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Seasonal infectious disease epidemiology

Grassly, Nicholas C; Fraser, Christophe
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.04%
Seasonal change in the incidence of infectious diseases is a common phenomenon in both temperate and tropical climates. However, the mechanisms responsible for seasonal disease incidence, and the epidemiological consequences of seasonality, are poorly understood with rare exception. Standard epidemiological theory and concepts such as the basic reproductive number R0 no longer apply, and the implications for interventions that themselves may be periodic, such as pulse vaccination, have not been formally examined. This paper examines the causes and consequences of seasonality, and in so doing derives several new results concerning vaccination strategy and the interpretation of disease outbreak data. It begins with a brief review of published scientific studies in support of different causes of seasonality in infectious diseases of humans, identifying four principal mechanisms and their association with different routes of transmission. It then describes the consequences of seasonality for R0, disease outbreaks, endemic dynamics and persistence. Finally, a mathematical analysis of routine and pulse vaccination programmes for seasonal infections is presented. The synthesis of seasonal infectious disease epidemiology attempted by this paper highlights the need for further empirical and theoretical work.

A brief perspective on the early history of American infectious disease epidemiology.

Kass, E. H.
Fonte: Yale Journal of Biology and Medicine Publicador: Yale Journal of Biology and Medicine
Tipo: Artigo de Revista Científica
Publicado em //1987 EN
Relevância na Pesquisa
66.04%
The early history of epidemiology is closely linked to the history of infectious diseases and can be divided into three distinct periods. The earliest period, which can be traced to the writings of Hippocrates in the third and fourth centuries B.C., was that of clinical description of diseases with little investigation into their specific characteristics and etiologies. The second period, spanning the eighteenth and nineteenth centuries, may be distinguished by the rejection of early Hippocratic and Galenic doctrines and the more systematic description of morbid conditions. The third period, which was marked by the discovery of specific microbial causes of disease, spurred an extraordinary growth of knowledge and scientific exploration. This period will be the main focus of the paper, as it had the greatest influence on the development of American infectious disease epidemiology.

Relationship between acute and chronic disease epidemiology.

Kuller, L. H.
Fonte: Yale Journal of Biology and Medicine Publicador: Yale Journal of Biology and Medicine
Tipo: Artigo de Revista Científica
Publicado em //1987 EN
Relevância na Pesquisa
56.14%
Epidemiology is the study of epidemics. The primary goal of epidemiological studies should be the identification of the determinants of disease in order to decrease morbidity and mortality. Epidemiological studies evolve through descriptive, analytical, and experimental approaches. The traditional infectious disease epidemiology studies were primarily concerned with identification of an agent, incubation period, mode of transmission, population at risk, and methods of disease control. Chronic disease epidemiology has tended to emphasize a more complex interaction of independent and dependent disease variables that resulted in a greater need for statistical methodology. There has been relatively little interest in chronic disease epidemiology either in modes of disease transmission or in incubation periods. Chronic disease epidemiology has also focused more on analytical epidemiology than on experimental, clinical trials. Many chronic diseases are probably caused by living organisms such as viruses. The fundamental difference in methodology may relate to length of incubation period. Chronic disease epidemiology should probably build more on successful methods of infectious disease epidemiology, especially modes of disease transmission...

Emerging infectious diseases in an island ecosystem: the New Zealand perspective.

Crump, J. A.; Murdoch, D. R.; Baker, M. G.
Fonte: Centers for Disease Control Publicador: Centers for Disease Control
Tipo: Artigo de Revista Científica
Publicado em //2001 EN
Relevância na Pesquisa
55.95%
Several unique features characterize infectious disease epidemiology in New Zealand. Historically, well-organized, government-run control programs have eliminated several zoonoses. More recently, however, communicable disease control has been mixed. Rates of rheumatic fever, tuberculosis, and enteric infectious are high, and rates of meningococcal disease are increasing. These diseases are over-represented in New Zealanders of Polynesian descent, who generally live in more deprived and overcrowded conditions than do those of European descent. Measles and pertussis epidemics are recurring because of inadequate vaccine coverage, despite a well-developed childhood immunization program. A progressive response to the HIV epidemic has resulted in relatively low rates of infection, particularly among injecting drug users; however, the response to other sexually transmitted infections has been poor. A key challenge for the future is to build on successful strategies and apply them to persisting and emerging infectious disease threats in a small, geographically isolated country with limited economic resources.

