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Sample records for epidemiologic methods

  1. Epidemiologic methods in analysis of scientific issues

    NASA Astrophysics Data System (ADS)

    Erdreich, Linda S.

    2003-10-01

    Studies of human populations provide much of the information that is used to evaluate compensation cases for hearing loss, including rates of hearing loss by age, and dose-response relationships. The reference data used to make decisions regarding workman's compensation is based on epidemiologic studies of cohorts of workers exposed to various noise levels. Epidemiology and its methods can be used in other ways in the courtroom; to assess the merits of a complaint, to support Daubert criteria, and to explain scientific issues to the trier of fact, generally a layperson. Using examples other than occupational noise induced hearing loss, these methods will be applied to respond to a complaint that hearing loss followed exposure to a sudden noise, a medication, or an occupational chemical, and thus was caused by said exposure. The standard criteria for assessing the weight of the evidence, and epidemiologic criteria for causality show the limits of such anecdotal data and incorporate quantitative and temporal issues. Reports of clusters of cases are also intuitively convincing to juries. Epidemiologic methods provide a scientific approach to assess whether rates of the outcome are indeed increased, and the extent to which increased rates provide evidence for causality.

  2. Kinetics methods for clinical epidemiology problems

    PubMed Central

    Corlan, Alexandru Dan; Ross, John

    2015-01-01

    Calculating the probability of each possible outcome for a patient at any time in the future is currently possible only in the simplest cases: short-term prediction in acute diseases of otherwise healthy persons. This problem is to some extent analogous to predicting the concentrations of species in a reactor when knowing initial concentrations and after examining reaction rates at the individual molecule level. The existing theoretical framework behind predicting contagion and the immediate outcome of acute diseases in previously healthy individuals is largely analogous to deterministic kinetics of chemical systems consisting of one or a few reactions. We show that current statistical models commonly used in chronic disease epidemiology correspond to simple stochastic treatment of single reaction systems. The general problem corresponds to stochastic kinetics of complex reaction systems. We attempt to formulate epidemiologic problems related to chronic diseases in chemical kinetics terms. We review methods that may be adapted for use in epidemiology. We show that some reactions cannot fit into the mass-action law paradigm and solutions to these systems would frequently exhibit an antiportfolio effect. We provide a complete example application of stochastic kinetics modeling for a deductive meta-analysis of two papers on atrial fibrillation incidence, prevalence, and mortality. PMID:26578757

  3. Kinetics methods for clinical epidemiology problems.

    PubMed

    Corlan, Alexandru Dan; Ross, John

    2015-11-17

    Calculating the probability of each possible outcome for a patient at any time in the future is currently possible only in the simplest cases: short-term prediction in acute diseases of otherwise healthy persons. This problem is to some extent analogous to predicting the concentrations of species in a reactor when knowing initial concentrations and after examining reaction rates at the individual molecule level. The existing theoretical framework behind predicting contagion and the immediate outcome of acute diseases in previously healthy individuals is largely analogous to deterministic kinetics of chemical systems consisting of one or a few reactions. We show that current statistical models commonly used in chronic disease epidemiology correspond to simple stochastic treatment of single reaction systems. The general problem corresponds to stochastic kinetics of complex reaction systems. We attempt to formulate epidemiologic problems related to chronic diseases in chemical kinetics terms. We review methods that may be adapted for use in epidemiology. We show that some reactions cannot fit into the mass-action law paradigm and solutions to these systems would frequently exhibit an antiportfolio effect. We provide a complete example application of stochastic kinetics modeling for a deductive meta-analysis of two papers on atrial fibrillation incidence, prevalence, and mortality. PMID:26578757

  4. Methods of Measurement in epidemiology: Sedentary Behaviour

    PubMed Central

    Atkin, Andrew J; Gorely, Trish; Clemes, Stacy A; Yates, Thomas; Edwardson, Charlotte; Brage, Soren; Salmon, Jo; Marshall, Simon J; Biddle, Stuart JH

    2012-01-01

    Background Research examining sedentary behaviour as a potentially independent risk factor for chronic disease morbidity and mortality has expanded rapidly in recent years. Methods We present a narrative overview of the sedentary behaviour measurement literature. Subjective and objective methods of measuring sedentary behaviour suitable for use in population-based research with children and adults are examined. The validity and reliability of each method is considered, gaps in the literature specific to each method identified and potential future directions discussed. Results To date, subjective approaches to sedentary behaviour measurement, e.g. questionnaires, have focused predominantly on TV viewing or other screen-based behaviours. Typically, such measures demonstrate moderate reliability but slight to moderate validity. Accelerometry is increasingly being used for sedentary behaviour assessments; this approach overcomes some of the limitations of subjective methods, but detection of specific postures and postural changes by this method is somewhat limited. Instruments developed specifically for the assessment of body posture have demonstrated good reliability and validity in the limited research conducted to date. Miniaturization of monitoring devices, interoperability between measurement and communication technologies and advanced analytical approaches are potential avenues for future developments in this field. Conclusions High-quality measurement is essential in all elements of sedentary behaviour epidemiology, from determining associations with health outcomes to the development and evaluation of behaviour change interventions. Sedentary behaviour measurement remains relatively under-developed, although new instruments, both objective and subjective, show considerable promise and warrant further testing. PMID:23045206

  5. An Introduction to Epidemiologic and Statistical Methods Useful in Environmental Epidemiology

    PubMed Central

    Nitta, Hiroshi; Yamazaki, Shin; Omori, Takashi; Sato, Tosiya

    2010-01-01

    Many developments in the design and analysis of environmental epidemiology have been made in air pollution studies. In the analysis of the short-term effects of particulate matter on daily mortality, Poisson regression models with flexible smoothing methods have been developed for the analysis of time-series data. Another option for such studies is the use of case–crossover designs, and there have been extensive discussions on the selection of control periods. In the Study on Respiratory Disease and Automobile Exhaust project conducted by the Japanese Ministry of the Environment, we adopted a new 2-stage case–control design that is efficient when both exposure and disease are rare. Based on our experience in conducting air pollution epidemiologic studies, we review 2-stage case–control designs, case–crossover designs, generalized linear models, generalized additive models, and generalized estimating equations, all of which are useful approaches in environmental epidemiology. PMID:20431236

  6. Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship.

    PubMed

    Morgan, Daniel J; Safdar, Nasia; Milstone, Aaron M; Anderson, Deverick J

    2016-06-01

    Research in Healthcare Epidemiology and Antimicrobial Stewardship (HE&AS) is rapidly expanding with the involvement of researchers from varied countries and backgrounds. Researchers must use scientific methods that will provide the strongest evidence to advance healthcare epidemiology, but there are limited resources for information on specific aspects of HE&AS research or easy ways to access examples of studies using specific methods with HE&AS. In response to this need, the SHEA Research Committee has developed a series of white papers on research methods in HE&AS. The objective of this series is to promote rigorous healthcare epidemiology research by summarizing critical components, practical considerations, and pitfalls of commonly used research methods. Infect Control Hosp Epidemiol 2016;37:627-628. PMID:27074955

  7. Strain Typing Methods and Molecular Epidemiology of Pneumocystis Pneumonia

    PubMed Central

    Roux, Patricia; Nevez, Gilles; Hauser, Philippe M.; Kovacs, Joseph A.; Unnasch, Thomas R.; Lundgren, Bettina

    2004-01-01

    Pneumocystis pneumonia (PCP) caused by the opportunistic fungal agent Pneumocystis jirovecii (formerly P. carinii) continues to cause illness and death in HIV-infected patients. In the absence of a culture system to isolate and maintain live organisms, efforts to type and characterize the organism have relied on polymerase chain reaction–based approaches. Studies using these methods have improved understanding of PCP epidemiology, shedding light on sources of infection, transmission patterns, and potential emergence of antimicrobial resistance. One concern, however, is the lack of guidance regarding the appropriateness of different methods and standardization of these methods, which would facilitate comparing results reported by different laboratories. PMID:15504257

  8. Epidemiological designs for vaccine safety assessment: methods and pitfalls.

    PubMed

    Andrews, Nick

    2012-09-01

    Three commonly used designs for vaccine safety assessment post licensure are cohort, case-control and self-controlled case series. These methods are often used with routine health databases and immunisation registries. This paper considers the issues that may arise when designing an epidemiological study, such as understanding the vaccine safety question, case definition and finding, limitations of data sources, uncontrolled confounding, and pitfalls that apply to the individual designs. The example of MMR and autism, where all three designs have been used, is presented to help consider these issues. PMID:21985898

  9. Using Epidemiologic Methods to Test Hypotheses regarding Causal Influences on Child and Adolescent Mental Disorders

    ERIC Educational Resources Information Center

    Lahey, Benjamin B.; D'Onofrio, Brian M.; Waldman, Irwin D.

    2009-01-01

    Epidemiology uses strong sampling methods and study designs to test refutable hypotheses regarding the causes of important health, mental health, and social outcomes. Epidemiologic methods are increasingly being used to move developmental psychopathology from studies that catalogue correlates of child and adolescent mental health to designs that…

  10. The Role of Applied Epidemiology Methods in the Disaster Management Cycle

    PubMed Central

    Malilay, Josephine; Heumann, Michael; Perrotta, Dennis; Wolkin, Amy F.; Schnall, Amy H.; Podgornik, Michelle N.; Cruz, Miguel A.; Horney, Jennifer A.; Zane, David; Roisman, Rachel; Greenspan, Joel R.; Thoroughman, Doug; Anderson, Henry A.; Wells, Eden V.; Simms, Erin F.

    2015-01-01

    Disaster epidemiology (i.e., applied epidemiology in disaster settings) presents a source of reliable and actionable information for decision-makers and stakeholders in the disaster management cycle. However, epidemiological methods have yet to be routinely integrated into disaster response and fully communicated to response leaders. We present a framework consisting of rapid needs assessments, health surveillance, tracking and registries, and epidemiological investigations, including risk factor and health outcome studies and evaluation of interventions, which can be practiced throughout the cycle. Applying each method can result in actionable information for planners and decision-makers responsible for preparedness, response, and recovery. Disaster epidemiology, once integrated into the disaster management cycle, can provide the evidence base to inform and enhance response capability within the public health infrastructure. PMID:25211748

  11. Complex mixtures and indoor air pollution: overview of epidemiologic methods.

    PubMed Central

    Weiss, N S

    1993-01-01

    The likelihood of an epidemiologic study correctly identifying an adverse health outcome associated with exposure to indoor air pollutants is increased if a) substantial variation exists in the frequency or level of exposure among study subjects otherwise at similar risk of the health outcome; b) the number of study subjects or study communities is large; c) the health outcome can be assessed with accuracy; d) relevant exposure levels can be measured with accuracy; e) an unbiased sample of exposed and nonexposed subjects is selected for study; and f) other determinants of the adverse health outcome can be measured. Nonetheless, given a strong enough impact of exposure to one pollutant or a mixture of pollutants on the risk of illness, it is possible for epidemiologic studies to discern a relation even if only some of the above circumstances are present. PMID:8206026

  12. Concordance and discordance of sequence survey methods for molecular epidemiology

    PubMed Central

    Hasan, Nur A.; Cebula, Thomas A.; Colwell, Rita R.; Robison, Richard A.; Johnson, W. Evan; Crandall, Keith A.

    2015-01-01

    The post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. However, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. We sequenced whole genomes of bacterial pathogens, Burkholderia pseudomallei, Yersinia pestis, and Brucella spp. (60 new genomes), and combined them with 55 genomes from GenBank to address how different molecular survey approaches (whole genomes, SNPs, and MLST) impact downstream inferences on molecular evolutionary parameters, evolutionary relationships, and trait character associations. We selected isolates for sequencing to represent temporal, geographic origin, and host range variability. We found that substitution rate estimates vary widely among approaches, and that SNP and genomic datasets yielded different but strongly supported phylogenies. MLST yielded poorly supported phylogenies, especially in our low diversity dataset, i.e., Y. pestis. Trait associations showed that B. pseudomallei and Y. pestis phylogenies are significantly associated with geography, irrespective of the molecular survey approach used, while Brucella spp. phylogeny appears to be strongly associated with geography and host origin. We contrast inferences made among monomorphic (clonal) and non-monomorphic bacteria, and between intra- and inter-specific datasets. We also discuss our results in light of underlying assumptions of different approaches. PMID:25737810

  13. From Smallpox to Big Data: The Next 100 Years of Epidemiologic Methods.

    PubMed

    Gange, Stephen J; Golub, Elizabeth T

    2016-03-01

    For more than a century, epidemiology has seen major shifts in both focus and methodology. Taking into consideration the explosion of "big data," the advent of more sophisticated data collection and analytical tools, and the increased interest in evidence-based solutions, we present a framework that summarizes 3 fundamental domains of epidemiologic methods that are relevant for the understanding of both historical contributions and future directions in public health. First, the manner in which populations and their follow-up are defined is expanding, with greater interest in online populations whose definition does not fit the usual classification by person, place, and time. Second, traditional data collection methods, such as population-based surveillance and individual interviews, have been supplemented with advances in measurement. From biomarkers to mobile health, innovations in the measurement of exposures and diseases enable refined accuracy of data collection. Lastly, the comparison of populations is at the heart of epidemiologic methodology. Risk factor epidemiology, prediction methods, and causal inference strategies are areas in which the field is continuing to make significant contributions to public health. The framework presented herein articulates the multifaceted ways in which epidemiologic methods make such contributions and can continue to do so as we embark upon the next 100 years. PMID:26443419

  14. Typing methods used in the molecular epidemiology of microbial pathogens: a how-to guide.

    PubMed

    Ranjbar, Reza; Karami, Ali; Farshad, Shohreh; Giammanco, Giovanni M; Mammina, Caterina

    2014-01-01

    Microbial typing is often employed to determine the source and routes of infections, confirm or rule out outbreaks, trace cross-transmission of healthcare-associated pathogens, recognize virulent strains and evaluate the effectiveness of control measures. Conventional microbial typing methods have occasionally been useful in describing the epidemiology of infectious diseases. However, these methods are generally considered too variable, labour intensive and time-consuming to be of practical value in epidemiological investigations. Moreover, these approaches have proved to be insufficiently discriminatory and poorly reproducible. DNA-based typing methods rely on the analysis of the genetic material of a microorganism. In recent years, several methods have been introduced and developed for investigation of the molecular epidemiology of microbial pathogens. Each of them has advantages and limitations that make them useful in some studies and restrictive in others. The choice of a molecular typing method therefore will depend on the skill level and resources of the laboratory and the aim and scale of the investigation. This study reviews the most popular DNA-based molecular typing methods used in the epidemiology of bacterial pathogens together with their advantages and limitations. PMID:24531166

  15. Influence of DNA extraction methods on relative telomere length measurements and its impact on epidemiological studies

    PubMed Central

    Raschenberger, Julia; Lamina, Claudia; Haun, Margot; Kollerits, Barbara; Coassin, Stefan; Boes, Eva; Kedenko, Ludmilla; Köttgen, Anna; Kronenberg, Florian

    2016-01-01

    Measurement of telomere length is widely used in epidemiologic studies. Insufficient standardization of the measurements processes has, however, complicated the comparison of results between studies. We aimed to investigate whether DNA extraction methods have an influence on measured values of relative telomere length (RTL) and whether this has consequences for epidemiological studies. We performed four experiments with RTL measurement in quadruplicate by qPCR using DNA extracted with different methods: 1) a standardized validation experiment including three extraction methods (magnetic-particle-method EZ1, salting-out-method INV, phenol-chloroform-isoamyl-alcohol PCI) each in the same 20 samples demonstrated pronounced differences in RTL with lowest values with EZ1 followed by INV and PCI-isolated DNA; 2) a comparison of 307 samples from an epidemiological study showing EZ1-measurements 40% lower than INV-measurements; 3) a matching-approach of two similar non-diseased control groups including 143 pairs of subjects revealed significantly shorter RTL in EZ1 than INV-extracted DNA (0.844 ± 0.157 vs. 1.357 ± 0.242); 4) an association analysis of RTL with prevalent cardiovascular disease detected a stronger association with INV than with EZ1-extracted DNA. In summary, DNA extraction methods have a pronounced influence on the measured RTL-values. This might result in spurious or lost associations in epidemiological studies under certain circumstances. PMID:27138987

  16. Influence of DNA extraction methods on relative telomere length measurements and its impact on epidemiological studies.

