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3.
Integr Zool ; 15(1): 69-78, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31305020

RESUMO

Plague, a devastating infectious disease caused by Yersinia pestis, has killed millions of people in the past and is still active in the natural foci of the world today. Understanding the spatiotemporal patterns of plague outbreaks in history is critically important, as it may help to facilitate prevention and control of potential future outbreaks. In this study, we explored spatiotemporal clusters of human plague occurrences in China using a machine-learning clustering method and reconstructed the potential transmission pattern during the Third Pandemic (1772-1964). We succeeded in identifying 6 clusters in the space domain (2D) and 13 clusters in the spatiotemporal domain (3D). Our results suggest that there were several temporal outbreaks and transmissions of plague in different spatial clusters. Together with the spatiotemporal nearest neighbor approach (ST-NNA), this method could allow us to have a clearer look at the spatiotemporal patterns of plague.


Assuntos
Análise por Conglomerados , Pandemias , Peste/epidemiologia , Peste/história , China/epidemiologia , História do Século XVIII , História do Século XIX , História do Século XX , Humanos , Fatores de Tempo
6.
Int J Nanomedicine ; 14: 8469-8481, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695375

RESUMO

Background: A pandemic influenza viral strain, influenza A/California/07/2009 (pdmH1N1), has been considered to be a potential issue that needs to be controlled to avoid the seasonal emergence of mutated strains. Materials and methods: In this study, aptamer-antibody complementation was implemented on a multiwalled carbon nanotube-gold conjugated sensing surface with a dielectrode to detect pandemic pdmH1N1. Preliminary biomolecular and dielectrode surface analyses were performed by molecular and microscopic methods. A stable anti-pdmH1N1 aptamer sequence interacted with hemagglutinin (HA) and was compared with the antibody interaction. Both aptamer and antibody attachments on the surface as the basic molecule attained the saturation at nanomolar levels. Results: Aptamers were found to have higher affinity and electric response than antibodies against HA of pdmH1N1. Linear regression with aptamer-HA interaction displays sensitivity in the range of 10 fM, whereas antibody-HA interaction shows a 100-fold lower level (1 pM). When sandwich-based detection of aptamer-HA-antibody and antibody-HA-aptamer was performed, a higher response of current was observed in both cases. Moreover, the detection strategy with aptamer clearly discriminated the closely related HA of influenza B/Tokyo/53/99 and influenza A/Panama/2007/1999 (H3N2). Conclusion: The high performance of the abovementioned detection methods was supported by the apparent specificity and reproducibility by the demonstrated sensing system.


Assuntos
Anticorpos Antivirais/imunologia , Aptâmeros de Nucleotídeos/química , Ouro/química , Vírus da Influenza A Subtipo H1N1/imunologia , Nanotubos de Carbono/química , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Pandemias , Suínos/virologia , Animais , Proteínas do Sistema Complemento/metabolismo , Eletrodos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Transdução Genética
8.
Nat Commun ; 10(1): 4470, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578321

RESUMO

The second plague pandemic, caused by Yersinia pestis, devastated Europe and the nearby regions between the 14th and 18th centuries AD. Here we analyse human remains from ten European archaeological sites spanning this period and reconstruct 34 ancient Y. pestis genomes. Our data support an initial entry of the bacterium through eastern Europe, the absence of genetic diversity during the Black Death, and low within-outbreak diversity thereafter. Analysis of post-Black Death genomes shows the diversification of a Y. pestis lineage into multiple genetically distinct clades that may have given rise to more than one disease reservoir in, or close to, Europe. In addition, we show the loss of a genomic region that includes virulence-related genes in strains associated with late stages of the pandemic. The deletion was also identified in genomes connected with the first plague pandemic (541-750 AD), suggesting a comparable evolutionary trajectory of Y. pestis during both events.


