

RESUMO

The Nipah virus was discovered twenty years ago, and there is considerable information available regarding the specificities surrounding this virus such as transmission, pathogenesis and genome. Belonging to the Henipavirus genus, this virus can cause fever, encephalitis and respiratory disorders. The first cases were reported in Malaysia and Singapore in 1998, when affected individuals presented with severe febrile encephalitis. Since then, much has been identified about this virus. These single-stranded RNA viruses gain entry into target cells via a process known as macropinocytosis. The viral genome is released into the cell cytoplasm via a cascade of processes that involves conformational changes in G and F proteins which allow for attachment of the viral membrane to the cell membrane. In addition to this, the natural reservoirs of this virus have been identified to be fruit bats from the genus Pteropus. Five of the 14 species of bats in Malaysia have been identified as carriers, and this virus affects horses, cats, dogs, pigs and humans. Various mechanisms of transmission have been proposed such as contamination of date palm saps by bat feces and saliva, nosocomial and human-to-human transmissions. Physical contact was identified as the strongest risk factor for developing an infection in the 2004 Faridpur outbreak. Geographically, the virus seems to favor the Indian sub-continent, Indonesia, Southeast Asia, Pakistan, southern China, northern Australia and the Philippines, as demonstrated by the multiple outbreaks in 2001, 2004, 2007, 2012 in Bangladesh, India and Pakistan as well as the initial outbreaks in Malaysia and Singapore. Multiple routes of the viremic spread in the human body have been identified such as the central nervous system (CNS) and respiratory system, while virus levels in the body remain low, detection in the cerebrospinal fluid is comparatively high. The virus follows an incubation period of 4 days to 2 weeks which is followed by the development of symptoms. The primary clinical signs include fever, headache, vomiting and dizziness, while the characteristic symptoms consist of segmental myoclonus, tachycardia, areflexia, hypotonia, abnormal pupillary reflexes and hypertension. The serum neutralization test (SNT) is the gold standard of diagnosis followed by ELISA if SNT cannot be carried out. On the other hand, treatment is supportive since there a lack of effective pharmacological therapy and only one equine vaccine is currently licensed for use. Prevention of outbreaks seems to be a more viable approach until specific therapeutic strategies are devised.


Assuntos
Doenças Transmissíveis Emergentes/epidemiologia , Epidemias/estatística & dados numéricos , Infecções por Henipavirus/epidemiologia , Vírus Nipah , Animais , Ásia/epidemiologia , Gatos , Quirópteros/virologia , Doenças Transmissíveis Emergentes/terapia , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/veterinária , Reservatórios de Doenças , Cães , Infecções por Henipavirus/terapia , Infecções por Henipavirus/transmissão , Infecções por Henipavirus/veterinária , Cavalos , Humanos , Vírus Nipah/genética , Vírus Nipah/isolamento & purificação , Pinocitose , Suínos , Avaliação de Sintomas , Vacinação/métodos , Vacinação/veterinária , Internalização do Vírus
16.
N Engl J Med ; 380(19): 1804-1814, 2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31067370

RESUMO

BACKGROUND: Nipah virus is a highly virulent zoonotic pathogen that can be transmitted between humans. Understanding the dynamics of person-to-person transmission is key to designing effective interventions. METHODS: We used data from all Nipah virus cases identified during outbreak investigations in Bangladesh from April 2001 through April 2014 to investigate case-patient characteristics associated with onward transmission and factors associated with the risk of infection among patient contacts. RESULTS: Of 248 Nipah virus cases identified, 82 were caused by person-to-person transmission, corresponding to a reproduction number (i.e., the average number of secondary cases per case patient) of 0.33 (95% confidence interval [CI], 0.19 to 0.59). The predicted reproduction number increased with the case patient's age and was highest among patients 45 years of age or older who had difficulty breathing (1.1; 95% CI, 0.4 to 3.2). Case patients who did not have difficulty breathing infected 0.05 times as many contacts (95% CI, 0.01 to 0.3) as other case patients did. Serologic testing of 1863 asymptomatic contacts revealed no infections. Spouses of case patients were more often infected (8 of 56 [14%]) than other close family members (7 of 547 [1.3%]) or other contacts (18 of 1996 [0.9%]). The risk of infection increased with increased duration of exposure of the contacts (adjusted odds ratio for exposure of >48 hours vs. ≤1 hour, 13; 95% CI, 2.6 to 62) and with exposure to body fluids (adjusted odds ratio, 4.3; 95% CI, 1.6 to 11). CONCLUSIONS: Increasing age and respiratory symptoms were indicators of infectivity of Nipah virus. Interventions to control person-to-person transmission should aim to reduce exposure to body fluids. (Funded by the National Institutes of Health and others.).