    PubMed

    Raschenberger, Julia; Lamina, Claudia; Haun, Margot; Kollerits, Barbara; Coassin, Stefan; Boes, Eva; Kedenko, Ludmilla; Köttgen, Anna; Kronenberg, Florian

    2016-01-01

    Measurement of telomere length is widely used in epidemiologic studies. Insufficient standardization of the measurements processes has, however, complicated the comparison of results between studies. We aimed to investigate whether DNA extraction methods have an influence on measured values of relative telomere length (RTL) and whether this has consequences for epidemiological studies. We performed four experiments with RTL measurement in quadruplicate by qPCR using DNA extracted with different methods: 1) a standardized validation experiment including three extraction methods (magnetic-particle-method EZ1, salting-out-method INV, phenol-chloroform-isoamyl-alcohol PCI) each in the same 20 samples demonstrated pronounced differences in RTL with lowest values with EZ1 followed by INV and PCI-isolated DNA; 2) a comparison of 307 samples from an epidemiological study showing EZ1-measurements 40% lower than INV-measurements; 3) a matching-approach of two similar non-diseased control groups including 143 pairs of subjects revealed significantly shorter RTL in EZ1 than INV-extracted DNA (0.844 ± 0.157 vs. 1.357 ± 0.242); 4) an association analysis of RTL with prevalent cardiovascular disease detected a stronger association with INV than with EZ1-extracted DNA. In summary, DNA extraction methods have a pronounced influence on the measured RTL-values. This might result in spurious or lost associations in epidemiological studies under certain circumstances. PMID:27138987

  17. Trends in Citations to Books on Epidemiological and Statistical Methods in the Biomedical Literature

    PubMed Central

    Porta, Miquel; Vandenbroucke, Jan P.; Ioannidis, John P. A.; Sanz, Sergio; Fernandez, Esteve; Bhopal, Raj; Morabia, Alfredo; Victora, Cesar; Lopez, Tomàs

    2013-01-01

    Background There are no analyses of citations to books on epidemiological and statistical methods in the biomedical literature. Such analyses may shed light on how concepts and methods changed while biomedical research evolved. Our aim was to analyze the number and time trends of citations received from biomedical articles by books on epidemiological and statistical methods, and related disciplines. Methods and Findings The data source was the Web of Science. The study books were published between 1957 and 2010. The first year of publication of the citing articles was 1945. We identified 125 books that received at least 25 citations. Books first published in 1980–1989 had the highest total and median number of citations per year. Nine of the 10 most cited texts focused on statistical methods. Hosmer & Lemeshow's Applied logistic regression received the highest number of citations and highest average annual rate. It was followed by books by Fleiss, Armitage, et al., Rothman, et al., and Kalbfleisch and Prentice. Fifth in citations per year was Sackett, et al., Evidence-based medicine. The rise of multivariate methods, clinical epidemiology, or nutritional epidemiology was reflected in the citation trends. Educational textbooks, practice-oriented books, books on epidemiological substantive knowledge, and on theory and health policies were much less cited. None of the 25 top-cited books had the theoretical or sociopolitical scope of works by Cochrane, McKeown, Rose, or Morris. Conclusions Books were mainly cited to reference methods. Books first published in the 1980s continue to be most influential. Older books on theory and policies were rooted in societal and general medical concerns, while the most modern books are almost purely on methods. PMID:23667447

  18. Overview of molecular typing methods for outbreak detection and epidemiological surveillance.

    PubMed

    Sabat, A J; Budimir, A; Nashev, D; Sá-Leão, R; van Dijl, J m; Laurent, F; Grundmann, H; Friedrich, A W

    2013-01-01

    Typing methods for discriminating different bacterial isolates of the same species are essential epidemiological tools in infection prevention and control. Traditional typing systems based on phenotypes, such as serotype, biotype, phage-type, or antibiogram, have been used for many years. However, more recent methods that examine the relatedness of isolates at a molecular level have revolutionised our ability to differentiate among bacterial types and subtypes. Importantly, the development of molecular methods has provided new tools for enhanced surveillance and outbreak detection. This has resulted in better implementation of rational infection control programmes and efficient allocation of resources across Europe. The emergence of benchtop sequencers using next generation sequencing technology makes bacterial whole genome sequencing (WGS) feasible even in small research and clinical laboratories. WGS has already been used for the characterisation of bacterial isolates in several large outbreaks in Europe and, in the near future, is likely to replace currently used typing methodologies due to its ultimate resolution. However, WGS is still too laborious and time-consuming to obtain useful data in routine surveillance. Also, a largely unresolved question is how genome sequences must be examined for epidemiological characterisation. In the coming years, the lessons learnt from currently used molecular methods will allow us to condense the WGS data into epidemiologically useful information. On this basis, we have reviewed current and new molecular typing methods for outbreak detection and epidemiological surveillance of bacterial pathogens in clinical practice, aiming to give an overview of their specific advantages and disadvantages. PMID:23369389

  19. Outcome modelling strategies in epidemiology: traditional methods and basic alternatives.

    PubMed

    Greenland, Sander; Daniel, Rhian; Pearce, Neil

    2016-04-01

    Controlling for too many potential confounders can lead to or aggravate problems of data sparsity or multicollinearity, particularly when the number of covariates is large in relation to the study size. As a result, methods to reduce the number of modelled covariates are often deployed. We review several traditional modelling strategies, including stepwise regression and the 'change-in-estimate' (CIE) approach to deciding which potential confounders to include in an outcome-regression model for estimating effects of a targeted exposure. We discuss their shortcomings, and then provide some basic alternatives and refinements that do not require special macros or programming. Throughout, we assume the main goal is to derive the most accurate effect estimates obtainable from the data and commercial software. Allowing that most users must stay within standard software packages, this goal can be roughly approximated using basic methods to assess, and thereby minimize, mean squared error (MSE). PMID:27097747

  20. Outcome modelling strategies in epidemiology: traditional methods and basic alternatives

    PubMed Central

    Greenland, Sander; Daniel, Rhian; Pearce, Neil

    2016-01-01

    Controlling for too many potential confounders can lead to or aggravate problems of data sparsity or multicollinearity, particularly when the number of covariates is large in relation to the study size. As a result, methods to reduce the number of modelled covariates are often deployed. We review several traditional modelling strategies, including stepwise regression and the ‘change-in-estimate’ (CIE) approach to deciding which potential confounders to include in an outcome-regression model for estimating effects of a targeted exposure. We discuss their shortcomings, and then provide some basic alternatives and refinements that do not require special macros or programming. Throughout, we assume the main goal is to derive the most accurate effect estimates obtainable from the data and commercial software. Allowing that most users must stay within standard software packages, this goal can be roughly approximated using basic methods to assess, and thereby minimize, mean squared error (MSE). PMID:27097747

  1. [Mendelian randomisation - a genetic approach to an epidemiological method].

    PubMed

    Stensrud, Mats Julius

    2016-06-01

    BACKGROUND Genetic information is becoming more easily available, and rapid progress is being made in developing methods of illuminating issues of interest. Mendelian randomisation makes it possible to study causes of disease using observational data. The name refers to the random distribution of gene variants in meiosis. The methodology makes use of genes that influence a risk factor for a disease, without influencing the disease itself. In this review article I explain the principles behind Mendelian randomisation and present the areas of application for this methodology.MATERIAL AND METHOD Methodology articles describing Mendelian randomisation were reviewed. The articles were found through a search in PubMed with the combination «mendelian randomization» OR «mendelian randomisation», and a search in McMaster Plus with the combination «mendelian randomization». A total of 15 methodology articles were read in full text. Methodology articles were supplemented by clinical studies found in the PubMed search.RESULTS In contrast to traditional observational studies, Mendelian randomisation studies are not affected by two important sources of error: conventional confounding variables and reverse causation. Mendelian randomisation is therefore a promising tool for studying causality. Mendelian randomisation studies have already provided valuable knowledge on the risk factors for a wide range of diseases. It is nevertheless important to be aware of the limitations of the methodology. As a result of the rapid developments in genetics research, Mendelian randomisation will probably be widely used in future years.INTERPRETATION If Mendelian randomisation studies are conducted correctly, they may help to reveal both modifiable and non-modifiable causes of disease. PMID:27325033

  2. Violent crime in San Antonio, Texas: an application of spatial epidemiological methods.

    PubMed

    Sparks, Corey S

    2011-12-01

    Violent crimes are rarely considered a public health problem or investigated using epidemiological methods. But patterns of violent crime and other health conditions are often affected by similar characteristics of the built environment. In this paper, methods and perspectives from spatial epidemiology are used in an analysis of violent crimes in San Antonio, TX. Bayesian statistical methods are used to examine the contextual influence of several aspects of the built environment. Additionally, spatial regression models using Bayesian model specifications are used to examine spatial patterns of violent crime risk. Results indicate that the determinants of violent crime depend on the model specification, but are primarily related to the built environment and neighborhood socioeconomic conditions. Results are discussed within the context of a rapidly growing urban area with a diverse population. PMID:22748228

  3. The Swedish Longitudinal Gambling Study (Swelogs): design and methods of the epidemiological (EP-) track

    PubMed Central

    Romild, Ulla; Volberg, Rachel; Abbott, Max

    2014-01-01

    Swelogs (Swedish Longitudinal Gambling Study) epidemiological (EP-) track is a prospective study with four waves of data-collection among Swedish citizens aged 16–84 years at baseline. The major objectives of this track are to provide general population estimates of the prevalence and incidence of problem and at-risk gambling and enable comparisons with the first Swedish national study on gambling and problem gambling (Swegs) conducted in 1997/1998. The overall study (Swelogs) comprises three tracks of data collection; one epidemiological, one in-depth and one follow-up. It is expected to provide information that will inform the development of evidence-based methods and strategies to prevent the development of gambling problems. This paper gives an overview of the design of the epidemiological track, especially of its two first waves. The baseline wave, performed between October 2008 and August 2009, included 8165 subjects, of whom 6021 were re-assessed one year later. A stratified random sampling procedure was applied. Computer-supported telephone interviews were used as the primary method. Postal questionnaires were used to follow-up those not reached by telephone. The response rate was 55% in the first wave and 74% in the second. The interview and questionnaire data are supplemented by register data. © 2014 The Authors. International Journal of Methods in Psychiatric Research published by John Wiley & Sons Ltd. PMID:24942902

  4. Methods for measuring utilization of mental health services in two epidemiologic studies

    PubMed Central

    NOVINS, DOUGLAS K.; BEALS, JANETTE; CROY, CALVIN; MANSON, SPERO M.

    2015-01-01

    Objectives of Study Psychiatric epidemiologic studies often include two or more sets of questions regarding service utilization, but the agreement across these different questions and the factors associated with their endorsement have not been examined. The objectives of this study were to describe the agreement of different sets of mental health service utilization questions that were included in the American Indian Service Utilization Psychiatric Epidemiology Risk and Protective Factors Project (AI-SUPERPFP), and compare the results to similar questions included in the baseline National Comorbidity Survey (NCS). Methods Responses to service utilization questions by 2878 AI-SUPERPFP and 5877 NCS participants were examined by calculating estimates of service use and agreement (κ) across the different sets of questions. Logistic regression models were developed to identify factors associated with endorsement of specific sets of questions. Results In both studies, estimates of mental health service utilization varied across the different sets of questions. Agreement across the different question sets was marginal to good (κ = 0.27–0.69). Characteristics of identified service users varied across the question sets. Limitations Neither survey included data to examine the validity of participant responses to service utilization questions. Recommendations for Further Research Question wording and placement appear to impact estimates of service utilization in psychiatric epidemiologic studies. Given the importance of these estimates for policy-making, further research into the validity of survey responses as well as impacts of question wording and context on rates of service utilization is warranted. PMID:18767205

  5. A Review for Detecting Gene-Gene Interactions Using Machine Learning Methods in Genetic Epidemiology

    PubMed Central

    Koo, Ching Lee; Liew, Mei Jing; Mohamad, Mohd Saberi

    2013-01-01

    Recently, the greatest statistical computational challenge in genetic epidemiology is to identify and characterize the genes that interact with other genes and environment factors that bring the effect on complex multifactorial disease. These gene-gene interactions are also denoted as epitasis in which this phenomenon cannot be solved by traditional statistical method due to the high dimensionality of the data and the occurrence of multiple polymorphism. Hence, there are several machine learning methods to solve such problems by identifying such susceptibility gene which are neural networks (NNs), support vector machine (SVM), and random forests (RFs) in such common and multifactorial disease. This paper gives an overview on machine learning methods, describing the methodology of each machine learning methods and its application in detecting gene-gene and gene-environment interactions. Lastly, this paper discussed each machine learning method and presents the strengths and weaknesses of each machine learning method in detecting gene-gene interactions in complex human disease. PMID:24228248

  6. A review for detecting gene-gene interactions using machine learning methods in genetic epidemiology.

    PubMed

    Koo, Ching Lee; Liew, Mei Jing; Mohamad, Mohd Saberi; Salleh, Abdul Hakim Mohamed

    2013-01-01

    Recently, the greatest statistical computational challenge in genetic epidemiology is to identify and characterize the genes that interact with other genes and environment factors that bring the effect on complex multifactorial disease. These gene-gene interactions are also denoted as epitasis in which this phenomenon cannot be solved by traditional statistical method due to the high dimensionality of the data and the occurrence of multiple polymorphism. Hence, there are several machine learning methods to solve such problems by identifying such susceptibility gene which are neural networks (NNs), support vector machine (SVM), and random forests (RFs) in such common and multifactorial disease. This paper gives an overview on machine learning methods, describing the methodology of each machine learning methods and its application in detecting gene-gene and gene-environment interactions. Lastly, this paper discussed each machine learning method and presents the strengths and weaknesses of each machine learning method in detecting gene-gene interactions in complex human disease. PMID:24228248

  7. New Saliva DNA Collection Method Compared to Buccal Cell Collection Techniques for Epidemiological Studies

    PubMed Central

    ROGERS, NIKKI L.; COLE, SHELLEY A.; LAN, HAO-CHANG; CROSSA, ALDO; DEMERATH, ELLEN W.

    2009-01-01

    Epidemiological studies may require noninvasive methods for off-site DNA collection. We compared the DNA yield and quality obtained using a whole-saliva collection device (Oragene™ DNA collection kit) to those from three established noninvasive methods (cytobrush, foam swab, and oral rinse). Each method was tested on 17 adult volunteers from our center, using a random crossover collection design and analyzed using repeated-measures statistics. DNA yield and quality were assessed via gel electrophoresis, spectophotometry, and polymerase chain reaction (PCR) amplification rate. The whole-saliva method provided a significantly greater DNA yield (mean ± SD = 154.9 ± 103.05 μg, median = 181.88) than the other methods (oral rinse = 54.74 ± 41.72 μg, 36.56; swab = 11.44 ± 7.39 μg, 10.72; cytobrush = 12.66 ± 6.19, 13.22 μg) (all pairwise P < 0.05). Oral-rinse and whole-saliva samples provided the best DNA quality, whereas cytobrush and swab samples provided poorer quality DNA, as shown by lower OD260/OD280 and OD260/OD230 ratios. We conclude that both a 10-ml oral-rinse sample and 2-ml whole-saliva sample provide sufficient DNA quantity and better quality DNA for genetic epidemiological studies than do the commonly used buccal swab and brush techniques. PMID:17421001

  8. New saliva DNA collection method compared to buccal cell collection techniques for epidemiological studies.

    PubMed

    Rogers, Nikki L; Cole, Shelley A; Lan, Hao-Chang; Crossa, Aldo; Demerath, Ellen W

    2007-01-01

    Epidemiological studies may require noninvasive methods for off-site DNA collection. We compared the DNA yield and quality obtained using a whole-saliva collection device (Oragene DNA collection kit) to those from three established noninvasive methods (cytobrush, foam swab, and oral rinse). Each method was tested on 17 adult volunteers from our center, using a random crossover collection design and analyzed using repeated-measures statistics. DNA yield and quality were assessed via gel electrophoresis, spectophotometry, and polymerase chain reaction (PCR) amplification rate. The whole-saliva method provided a significantly greater DNA yield (mean +/- SD = 154.9 +/- 103.05 microg, median = 181.88) than the other methods (oral rinse = 54.74 +/- 41.72 microg, 36.56; swab = 11.44 +/- 7.39 microg, 10.72; cytobrush = 12.66 +/- 6.19, 13.22 microg) (all pairwise P < 0.05). Oral-rinse and whole-saliva samples provided the best DNA quality, whereas cytobrush and swab samples provided poorer quality DNA, as shown by lower OD(260)/OD(280) and OD(260)/OD(230) ratios. We conclude that both a 10-ml oral-rinse sample and 2-ml whole-saliva sample provide sufficient DNA quantity and better quality DNA for genetic epidemiological studies than do the commonly used buccal swab and brush techniques. PMID:17421001

  9. Diagnostic Methods of Helicobacter pylori Infection for Epidemiological Studies: Critical Importance of Indirect Test Validation.

    PubMed

    Miftahussurur, Muhammad; Yamaoka, Yoshio

    2016-01-01

    Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2-90.8% and 83.3-86.9% and a specificity of 97.7-98.8% and 95.1-97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values. PMID:26904678

  10. Diagnostic Methods of Helicobacter pylori Infection for Epidemiological Studies: Critical Importance of Indirect Test Validation

    PubMed Central

    Miftahussurur, Muhammad; Yamaoka, Yoshio

    2016-01-01

    Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2–90.8% and 83.3–86.9% and a specificity of 97.7–98.8% and 95.1–97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values. PMID:26904678

  11. A practical method for use in epidemiological studies on enamel hypomineralisation.

    PubMed

    Ghanim, A; Elfrink, M; Weerheijm, K; Mariño, R; Manton, D

    2015-06-01

    With the development of the European Academy of Paediatric Dentistry (EAPD) judgment criteria, there has been increasing interest worldwide in investigation of the prevalence of demarcated opacities in tooth enamel substance, known as molar-incisor hypomineralisation (MIH). However, the lack of a standardised system for the purpose of recording MIH data in epidemiological surveys has contributed greatly to the wide variations in the reported prevalence between studies. The present publication describes the rationale, development, and content of a scoring method for MIH diagnosis in epidemiological studies as well as clinic- and hospital-based studies. The proposed grading method allows separate classification of demarcated hypomineralisation lesions and other enamel defects identical to MIH. It yields an informative description of the severity of MIH-affected teeth in terms of the stage of visible enamel destruction and the area of tooth surface affected (i.e. lesion clinical status and extent, respectively). In order to preserve the maximum amount of information from a clinical examination consistent with the need to permit direct comparisons between prevalence studies, two forms of the charting are proposed, a short form for simple screening surveys and a long form desirable for prospective, longitudinal observational research where aetiological factors in demarcated lesions are to be investigated in tandem with lesions distribution. Validation of the grading method is required, and its reliability and usefulness need to be tested in different age groups and different populations. PMID:25916282

  12. Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship: Randomized Controlled Trials.