Relating Phylogenetic Trees to Transmission Trees of Infectious Disease Outbreaks

Ypma, Rolf J. F.; van Ballegooijen, W. Marijn; Wallinga, Jacco
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /11/2013 EN
Relevância na Pesquisa
56.05%
Transmission events are the fundamental building blocks of the dynamics of any infectious disease. Much about the epidemiology of a disease can be learned when these individual transmission events are known or can be estimated. Such estimations are difficult and generally feasible only when detailed epidemiological data are available. The genealogy estimated from genetic sequences of sampled pathogens is another rich source of information on transmission history. Optimal inference of transmission events calls for the combination of genetic data and epidemiological data into one joint analysis. A key difficulty is that the transmission tree, which describes the transmission events between infected hosts, differs from the phylogenetic tree, which describes the ancestral relationships between pathogens sampled from these hosts. The trees differ both in timing of the internal nodes and in topology. These differences become more pronounced when a higher fraction of infected hosts is sampled. We show how the phylogenetic tree of sampled pathogens is related to the transmission tree of an outbreak of an infectious disease, by the within-host dynamics of pathogens. We provide a statistical framework to infer key epidemiological and mutational parameters by simultaneously estimating the phylogenetic tree and the transmission tree. We test the approach using simulations and illustrate its use on an outbreak of foot-and-mouth disease. The approach unifies existing methods in the emerging field of phylodynamics with transmission tree reconstruction methods that are used in infectious disease epidemiology.

A Brief Perspective on the Early History of American Infectious Disease Epidemiology

Kass, Edward Harold
Fonte: Yale Journal of Biology and Medicine Publicador: Yale Journal of Biology and Medicine
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
66.04%
The early history of epidemiology is closely linked to the history of infectious diseases and can be divided into three distinct periods. The earliest period, which can be traced to the writings of Hippocrates in the third and fourth centuries B.C., was that of clinical description of diseases with little investigation into their specific characteristics and etiologies. The second period, spanning the eighteenth and nineteenth centuries, may be distinguished by the rejection of early Hippocratic and Galenic doctrines and the more systematic description of morbid conditions. The third period, which was marked by the discovery of specific microbial causes of disease, spurred an extraordinary growth of knowledge and scientific exploration. This period will be the main focus of the paper, as it had the greatest influence on the development of American infectious disease epidemiology.

Laboratory and Clinical Predictors of Disease Progression following Initiation of Combination Therapy in HIV-Infected Adults in Thailand

Duong, Trinh; Jourdain, Gonzague Joseph Albert; Ngo-Giang-Huong, Nicole; Le Cœur, Sophie; Kantipong, Pacharee; Buranabanjasatean, Sudanee; Leenasirimakul, Prattana; Ariyadej, Sriprapar; Tansuphasawasdikul, Somboon; Thongpaen, Suchart; Lallemant, Marc Jea
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.04%
Background: Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Methods: Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged ≥18 years within a multi-centre cohort in Thailand. Results: Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6–6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm3, survival improved steadily with CD4, with mortality rare at ≥500 cells/mm3 (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at ≥100...

Influence of Spatial Resolution on Space-Time Disease Cluster Detection

Jones, Stephen G.; Kulldorff, Martin
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.09%
Background: Utilizing highly precise spatial resolutions within disease outbreak detection, such as the patients’ address, is most desirable as this provides the actual residential location of the infected individual(s). However, this level of precision is not always readily available or only available for purchase, and when utilized, increases the risk of exposing protected health information. Aggregating data to less precise scales (e.g., ZIP code or county centroids) may mitigate this risk but at the expense of potentially masking smaller isolated high risk areas. Methods: To experimentally examine the effect of spatial data resolution on space-time cluster detection, we extracted administrative medical claims data for 122500 viral lung episodes occurring during 2007–2010 in Tennessee. We generated 10000 spatial datasets with varying cluster location, size and intensity at the address-level. To represent spatial data aggregation (i.e., reduced resolution), we then created 10000 corresponding datasets both at the ZIP code and county level for a total of 30000 datasets. Using the space-time permutation scan statistic and the SaTScan™ cluster software, we evaluated statistical power, sensitivity and positive predictive values of outbreak detection when using exact address locations compared to ZIP code and county level aggregations. Results: The power to detect disease outbreaks did not largely diminish when using spatially aggregated data compared to more precise address information. However...