Assuntos
DNA Bacteriano/genética , Genoma Bacteriano/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Pandemias , Peste/epidemiologia , Yersinia pestis/genética , Arqueologia/métodos , DNA Bacteriano/química , DNA Bacteriano/classificação , Europa Oriental/epidemiologia , Fósseis , Humanos , Filogenia , Filogeografia , Peste/microbiologia , Polimorfismo de Nucleotídeo Único , Fatores de Tempo , Virulência/genética , Yersinia pestis/patogenicidade
11.
Nat Microbiol ; 4(10): 1612-1619, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31541212

RESUMO

The continued growth of the world's population and increased interconnectivity heighten the risk that infectious diseases pose for human health worldwide. Epidemiological modelling is a tool that can be used to mitigate this risk by predicting disease spread or quantifying the impact of different intervention strategies on disease transmission dynamics. We illustrate how four decades of methodological advances and improved data quality have facilitated the contribution of modelling to address global health challenges, exemplified by models for the HIV crisis, emerging pathogens and pandemic preparedness. Throughout, we discuss the importance of designing a model that is appropriate to the research question and the available data. We highlight pitfalls that can arise in model development, validation and interpretation. Close collaboration between empiricists and modellers continues to improve the accuracy of predictions and the optimization of models for public health decision-making.


Assuntos
Doenças Transmissíveis/epidemiologia , Saúde Global , Modelos Biológicos , Controle de Doenças Transmissíveis , Doenças Transmissíveis/transmissão , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/transmissão , Coleta de Dados , Tomada de Decisões , Humanos , Pandemias/prevenção & controle
12.
PLoS Comput Biol ; 15(9): e1007305, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513578

RESUMO

A key question in ecology is the relative impact of internal nonlinear dynamics and external perturbations on the long-term trajectories of natural systems. Measles has been analyzed extensively as a paradigm for consumer-resource dynamics due to the oscillatory nature of the host-pathogen life cycle, the abundance of rich data to test theory, and public health relevance. The dynamics of measles in London, in particular, has acted as a prototypical test bed for such analysis using incidence data from the pre-vaccination era (1944-1967). However, during this timeframe there were few external large-scale perturbations, limiting an assessment of the relative impact of internal and extra demographic perturbations to the host population. Here, we extended the previous London analyses to include nearly a century of data that also contains four major demographic changes: the First and Second World Wars, the 1918 influenza pandemic, and the start of a measles mass vaccination program. By combining mortality and incidence data using particle filtering methods, we show that a simple stochastic epidemic model, with minimal historical specifications, can capture the nearly 100 years of dynamics including changes caused by each of the major perturbations. We show that the majority of dynamic changes are explainable by the internal nonlinear dynamics of the system, tuned by demographic changes. In addition, the 1918 influenza pandemic and World War II acted as extra perturbations to this basic epidemic oscillator. Our analysis underlines that long-term ecological and epidemiological dynamics can follow very simple rules, even in a non-stationary population subject to significant perturbations and major secular changes.


Assuntos
Sarampo , Pandemias/estatística & dados numéricos , Vacinação/estatística & dados numéricos , Biologia Computacional , História do Século XX , Humanos , Incidência , Influenza Humana/epidemiologia , Influenza Humana/história , Londres/epidemiologia , Sarampo/epidemiologia , Sarampo/história , Sarampo/prevenção & controle , Sarampo/transmissão , Pandemias/história , Vacinação/história , I Guerra Mundial , II Guerra Mundial
13.
Acta Biochim Pol ; 66(3): 329-336, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31531422

RESUMO

The potential emergence of deadly pandemic influenza viruses is unpredictable and most have emerged with no forewarning. The distinct epidemiological and pathological patterns of the Spanish (H1N1), pandemic-2009 (H1N1), and avian influenza (H5N1), known as bird flu, viruses may allow us to develop a 'template' for possible emergence of devastating pandemic strains. Here, we provide a detailed molecular dissection of the structural and nonstructural proteins of this triad of viruses. GenBank data for three representative strains were analyzed to determine the polymorphic amino acids, genetic distances, and isoelectric points, hydrophobicity plot, and protein modeling of various proteins. We propose that the most devastating pandemic strains may have full-length PB1-F2 protein with unique residues, highly cleavable HA, and a basic NS1. Any newly emerging strain should be compared with these three strains, so that resources can be directed appropriately.