    PubMed

    Anderson, Deverick J; Juthani-Mehta, Manisha; Morgan, Daniel J

    2016-06-01

    Randomized controlled trials (RCT) produce the strongest level of clinical evidence when comparing interventions. RCTs are technically difficult, costly, and require specific considerations including the use of patient- and cluster-level randomization and outcome selection. In this methods paper, we focus on key considerations for RCT methods in healthcare epidemiology and antimicrobial stewardship (HE&AS) research, including the need for cluster randomization, conduct at multiple sites, behavior modification interventions, and difficulty with identifying appropriate outcomes. We review key RCTs in HE&AS with a focus on advantages and disadvantages of methods used. A checklist is provided to aid in the development of RCTs in HE&AS. Infect Control Hosp Epidemiol 2016;37:629-634. PMID:27108848

  13. A rapid method of grading cataract in epidemiological studies and eye surveys.

    PubMed Central

    Mehra, V; Minassian, D C

    1988-01-01

    A rapid method of grading clinically important central lens opacities has been developed for use in eye surveys and in epidemiological studies of cataract and has been field-tested in a specifically designed observer agreement study in a survey of a rural community in Central India. The grading method is based on simple measurement of the area of lens opacity that obscures the red reflex relative to the area of clear red reflex, as visualised through the undilated normal pupil. Good to almost perfect agreements were attained between two ophthalmologists and two trained ophthalmic assistants for overall grades of central lens opacity. Most disagreements were trivial in nature and were concerned with difficulties in distinguishing grade 0 from grade 1, and with hazy appearance of the red reflex in high myopes and in cases of early nuclear sclerosis. Teaching materials including video tape and slides for training survey teams and other workers are in preparation. PMID:3207653

  14. [Application of molecular methods in the diagnosis and epidemiological study of viral respiratory infections].

    PubMed

    Pozo, Francisco; Casas, Inmaculada; Ruiz, Guillermo; Falcón, Ana; Pérez-Breña, Pilar

    2008-07-01

    To date, more than two hundred viruses, belonging to six different taxonomic families, have been associated with human respiratory tract infection. The widespread incorporation of molecular methods into clinical microbiology laboratories has not only led to notable advances in the etiological diagnosis of viral respiratory infections but has also increased insight into the pathology and epidemiological profiles of the causative viruses. Because of their high sensitivity, molecular techniques markedly increase the efficiency of viral detection in respiratory specimens, particularly those that fail to propagate successfully in common cell cultures, thus allowing more rapid etiologic diagnosis. However, there are also some disadvantages in the use of these new technologies such as detection of viruses that merely colonize the respiratory tract of healthy people, or those found in the nasopharyngeal secretions of patients who have recovered from respiratory infections, due to longterm viral shedding, when the viruses are unlikely to act as pathogens. Additionally, sequencing of the amplification products allows further characterization of detected viruses, including molecular epidemiology, genotyping, or detection of antiviral resistance, to cite only a few examples. PMID:19195443

  15. Comparison of Methods to Account for Implausible Reporting of Energy Intake in Epidemiologic Studies

    PubMed Central

    Rhee, Jinnie J.; Sampson, Laura; Cho, Eunyoung; Hughes, Michael D.; Hu, Frank B.; Willett, Walter C.

    2015-01-01

    In a recent article in the American Journal of Epidemiology by Mendez et al. (Am J Epidemiol. 2011;173(4):448–458), the use of alternative approaches to the exclusion of implausible energy intakes led to significantly different cross-sectional associations between diet and body mass index (BMI), whereas the use of a simpler recommended criteria (<500 and >3,500 kcal/day) yielded no meaningful change. However, these findings might have been due to exclusions made based on weight, a primary determinant of BMI. Using data from 52,110 women in the Nurses' Health Study (1990), we reproduced the cross-sectional findings of Mendez et al. and compared the results from the recommended method with those from 2 weight-dependent alternative methods (the Goldberg method and predicted total energy expenditure method). The same 3 exclusion criteria were then used to examine dietary variables prospectively in relation to change in BMI, which is not a direct function of attained weight. We found similar associations using the 3 methods. In a separate cross-sectional analysis using biomarkers of dietary factors, we found similar correlations for intakes of fatty acids (n = 439) and carotenoids and retinol (n = 1,293) using the 3 methods for exclusions. These results do not support the general conclusion that use of exclusion criteria based on the alternative methods might confer an advantage over the recommended exclusion method. PMID:25656533

  16. Development of the residential case-specular epidemiologic investigation method. Final report

    SciTech Connect

    Zaffanella, L.E.; Savitz, D.A.

    1995-11-01

    The residential case-specular method is an innovative approach to epidemiologic studies of the association between wire codes and childhood cancer. This project was designed to further the development of the residential case-specular method, which seeks to help resolve the ``wire code paradox``. For years, wire codes have been used as surrogate measures of past electric and magnetic field (EMF) exposure. There is a magnetic field hypothesis that suggests childhood cancer is associated with exposure to magnetic fields, with wire codes as a proxy for these fields. The neighborhood hypothesis suggests that childhood cancer is associated with neighborhood characteristics and exposures other than magnetic fields, with wire codes as a proxy for these characteristics and exposures. The residential case-specular method was designed to discriminate between the magnetic field and the neighborhood hypothesis. Two methods were developed for determining the specular of a residence. These methods were tested with 400 randomly selected residences. The main advantage of the residential case-specular method is that it may efficiently confirm or eliminate the suspicion that control selection bias or confounding by neighborhood factors affected the results of case-control studies of childhood cancer and magnetic fields. The method may be applicable to both past and ongoing studies. The main disadvantage is that the method is untried. Consequently, further work is required to verify its validity and to ensure that sufficient statistical power can be obtained in a cost-effective manner.

  17. Imputation method for lifetime exposure assessment in air pollution epidemiologic studies

    PubMed Central

    2013-01-01

    Background Environmental epidemiology, when focused on the life course of exposure to a specific pollutant, requires historical exposure estimates that are difficult to obtain for the full time period due to gaps in the historical record, especially in earlier years. We show that these gaps can be filled by applying multiple imputation methods to a formal risk equation that incorporates lifetime exposure. We also address challenges that arise, including choice of imputation method, potential bias in regression coefficients, and uncertainty in age-at-exposure sensitivities. Methods During time periods when parameters needed in the risk equation are missing for an individual, the parameters are filled by an imputation model using group level information or interpolation. A random component is added to match the variance found in the estimates for study subjects not needing imputation. The process is repeated to obtain multiple data sets, whose regressions against health data can be combined statistically to develop confidence limits using Rubin’s rules to account for the uncertainty introduced by the imputations. To test for possible recall bias between cases and controls, which can occur when historical residence location is obtained by interview, and which can lead to misclassification of imputed exposure by disease status, we introduce an “incompleteness index,” equal to the percentage of dose imputed (PDI) for a subject. “Effective doses” can be computed using different functional dependencies of relative risk on age of exposure, allowing intercomparison of different risk models. To illustrate our approach, we quantify lifetime exposure (dose) from traffic air pollution in an established case–control study on Long Island, New York, where considerable in-migration occurred over a period of many decades. Results The major result is the described approach to imputation. The illustrative example revealed potential recall bias, suggesting that regressions

  18. Regression calibration method for correcting measurement-error bias in nutritional epidemiology.

    PubMed

    Spiegelman, D; McDermott, A; Rosner, B

    1997-04-01

    Regression calibration is a statistical method for adjusting point and interval estimates of effect obtained from regression models commonly used in epidemiology for bias due to measurement error in assessing nutrients or other variables. Previous work developed regression calibration for use in estimating odds ratios from logistic regression. We extend this here to estimating incidence rate ratios from Cox proportional hazards models and regression slopes from linear-regression models. Regression calibration is appropriate when a gold standard is available in a validation study and a linear measurement error with constant variance applies or when replicate measurements are available in a reliability study and linear random within-person error can be assumed. In this paper, the method is illustrated by correction of rate ratios describing the relations between the incidence of breast cancer and dietary intakes of vitamin A, alcohol, and total energy in the Nurses' Health Study. An example using linear regression is based on estimation of the relation between ultradistal radius bone density and dietary intakes of caffeine, calcium, and total energy in the Massachusetts Women's Health Study. Software implementing these methods uses SAS macros. PMID:9094918

  19. An overview of various typing methods for clinical epidemiology of the emerging pathogen Stenotrophomonas maltophilia.

    PubMed

    Gherardi, Giovanni; Creti, Roberta; Pompilio, Arianna; Di Bonaventura, Giovanni

    2015-03-01

    Typing of bacterial isolates has been used for decades to study local outbreaks as well as in national and international surveillances for monitoring newly emerging resistant clones. Despite being recognized as a nosocomial pathogen, the precise modes of transmission of Stenotrophomonas maltophilia in health care settings are unknown. Due to the high genetic diversity observed among S. maltophilia clinical isolates, the typing results might be better interpreted if also environmental strains were included. This could help to identify preventative measures to be designed and implemented for decreasing the possibility of outbreaks and nosocomial infections. In this review, we attempt to provide an overview on the most common typing methods used for clinical epidemiology of S. maltophilia strains, such as PCR-based fingerprinting analyses, pulsed-field gel electrophoresis, multilocus variable number tandem repeat analysis, and multilocus sequence type. Application of the proteomic-based mass spectrometry by matrix-assisted laser desorption ionization-time of flight is also described. Improvements of typing methods already in use have to be achieved to facilitate S. maltophilia infection control at any level. In the near future, when novel Web-based platforms for rapid data processing and analysis will be available, whole genome sequencing technologies will likely become a highly powerful tool for outbreak investigations and surveillance studies in routine clinical practices. PMID:25592000

  20. Radrue method for reconstruction of external photon doses for Chernobyl liquidators in epidemiological studies.

    PubMed

    Kryuchkov, Victor; Chumak, Vadim; Maceika, Evaldas; Anspaugh, Lynn R; Cardis, Elisabeth; Bakhanova, Elena; Golovanov, Ivan; Drozdovitch, Vladimir; Luckyanov, Nickolas; Kesminiene, Ausrele; Voillequé, Paul; Bouville, André

    2009-10-01

    Between 1986 and 1990, several hundred thousand workers, called "liquidators" or "clean-up workers," took part in decontamination and recovery activities within the 30-km zone around the Chernobyl nuclear power plant in Ukraine, where a major accident occurred in April 1986. The Chernobyl liquidators were mainly exposed to external ionizing radiation levels that depended primarily on their work locations and the time after the accident when the work was performed. Because individual doses were often monitored inadequately or were not monitored at all for the majority of liquidators, a new method of photon (i.e., gamma and x rays) dose assessment, called "RADRUE" (Realistic Analytical Dose Reconstruction with Uncertainty Estimation), was developed to obtain unbiased and reasonably accurate estimates for use in three epidemiologic studies of hematological malignancies and thyroid cancer among liquidators. The RADRUE program implements a time-and-motion dose-reconstruction method that is flexible and conceptually easy to understand. It includes a large exposure rate database and interpolation and extrapolation techniques to calculate exposure rates at places where liquidators lived and worked within approximately 70 km of the destroyed reactor. The RADRUE technique relies on data collected from subjects' interviews conducted by trained interviewers, and on expert dosimetrists to interpret the information and provide supplementary information, when necessary, based upon their own Chernobyl experience. The RADRUE technique was used to estimate doses from external irradiation, as well as uncertainties, to the bone marrow for 929 subjects and to the thyroid gland for 530 subjects enrolled in epidemiologic studies. Individual bone marrow dose estimates were found to range from less than one muGy to 3,300 mGy, with an arithmetic mean of 71 mGy. Individual thyroid dose estimates were lower and ranged from 20 muGy to 507 mGy, with an arithmetic mean of 29 mGy. The

  1. RADRUE METHOD FOR RECONSTRUCTION OF EXTERNAL PHOTON DOSES TO CHERNOBYL LIQUIDATORS IN EPIDEMIOLOGICAL STUDIES

    PubMed Central

    Kryuchkov, Victor; Chumak, Vadim; Maceika, Evaldas; Anspaugh, Lynn R.; Cardis, Elisabeth; Bakhanova, Elena; Golovanov, Ivan; Drozdovitch, Vladimir; Luckyanov, Nickolas; Kesminiene, Ausrele; Voillequé, Paul; Bouville, André

    2010-01-01

    Between 1986 and 1990, several hundred thousand workers, called “liquidators” or “clean-up workers”, took part in decontamination and recovery activities within the 30-km zone around the Chernobyl nuclear power plant in Ukraine, where a major accident occurred in April 1986. The Chernobyl liquidators were mainly exposed to external ionizing radiation levels that depended primarily on their work locations and the time after the accident when the work was performed. Because individual doses were often monitored inadequately or were not monitored at all for the majority of liquidators, a new method of photon (i.e. gamma and x-rays) dose assessment, called “RADRUE” (Realistic Analytical Dose Reconstruction with Uncertainty Estimation) was developed to obtain unbiased and reasonably accurate estimates for use in three epidemiologic studies of hematological malignancies and thyroid cancer among liquidators. The RADRUE program implements a time-and-motion dose reconstruction method that is flexible and conceptually easy to understand. It includes a large exposure rate database and interpolation and extrapolation techniques to calculate exposure rates at places where liquidators lived and worked within ~70 km of the destroyed reactor. The RADRUE technique relies on data collected from subjects’ interviews conducted by trained interviewers, and on expert dosimetrists to interpret the information and provide supplementary information, when necessary, based upon their own Chernobyl experience. The RADRUE technique was used to estimate doses from external irradiation, as well as uncertainties, to the bone-marrow for 929 subjects and to the thyroid gland for 530 subjects enrolled in epidemiologic studies. Individual bone-marrow dose estimates were found to range from less than one μGy to 3,300 mGy, with an arithmetic mean of 71 mGy. Individual thyroid dose estimates were lower and ranged from 20 μGy to 507 mGy, with an arithmetic mean of 29 mGy. The

  2. [Occupational epidemiology].

    PubMed

    Ahrens, W; Behrens, T; Mester, B; Schmeisser, N

    2008-03-01

    The aim of occupational epidemiology is to describe workplace-related diseases and to identify their underlying causes. Its primary goal is to protect workers from hazardous effects of the working process by applying work-related primary and secondary prevention measures. To assess health risks different study designs and a wide array of complex study instruments and methods are frequently employed that cannot be replaced by toxicological investigations. This paper primarily addresses health risks by agent exposures. In this context a central task of occupational epidemiology is careful assessment of exposure. Different data sources, such as work site measurements, register data, archive material, experts' opinion, and the workers' personal estimates of exposure may be used during this process. In addition, biological markers can complement exposure assessment. Since thorough occupational epidemiologic studies allow assessment of disease risks under realistic exposure conditions, their results should be more frequently used to derive workplace-related threshold limit values. PMID:18311483

  3. Genetic diversity of Bacillus anthracis in Europe: genotyping methods in forensic and epidemiologic investigations.

    PubMed

    Derzelle, Sylviane; Thierry, Simon

    2013-09-01

    Bacillus anthracis, the etiological agent of anthrax, a zoonosis relatively common throughout the world, can be used as an agent of bioterrorism. In naturally occurring outbreaks and in criminal release of this pathogen, a fast and accurate diagnosis is crucial to an effective response. Microbiological forensics and epidemiologic investigations increasingly rely on molecular markers, such as polymorphisms in DNA sequence, to obtain reliable information regarding the identification or source of a suspicious strain. Over the past decade, significant research efforts have been undertaken to develop genotyping methods with increased power to differentiate B. anthracis strains. A growing number of DNA signatures have been identified and used to survey B. anthracis diversity in nature, leading to rapid advances in our understanding of the global population of this pathogen. This article provides an overview of the different phylogenetic subgroups distributed across the world, with a particular focus on Europe. Updated information on the anthrax situation in Europe is reported. A brief description of some of the work in progress in the work package 5.1 of the AniBioThreat project is also presented, including (1) the development of a robust typing tool based on a suspension array technology and multiplexed single nucleotide polymorphisms scoring and (2) the typing of a collection of DNA from European isolates exchanged between the partners of the project. The know-how acquired will contribute to improving the EU's ability to react rapidly when the identity and real origin of a strain need to be established. PMID:23971802

  4. Discriminatory Indices of Typing Methods for Epidemiologic Analysis of Contemporary Staphylococcus aureus Strains

    PubMed Central

    Rodriguez, Marcela; Hogan, Patrick G.; Satola, Sarah W.; Crispell, Emily; Wylie, Todd; Gao, Hongyu; Sodergren, Erica; Weinstock, George M.; Burnham, Carey-Ann D.; Fritz, Stephanie A.