Mapping populations at risk: improving spatial demographic data for infectious disease modeling and metric derivation

Tatem, Andrew J; Adamo, Susana; Bharti, Nita; Burgert, Clara R; Castro, Marcia C.de; Dorelien, Audrey; Fink, Gunter; Linard, Catherine; John, Mendelsohn; Montana, Livia; Montgomery, Mark R; Nelson, Andrew; Noor, Abdisalan M; Pindolia, Deepa; Yetman, Greg;
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
55.99%
The use of Global Positioning Systems (GPS) and Geographical Information Systems (GIS) in disease surveys and reporting is becoming increasingly routine, enabling a better understanding of spatial epidemiology and the improvement of surveillance and control strategies. In turn, the greater availability of spatially referenced epidemiological data is driving the rapid expansion of disease mapping and spatial modeling methods, which are becoming increasingly detailed and sophisticated, with rigorous handling of uncertainties. This expansion has, however, not been matched by advancements in the development of spatial datasets of human population distribution that accompany disease maps or spatial models. Where risks are heterogeneous across population groups or space or dependent on transmission between individuals, spatial data on human population distributions and demographic structures are required to estimate infectious disease risks, burdens, and dynamics. The disease impact in terms of morbidity, mortality, and speed of spread varies substantially with demographic profiles, so that identifying the most exposed or affected populations becomes a key aspect of planning and targeting interventions. Subnational breakdowns of population counts by age and sex are routinely collected during national censuses and maintained in finer detail within microcensus data. Moreover...

Systematic Review and Meta-Analysis on the Association Between Outpatient Statins Use and Infectious Disease-Related Mortality

Ma, Yu; Wen, Xiaozhong; Peng, Jing; Lu, Yi; Guo, Zhongmin; Lu, Jiahai
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
76.15%
Background: To update and refine systematic literature review on the association between outpatient statins use and mortality in patients with infectious disease. Materials and Methods: We searched articles published before September 31, 2012, on the association between statins and infectious disease-related mortality through electronic databases. Eligible articles were analyzed in Review Manager 5.1. We conducted stratification analysis by study design, infection types, clinical outcomes and study locations. Results: The pooled odds ratio (OR) for death (statins use vs. no use) across the 41 included studies was 0.71 (95% confidence interval: 0.64, 0.78). The corresponding pooled ORs were 0.58 (0.38, 0.90), 0.66 (0.57, 0.75), 0.71 (0.57, 0.89) and 0.83 (0.67, 1.04) for the case-control study, retrospective cohort studies, prospective cohort studies and RCTs; 0.40 (0.20, 0.78), 0.61 (0.41, 0.90), 0.69 (0.62, 0.78) and 0.86 (0.68, 1.09) for bacteremia, sepsis, pneumonia and other infections; 0.62 (0.534, 0.72), 0.68 (0.53, 0.89), 0.71 (0.61, 0.83) and 0.86 (0.70, 1.07) for 30-day, 90-day, in-hospital and long-term (>1 year) mortality, respectively. Conclusions: Outpatient statins use is associated with a lower risk of death in patients with infectious disease in observational studies...

Risk Factors for Late-Stage HIV Disease Presentation at Initial HIV Diagnosis in Durban, South Africa

Drain, Paul; Losina, Elena; Parker, Gary; Giddy, Janet; Ross, Douglas; Katz, Jeffrey Neil; Coleman, Sharon M.; Bogart, Laura M.; Freedberg, Kenneth A.; Walensky, Rochelle P.; Bassett, Ingrid Valerie
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.04%
Background: After observing persistently low CD4 counts at initial HIV diagnosis in South Africa, we sought to determine risk factors for late-stage HIV disease presentation among adults. Methods: We surveyed adults prior to HIV testing at four outpatient clinics in Durban from August 2010 to November 2011. All HIV-infected adults were offered CD4 testing, and late-stage HIV disease was defined as a CD4 count (<100 cells/mm^{3}). We used multivariate regression models to determine the effects of sex, emotional health, social support, distance from clinic, employment, perceived barriers to receiving healthcare, and foregoing healthcare to use money for food, clothing, or housing (“competing needs to healthcare”) on presentation with late-stage HIV disease. Results: Among 3,669 adults screened, 830 were enrolled, newly-diagnosed with HIV and obtained a CD4 result. Among those, 279 (33.6%) presented with late-stage HIV disease. In multivariate analyses, participants who lived ≥5 kilometers from the test site [adjusted odds ratio (AOR) 2.8, 95% CI 1.7–4.7], reported competing needs to healthcare (AOR 1.7, 95% CI 1.2–2.4), were male (AOR 1.7, 95% CI 1.2–2.3), worked outside the home (AOR 1.5, 95% CI 1.1–2.1), perceived health service delivery barriers (AOR 1.5...