Assuntos
Simulação por Computador , Vírus da Influenza A Subtipo H1N1/genética , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Influenza Humana/virologia , Proteínas Virais/química , Animais , Aves , Transmissão de Doença Infecciosa , Genoma Viral , Humanos , Influenza Pandêmica, 1918-1919 , Vacinas contra Influenza , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pandemias , Conformação Proteica em alfa-Hélice , Proteínas Virais/genética
14.
Internist (Berl) ; 60(11): 1127-1135, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31478058

RESUMO

BACKGROUND: The influenza virus (IV)-associated mortality and morbidity remains high in Europe. OBJECTIVE: This article gives an overview of the pathogenesis, diagnostics and treatment optimization strategies according to the currently existing guidelines and clinical trials. MATERIAL AND METHODS: Literature search and analysis of national and international guidelines for the epidemiology, diagnostics, treatment and prevention of IV infections. RESULTS AND CONCLUSION: Although the incidence of IV infections remains underrecognized, it is the leading infectious disease-associated cause of mortality and morbidity in Europe. Viruses are mainly transmitted by aerosol inhalation and can cause a wide spectrum of symptoms, ranging from mild signs of a cold to severe respiratory failure requiring mechanical ventilation. The clinical diagnosis should be verified through a PCR-based test in patients with indications for treatment. Neuraminidase inhibitors are currently the treatment of choice for IV infections. Seasonal influenza vaccination is an efficient preventive method. It is therefore imperative to improve vaccination rates in Germany, which have been continuously declining since the pandemic of 2009/2010.


Assuntos
Antivirais/uso terapêutico , Vacinas contra Influenza/administração & dosagem , Influenza Humana/tratamento farmacológico , Influenza Humana/prevenção & controle , Neuraminidase/uso terapêutico , Europa (Continente)/epidemiologia , Humanos , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Morbidade , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/tratamento farmacológico , Síndrome do Desconforto Respiratório do Adulto
15.
BMC Public Health ; 19(1): 1237, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492122

RESUMO

BACKGROUND: Mathematical and statistical models are used to project the future time course of infectious disease epidemics and the expected future burden on health care systems and economies. Influenza is a particularly important disease in this context because it causes annual epidemics and occasional pandemics. In order to forecast health care utilization during epidemics-and the effects of hospitalizations and deaths on the contact network and, in turn, on transmission dynamics-modellers must make assumptions about the lengths of time between infection, visiting a physician, being admitted to hospital, leaving hospital, and death. More reliable forecasts could be be made if the distributions of times between these types of events ("delay distributions") were known. METHODS: We estimated delay distributions in the province of Ontario, Canada, between 2006 and 2010. To do so, we used encrypted health insurance numbers to link 1.34 billion health care billing records to 4.27 million hospital inpatient stays. Because the four year period we studied included three typical influenza seasons and the 2009 influenza pandemic, we were able to compare the delay distributions in non-pandemic and pandemic settings. We also estimated conditional probabilities such as the probability of hospitalization within the year if diagnosed with influenza. RESULTS: In non-pandemic [pandemic] years, delay distribution medians (inter-quartile ranges) were: Service to Admission 6.3 days (0.1-17.6 days) [2.4 days (-0.3-13.6 days)], Admission to Discharge 3 days (1.4-5.9 days) [2.6 days (1.2-5.1 days)], Admission to Death 5.3 days (2.1-11 days) [6 days (2.6-13.1 days)]. (Service date is defined as the date, within the year, of the first health care billing that included a diagnostic code for influenza-like-illness.) Among individuals diagnosed with either pneumonia or influenza in a given year, 19% [16%] were hospitalized within the year and 3% [2%] died in hospital. Among all individuals who were hospitalized, 10% [12%] were diagnosed with pneumonia or influenza during the year and 5% [5%] died in hospital. CONCLUSION: Our empirical delay distributions and conditional probabilities should help facilitate more accurate forecasts in the future, including improved predictions of hospital bed demands during influenza outbreaks, and the expected effects of hospitalizations on epidemic dynamics.