    2015-01-01

    Abstract Historically, a number of typing methods have been evaluated for Staphylococcus aureus strain characterization. The emergence of contemporary strains of community-associated S. aureus, and the ensuing epidemic with a predominant strain type (USA300), necessitates re-evaluation of the discriminatory power of these typing methods for discerning molecular epidemiology and transmission dynamics, essential to investigations of hospital and community outbreaks. We compared the discriminatory index of 5 typing methods for contemporary S. aureus strain characterization. Children presenting to St. Louis Children's Hospital and community pediatric practices in St. Louis, Missouri (MO), with community-associated S. aureus infections were enrolled. Repetitive sequence-based PCR (repPCR), pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal protein A (spa), and staphylococcal cassette chromosome (SCC) mec typing were performed on 200 S. aureus isolates. The discriminatory index of each method was calculated using the standard formula for this metric, where a value of 1 is highly discriminatory and a value of 0 is not discriminatory. Overall, we identified 26 distinct strain types by repPCR, 17 strain types by PFGE, 30 strain types by MLST, 68 strain types by spa typing, and 5 strain types by SCCmec typing. RepPCR had the highest discriminatory index (D) of all methods (D = 0.88), followed by spa typing (D = 0.87), MLST (D = 0.84), PFGE (D = 0.76), and SCCmec typing (D = 0.60). The method with the highest D among MRSA isolates was repPCR (D = 0.64) followed by spa typing (D = 0.45) and MLST (D = 0.44). The method with the highest D among MSSA isolates was spa typing (D = 0.98), followed by MLST (D = 0.93), repPCR (D = 0.92), and PFGE (D = 0.89). Among isolates designated USA300 by PFGE, repPCR was most discriminatory, with 10 distinct strain types identified (D = 0.63). We

  5. Wastewater-Based Epidemiology of Stimulant Drugs: Functional Data Analysis Compared to Traditional Statistical Methods

    PubMed Central

    Salvatore, Stefania; Bramness, Jørgen Gustav; Reid, Malcolm J.; Thomas, Kevin Victor; Harman, Christopher; Røislien, Jo

    2015-01-01

    Background Wastewater-based epidemiology (WBE) is a new methodology for estimating the drug load in a population. Simple summary statistics and specification tests have typically been used to analyze WBE data, comparing differences between weekday and weekend loads. Such standard statistical methods may, however, overlook important nuanced information in the data. In this study, we apply functional data analysis (FDA) to WBE data and compare the results to those obtained from more traditional summary measures. Methods We analysed temporal WBE data from 42 European cities, using sewage samples collected daily for one week in March 2013. For each city, the main temporal features of two selected drugs were extracted using functional principal component (FPC) analysis, along with simpler measures such as the area under the curve (AUC). The individual cities’ scores on each of the temporal FPCs were then used as outcome variables in multiple linear regression analysis with various city and country characteristics as predictors. The results were compared to those of functional analysis of variance (FANOVA). Results The three first FPCs explained more than 99% of the temporal variation. The first component (FPC1) represented the level of the drug load, while the second and third temporal components represented the level and the timing of a weekend peak. AUC was highly correlated with FPC1, but other temporal characteristic were not captured by the simple summary measures. FANOVA was less flexible than the FPCA-based regression, and even showed concordance results. Geographical location was the main predictor for the general level of the drug load. Conclusion FDA of WBE data extracts more detailed information about drug load patterns during the week which are not identified by more traditional statistical methods. Results also suggest that regression based on FPC results is a valuable addition to FANOVA for estimating associations between temporal patterns and covariate

  6. Age-Based Methods to Explore Time-Related Variables in Occupational Epidemiology Studies

    SciTech Connect

    Janice P. Watkins, Edward L. Frome, Donna L. Cragle

    2005-08-31

    Although age is recognized as the strongest predictor of mortality in chronic disease epidemiology, a calendar-based approach is often employed when evaluating time-related variables. An age-based analysis file, created by determining the value of each time-dependent variable for each age that a cohort member is followed, provides a clear definition of age at exposure and allows development of diverse analytic models. To demonstrate methods, the relationship between cancer mortality and external radiation was analyzed with Poisson regression for 14,095 Oak Ridge National Laboratory workers. Based on previous analysis of this cohort, a model with ten-year lagged cumulative radiation doses partitioned by receipt before (dose-young) or after (dose-old) age 45 was examined. Dose-response estimates were similar to calendar-year-based results with elevated risk for dose-old, but not when film badge readings were weekly before 1957. Complementary results showed increasing risk with older hire ages and earlier birth cohorts, since workers hired after age 45 were born before 1915, and dose-young and dose-old were distributed differently by birth cohorts. Risks were generally higher for smokingrelated than non-smoking-related cancers. It was difficult to single out specific variables associated with elevated cancer mortality because of: (1) birth cohort differences in hire age and mortality experience completeness, and (2) time-period differences in working conditions, dose potential, and exposure assessment. This research demonstrated the utility and versatility of the age-based approach.

  7. Epidemiological causality.

    PubMed

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population. PMID:16898206

  8. Epidemiologic study of residential proximity to transmission lines and childhood cancer in California: description of design, epidemiologic methods and study population.

    PubMed

    Kheifets, Leeka; Crespi, Catherine M; Hooper, Chris; Oksuzyan, Sona; Cockburn, Myles; Ly, Thomas; Mezei, Gabor

    2015-01-01

    We conducted a large epidemiologic case-control study in California to examine the association between childhood cancer risk and distance from the home address at birth to the nearest high-voltage overhead transmission line as a replication of the study of Draper et al. in the United Kingdom. We present a detailed description of the study design, methods of case ascertainment, control selection, exposure assessment and data analysis plan. A total of 5788 childhood leukemia cases and 3308 childhood central nervous system cancer cases (included for comparison) and matched controls were available for analysis. Birth and diagnosis addresses of cases and birth addresses of controls were geocoded. Distance from the home to nearby overhead transmission lines was ascertained on the basis of the electric power companies' geographic information system (GIS) databases, additional Google Earth aerial evaluation and site visits to selected residences. We evaluated distances to power lines up to 2000 m and included consideration of lower voltages (60-69 kV). Distance measures based on GIS and Google Earth evaluation showed close agreement (Pearson correlation >0.99). Our three-tiered approach to exposure assessment allowed us to achieve high specificity, which is crucial for studies of rare diseases with low exposure prevalence. PMID:24045429

  9. Methicillin-resistant Staphylococcus aureus in Spain: molecular epidemiology and utility of different typing methods.

    PubMed

    Vindel, Ana; Cuevas, Oscar; Cercenado, Emilia; Marcos, Carmen; Bautista, Verónica; Castellares, Carol; Trincado, Pilar; Boquete, Teresa; Pérez-Vázquez, Maria; Marín, Mercedes; Bouza, Emilio

    2009-06-01

    In a point-prevalence study performed in 145 Spanish hospitals in 2006, we collected 463 isolates of Staphylococcus aureus in a single day. Of these, 135 (29.2%) were methicillin (meticillin)-resistant S. aureus (MRSA) isolates. Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE) after SmaI digestion, staphylococcal chromosomal cassette mec (SCCmec) typing, agr typing, spa typing with BURP (based-upon-repeat-pattern) analysis, and multilocus sequence typing (MLST). The 135 MRSA isolates showed resistance to ciprofloxacin (93.3%), tobramycin (72.6%), gentamicin (20.0%), erythromycin (66.7%), and clindamycin (39.3%). Among the isolates resistant to erythromycin, 27.4% showed the M phenotype. All of the isolates were susceptible to glycopeptides. Twelve resistance patterns were found, of which four accounted for 65% of the isolates. PFGE revealed 36 different patterns, with 13 major clones (including 2 predominant clones with various antibiotypes that accounted for 52.5% of the MRSA isolates) and 23 sporadic profiles. Two genotypes were observed for the first time in Spain. SCCmec type IV accounted for 6.7% of the isolates (70.1% were type IVa, 23.9% were type IVc, 0.9% were type IVd, and 5.1% were type IVh), and SCCmec type I and SCCmec type II accounted for 7.4% and 5.2% of the isolates, respectively. One isolate was nontypeable. Only one of the isolates produced the Panton-Valentine leukocidin. The isolates presented agr type 2 (82.2%), type 1 (14.8%), and type 3 (3.0%). spa typing revealed 32 different types, the predominant ones being t067 (48.9%) and t002 (14.8%), as well as clonal complex 067 (78%) by BURP analysis. The MRSA clone of sequence type 125 and SCCmec type IV was the most prevalent throughout Spain. In our experience, PFGE, spa typing, SCCmec typing, and MLST presented good correlations for the majority of the MRSA strains; we suggest the

  10. Evaluation of the Epidemiologic Utility of Secondary Typing Methods for Differentiation of Mycobacterium tuberculosis Isolates

    PubMed Central

    Kwara, Awewura; Schiro, Ronald; Cowan, Lauren S.; Hyslop, Newton E.; Wiser, Mark F.; Roahen Harrison, Stephanie; Kissinger, Patricia; Diem, Lois; Crawford, Jack T.

    2003-01-01

    Spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis (MIRU-VNTR) were evaluated for the ability to differentiate 64 Mycobacterium tuberculosis isolates from 10 IS6110-defined clusters. MIRU-VNTR performed slightly better than spoligotyping in reducing the number of clustered isolates and the sizes of the clusters. All epidemiologically related isolates remained clustered by MIRU-VNTR but not by spoligotyping. PMID:12791904

  11. Review of methods of dose estimation for epidemiological studies of the radiological impact of nevada test site and global fallout.

    PubMed

    Beck, Harold L; Anspaugh, Lynn R; Bouville, André; Simon, Steven L

    2006-07-01

    Methods to assess radiation doses from nuclear weapons test fallout have been used to estimate doses to populations and individuals in a number of studies. However, only a few epidemiology studies have relied on fallout dose estimates. Though the methods for assessing doses from local and regional compared to global fallout are similar, there are significant differences in predicted doses and contributing radionuclides depending on the source of the fallout, e.g. whether the nuclear debris originated in Nevada at the U.S. nuclear test site or whether it originated at other locations worldwide. The sparse historical measurement data available are generally sufficient to estimate external exposure doses reasonably well. However, reconstruction of doses to body organs from ingestion and inhalation of radionuclides is significantly more complex and is almost always more uncertain than are external dose estimates. Internal dose estimates are generally based on estimates of the ground deposition per unit area of specific radionuclides and subsequent transport of radionuclides through the food chain. A number of technical challenges to correctly modeling deposition of fallout under wet and dry atmospheric conditions still remain, particularly at close-in locations where sizes of deposited particles vary significantly over modest changes in distance. This paper summarizes the various methods of dose estimation from weapons test fallout and the most important dose assessment and epidemiology studies that have relied on those methods. PMID:16808609

  12. [The mode of infection of tuberculosis--analysis using molecular epidemiologic methods].

    PubMed

    Abe, C

    1995-11-01

    In the 1950's, evidence showed that INH-resistant Mycobacterium tuberculosis organisms were attenuated in both virulence and pathogenicity in animals, and it was postulated that these bacilli might also be attenuated in their virulence to humans. Subsequent studies, however, indicated that all INH-resistant strains should not be considered as being attenuated in their virulence to humans. The general conclusion was that patients excreting INH-resistant organisms are somewhat less infectious to their contacts than patients excreting INH-susceptible organisms. Insertion sequences are suitable tools for the diagnosis and epidemiology of tuberculosis because of the highly variable copy number and variability of insertion sites in the chromosome. This variability allows the subtyping of M. tuberculosis strains by restriction fragment length polymorphism (RFLP) analysis. Patients with the same RFLP pattern constitute an epidemiologically linked cluster. Clustering indicates recent infection and rapid progression to clinical illness. Nearly one thirds of new cases of tuberculosis in San Francisco are the result of recent infection. In Thailand, tuberculosis has now emerged as the most common opportunistic disease associated with HIV infection. Cluster analysis showed the risk of progression to active tuberculosis among individuals infected with HIV. Ther have been numerous outbreaks of multidrug-resistant tuberculosis in the United States. Most of such outbreaks have primarily involved persons infected with HIV, who are thought to have been exposed to the strains in medical or correctional facilities. PMID:8656589

  13. Foot-and-mouth disease in pigs: current epidemiological situation and control methods.

    PubMed

    León, Emilio A

    2012-03-01

    Foot-and-mouth disease (FMD) is the paradigm of a transboundary animal disease. Beyond any doubt, it is the most serious challenge for livestock's health. Official Veterinary Services from free countries invest considerable amount of money to prevent its introduction, whereas those from endemic countries invest most of their resources in the control of the disease. A very important volume of scientific production is developed every year in different aspects of FMD, and for that reason, the current knowledge makes the diagnosis of the disease easier to a great extent. However, FMD is still endemic in about two-thirds of the countries, and periodically re-emergent in several countries. This paper is a review of recent publications, focusing mainly on control measures and current world epidemiological situation, emphasizing primarily pigs. PMID:22225815

  14. Measuring socio-economic position for epidemiological studies in low- and middle-income countries: a methods of measurement in epidemiology paper

    PubMed Central

    Howe, Laura D; Galobardes, Bruna; Matijasevich, Alicia; Gordon, David; Johnston, Deborah; Onwujekwe, Obinna; Patel, Rita; Webb, Elizabeth A; Lawlor, Debbie A; Hargreaves, James R

    2012-01-01

    Much has been written about the measurement of socio-economic position (SEP) in high-income countries (HIC). Less has been written for an epidemiology, health systems and public health audience about the measurement of SEP in low- and middle-income countries (LMIC). The social stratification processes in many LMIC—and therefore the appropriate measurement tools—differ considerably from those in HIC. Many measures of SEP have been utilized in epidemiological studies; the aspects of SEP captured by these measures and the pathways through which they may affect health are likely to be slightly different but overlapping. No single measure of SEP will be ideal for all studies and contexts; the strengths and limitations of a given indicator are likely to vary according to the specific research question. Understanding the general properties of different indicators, however, is essential for all those involved in the design or interpretation of epidemiological studies. In this article, we describe the measures of SEP used in LMIC. We concentrate on measures of individual or household-level SEP rather than area-based or ecological measures such as gross domestic product. We describe each indicator in terms of its theoretical basis, interpretation, measurement, strengths and limitations. We also provide brief comparisons between LMIC and HIC for each measure. PMID:22438428

  15. Epidemiologic Methods Lessons Learned from Environmental Public Health Disasters: Chernobyl, the World Trade Center, Bhopal, and Graniteville, South Carolina

    PubMed Central

    Svendsen, Erik R.; Runkle, Jennifer R.; Dhara, Venkata Ramana; Lin, Shao; Naboka, Marina; Mousseau, Timothy A.; Bennett, Charles

    2012-01-01

    Background: Environmental public health disasters involving hazardous contaminants may have devastating effects. While much is known about their immediate devastation, far less is known about long-term impacts of these disasters. Extensive latent and chronic long-term public health effects may occur. Careful evaluation of contaminant exposures and long-term health outcomes within the constraints imposed by limited financial resources is essential. Methods: Here, we review epidemiologic methods lessons learned from conducting long-term evaluations of four environmental public health disasters involving hazardous contaminants at Chernobyl, the World Trade Center, Bhopal, and Graniteville (South Carolina, USA). Findings: We found several lessons learned which have direct implications for the on-going disaster recovery work following the Fukushima radiation disaster or for future disasters. Interpretation: These lessons should prove useful in understanding and mitigating latent health effects that may result from the nuclear reactor accident in Japan or future environmental public health disasters. PMID:23066404

  16. Measuring sun exposure in epidemiological studies: Matching the method to the research question.

    PubMed

    King, Laura; Xiang, Fan; Swaminathan, Ashwin; Lucas, Robyn M

    2015-12-01

    Sun exposure has risks and benefits for health. Testing these associations requires tools for measuring sun exposure that are feasible and relevant to the time-course of the health outcome. Recent sun exposure, e.g. the last week, is best captured by dosimeters and sun diaries. These can also be used for medium-term sun exposure e.g. over several weeks, but incur a high participant burden. Self-reported data on "typical time outdoors" for working and non-working days, is less detailed and not influenced by day-to-day variation. Over a longer period, e.g. the lifetime, or for particular life stages, proxies of sun exposure, such as latitude of residence or ambient ultraviolet (UV) radiation levels (from satellites or ground-level monitoring) can be used, with additional detail provided by lifetime sun exposure calendars that include locations of residence, usual time outdoors, and detail of sunburn episodes. Objective measures of lifetime sun exposure include microtopography of sun-exposed skin (e.g. using silicone casts) or conjunctival UV autofluorescence. Potential modifiers of the association between sun exposure and the health outcome, such as clothing coverage and skin colour, may also need to be measured. We provide a systematic approach to selecting sun exposure measures for use in epidemiological health research. PMID:26555640

  17. Realist explanatory theory building method for social epidemiology: a protocol for a mixed method multilevel study of neighbourhood context and postnatal depression.

    PubMed

    Eastwood, John G; Jalaludin, Bin B; Kemp, Lynn A

    2014-01-01

    A recent criticism of social epidemiological studies, and multi-level studies in particular has been a paucity of theory. We will present here the protocol for a study that aims to build a theory of the social epidemiology of maternal depression. We use a critical realist approach which is trans-disciplinary, encompassing both quantitative and qualitative traditions, and that assumes both ontological and hierarchical stratification of reality. We describe a critical realist Explanatory Theory Building Method comprising of an: 1) emergent phase, 2) construction phase, and 3) confirmatory phase. A concurrent triangulated mixed method multilevel cross-sectional study design is described. The Emergent Phase uses: interviews, focus groups, exploratory data analysis, exploratory factor analysis, regression, and multilevel Bayesian spatial data analysis to detect and describe phenomena. Abductive and retroductive reasoning will be applied to: categorical principal component analysis, exploratory factor analysis, regression, coding of concepts and categories, constant comparative analysis, drawing of conceptual networks, and situational analysis to generate theoretical concepts. The Theory Construction Phase will include: 1) defining stratified levels; 2) analytic resolution; 3) abductive reasoning; 4) comparative analysis (triangulation); 5) retroduction; 6) postulate and proposition development; 7) comparison and assessment of theories; and 8) conceptual frameworks and model development. The strength of the critical realist methodology described is the extent to which this paradigm is able to support the epistemological, ontological, axiological, methodological and rhetorical positions of both quantitative and qualitative research in the field of social epidemiology. The extensive multilevel Bayesian studies, intensive qualitative studies, latent variable theory, abductive triangulation, and Inference to Best Explanation provide a strong foundation for Theory

  18. Review and International Recommendation of Methods for Typing Neisseria gonorrhoeae Isolates and Their Implications for Improved Knowledge of Gonococcal Epidemiology, Treatment, and Biology

    PubMed Central

    Unemo, Magnus; Dillon, Jo-Anne R.