Outcomes among HIV-1 Infected Individuals First Starting Antiretroviral Therapy with Concurrent Active TB or Other AIDS-Defining Disease

Périssé, André R. S.; Smeaton, Laura; Chen, Yun; La Rosa, Alberto; Walawander, Ann; Nair, Apsara; Grinsztejn, Beatriz; Santos, Breno; Kanyama, Cecilia; Hakim, James; Nyirenda, Mulinda; Kumarasamy, Nagalingeswaran; Lalloo, Umesh G.; Flanigan, Timothy; C
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.08%
Background: Tuberculosis (TB) is common among HIV-infected individuals in many resource-limited countries and has been associated with poor survival. We evaluated morbidity and mortality among individuals first starting antiretroviral therapy (ART) with concurrent active TB or other AIDS-defining disease using data from the “Prospective Evaluation of Antiretrovirals in Resource-Limited Settings” (PEARLS) study. Methods: Participants were categorized retrospectively into three groups according to presence of active confirmed or presumptive disease at ART initiation: those with pulmonary and/or extrapulmonary TB (“TB” group), those with other non-TB AIDS-defining disease (“other disease”), or those without concurrent TB or other AIDS-defining disease (“no disease”). Primary outcome was time to the first of virologic failure, HIV disease progression or death. Since the groups differed in characteristics, proportional hazard models were used to compare the hazard of the primary outcome among study groups, adjusting for age, sex, country, screening CD4 count, baseline viral load and ART regimen. Results: 31 of 102 participants (30%) in the “TB” group, 11 of 56 (20%) in the “other disease” group, and 287 of 1413 (20%) in the “no disease” group experienced a primary outcome event (p = 0.042). This difference reflected higher mortality in the TB group: 15 (15%)...

High Rates of Potentially Infectious Tuberculosis and Multidrug-Resistant Tuberculosis (MDR-TB) among Hospital Inpatients in KwaZulu Natal, South Africa Indicate Risk of Nosocomial Transmission

Bantubani, Nonkqubela; Kabera, Gaetan; Connolly, Catherine; Rustomjee, Roxana; Reddy, Tarylee; Cohen, Ted; Pym, Alexander S.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.04%
Background: Nosocomial transmission has been implicated as a key factor in the outbreak of extensively drug resistant (XDR) and multidrug-resistant (MDR-TB) tuberculosis at Church of Scotland Hospital (CoSH), in KwaZulu-Natal (KZN), South Africa. The aim of this study was to quantify the burden of potentially infectious tuberculosis and the proportion of drug resistance among hospital inpatients throughout the province of KZN. Methods: Inpatients with current cough, capable of producing sputum were selected from 19 public hospitals in KZN. After informed consent, demographic and clinical data, and sputum samples were collected. Samples were processed for fluorescent microscopy, liquid culture and first and second-line anti-tuberculosis drug susceptibility testing. Results: There were a total of 2,964 inpatients where sampling was done. About 1,585 inpatients (53%) had a current cough and sufficient microbiological and clinical data for inclusion. Mycobacterium tuberculosis was isolated from 543 inpatients (34% of those tested and 18% of all inpatients). Eighty-four (15%) inpatients with TB were found to be MDR-TB infected and 16 (3%) had XDR-TB. There was no association between the prevalence of MDR-TB and proximity to CoSH. Among patients with microbiologically confirmed TB...

Quantification of Shared Air: A Social and Environmental Determinant of Airborne Disease Transmission

Wood, Robin; Morrow, Carl; Ginsberg, Samuel; Piccoli, Elizabeth; Kalil, Darryl; Sassi, Angelina; Walensky, Rochelle P.; Andrews, Jason R.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.19%
Background: Tuberculosis is endemic in Cape Town, South Africa where a majority of the population become tuberculosis infected before adulthood. While social contact patterns impacting tuberculosis and other respiratory disease spread have been studied, the environmental determinants driving airborne transmission have not been quantified. Methods: Indoor carbon dioxide levels above outdoor levels reflect the balance of exhaled breath by room occupants and ventilation. We developed a portable monitor to continuously sample carbon dioxide levels, which were combined with social contact diary records to estimate daily rebreathed litres. A pilot study established the practicality of monitor use up to 48-hours. We then estimated the daily volumes of air rebreathed by adolescents living in a crowded township. Results: One hundred eight daily records were obtained from 63 adolescents aged between 12- and 20-years. Forty-five lived in wooden shacks and 18 in brick-built homes with a median household of 4 members (range 2–9). Mean daily volume of rebreathed air was 120.6 (standard error: 8.0) litres/day, with location contributions from household (48%), school (44%), visited households (4%), transport (0.5%) and other locations (3.4%). Independent predictors of daily rebreathed volumes included household type (p = 0.002)...