Assuntos
Hospitalização/estatística & dados numéricos , Influenza Humana/epidemiologia , Influenza Humana/terapia , Pandemias/estatística & dados numéricos , Previsões , Humanos , Influenza Humana/mortalidade , Seguro Saúde , Modelos Teóricos , Ontário/epidemiologia , Probabilidade , Estações do Ano
17.
Crit Care Clin ; 35(4): 609-618, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31445608

RESUMO

In the twenty-first century, severe acute respiratory syndrome (SARS), 2009 A(H1N1) influenza, and Ebola have all placed strains on critical care systems. In addition to the increased patient needs common to many disasters, epidemics may further degrade ICU capability when staff members fall ill, including in the course of direct patient care. In a large-scale pandemic, shortages of equipment and medications can further limit an ICU's ability to provide the normal standard of care. Hospital preparedness for epidemics must include strategies to maintain staff safety, secure adequate supplies, and have plans for triage and prioritization of care when necessary.


Assuntos
Planejamento em Desastres , Unidades de Terapia Intensiva , Pandemias , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/terapia , Humanos , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Influenza Humana/terapia , Unidades de Terapia Intensiva/organização & administração , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/terapia
18.
Curr Top Microbiol Immunol ; 424: 1-20, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31463536

RESUMO

Predicting which pathogen will confer the highest global catastrophic biological risk (GCBR) of a pandemic is a difficult task. Many approaches are retrospective and premised on prior pandemics; however, such an approach may fail to appreciate novel threats that do not have exact historical precedent. In this paper, based on a study and project we undertook, a new paradigm for pandemic preparedness is presented. This paradigm seeks to root pandemic risk in actual attributes possessed by specific classes of microbial organisms and leads to specific recommendations to augment preparedness activities.


Assuntos
Planejamento em Desastres/métodos , Monitoramento Epidemiológico , Microbiologia , Pandemias , Humanos , Medição de Risco
20.
Nat Commun ; 10(1): 3255, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332179

RESUMO

Syphilis is a sexually transmitted infection caused by Treponema pallidum subspecies pallidum and may lead to severe complications. Recent years have seen striking increases in syphilis in many countries. Previous analyses have suggested one lineage of syphilis, SS14, may have expanded recently, indicating emergence of a single pandemic azithromycin-resistant cluster. Here we use direct sequencing of T. pallidum combined with phylogenomic analyses to show that both SS14- and Nichols-lineages are simultaneously circulating in clinically relevant populations in multiple countries. We correlate the appearance of genotypic macrolide resistance with multiple independently evolved SS14 sub-lineages and show that genotypically resistant and sensitive sub-lineages are spreading contemporaneously. These findings inform our understanding of the current syphilis epidemic by demonstrating how macrolide resistance evolves in Treponema subspecies and provide a warning on broader issues of antimicrobial resistance.


Assuntos
Farmacorresistência Bacteriana/efeitos dos fármacos , Macrolídeos/farmacologia , Sífilis/tratamento farmacológico , Treponema pallidum/genética , Antibacterianos/farmacologia , Azitromicina/farmacologia , Farmacorresistência Bacteriana/genética , Genoma Bacteriano/genética , Genômica , Genótipo , Humanos , Epidemiologia Molecular , Pandemias/prevenção & controle , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Sífilis/epidemiologia , Sífilis/microbiologia , Treponema pallidum/classificação , Treponema pallidum/fisiologia
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