    2011-01-01

    Summary: Gonorrhea, which may become untreatable due to multiple resistance to available antibiotics, remains a public health problem worldwide. Precise methods for typing Neisseria gonorrhoeae, together with epidemiological information, are crucial for an enhanced understanding regarding issues involving epidemiology, test of cure and contact tracing, identifying core groups and risk behaviors, and recommending effective antimicrobial treatment, control, and preventive measures. This review evaluates methods for typing N. gonorrhoeae isolates and recommends various methods for different situations. Phenotypic typing methods, as well as some now-outdated DNA-based methods, have limited usefulness in differentiating between strains of N. gonorrhoeae. Genotypic methods based on DNA sequencing are preferred, and the selection of the appropriate genotypic method should be guided by its performance characteristics and whether short-term epidemiology (microepidemiology) or long-term and/or global epidemiology (macroepidemiology) matters are being investigated. Currently, for microepidemiological questions, the best methods for fast, objective, portable, highly discriminatory, reproducible, typeable, and high-throughput characterization are N. gonorrhoeae multiantigen sequence typing (NG-MAST) or full- or extended-length porB gene sequencing. However, pulsed-field gel electrophoresis (PFGE) and Opa typing can be valuable in specific situations, i.e., extreme microepidemiology, despite their limitations. For macroepidemiological studies and phylogenetic studies, DNA sequencing of chromosomal housekeeping genes, such as multilocus sequence typing (MLST), provides a more nuanced understanding. PMID:21734242

  19. The causal pie model: an epidemiological method applied to evolutionary biology and ecology.

    PubMed

    Wensink, Maarten; Westendorp, Rudi G J; Baudisch, Annette

    2014-05-01

    A general concept for thinking about causality facilitates swift comprehension of results, and the vocabulary that belongs to the concept is instrumental in cross-disciplinary communication. The causal pie model has fulfilled this role in epidemiology and could be of similar value in evolutionary biology and ecology. In the causal pie model, outcomes result from sufficient causes. Each sufficient cause is made up of a "causal pie" of "component causes". Several different causal pies may exist for the same outcome. If and only if all component causes of a sufficient cause are present, that is, a causal pie is complete, does the outcome occur. The effect of a component cause hence depends on the presence of the other component causes that constitute some causal pie. Because all component causes are equally and fully causative for the outcome, the sum of causes for some outcome exceeds 100%. The causal pie model provides a way of thinking that maps into a number of recurrent themes in evolutionary biology and ecology: It charts when component causes have an effect and are subject to natural selection, and how component causes affect selection on other component causes; which partitions of outcomes with respect to causes are feasible and useful; and how to view the composition of a(n apparently homogeneous) population. The diversity of specific results that is directly understood from the causal pie model is a test for both the validity and the applicability of the model. The causal pie model provides a common language in which results across disciplines can be communicated and serves as a template along which future causal analyses can be made. PMID:24963386

  20. Global Dissemination of Carbapenemase-Producing Klebsiella pneumoniae: Epidemiology, Genetic Context, Treatment Options, and Detection Methods

    PubMed Central

    Lee, Chang-Ro; Lee, Jung Hun; Park, Kwang Seung; Kim, Young Bae; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    The emergence of carbapenem-resistant Gram-negative pathogens poses a serious threat to public health worldwide. In particular, the increasing prevalence of carbapenem-resistant Klebsiella pneumoniae is a major source of concern. K. pneumoniae carbapenemases (KPCs) and carbapenemases of the oxacillinase-48 (OXA-48) type have been reported worldwide. New Delhi metallo-β-lactamase (NDM) carbapenemases were originally identified in Sweden in 2008 and have spread worldwide rapidly. In this review, we summarize the epidemiology of K. pneumoniae producing three carbapenemases (KPCs, NDMs, and OXA-48-like). Although the prevalence of each resistant strain varies geographically, K. pneumoniae producing KPCs, NDMs, and OXA-48-like carbapenemases have become rapidly disseminated. In addition, we used recently published molecular and genetic studies to analyze the mechanisms by which these three carbapenemases, and major K. pneumoniae clones, such as ST258 and ST11, have become globally prevalent. Because carbapenemase-producing K. pneumoniae are often resistant to most β-lactam antibiotics and many other non-β-lactam molecules, the therapeutic options available to treat infection with these strains are limited to colistin, polymyxin B, fosfomycin, tigecycline, and selected aminoglycosides. Although, combination therapy has been recommended for the treatment of severe carbapenemase-producing K. pneumoniae infections, the clinical evidence for this strategy is currently limited, and more accurate randomized controlled trials will be required to establish the most effective treatment regimen. Moreover, because rapid and accurate identification of the carbapenemase type found in K. pneumoniae may be difficult to achieve through phenotypic antibiotic susceptibility tests, novel molecular detection techniques are currently being developed. PMID:27379038

  1. Global Dissemination of Carbapenemase-Producing Klebsiella pneumoniae: Epidemiology, Genetic Context, Treatment Options, and Detection Methods.

    PubMed

    Lee, Chang-Ro; Lee, Jung Hun; Park, Kwang Seung; Kim, Young Bae; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    The emergence of carbapenem-resistant Gram-negative pathogens poses a serious threat to public health worldwide. In particular, the increasing prevalence of carbapenem-resistant Klebsiella pneumoniae is a major source of concern. K. pneumoniae carbapenemases (KPCs) and carbapenemases of the oxacillinase-48 (OXA-48) type have been reported worldwide. New Delhi metallo-β-lactamase (NDM) carbapenemases were originally identified in Sweden in 2008 and have spread worldwide rapidly. In this review, we summarize the epidemiology of K. pneumoniae producing three carbapenemases (KPCs, NDMs, and OXA-48-like). Although the prevalence of each resistant strain varies geographically, K. pneumoniae producing KPCs, NDMs, and OXA-48-like carbapenemases have become rapidly disseminated. In addition, we used recently published molecular and genetic studies to analyze the mechanisms by which these three carbapenemases, and major K. pneumoniae clones, such as ST258 and ST11, have become globally prevalent. Because carbapenemase-producing K. pneumoniae are often resistant to most β-lactam antibiotics and many other non-β-lactam molecules, the therapeutic options available to treat infection with these strains are limited to colistin, polymyxin B, fosfomycin, tigecycline, and selected aminoglycosides. Although, combination therapy has been recommended for the treatment of severe carbapenemase-producing K. pneumoniae infections, the clinical evidence for this strategy is currently limited, and more accurate randomized controlled trials will be required to establish the most effective treatment regimen. Moreover, because rapid and accurate identification of the carbapenemase type found in K. pneumoniae may be difficult to achieve through phenotypic antibiotic susceptibility tests, novel molecular detection techniques are currently being developed. PMID:27379038

  2. Sequence Analysis of lip R: A Good Method for Molecular Epidemiology of Clinical Isolates of Mycobacterium tuberculosis.

    PubMed

    Saedi, Samaneh; Youssefi, Masoud; Safdari, Hadi; Soleimanpour, Saman; Marouzi, Parviz; Ghazvini, Kiarash

    2015-10-01

    Advances in DNA sequencing have greatly enhanced the molecular epidemiology studies. In order to assess evolutionary and phylogenetic relation of Mycobacterium tuberculosis isolates several gene targets were evaluated. In this study, appropriate fragments of 5 highly variable genes (rpsL, mprA, lipR, katG, and fgd1 genes) were sequenced. The sequence data were analyzed with neighbor-joining method using mega and Geneious software. The phylogenetic trees analyzes revealed that the discriminatory power of lipR is much stronger than that observed in the other genes. lipR could distinguish between more clinical isolates. Therefore, lipR is a promising target for sequence analyzes of M. tuberculosis. PMID:26063445

  3. Fast and simple epidemiological typing of Pseudomonas aeruginosa using the double-locus sequence typing (DLST) method.

    PubMed

    Basset, P; Blanc, D S

    2014-06-01

    Although the molecular typing of Pseudomonas aeruginosa is important to understand the local epidemiology of this opportunistic pathogen, it remains challenging. Our aim was to develop a simple typing method based on the sequencing of two highly variable loci. Single-strand sequencing of three highly variable loci (ms172, ms217, and oprD) was performed on a collection of 282 isolates recovered between 1994 and 2007 (from patients and the environment). As expected, the resolution of each locus alone [number of types (NT) = 35-64; index of discrimination (ID) = 0.816-0.964] was lower than the combination of two loci (NT = 78-97; ID = 0.966-0.971). As each pairwise combination of loci gave similar results, we selected the most robust combination with ms172 [reverse; R] and ms217 [R] to constitute the double-locus sequence typing (DLST) scheme for P. aeruginosa. This combination gave: (i) a complete genotype for 276/282 isolates (typability of 98%), (ii) 86 different types, and (iii) an ID of 0.968. Analysis of multiple isolates from the same patients or taps showed that DLST genotypes are generally stable over a period of several months. The high typability, discriminatory power, and ease of use of the proposed DLST scheme makes it a method of choice for local epidemiological analyses of P. aeruginosa. Moreover, the possibility to give unambiguous definition of types allowed to develop an Internet database ( http://www.dlst.org ) accessible by all. PMID:24326699

  4. Epidemiology of Toxoplasmosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection with Toxoplasma gondii is highly prevalent throughout the world. This chapter discusses modes of transmission, the epidemiology of T. gondii infection worldwide and in Brazil, and methods of prevention and control....

  5. MEASUREMENT ERROR ESTIMATION AND CORRECTION METHODS TO MINIMIZE EXPOSURE MISCLASSIFICATION IN EPIDEMIOLOGICAL STUDIES: PROJECT SUMMARY

    EPA Science Inventory

    This project summary highlights recent findings from research undertaken to develop improved methods to assess potential human health risks related to drinking water disinfection byproduct (DBP) exposures.

  6. [Epidemiology and heterogeny].

    PubMed

    Breilh, J; Granda, E

    1989-01-01

    The innovation of epidemiology plays a crucial role in the development of the health sciences. The authors emphasize the importance of epistemological analysis related to scientific and technical production. They focus on the theoretical and methodological contributions of the principal Latin American groups in the field of epidemiology, stating their main accomplishments, issues and potentials. When reviewing those conceptual and practical innovations, the authors analyse the effects of broader historical conditions on scientific work. To them, Latin American contemporary innovative epidemiological research and production have developed clearly differentiated principles, methods and technical projections which have led to a movement of critical or 'social' epidemiology. The functionalist approach of conventional epidemiology, characterized by an empiricist viewpoint, is being overcome by a more rigorous and analytical approach. This new epidemiological approach, in which the authors as members of CEAS (Health Research and Advisory Center) are working, has selectively incorporated some of the technical instruments of conventional epidemiology, subordinating them to a different theoretical and logical paradigm. The new framework of this group explains the need to consider the people's objective situation and necessities, when constructing scientific interpretations and planning technical action. In order to accomplish this goal, epidemiological reasoning has to reflect the unity of external epidemiological facts and associations, the so-called phenomenological aspect of health, with the underlying determinants and conditioning processes or internal relations, which are the essence of the health-disease production and distribution process. Epidemiological analysis is considered not only as a problem of empirical observation but as a process of theoretical construction, in which there is a dynamic fusion of deductive and inductive reasoning.(ABSTRACT TRUNCATED AT 250

  7. Review of pathogenesis and diagnostic methods of immediate relevance for epidemiology and control of Salmonella Dublin in cattle.

    PubMed

    Nielsen, Liza Rosenbaum

    2013-02-22

    Salmonella enterica subsp. enterica serovar Dublin (S. Dublin) receives increasing attention in cattle production. It is host-adapted to cattle, and leads to unacceptable levels of morbidity, mortality and production losses in both newly and persistently infected herds. Cattle health promoting institutions in several countries are currently constructing active surveillance programmes or voluntary certification programmes, and encourage control and eradication of S. Dublin infected cattle herds. There is a need to understand the underlying pathogenesis of the infection at both animal and herd level to design successful programmes. Furthermore, knowledge about and access to diagnostic tests for use in practice including information about test accuracy and interpretation of available diagnostic test methods are requested. The aim is to synthesise the abundant literature on elements of pathogenesis and diagnosis of immediate relevance for epidemiology and control of S. Dublin at animal and herd level. Relatively few in vivo studies on S. Dublin pathogenesis in cattle included more than a few animals and often showed varying result. It makes it difficult to draw conclusions about mechanisms that affect dissemination in cattle and that might be targets for control methods directed towards improving resistance against the bacteria, e.g. new vaccines. It is recommended to perform larger studies to elucidate dose-response relationships and age- and genetic effects of immunity. Furthermore, it is recommended to attempt to develop faster and more sensitive methods for detection of S. Dublin for diagnosis of infectious animals. PMID:22925272

  8. INFLUENCE OF EXPOSURE ASSESSMENT METHOD IN AN EPIDEMIOLOGIC STUDY OF TRIHALOMETHANE EXPOSURE AND SPONTANEOUS ABORTION

    EPA Science Inventory

    Trihalomethanes are common contaminants of chlorinated drinking water. Studies of their health effects have been hampered by exposure misclassification, due in part to limitations inherent in using utility sampling records. We used two exposure assessment methods, one based on ut...

  9. A data-driven epidemiological prediction method for dengue outbreaks using local and remote sensing data

    PubMed Central

    2012-01-01

    Background Dengue is the most common arboviral disease of humans, with more than one third of the world’s population at risk. Accurate prediction of dengue outbreaks may lead to public health interventions that mitigate the effect of the disease. Predicting infectious disease outbreaks is a challenging task; truly predictive methods are still in their infancy. Methods We describe a novel prediction method utilizing Fuzzy Association Rule Mining to extract relationships between clinical, meteorological, climatic, and socio-political data from Peru. These relationships are in the form of rules. The best set of rules is automatically chosen and forms a classifier. That classifier is then used to predict future dengue incidence as either HIGH (outbreak) or LOW (no outbreak), where these values are defined as being above and below the mean previous dengue incidence plus two standard deviations, respectively. Results Our automated method built three different fuzzy association rule models. Using the first two weekly models, we predicted dengue incidence three and four weeks in advance, respectively. The third prediction encompassed a four-week period, specifically four to seven weeks from time of prediction. Using previously unused test data for the period 4–7 weeks from time of prediction yielded a positive predictive value of 0.686, a negative predictive value of 0.976, a sensitivity of 0.615, and a specificity of 0.982. Conclusions We have developed a novel approach for dengue outbreak prediction. The method is general, could be extended for use in any geographical region, and has the potential to be extended to other environmentally influenced infections. The variables used in our method are widely available for most, if not all countries, enhancing the generalizability of our method. PMID:23126401

  10. Investigation of major cattle production constraints in Kembata Tambaro zone of Southern Ethiopia using participatory epidemiology methods.

    PubMed

    Ayele, Birhanu; Tigre, Worku; Deresa, Benti

    2016-01-01

    Ethiopia has enormous livestock resources from which rural households derive their livelihoods. A cross-sectional study based on participatory appraisal methods was conducted in Kembata Tambaro zone to assess major constraints to livestock production and major diseases of cattle and their treatment options. Four districts were selected purposively for this study, and 18 peasant associations were randomly sampled from the selected districts. Focus group discussion, semistructured interviews, simple ranking and scoring, proportional piling, pairwise ranking, and matrix scoring were the participatory epidemiological tools used in the study. Feed and free grazing land shortages and diseases were found to be the major constraints to cattle production in the area. Mastitis was ranked as the most serious disease of cattle. Modern veterinary treatments are used alongside traditional herbal remedies. Matrix scoring showed strong agreement between focus groups in identifying the major diseases using their indicators (clinical signs). Hence, it was concluded that indigenous knowledge complemented with participatory methods and approaches allow community and field researchers to jointly study specific livestock problems and help identify appropriate solutions. PMID:26477032

  11. Novel Microbiological and Spatial Statistical Methods to Improve Strength of Epidemiological Evidence in a Community-Wide Waterborne Outbreak

    PubMed Central

    Jalava, Katri; Rintala, Hanna; Ollgren, Jukka; Maunula, Leena; Gomez-Alvarez, Vicente; Revez, Joana; Palander, Marja; Antikainen, Jenni; Kauppinen, Ari; Räsänen, Pia; Siponen, Sallamaari; Nyholm, Outi; Kyyhkynen, Aino; Hakkarainen, Sirpa; Merentie, Juhani; Pärnänen, Martti; Loginov, Raisa; Ryu, Hodon; Kuusi, Markku; Siitonen, Anja; Miettinen, Ilkka; Santo Domingo, Jorge W.; Hänninen, Marja-Liisa; Pitkänen, Tarja

    2014-01-01

    Failures in the drinking water distribution system cause gastrointestinal outbreaks with multiple pathogens. A water distribution pipe breakage caused a community-wide waterborne outbreak in Vuorela, Finland, July 2012. We investigated this outbreak with advanced epidemiological and microbiological methods. A total of 473/2931 inhabitants (16%) responded to a web-based questionnaire. Water and patient samples were subjected to analysis of multiple microbial targets, molecular typing and microbial community analysis. Spatial analysis on the water distribution network was done and we applied a spatial logistic regression model. The course of the illness was mild. Drinking untreated tap water from the defined outbreak area was significantly associated with illness (RR 5.6, 95% CI 1.9–16.4) increasing in a dose response manner. The closer a person lived to the water distribution breakage point, the higher the risk of becoming ill. Sapovirus, enterovirus, single Campylobacter jejuni and EHEC O157:H7 findings as well as virulence genes for EPEC, EAEC and EHEC pathogroups were detected by molecular or culture methods from the faecal samples of the patients. EPEC, EAEC and EHEC virulence genes and faecal indicator bacteria were also detected in water samples. Microbial community sequencing of contaminated tap water revealed abundance of Arcobacter species. The polyphasic approach improved the understanding of the source of the infections, and aided to define the extent and magnitude of this outbreak. PMID:25147923

  12. Statistical methods in epidemiology: Karl Pearson, Ronald Ross, Major Greenwood and Austin Bradford Hill, 1900-1945.

    PubMed

    Hardy, Anne; Magnello, M Eileen

    2002-01-01

    The tradition of epidemiological study through observation and the use of vital statistics dates back to the 18th century in Britain. At the close of the 19th century, however, a new and more sophisticated statistical approach emerged, from a base in the discipline of mathematics, which was eventually to transform the practice of epidemiology. This paper traces the evolution of that new analytical approach within English epidemiology through the work of four key contributors to its inception and establishment within the wider discipline. PMID:12134737

  13. Method to Select Metropolitan Areas of Epidemiologic Interest for Enhanced Air Quality Monitoring

    EPA Science Inventory

    The U.S. Environmental Protection Agency’s current Speciation Trends Network (STN) covers most major U.S. metropolitan areas and a wide range of particulate matter (PM) constituents and gaseous co-pollutants. However, using filter-based methods, most PM constituents are measured ...