The Association of Meningococcal Disease with Influenza in the United States, 1989–2009

Jacobs, Jessica Hartman; Viboud, Cécile; Tchetgen, Eric Tchetgen; Schwartz, Joel; Steiner, Claudia; Simonsen, Lone; Lipsitch, Marc
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.11%
Importance and Objective Prior influenza infection is a risk factor for invasive meningococcal disease. Quantifying the fraction of meningococcal disease attributable to influenza could improve understanding of viral-bacterial interaction and indicate additional health benefits to influenza immunization. Design, Setting and Participants A time series analysis of the association of influenza and meningococcal disease using hospitalizations in 9 states from 1989–2009 included in the State Inpatient Databases from the Agency for Healthcare Research and Quality and the proportion of positive influenza tests by subtype reported to the Centers for Disease Control. The model accounts for the autocorrelation of meningococcal disease and influenza between weeks, temporal trends, co-circulating respiratory syncytial virus, and seasonality. The influenza-subtype-attributable fraction was estimated using the model coefficients. We analyzed the synchrony of seasonal peaks in hospitalizations for influenza, respiratory syncytial virus, and meningococcal disease. Results and Conclusions In 19 of 20 seasons, influenza peaked≤2 weeks before meningococcal disease, and peaks were highly correlated in time (ρ = 0.95; P <.001). H3N2 and H1N1 peaks were highly synchronized with meningococcal disease while pandemic H1N1...

On SARS Type Economic Effects During Infectious Disease Outbreaks

Brahmbhatt, Milan; Dutta, Arindam
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Relevância na Pesquisa
66.16%
Infectious disease outbreaks can exact a high human and economic cost through illness and death. But, as with severe acute respiratory syndrome (SARS) in East Asia in 2003, or the plague outbreak in Surat, India, in 1994, they can also create severe economic disruptions even when there is, ultimately, relatively little illness or death. Such disruptions are commonly the result of uncoordinated and panicky efforts by individuals to avoid becoming infected, of preventive activity. This paper places these "SARS type" effects in the context of research on economic epidemiology, in which behavioral responses to disease risk have both economic and epidemiological consequences. The paper looks in particular at how people form subjective probability judgments about disease risk. Public opinion surveys during the SARS outbreak provide suggestive evidence that people did indeed at times hold excessively high perceptions of the risk of becoming infected, or, if infected, of dying from the disease. The paper discusses research in behavioral economics and the theory of information cascades that may shed light on the origin of such biases. The authors consider whether public information strategies can help reduce unwarranted panic. A preliminary question is why governments often seem to have strong incentives to conceal information about infectious disease outbreaks. The paper reviews recent game-theoretic analysis that clarifies government incentives. An important finding is that government incentives to conceal decline the more numerous are non-official sources of information about a possible disease outbreak. The findings suggest that honesty may indeed be the best public policy under modern conditions of easy mass global communications.

The effect of arsenic mitigation interventions on disease burden in Bangladesh

Lokuge, Kamalini M.; Smith, Wayne T; Caldwell, Bruce; Dear, Keith; Milton, Abdul
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Journal article; Published Version Formato: 6 pages
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56.05%
Many interventions have been advocated to mitigate the impact of arsenic contamination of drinking water in Bangladesh. However, there are few data on the true magnitude of arsenic-related disease in Bangladesh nationally. There has also been little consideration given to possible adverse effects of such interventions, in particular, diarrheal disease. The purpose of this study was to estimate and compare the likely impacts of arsenic mitigation interventions on both arsenic-related disease and water-borne infectious disease. We found that arsenic-related disease currently results in 9,136 deaths per year and 174,174 disability-adjusted life years (DALYs ; undiscounted) lost per year in those exposed to arsenic concentrations > 50 µg/L. This constitutes 0.3% of the total disease burden in Bangladesh in terms of undiscounted DALYs. We found intervention to be of overall benefit in reducing disease burden in most scenarios examined, but the concomitant increase in water-related infectious disease significantly reduced the potential benefits gained from intervention. A minimum reduction in arsenic-related DALYs of 77% was necessary before intervention achieved any reduction in net disease burden. This is assuming that interventions were provided to those exposed to > 50 µg/L and would concomitantly result in a 20% increase in water-related infectious disease in those without access to adequate sanitation. Intervention appears to be justified for those populations exposed to high levels of arsenic...