Assuntos
Infecções por Henipavirus/transmissão , Vírus Nipah , Adolescente , Adulto , Fatores Etários , Animais , Bangladesh/epidemiologia , Líquidos Corporais/virologia , Criança , Busca de Comunicante , Transmissão de Doença Infecciosa/prevenção & controle , Feminino , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem , Zoonoses/transmissão
17.
Emerg Infect Dis ; 25(5): 1003-1006, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31002049

RESUMO

We retrieved Nipah virus (NiV) sequences from 4 human and 3 fruit bat (Pteropus medius) samples from a 2018 outbreak in Kerala, India. Phylogenetic analysis demonstrated that NiV from humans was 96.15% similar to a Bangladesh strain but 99.7%-100% similar to virus from Pteropus spp. bats, indicating bats were the source of the outbreak.


Assuntos
Quirópteros/virologia , Surtos de Doenças , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/virologia , Vírus Nipah/classificação , Vírus Nipah/genética , Animais , Células Cultivadas , Efeito Citopatogênico Viral , Infecções por Henipavirus/história , Infecções por Henipavirus/transmissão , História do Século XXI , Humanos , Índia/epidemiologia , Mutação , Vigilância em Saúde Pública
19.
Int J Epidemiol ; 48(4): 1219-1227, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977803

RESUMO

BACKGROUND: Understanding the true burden of emergent diseases is critical for assessing public-health impact. However, surveillance often relies on hospital systems that only capture a minority of cases. We use the example of Nipah-virus infection in Bangladesh, which has a high case-fatality ratio and frequent person-to-person transmission, to demonstrate how healthcare-seeking data can estimate true burden. METHODS: We fit logistic-regression models to data from a population-based, healthcare-seeking study of encephalitis cases to characterize the impact of distance and mortality on attending one of three surveillance hospital sites. The resulting estimates of detection probabilities, as a function of distance and outcome, are applied to all observed Nipah outbreaks between 2007 and 2014 to estimate the true burden. RESULTS: The probability of attending a surveillance hospital fell from 82% for people with fatal encephalitis living 10 km away from a surveillance hospital to 54% at 50 km away. The odds of attending a surveillance hospital are 3.2 (95% confidence interval: 1.6, 6.6) times greater for patients who eventually died (i.e. who were more severely ill) compared with those who survived. Using these probabilities, we estimated that 119 Nipah outbreaks (95% confidence interval: 103, 140)-an average of 15 outbreaks per Nipah season-occurred during 2007-14; 62 (52%) were detected. CONCLUSIONS: Our findings suggest hospital-based surveillance missed nearly half of all Nipah outbreaks. This analytical method allowed us to estimate the underlying burden of disease, which is important for emerging diseases where healthcare access may be limited.


Assuntos
Surtos de Doenças , Infecções por Henipavirus/epidemiologia , Hospitais/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Bangladesh/epidemiologia , Infecções por Henipavirus/diagnóstico , Humanos , Modelos Logísticos , Fatores de Risco , Vigilância de Evento Sentinela
20.
Vector Borne Zoonotic Dis ; 19(7): 455-465, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30985268

RESUMO

Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably increasing the known geographic distribution of henipaviruses. Africa is progressively being recognized as a new high prevalence zone for henipaviruses, as deduced from serological and molecular evidence of past infections in Madagascar, Ghana, Republic of Congo, Gulf of Guinea, Zambia, Tanzania, Cameroon, and Nigeria lately. Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species. All virus isolation attempts have been abortive, highlighting the need for further investigations. The genome of the Ghanaian bat henipavirus designated Ghana virus (GhV), which was detected in a pteropid Eidolon helvum bat, is the only African henipavirus that has been completely sequenced limiting our current knowledge on the genetic diversity and pathogenesis of African henipaviruses. In this review, we summarize the available data on the circulation of henipaviruses in Africa, discuss potential sources for virus spillover, and highlight existing research gaps.


Assuntos
Quirópteros/virologia , Infecções por Henipavirus/epidemiologia , Henipavirus , África/epidemiologia , Animais , Anticorpos Antivirais , Infecções por Henipavirus/veterinária , Infecções por Henipavirus/virologia , Humanos , Gado/virologia , Estudos Soroepidemiológicos , Zoonoses/virologia
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