  14. A survival tree method for the analysis of discrete event times in clinical and epidemiological studies.

    PubMed

    Schmid, Matthias; Küchenhoff, Helmut; Hoerauf, Achim; Tutz, Gerhard

    2016-02-28

    Survival trees are a popular alternative to parametric survival modeling when there are interactions between the predictor variables or when the aim is to stratify patients into prognostic subgroups. A limitation of classical survival tree methodology is that most algorithms for tree construction are designed for continuous outcome variables. Hence, classical methods might not be appropriate if failure time data are measured on a discrete time scale (as is often the case in longitudinal studies where data are collected, e.g., quarterly or yearly). To address this issue, we develop a method for discrete survival tree construction. The proposed technique is based on the result that the likelihood of a discrete survival model is equivalent to the likelihood of a regression model for binary outcome data. Hence, we modify tree construction methods for binary outcomes such that they result in optimized partitions for the estimation of discrete hazard functions. By applying the proposed method to data from a randomized trial in patients with filarial lymphedema, we demonstrate how discrete survival trees can be used to identify clinically relevant patient groups with similar survival behavior. PMID:26358826

  15. Epidemiology: Then and Now.

    PubMed

    Kuller, Lewis H

    2016-03-01

    Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies. PMID:26493266

  16. Genetic epidemiology of bilateral breast cancer: a linkage analysis using the affected-pedigree-member method.

    PubMed

    Haile, R W; Goldstein, A M; Weeks, D E; Sparkes, R S; Paganini-Hill, A

    1990-01-01

    We used the affected-pedigree-member (APM) method to conduct linkage analyses on 19 pedigrees in which the probands had premenopausal bilateral breast cancer. This method analyzes all affected pairs of relatives, as opposed to siblings only, and incorporates into the analyses information on the frequency of marker alleles. Fourteen codominant marker systems were evaluated in two separate analyses. In the first, only premenopausal cases of breast cancer were coded as affected because we assumed that postmenopausal cases were due to a different etiology. In the second analysis, all cases of breast cancer were coded as affected, irrespective of menopausal status. In the premenopausal-cases-only analysis, we observed evidence suggestive of nonindependent segregation for C3 and ESD. In the all-cases analysis, we observed much weaker evidence for C3 and ESD and noted a suggestion of nonindependent segregation for AMY2 and PGM1. PMID:2328913

  17. Evidence-based planning and costing palliative care services for children: novel multi-method epidemiological and economic exemplar

    PubMed Central

    2013-01-01

    Background Children’s palliative care is a relatively new clinical specialty. Its nature is multi-dimensional and its delivery necessarily multi-professional. Numerous diverse public and not-for-profit organisations typically provide services and support. Because services are not centrally coordinated, they are provided in a manner that is inconsistent and incoherent. Since the first children’s hospice opened in 1982, the epidemiology of life-limiting conditions has changed with more children living longer, and many requiring transfer to adult services. Very little is known about the number of children living within any given geographical locality, costs of care, or experiences of children with ongoing palliative care needs and their families. We integrated evidence, and undertook and used novel methodological epidemiological work to develop the first evidence-based and costed commissioning exemplar. Methods Multi-method epidemiological and economic exemplar from a health and not-for-profit organisation perspective, to estimate numbers of children under 19 years with life-limiting conditions, cost current services, determine child/parent care preferences, and cost choice of end-of-life care at home. Results The exemplar locality (North Wales) had important gaps in service provision and the clinical network. The estimated annual total cost of current children’s palliative care was about £5.5 million; average annual care cost per child was £22,771 using 2007 prevalence estimates and £2,437- £11,045 using new 2012/13 population-based prevalence estimates. Using population-based prevalence, we estimate 2271 children with a life-limiting condition in the general exemplar population and around 501 children per year with ongoing palliative care needs in contact with hospital services. Around 24 children with a wide range of life-limiting conditions require end-of-life care per year. Choice of end-of-life care at home was requested, which is not currently

  18. Epidemiology of Candida infection. II. Application of biochemical methods for typing of Candida albicans strains.

    PubMed

    Budak, A

    1990-01-01

    Biochemical profiles of 350 C. albicans isolates from five towns in Poland and from Freiburg in Germany were determined on the basis of nine biochemical tests of Odds and Abbott method. API 20 C AUX system and additionally a resistogram. The analysis of the strains according to Odds' and Abbotts's system showed that investigated strains can be typed into 9 profile codes of common biochemical patterns. There were some differences among the profiles according to their geographical origin and anatomical sources of the isolation. On the basis of the ability C. albicans strains to assimilate of carbon sources, 350 isolates were categorised into 13 separate auxotrophic profiles with the major one: 2,576,174 accounting for 81% of the total. The majority of the investigated isolates were susceptible to antifungal agents (83%). A disproportionate distribution of auxotrophic profiles limited the use of resistogram method and API 20 C AUX as systems for typing C. albicans strains. On the other hand, the method of Odds and Abbott provides valuable criteria for typing of C. albicans. PMID:2130802

  19. A graph-theory method for pattern identification in geographical epidemiology – a preliminary application to deprivation and mortality

    PubMed Central

    Maheswaran, Ravi; Craigs, Cheryl; Read, Simon; Bath, Peter A; Willett, Peter

    2009-01-01

    Background Graph theoretical methods are extensively used in the field of computational chemistry to search datasets of compounds to see if they contain particular molecular sub-structures or patterns. We describe a preliminary application of a graph theoretical method, developed in computational chemistry, to geographical epidemiology in relation to testing a prior hypothesis. We tested the methodology on the hypothesis that if a socioeconomically deprived neighbourhood is situated in a wider deprived area, then that neighbourhood would experience greater adverse effects on mortality compared with a similarly deprived neighbourhood which is situated in a wider area with generally less deprivation. Methods We used the Trent Region Health Authority area for this study, which contained 10,665 census enumeration districts (CED). Graphs are mathematical representations of objects and their relationships and within the context of this study, nodes represented CEDs and edges were determined by whether or not CEDs were neighbours (shared a common boundary). The overall area in this study was represented by one large graph comprising all CEDs in the region, along with their adjacency information. We used mortality data from 1988–1998, CED level population estimates and the Townsend Material Deprivation Index as an indicator of neighbourhood level deprivation. We defined deprived CEDs as those in the top 20% most deprived in the Region. We then set out to classify these deprived CEDs into seven groups defined by increasing deprivation levels in the neighbouring CEDs. 506 (24.2%) of the deprived CEDs had five adjacent CEDs and we limited pattern development and searching to these CEDs. We developed seven query patterns and used the RASCAL (Rapid Similarity Calculator) program to carry out the search for each of the query patterns. This program used a maximum common subgraph isomorphism method which was modified to handle geographical data. Results Of the 506 deprived CEDs

  20. Prevalence and epidemiologic characteristics of FASD from various research methods with an emphasis on recent in-school studies.

    PubMed

    May, Philip A; Gossage, J Phillip; Kalberg, Wendy O; Robinson, Luther K; Buckley, David; Manning, Melanie; Hoyme, H Eugene

    2009-01-01

    Researching the epidemiology and estimating the prevalence of fetal alcohol syndrome (FAS) and other fetal alcohol spectrum disorders (FASD) for mainstream populations anywhere in the world has presented a challenge to researchers. Three major approaches have been used in the past: surveillance and record review systems, clinic-based studies, and active case ascertainment methods. The literature on each of these methods is reviewed citing the strengths, weaknesses, prevalence results, and other practical considerations for each method. Previous conclusions about the prevalence of FAS and total FASD in the United States (US) population are summarized. Active approaches which provide clinical outreach, recruitment, and diagnostic services in specific populations have been demonstrated to produce the highest prevalence estimates. We then describe and review studies utilizing in-school screening and diagnosis, a special type of active case ascertainment. Selected results from a number of in-school studies in South Africa, Italy, and the US are highlighted. The particular focus of the review is on the nature of the data produced from in-school methods and the specific prevalence rates of FAS and total FASD which have emanated from them. We conclude that FAS and other FASD are more prevalent in school populations, and therefore the general population, than previously estimated. We believe that the prevalence of FAS in typical, mixed-racial, and mixed-socioeconomic populations of the US is at least 2 to 7 per 1,000. Regarding all levels of FASD, we estimate that the current prevalence of FASD in populations of younger school children may be as high as 2-5% in the US and some Western European countries. PMID:19731384

  1. [Opportunity and challenge on molecular epidemiology].

    PubMed

    Duan, G C; Chen, S Y

    2016-08-10

    Molecular epidemiology, a branch of epidemiology, combines the theories and methods, both in epidemiology and molecular biology. Molecular epidemiology mainly focuses on biological markers, describing the distribution, occurrence, development and prognosis of diseases at the molecular level. The completion of Human Genome Project and rapid development of Precision Medicine and Big Data not only offer the new development opportunities but also bring about a higher demand and new challenge for molecular epidemiology. PMID:27539332

  2. Epidemiology and changed surgical treatment methods for fractures of the distal radius

    PubMed Central

    2013-01-01

    Background and purpose The incidence of fractures of the distal radius may have changed over the last decade, and operative treatment has been commoner during that time. We investigated the incidence of fractures of the distal radius and changing trends in surgical treatment during the period 2004–2010. Patients and methods Registry data on 42,583 patients with a fracture of the distal radius from 2004 to 2010 were evaluated regarding diagnosis, age, sex, and surgical treatment. Results The crude incidence rate was 31 per 104 person-years with a bimodal distribution. After the age of 45 years, the incidence rate in women increased rapidly and leveled off first at a very high age. The incidence rate in postmenopausal women was lower than previously reported. In men, the incidence was low and it increased slowly until the age of 80 years, when it amounted to 31 per 104 person-years. The number of surgical procedures increased by more than 40% despite the fact that there was reduced incidence during the study period. In patients ≥ 18 years of age, the proportion of fractures treated with plating increased from 16% to 70% while the use of external fixation decreased by about the same amount. Interpretation The incidence rate of distal radius fractures in postmenopausal women appears to have decreased over the last few decades. There has been a shift in surgical treatment from external fixation to open reduction and plating. PMID:23594225

  3. Overview of the epidemiology methods and applications: strengths and limitations of observational study designs.

    PubMed

    Colditz, Graham A

    2010-01-01

    The impact of study design on the results of medical research has long been an area of both substantial debate and a smaller body of empirical research. Examples come from many disciplines within clinical and public health research. Among the early major contributions in the 1970s was work by Mosteller and colleagues (Gilbert et al., 1997), who noted that innovations in surgery and anesthesia showed greater gains than standard therapy when nonrandomized, controlled trials were evaluated compared with the gains reported in randomized, controlled trials. More recently, we and others have evaluated the impact of design in medical and surgical research, and concluded that the mean gain comparing new therapies to established therapies was biased by study design in nonrandomized trials (Colditz et al., 1989; Miller et al., 1989). Benson and Hartz (2000) conducted a study in which they focused only on studies reported after 1985. On the basis of 136 reports of 19 diverse treatments, Benson and Hartz concluded that in only 2 of the 19 analyses did the combined data from the observational studies lie outside the 95% confidence interval for the combined data from the randomized trials. A similar study drew only on data reported from 1991 to 1995, which showed remarkably similar results among observational studies and randomized, controlled trials (Concato et al., 2000). These more recent data suggest that advancing the study design and analytic methods may reduce bias in some evaluations of medical and public health interventions. Such methods apply not only to the original studies, but also to the approaches that are taken to quantitatively combine results by using meta-analytic approaches such as random effects meta-regression, Bayesian meta-analysis, and the like (Normand, 1999). By focusing attention on thorough data analysis, design issues can be understood and their impact or bias can be estimated, on average, and then ideally accounted for in the interpretation of

  4. Endodontic Epidemiology

    PubMed Central

    Shahravan, Arash; Haghdoost, Ali Akbar

    2014-01-01

    Epidemiology is the study of disease distribution and factors determining or affecting it. Likewise, endodontic epidemiology can be defined as the science of studying the distribution pattern and determinants of pulp and periapical diseases; specially apical periodontitis. Although different study designs have been used in endodontics, researchers must pay more attention to study designs with higher level of evidence such as randomized clinical trials. PMID:24688577

  5. Bayesian Decision-theoretic Methods for Parameter Ensembles with Application to Epidemiology

    NASA Astrophysics Data System (ADS)

    Gunterman, Haluna Penelope Frances

    and water-uptake behavior of CLs. Isolated CLs were made in-house and commercially and tested for their PC-S response. CLs have the propensity to be highly hydrophilic and require capillary pressures as low as -80 kPa to eject water. The presence of Pt or surface cracks increases hydrophilicity. These findings suggest that saturation in CLs, especially cracked CLs, may exacerbate poor transport. Lastly, this work includes early-stage development of a limiting-current measurement that can be used to calculate effective transport properties as a function of saturation. Results indicate that the method is valid, and different DM have higher transport depending on the operating condition. The technique is yet in a formative stage, and this work includes advice and recommendations for operation and design improvements.

  6. Traditional epidemiology, modern epidemiology, and public health.

    PubMed Central

    Pearce, N

    1996-01-01

    There have been significant developments in epidemiologic methodology during the past century, including changes in basic concepts, methods of data analysis, and methods of exposure measurement. However, the rise of modern epidemiology has been a mixed blessing, and the new paradigm has major shortcomings, both in public health and in scientific terms. The changes in the paradigm have not been neutral but have rather helped change--and have reflected changes in--the way in which epidemiologists think about health and disease. The key issue has been the shift in the level of analysis from the population to the individual. Epidemiology has largely ceased to function as part of a multidisciplinary approach to understanding the causation of disease in populations and has become a set of generic methods for measuring associations of exposure and disease in individuals. This reductionist approach focuses on the individual, blames the victim, and produces interventions that can be harmful. We seem to be using more and more advanced technology to study more and more trivial issues, while the major causes of disease are ignored. Epidemiology must reintegrate itself into public health and must rediscover the population perspective. PMID:8629719

  7. Statistical Reasoning and Methods in Epidemiology to Promote Individualized Health: In Celebration of the 100th Anniversary of the Johns Hopkins Bloomberg School of Public Health.

    PubMed

    Ogburn, Elizabeth L; Zeger, Scott L

    2016-03-01

    Epidemiology is concerned with determining the distribution and causes of disease. Throughout its history, epidemiology has drawn upon statistical ideas and methods to achieve its aims. Because of the exponential growth in our capacity to measure and analyze data on the underlying processes that define each person's state of health, there is an emerging opportunity for population-based epidemiologic studies to influence health decisions made by individuals in ways that take into account the individuals' characteristics, circumstances, and preferences. We refer to this endeavor as "individualized health." The present article comprises 2 sections. In the first, we describe how graphical, longitudinal, and hierarchical models can inform the project of individualized health. We propose a simple graphical model for informing individual health decisions using population-based data. In the second, we review selected topics in causal inference that we believe to be particularly useful for individualized health. Epidemiology and biostatistics were 2 of the 4 founding departments in the world's first graduate school of public health at Johns Hopkins University, the centennial of which we honor. This survey of a small part of the literature is intended to demonstrate that the 2 fields remain just as inextricably linked today as they were 100 years ago. PMID:26867776

  8. Polygenic Epidemiology

    PubMed Central

    2016-01-01

    ABSTRACT Much of the genetic basis of complex traits is present on current genotyping products, but the individual variants that affect the traits have largely not been identified. Several traditional problems in genetic epidemiology have recently been addressed by assuming a polygenic basis for disease and treating it as a single entity. Here I briefly review some of these applications, which collectively may be termed polygenic epidemiology. Methodologies in this area include polygenic scoring, linear mixed models, and linkage disequilibrium scoring. They have been used to establish a polygenic effect, estimate genetic correlation between traits, estimate how many variants affect a trait, stratify cases into subphenotypes, predict individual disease risks, and infer causal effects using Mendelian randomization. Polygenic epidemiology will continue to yield useful applications even while much of the specific variation underlying complex traits remains undiscovered. PMID:27061411

  9. Evaluation of method for secondary DNA typing of Mycobacterium tuberculosis with pTBN12 in epidemiologic study of tuberculosis.

    PubMed Central

    Yang, Z; Chaves, F; Barnes, P F; Burman, W J; Koehler, J; Eisenach, K D; Bates, J H; Cave, M D

    1996-01-01

    Secondary fingerprinting of Mycobacterium tuberculosis DNA with a probe containing the polymorphic GC-rich repetitive sequence present in pTBN12 has been found to have greater discriminating power than does fingerprinting with the insertion sequence IS6110 for strains carrying few copies of IS6110. To validate the use of pTBN12 fingerprinting in the molecular epidemiology of tuberculosis, M. tuberculosis isolates from 67 patients in five states in the United States and in Spain were fingerprinted with both IS6110 and pTBN12. Epidemiologic links among the 67 patients were evaluated by patient interview and/or review of medical records. The 67 isolates had 5 IS6110 fingerprint patterns with two to five copies of IS6110 and 18 pTBN12 patterns, of which 10 were shared by more than 1 isolate. Epidemiologic links are consistently found among patients whose isolates had identical pTBN12 patterns, whereas no links were found among patients whose isolates had unique pTBN12 patterns. This suggests that pTBN12 fingerprinting is a useful tool to identify epidemiologically linked tuberculosis patients whose isolates have identical IS6110 fingerprints containing fewer than six fragments. PMID:8940446

  10. Prevalence and Epidemiologic Characteristics of FASD From Various Research Methods with an Emphasis on Recent In-School Studies

    ERIC Educational Resources Information Center

    May, Philip A.; Gossage, J. Phillip; Kalberg, Wendy O.; Robinson, Luther K.; Buckley, David; Manning, Melanie; Hoyme, H. Eugene

    2009-01-01

    Researching the epidemiology and estimating the prevalence of fetal alcohol syndrome (FAS) and other fetal alcohol spectrum disorders (FASD) for mainstream populations anywhere in the world has presented a challenge to researchers. Three major approaches have been used in the past: surveillance and record review systems, clinic-based studies, and…

  11. Cognitive epidemiology

    PubMed Central

    Deary, Ian J; Batty, G David

    2007-01-01

    This glossary provides a guide to some concepts, findings and issues of discussion in the new field of research in which intelligence test scores are associated with mortality and morbidity. Intelligence tests are devised and studied by differential psychologists. Some of the major concepts in differential psychology are explained, especially those regarding cognitive ability testing. Some aspects of IQ (intelligence) tests are described and some of the major tests are outlined. A short guide is given to the main statistical techniques used by differential psychologists in the study of human mental abilities. There is a discussion of common epidemiological concepts in the context of cognitive epidemiology. PMID:17435201

  12. Nutritional Epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although observations on relationships between diet and health have always been recognized—the systematic science of nutritional epidemiology in populations is relatively recent. Important observations propelling the field of nutrition forward were numerous in the 18th and 19th centuries, as it was...