Factors Influencing Performance of Internet-Based Biosurveillance Systems Used in Epidemic Intelligence for Early Detection of Infectious Diseases Outbreaks

Barboza, Philippe; Vaillant, Laetitia; Le Strat, Yann; Hartley, David M.; Nelson, Noele P.; Mawudeku, Abla; Madoff, Lawrence C.; Linge, Jens P.; Collier, Nigel; Brownstein, John S.; Astagneau, Pascal
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
66.12%
Background: Internet-based biosurveillance systems have been developed to detect health threats using information available on the Internet, but system performance has not been assessed relative to end-user needs and perspectives. Method and Findings Infectious disease events from the French Institute for Public Health Surveillance (InVS) weekly international epidemiological bulletin published in 2010 were used to construct the gold-standard official dataset. Data from six biosurveillance systems were used to detect raw signals (infectious disease events from informal Internet sources): Argus, BioCaster, GPHIN, HealthMap, MedISys and ProMED-mail. Crude detection rates (C-DR), crude sensitivity rates (C-Se) and intrinsic sensitivity rates (I-Se) were calculated from multivariable regressions to evaluate the systems’ performance (events detected compared to the gold-standard) 472 raw signals (Internet disease reports) related to the 86 events included in the gold-standard data set were retrieved from the six systems. 84 events were detected before their publication in the gold-standard. The type of sources utilised by the systems varied significantly (p<0001). I-Se varied significantly from 43% to 71% (p = 0001) whereas other indicators were similar (C-DR: p = 020; C-Se...

Final CIDC Report to Defra; The Cambridge Infectious Diseases Consortium

Wood, James
Fonte: Universidade de Cambridge Publicador: Universidade de Cambridge
Tipo: Report; submitted version
EN
Relevância na Pesquisa
56.05%
The Cambridge Infectious Diseases Consortium (CIDC) was established to provide a multi-institutional, world class quality environment for infectious disease research addressing important questions and for the recruitment and training of high quality veterinarians into careers in infectious disease research. The programme has been a demonstrable success in achieving these overall aims. The institutions that have played a key role in the consortium include the Department of Veterinary Medicine, the Department of Zoology and The Department of Pathology in the University of Cambridge, The Wellcome Trust Sanger Institute (WTSI), The Animal Health Trust, The Veterinary Laboratories Agency (VLA), The Institute of Animal Health (IAH), The Institute of Zoology (London: IOZ) and the University of Pretoria. In terms of research infrastructure, the programme has successfully consolidated or established research and education collaborations with all of the participating institutions, including VLA, IAH, IOZ, WTSI and AHT. Since the inception of CIDC, additional collaborative research funds have supported collaborative projects in infectious disease dynamics with all of these institutions. Subject areas have included bovine Tuberculosis, Bluetongue serotype-8 vaccination...

Phylodynamic Methods for Infectious Disease Epidemiology

Rasmussen, David Alan
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014
Relevância na Pesquisa
76.01%

In this dissertation, I present a general statistical framework for phylodynamic inference that can be used to estimate epidemiological parameters and reconstruct disease dynamics from pathogen genealogies. This framework can be used to fit a broad class of epidemiological models, including nonlinear stochastic models, to genealogies by relating the population dynamics of a pathogen to its genealogy using coalescent theory. By combining Markov chain Monte Carlo and particle filtering methods, efficient Bayesian inference of all parameters and unobserved latent variables is possible even when analytical likelihood expressions are not available under the epidemiological model. Through extensive simulations, I show that this method can be used to reliably estimate epidemiological parameters of interest as well as reconstruct past disease dynamics from genealogies, or jointly from genealogies and other common sources of epidemiological data like time series. I then extend this basic framework to include different types of host population structure, including models with spatial structure, multiple-hosts or vectors, and different stages of infection. The later is demonstrated by using a multistage model of HIV infection to estimate stage-specific transmission rates and incidence from HIV sequence data collected in Detroit...