  13. An exploratory GIS-based method to identify and characterise landscapes with an elevated epidemiological risk of Rhodesian human African trypanosomiasis

    PubMed Central

    2012-01-01

    Background Specific land cover types and activities have been correlated with Trypanosoma brucei rhodesiense distributions, indicating the importance of landscape for epidemiological risk. However, methods proposed to identify specific areas with elevated epidemiological risk (i.e. where transmission is more likely to occur) tend to be costly and time consuming. This paper proposes an exploratory spatial analysis using geo-referenced human African trypanosomiasis (HAT) cases and matched controls from Serere hospital, Uganda (December 1998 to November 2002) to identify areas with an elevated epidemiological risk of HAT. Methods Buffers 3 km from each case and control were used to represent areas in which village inhabitants would carry out their daily activities. It was hypothesised that the selection of areas where several case village buffers overlapped would enable the identification of locations with increased risk of HAT transmission, as these areas were more likely to be frequented by HAT cases in several surrounding villages. The landscape within these overlap areas should more closely relate to the environment in which transmission occurs as opposed to using the full buffer areas. The analysis was carried out for each of four annual periods, for both cases and controls, using a series of threshold values (number of overlapping buffers), including a threshold of one, which represented the benchmark (e.g. use of the full buffer area as opposed to the overlap areas). Results A greater proportion of the overlap areas for cases consisted of seasonally flooding grassland and lake fringe swamp, than the control overlap areas, correlating well with the preferred habitat of the predominant tsetse species within the study area (Glossina fuscipes fuscipes). The use of overlap areas also resulted in a greater difference between case and control landscapes, when compared with the benchmark (using the full buffer area). Conclusions These results indicate that the overlap

  14. Cultural epidemiology of pandemic influenza in urban and rural Pune, India: a cross-sectional, mixed-methods study

    PubMed Central

    Sundaram, Neisha; Schaetti, Christian; Purohit, Vidula; Kudale, Abhay; Weiss, Mitchell G

    2014-01-01

    Objective To identify and compare sociocultural features of pandemic influenza with reference to illness-related experience, meaning and behaviour in urban and rural areas of India. Design Cross-sectional, mixed-methods, cultural epidemiological survey with vignette-based interviews. Semistructured explanatory model interviews were used to study community ideas of the 2009 influenza pandemic. In-depth interviews elaborated respondents’ experience during the pandemic. Setting Urban and rural communities, Pune district, western India. Participants Survey of urban (n=215) and rural (n=221) residents aged between 18 and 65 years. In-depth interviews of respondents with a history of 2009 pandemic influenza (n=6). Results More urban (36.7%) than rural respondents (16.3%, p<0.001) identified the illness in the vignette as ‘swine flu’. Over half (56.7%) believed the illness would be fatal without treatment, but with treatment 96% predicted full recovery. Worry (‘tension’) about the illness was reported as more troubling than somatic symptoms. The most common perceived causes—‘exposure to a dirty environment’ and ‘cough or sneeze of an infected person’–were more prominent in the urban group. Among rural respondents, climatic conditions, drinking contaminated water, tension and cultural ideas on humoral imbalance from heat-producing or cold-producing foods were more prominent. The most widely reported home treatment was herbal remedies; more rural respondents suggested reliance on prayer, and symptom relief was more of a priority for urban respondents. Government health services were preferred in the urban communities, and rural residents relied more than urban residents on private facilities. The important preventive measures emphasised were cleanliness, wholesome lifestyle and vaccines, and more urban respondents reported the use of masks. In-depth interviews indicated treatment delays during the 2009 pandemic, especially among rural patients

  15. The impact of chronic migraine: The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study methods and baseline results

    PubMed Central

    Serrano, Daniel; Buse, Dawn C; Reed, Michael L; Marske, Valerie; Fanning, Kristina M; Lipton, Richard B

    2015-01-01

    Background Longitudinal migraine studies have rarely assessed headache frequency and disability variation over a year. Methods The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study is a cross-sectional and longitudinal Internet study designed to characterize the course of episodic migraine (EM) and chronic migraine (CM). Participants were recruited from a Web-panel using quota sampling in an attempt to obtain a sample demographically similar to the US population. Participants who passed the screener were assessed every three months with the Core (baseline, six, and 12 months) and Snapshot (months three and nine) modules, which assessed headache frequency, headache-related disability, treatments, and treatment satisfaction. The Core also assessed resource use, health-related quality of life, and other features. One-time cross-sectional modules measured family burden, barriers to medical care, and comorbidities/endophenotypes. Results Of 489,537 invitees, we obtained 58,418 (11.9%) usable returns including 16,789 individuals who met ICHD-3 beta migraine criteria (EM (<15 headache days/mo): n = 15,313 (91.2%); CM (≥15 headache days/mo): n = 1476 (8.8%)). At baseline, all qualified respondents (n = 16,789) completed the Screener, Core, and Barriers to Care modules. Subsequent modules showed some attrition (Comorbidities/Endophenotypes, n = 12,810; Family Burden (Proband), n = 13,064; Family Burden (Partner), n = 4022; Family Burden (Child), n = 2140; Snapshot (three months), n = 9741; Core (six months), n = 7517; Snapshot (nine months), n = 6362; Core (12 months), n = 5915). A total of 3513 respondents (21.0%) completed all modules, and 3626 (EM: n = 3303 (21.6%); CM: n = 323 (21.9%)) completed all longitudinal assessments. Conclusions The CaMEO Study provides cross-sectional and longitudinal data that will contribute to our understanding of the course of migraine over one year and quantify variations in

  16. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  17. Epidemiology: Cornerstone for Health Education.

    ERIC Educational Resources Information Center

    Markellis, Victoria C.

    1986-01-01

    Epidemiology has been used historically to reduce the incidence of communicable diseases and is used presently to study chronic conditions, environmental conditions, and social conditions. Its analytical method is necessary for health educators to evaluate tactics and recommend programs. (MT)

  18. Epidemiological investigation of a Legionnaires' disease outbreak in Christchurch, New Zealand: the value of spatial methods for practical public health.

    PubMed

    White, P S; Graham, F F; Harte, D J G; Baker, M G; Ambrose, C D; Humphrey, A R G

    2013-04-01

    Between April and August 2005 Christchurch, New Zealand experienced an outbreak of Legionnaires' disease. There were 19 laboratory-confirmed case including three deaths. Legionella pneumophila serogroup 1 (Lpsg1) was identified as the causative agent for all cases. A case-control study indicated a geographical association between the cases but no specific common exposures. Rapid spatial epidemiological investigation confirmed the association and identified seven spatially significant case clusters. The clusters were all sourced in the same area and exhibited a clear anisotropic process (noticeable direction) revealing a plume effect consistent with aerosol dispersion from a prevailing southwesterly wind. Four out of five cases tested had indistinguishable allele profiles that also matched environmental isolates from a water cooling tower within the centre of the clusters. This tower was considered the most probable source for these clusters. The conclusion would suggest a maximum dispersal distance in this outbreak of 11·6 km. This work illustrated the value of geostatistical techniques for infectious disease epidemiology and for providing timely information during outbreak investigations. PMID:22697112

  19. The use of epidemiology in alcohol research

    PubMed Central

    Rossow, Ingeborg; Norström, Thor

    2013-01-01

    Aims This paper presents examples to illustrate the utility and limitations in the use of epidemiology in alcohol research and discusses some promising new directions. Methods Review of literature, concentrating on epidemiological alcohol research with relevance to public health. Findings and conclusion Epidemiology offers tools for assessment of causes and effects of alcohol consumption as well as the effects of efforts to prevent alcohol consumption and its consequences. Epidemiological studies have made significant contributions to alcohol research with respect to public health and public policy. Fixed-effects modelling, difference-in-differences estimation and integrated qualitative and epidemiological methods are promising but underused methods in epidemiological studies. Many epidemiological studies have limited transferability of knowledge to other cultures and jurisdictions. PMID:23134358

  20. Methodologic frontiers in environmental epidemiology.

    PubMed Central

    Rothman, K J

    1993-01-01

    Environmental epidemiology comprises the epidemiologic study of those environmental factors that are outside the immediate control of the individual. Exposures of interest to environmental epidemiologists include air pollution, water pollution, occupational exposure to physical and chemical agents, as well as psychosocial elements of environmental concern. The main methodologic problem in environmental epidemiology is exposure assessment, a problem that extends through all of epidemiologic research but looms as a towering obstacle in environmental epidemiology. One of the most promising developments in improving exposure assessment in environmental epidemiology is to find exposure biomarkers, which could serve as built-in dosimeters that reflect the biologic footprint left behind by environmental exposures. Beyond exposure assessment, epidemiologists studying environmental exposures face the difficulty of studying small effects that may be distorted by confounding that eludes easy control. This challenge may prompt reliance on new study designs, such as two-stage designs in which exposure and disease information are collected in the first stage, and covariate information is collected on a subset of subjects in state two. While the analytic methods already available for environmental epidemiology are powerful, analytic methods for ecologic studies need further development. This workshop outlines the range of methodologic issues that environmental epidemiologists must address so that their work meets the goals set by scientists and society at large. PMID:8206029

  1. A Review of the Epidemiological Methods Used to Investigate the Health Impacts of Air Pollution around Major Industrial Areas

    PubMed Central

    Pascal, Laurence; Bidondo, Marie-Laure; Cochet, Amandine; Sarter, Hélène; Stempfelet, Morgane; Wagner, Vérène

    2013-01-01

    We performed a literature review to investigate how epidemiological studies have been used to assess the health consequences of living in the vicinity of industries. 77 papers on the chronic effects of air pollution around major industrial areas were reviewed. Major health themes were cancers (27 studies), morbidity (25 studies), mortality (7 studies), and birth outcome (7 studies). Only 3 studies investigated mental health. While studies were available from many different countries, a majority of papers came from the United Kingdom, Italy, and Spain. Several studies were motivated by concerns from the population or by previous observations of an overincidence of cases. Geographical ecological designs were largely used for studying cancer and mortality, including statistical designs to quantify a relationship between health indicators and exposure. Morbidity was frequently investigated through cross-sectional surveys on the respiratory health of children. Few multicenter studies were performed. In a majority of papers, exposed areas were defined based on the distance to the industry and were located from <2 km to >20 km from the plants. Improving the exposure assessment would be an asset to future studies. Criteria to include industries in multicenter studies should be defined. PMID:23818910

  2. Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project: study design and methods for pooling results of genetic epidemiological studies

    PubMed Central

    2012-01-01

    Background For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields. PMID:22862891

  3. [Eco-epidemiology: towards epidemiology of complexity].

    PubMed

    Bizouarn, Philippe

    2016-05-01

    In order to solve public health problems posed by the epidemiology of risk factors centered on the individual and neglecting the causal processes linking the risk factors with the health outcomes, Mervyn Susser proposed a multilevel epidemiology called eco-epidemiology, addressing the interdependence of individuals and their connection with molecular, individual, societal, environmental levels of organization participating in the causal disease processes. The aim of this epidemiology is to integrate more than a level of organization in design, analysis and interpretation of health problems. After presenting the main criticisms of risk-factor epidemiology focused on the individual, we will try to show how eco-epidemiology and its development could help to understand the need for a broader and integrative epidemiology, in which studies designed to identify risk factors would be balanced by studies designed to answer other questions equally vital to public health. PMID:27225924

  4. Applying standard epidemiological methods for investigating foodborne disease outbreak in resource-poor settings: lessons from Vietnam.

    PubMed

    Vo, Thuan Huu; Nguyen, Dat Van; Le, Loan Thi Kim; Phan, Lan Trong; Nuorti, J Pekka; Tran Minh, Nguyen Nhu

    2014-07-01

    An outbreak of gastroenteritis occurred among workers of company X after eating lunch prepared by a catering service. Of 430 workers attending the meal, 56 were hospitalized with abdominal pain, diarrhea, vomiting, and nausea, according to the initial report. We conducted an investigation to identify the extent, vehicle, and source of the outbreak. In our case-control study, a case was a worker who attended the meal and who was hospitalized with acute gastroenteritis; controls were randomly selected from non-ill workers. Cases and controls were interviewed using a standard questionnaire. We used logistic regression to calculate adjusted odds ratios for the consumption of food items. Catering service facilities and food handlers working for the service were inspected. Food samples from the catering service were tested at reference laboratories. Of hospitalized cases, 54 fulfilled the case definition, but no stool specimens were collected for laboratory testing. Of four food items served during lunch, only "squash and pork soup" was significantly associated with gastroenteritis, with an adjusted odds ratio of 9.5 (95 % CI 3.2, 27.7). The caterer did not separate cooked from raw foods but used the same counter for both. Cooked foods were kept at room temperature for about 4 h before serving. Four of 14 food handlers were not trained on basic food safety principles and did not have health certificates. Although no microbiological confirmation was obtained, our epidemiological investigation suggested that squash and pork soup caused the outbreak. Hospitals should be instructed to obtain stool specimens from patients with gastroenteritis. Food catering services should be educated in basic food safety measures. PMID:24988035

  5. Epidemiological survey of anti-flea IgE in dogs in Japan by using an antigen-specific IgE quantitative measurement method

    PubMed Central

    Ichikawa, Y.; Beugnet, F.

    2012-01-01

    In Japan, an epidemiological survey was performed in dogs from October to December 2008 by using a quantitative measurement method for antigen-specific IgE towards specific Ctenocephalides felis antigens. 214 dogs from 22 veterinary clinics were included. These clinics were located as follows, from North to South: Hokkaido, Aomori, Fukushima, Tochigi, Saitama, Chiba, Tokyo (Tama-City and Ota-ku), Kanagawa, Gifu, Niigata, Kyoto, Nara, Osaka, Hyogo, Kagawa, Ehime, Hiroshima, Yamaguchi, Fukuoka, Kumamoto and Kagoshima. 110 dogs (51.4%) were seropositive for flea-specific IgE. No differences were associated with gender or breed. This survey confirms that flea infestation in dogs is a common problem in Japan. It especially shows that the infestation also occurs in Northern Japan where fleas are considered uncommon by the vet. PMID:22550629

  6. The Global Enteric Multicenter Study (GEMS) of Diarrheal Disease in Infants and Young Children in Developing Countries: Epidemiologic and Clinical Methods of the Case/Control Study

    PubMed Central

    Kotloff, Karen L.; Blackwelder, William C.; Nasrin, Dilruba; Nataro, James P.; Farag, Tamer H.; van Eijk, Annemieke; Adegbola, Richard A.; Alonso, Pedro L.; Breiman, Robert F.; Golam Faruque, Abu Syed; Saha, Debasish; Sow, Samba O.; Sur, Dipika; Zaidi, Anita K. M.; Biswas, Kousick; Panchalingam, Sandra; Clemens, John D.; Cohen, Dani; Glass, Roger I.; Mintz, Eric D.; Sommerfelt, Halvor; Levine, Myron M.

    2012-01-01

    Background. Diarrhea is a leading cause of illness and death among children aged <5 years in developing countries. This paper describes the clinical and epidemiological methods used to conduct the Global Enteric Multicenter Study (GEMS), a 3-year, prospective, age-stratified, case/control study to estimate the population-based burden, microbiologic etiology, and adverse clinical consequences of acute moderate-to-severe diarrhea (MSD) among a censused population of children aged 0–59 months seeking care at health centers in sub-Saharan Africa and South Asia. Methods. GEMS was conducted at 7 field sites, each serving a population whose demography and healthcare utilization practices for childhood diarrhea were documented. We aimed to enroll 220 MSD cases per year from selected health centers serving each site in each of 3 age strata (0–11, 12–23, and 24–59 months), along with 1–3 matched community controls. Cases and controls supplied clinical, epidemiologic, and anthropometric data at enrollment and again approximately 60 days later, and provided enrollment stool specimens for identification and characterization of potential diarrheal pathogens. Verbal autopsy was performed if a child died. Analytic strategies will calculate the fraction of MSD attributable to each pathogen and the incidence, financial costs, nutritional consequences, and case fatality overall and by pathogen. Conclusions. When completed, GEMS will provide estimates of the incidence, etiology, and outcomes of MSD among infants and young children in sub-Saharan Africa and South Asia. This information can guide development and implementation of public health interventions to diminish morbidity and mortality from diarrheal diseases. PMID:23169936

  7. Calculation of Evolutionary Correlation between Individual Genes and Full-Length Genome: A Method Useful for Choosing Phylogenetic Markers for Molecular Epidemiology

    PubMed Central

    Wang, Shuai; Luo, Xuenong; Wei, Wei; Zheng, Yadong; Dou, Yongxi; Cai, Xuepeng

    2013-01-01

    Individual genes or regions are still commonly used to estimate the phylogenetic relationships among viral isolates. The genomic regions that can faithfully provide assessments consistent with those predicted with full-length genome sequences would be preferable to serve as good candidates of the phylogenetic markers for molecular epidemiological studies of many viruses. Here we employed a statistical method to evaluate the evolutionary relationships between individual viral genes and full-length genomes without tree construction as a way to determine which gene can match the genome well in phylogenetic analyses. This method was performed by calculation of linear correlations between the genetic distance matrices of aligned individual gene sequences and aligned genome sequences. We applied this method to the phylogenetic analyses of porcine circovirus 2 (PCV2), measles virus (MV), hepatitis E virus (HEV) and Japanese encephalitis virus (JEV). Phylogenetic trees were constructed for comparisons and the possible factors affecting the method accuracy were also discussed in the calculations. The results revealed that this method could produce results consistent with those of previous studies about the proper consensus sequences that could be successfully used as phylogenetic markers. And our results also suggested that these evolutionary correlations could provide useful information for identifying genes that could be used effectively to infer the genetic relationships. PMID:24312527

  8. Sewage-based epidemiology in monitoring the use of new psychoactive substances: Validation and application of an analytical method using LC-MS/MS.

    PubMed

    Kinyua, Juliet; Covaci, Adrian; Maho, Walid; McCall, Ann-Kathrin; Neels, Hugo; van Nuijs, Alexander L N

    2015-09-01

    Sewage-based epidemiology (SBE) employs the analysis of sewage to detect and quantify drug use within a community. While SBE has been applied repeatedly for the estimation of classical illicit drugs, only few studies investigated new psychoactive substances (NPS). These compounds mimic effects of illicit drugs by introducing slight modifications to chemical structures of controlled illicit drugs. We describe the optimization, validation, and application of an analytical method using liquid chromatography coupled to positive electrospray tandem mass spectrometry (LC-ESI-MS/MS) for the determination of seven NPS in sewage: methoxetamine (MXE), butylone, ethylone, methylone, methiopropamine (MPA), 4-methoxymethamphetamine (PMMA), and 4-methoxyamphetamine (PMA). Sample preparation was performed using solid-phase extraction (SPE) with Oasis MCX cartridges. The LC separation was done with a HILIC (150 x 3 mm, 5 µm) column which ensured good resolution of the analytes with a total run time of 19 min. The lower limit of quantification (LLOQ) was between 0.5 and 5 ng/L for all compounds. The method was validated by evaluating the following parameters: sensitivity, selectivity, linearity, accuracy, precision, recoveries and matrix effects. The method was applied on sewage samples collected from sewage treatment plants in Belgium and Switzerland in which all investigated compounds were detected, except MPA and PMA. Furthermore, a consistent presence of MXE has been observed in most of the sewage samples at levels higher than LLOQ. PMID:25655588

  9. Comparison of Epidemiological Methods for Estimation of Hepatitis B Incidence and Residual Risk for Blood Donors in Southern Brazil

    PubMed Central

    Kupek, Emil; Petry, Andrea

    2011-01-01

    Background and Objective. The objective of this work was to compare three methods for estimating hepatitis B virus (HBV) incidence and residual risk. Methods. Computerized blood donor records in southern Brazil were examined for the period 2004–2006. The methods for estimating HBV incidence included stand-alone HBsAg, HBsAg yield method, and an extension of the latter which added recent anti-HBc seroconversions as incident HBV cases. Results. HBV incidences for the above methods were 9.91, 20.09, and 22.93 per 100000 repeat donors, respectively. In the same order, corresponding residual risks were 1 : 62482, 1 : 30821, and 1 : 47559, respectively. First-time donors had 52 higher HBV incidence compared to repeat donors. Conclusion. Although the three methods compared produced overlapping 95% confidence intervals, their variation was considerably lower for the method which included recent anti-HBc seroconversions. First-time donors are primary cause for concern regarding HBV transmission via blood transfusion in southern Brazil. PMID:25346858

  10. Comparative Performance of Four Methods for High-throughput Glycosylation Analysis of Immunoglobulin G in Genetic and Epidemiological Research*

    PubMed Central

    Huffman, Jennifer E.; Pučić-Baković, Maja; Klarić, Lucija; Hennig, René; Selman, Maurice H. J.; Vučković, Frano; Novokmet, Mislav; Krištić, Jasminka; Borowiak, Matthias; Muth, Thilo; Polašek, Ozren; Razdorov, Genadij; Gornik, Olga; Plomp, Rosina; Theodoratou, Evropi; Wright, Alan F.; Rudan, Igor; Hayward, Caroline; Campbell, Harry; Deelder, André M.; Reichl, Udo; Aulchenko, Yurii S.; Rapp, Erdmann; Wuhrer, Manfred; Lauc, Gordan

    2014-01-01

    The biological and clinical relevance of glycosylation is becoming increasingly recognized, leading to a growing interest in large-scale clinical and population-based studies. In the past few years, several methods for high-throughput analysis of glycans have been developed, but thorough validation and standardization of these methods is required before significant resources are invested in large-scale studies. In this study, we compared liquid chromatography, capillary gel electrophoresis, and two MS methods for quantitative profiling of N-glycosylation of IgG in the same data set of 1201 individuals. To evaluate the accuracy of the four methods we then performed analysis of association with genetic polymorphisms and age. Chromatographic methods with either fluorescent or MS-detection yielded slightly stronger associations than MS-only and multiplexed capillary gel electrophoresis, but at the expense of lower levels of throughput. Advantages and disadvantages of each method were identified, which should inform the selection of the most appropriate method in future studies. PMID:24719452

  11. Infectious Agents and Cancer Epidemiology Research Webinar Series

    Cancer.gov

    Infectious Agents and Cancer Epidemiology Research Webinar Series highlights emerging and cutting-edge research related to infection-associated cancers, shares scientific knowledge about technologies and methods, and fosters cross-disciplinary discussions on infectious agents and cancer epidemiology.

  12. [A method for studying social security records in epidemiology. Use in a study on the prognosis of chronic bronchitis (author's transl)].

    PubMed

    Kauffmann, F; Bahi, J; Brille, D

    1976-01-01

    A method is presented to study, in an epidemiological research, the social security records. This study is based upon records of workers affiliated to the french social security general system. To obtain data which may be compared, it was necessary to take the legislation as a basis; this legislation gives the data which must be in the records. A study of laws and rules has been done to find out these data in the medical record and in the administrative one. A questionnaire is presented. This basic questionnaire should be modified according to the precise objectives of each study and to the characteristics of the population sample. To illustrate this method, some results of a study of chronic bronchitis risk factors are presented in the second part. These results concern 950 men, born in France, aged 30 to 59 in 1960 an still alive in 1972. The study of the long reductions of the ability to work, happened from 1960 to 1971, confirm the disabling character of the group "chronic bronchitis, asthma, emphysema, respiratory insufficiency" which follows immediately cardiovascular and rheumatic diseases. The total number of beneficiaries of the social security is already very important and the whole population will be soon concerned. The use of the social security records as data source could give very interesting informations about morbidity. So, it is possible to study representative samples of the general population or of some particular groups, which has up to now, been done only in a slight extent. PMID:1019402

  13. METHODS DEVELOPMENT FOR ASSESSING AIR POLLUTION CONTROL BENEFITS. VOLUME I. EXPERIMENTS IN THE ECONOMICS OF AIR POLLUTION EPIDEMIOLOGY

    EPA Science Inventory

    The volume employs the analytical and empirical methods of economics to develop hypotheses on disease etiologies and to value labor productivity and consumer losses due to air pollution-induced mortality and morbidity. In the mortality work, 1970 city-wide mortality rates for maj...

  14. Environmental epidemiology: challenges and opportunities.

    PubMed Central

    Pekkanen, J; Pearce, N

    2001-01-01

    Epidemiology is struggling increasingly with problems with correlated exposures and small relative risks. As a consequence, some scholars have strongly emphasized molecular epidemiology, whereas others have argued for the importance of the population context and the reintegration of epidemiology into public health. Environmental epidemiology has several unique features that make these debates especially pertinent to it. The very large number of environmental exposures require prioritization, and the relative risks are usually very low. Furthermore, many environmental exposures can be addressed only by comparing populations rather than individuals, and the disruption of both local and global ecosystems requires us to develop new methods of study design. The population context is also very important to consider in risk management decisions because of the involuntary nature of most environmental exposures and the diversity of possible outcomes, both health- and nonhealth-related. Studies at the individual or molecular level tend to focus the research hypotheses and subsequent interventions at that level, even when research and interventions at other levels may be more appropriate. Thus, only by starting from the population and ecosystem levels can we ensure that these are given appropriate consideration. Although better research is needed at all levels, it is crucially important to choose the most appropriate level, or levels, of research for a particular problem. Only by conducting research at all these levels and by developing further methods to combine evidence from these different levels can we hope to address the challenges facing environmental epidemiology today. PMID:11171517

  15. International Lymphoma Epidemiology Consortium

    Cancer.gov

    The InterLymph Consortium, or formally the International Consortium of Investigators Working on Non-Hodgkin's Lymphoma Epidemiologic Studies, is an open scientific forum for epidemiologic research in non-Hodgkin's lymphoma.

  16. Typing multidrug-resistant Staphylococcus aureus: conflicting epidemiological data produced by genotypic and phenotypic methods clarified by phylogenetic analysis.

    PubMed Central

    Jorgensen, M; Givney, R; Pegler, M; Vickery, A; Funnell, G

    1996-01-01

    An outbreak of an unusual tetracycline-sensitive, rifampicin- and ciprofloxacin-resistant, methicillin-resistant Staphylococcus aureus (MRSA) strain at a large teaching hospital was investigated. Two typing methods, phage typing and restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (RFLP-PFGE), gave conflicting results which were clarified by phylogenetic analysis. Phage typing identified all the "epidemic-associated" strains as identical, while RFLP-PFGE further divided these strains into four pulsotypes. Phylogenetic analysis showed these four pulsotypes were related genetically and also recognized a second strain of MRSA causing a continuing cross-infection problem. Variation in the RFLP-PFGE pattern was shown to occur following lysogenization of phage-sensitive MRSA. These results indicate that in analyzing outbreaks caused by subgroups of clonal organisms like MRSA, it is necessary to use at least two typing methods and that conflicts between these could be resolved by phylogenetic analysis. PMID:8789023

  17. A novel method for reducing the number of agents to be studied in an occupational epidemiologic study.

    PubMed

    Pierce, Jennifer S; Esmen, Nurtan A

    2011-04-01

    A novel screening tool method to select chemicals for exposure reconstruction was developed and validated using data generated for a hypothetical work force consisting of 10 job classes (ranging from 10,000 to 55,000 person-years). To achieve the required efficiency in the reconstruction of exposures, this method treats each product (defined as a part or process) as an "exposure." Exposure to 10 products was assigned to each job class at random using a computer program. The expected rate of a given disease was assumed to be constant throughout the job classes (tested at five levels), and the observed numbers of cases in the job classes were generated based on neutral deviations from background with error rates of ± 1% to 16%. One job class was assigned to be the "excess-class" and the number of cases in that class was increased by a factor of Q, which was set at levels that ranged from 1.25 to 5. All of the experimental conditions were replicated 10,000 times in a Monte Carlo scheme for scenarios in which each job class had been designated as the excess-class. Following each run, significant excesses (if any) were determined using a modified version of Daniel's method, and the percentages of false positive and false negative identifications were tabulated. We found that the sensitivity of the method is largely dependent on the relative risk (Q) associated with the exposure. Specifically, the results indicate that as the relative risk increases, the percentage of false negative identifications of the excesses is reduced to nearly 0% and the percentage of false positive identifications is approximately 13%. When applied to real data, should an association be detected between any product and a health outcome, this preliminary analysis will yield a reduced "product" set that can then be investigated in detail and the agents involved considered further for quantitative reconstruction. The proposed method is highly efficient and has the potential to benefit future

  18. Epidemiology, Science as Inquiry and Scientific Literacy

    ERIC Educational Resources Information Center

    Kaelin, Mark; Huebner, Wendy

    2003-01-01

    The recent worldwide SARS outbreak has put the science of epidemiology into the headlines once again. Epidemiology is "... the study of the distribution and the determinants of health-related states or events and the application of these methods to the control of health problems" (Gordis 2000). In this context, the authors have developed a…

  19. Cancer Epidemiology Matters Blog

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  20. Classification of personal exposure to radio frequency electromagnetic fields (RF-EMF) for epidemiological research: Evaluation of different exposure assessment methods.

    PubMed

    Frei, Patrizia; Mohler, Evelyn; Bürgi, Alfred; Fröhlich, Jürg; Neubauer, Georg; Braun-Fahrländer, Charlotte; Röösli, Martin

    2010-10-01

    The use of personal exposure meters (exposimeters) has been recommended for measuring personal exposure to radio frequency electromagnetic fields (RF-EMF) from environmental far-field sources in everyday life. However, it is unclear to what extent exposimeter readings are affected by measurements taken when personal mobile and cordless phones are used. In addition, the use of exposimeters in large epidemiological studies is limited due to high costs and large effort for study participants. In the current analysis we aimed to investigate the impact of personal phone use on exposimeter readings and to evaluate different exposure assessment methods potentially useful in epidemiological studies. We collected personal exposimeter measurements during one week and diary data from 166 study participants. Moreover, we collected spot measurements in the participants' bedrooms and data on self-estimated exposure, assessed residential exposure to fixed site transmitters by calculating the geo-coded distance and mean RF-EMF from a geospatial propagation model, and developed an exposure prediction model based on the propagation model and exposure relevant behavior. The mean personal exposure was 0.13 mW/m(2), when measurements during personal phone calls were excluded and 0.15 mW/m(2), when such measurements were included. The Spearman correlation with personal exposure (without personal phone calls) was 0.42 (95%-CI: 0.29 to 0.55) for the spot measurements, -0.03 (95%-CI: -0.18 to 0.12) for the geo-coded distance, 0.28 (95%-CI: 0.14 to 0.42) for the geospatial propagation model, 0.50 (95%-CI: 0.37 to 0.61) for the full exposure prediction model and 0.06 (95%-CI: -0.10 to 0.21) for self-estimated exposure. In conclusion, personal exposure measured with exposimeters correlated best with the full exposure prediction model and spot measurements. Self-estimated exposure and geo-coded distance turned out to be poor surrogates for personal exposure. PMID:20538340

  1. PCR amplification of rRNA intergenic spacer regions as a method for epidemiologic typing of Clostridium difficile.

    PubMed Central

    Cartwright, C P; Stock, F; Beekmann, S E; Williams, E C; Gill, V J

    1995-01-01

    From January to March 1993, a suspected outbreak of antibiotic-associated diarrhea occurred on a pediatric oncology ward of the Clinical Center Hospital at the National Institutes of Health. Isolates of Clostridium difficile obtained from six patients implicated in this outbreak were typed by both PCR amplification of rRNA intergenic spacer regions (PCR ribotyping) and restriction endonuclease analysis of genomic DNA. Comparable results were obtained with both methods; five of the six patients were infected with the same strain of C. difficile. Subsequent analysis of 102 C. difficile isolates obtained from symptomatic patients throughout the Clinical Center revealed the existence of 41 distinct and reproducible PCR ribotypes. These data suggest that PCR ribotyping provides a discriminatory, reproducible, and simple alternative to conventional molecular approaches for typing strains of C. difficile. PMID:7699038

  2. Evaluation of five susceptibility test methods for detection of tobramycin resistance in a cluster of epidemiologically related Acinetobacter baumannii isolates.

    PubMed

    Moodley, V Mischka; Oliver, Stephen P; Shankland, Iva; Elisha, B Gay

    2013-08-01

    Acinetobacter baumannii is a major nosocomial pathogen causing infections in critically ill patients. This organism has acquired the propensity to rapidly develop resistance to most antibiotics. At several hospitals within Cape Town, South Africa, tobramycin and colistin are frequently the only therapeutic options. Vitek2 automated susceptibility testing (AST) is used in the clinical laboratory to determine selected susceptibility profiles. The suspicion of a possible AST-related technical error when testing for susceptibility to tobramycin in A. baumannii precipitated this study. Thirty-nine A. baumannii strains isolated from clinical specimens (June to December 2006) were included in this prospective study. Tobramycin susceptibility testing results obtained by AST, disc diffusion, the epsilometer test (Etest), and agar dilution were compared to those for broth microdilution (BMD), the reference method. The tobramycin susceptibility results revealed errors in 25/39 (64%) isolates (10 very major and 15 minor errors) when AST was compared to BMD, 12/39 (31%) (2 very major and 10 minor errors) when Etest was compared to BMD, 16/39 (41%) (3 very major and 13 minor errors) when disc diffusion was compared to BMD, and 21/39 (54%) (10 very major and 11 minor errors) when agar dilution was compared to BMD. Using PCR, we detected aac(3)-IIa, which is associated with tobramycin resistance, in 21/25 of the discrepant isolates. Molecular typing (using pulsed-field gel electrophoresis and repetitive sequence-based PCR [rep-PCR]) showed that these isolates were genetically related. Clinical laboratories that routinely use the Vitek2 system should consider an alternative testing method for determining susceptibility to tobramycin. PMID:23698528

  3. A New Method to Predict the Epidemiology of Fungal Keratitis by Monitoring the Sales Distribution of Antifungal Eye Drops in Brazil

    PubMed Central

    Ibrahim, Marlon Moraes; de Angelis, Rafael; Lima, Acacio Souza; Viana de Carvalho, Glauco Dreyer; Ibrahim, Fuad Moraes; Malki, Leonardo Tannus; de Paula Bichuete, Marina; de Paula Martins, Wellington; Rocha, Eduardo Melani

    2012-01-01

    Purpose Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. Methods Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. Results A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01). Conclusions Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects. PMID:22457787

  4. Epidemiological Cutoff Values for Fluconazole, Itraconazole, Posaconazole, and Voriconazole for Six Candida Species as Determined by the Colorimetric Sensititre YeastOne Method

    PubMed Central

    Pemán, Javier; Iñiguez, Carmen; Hervás, David; Lopez-Hontangas, Jose L.; Pina-Vaz, Cidalia; Camarena, Juan J.; Campos-Herrero, Isolina; García-García, Inmaculada; García-Tapia, Ana M.; Guna, Remedios; Merino, Paloma; Pérez del Molino, Luisa; Rubio, Carmen; Suárez, Anabel

    2013-01-01

    In the absence of clinical breakpoints (CBP), epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of susceptibility tests. Sensititre YeastOne (SYO) is a widely used method to determine susceptibility of Candida spp. to antifungal agents. The CLSI CBP have been established, but not for the SYO method. The ECVs for four azoles, obtained using MIC distributions determined by the SYO method, were calculated via five methods (three statistical methods and based on the MIC50 and modal MIC). Respectively, the median ECVs (in mg/liter) of the five methods for fluconazole, itraconazole, posaconazole, and voriconazole (in parentheses: the percentage of isolates inhibited by MICs equal to or less than the ECVs; the number of isolates tested) were as follows: 2 (94.4%; 944), 0.5 (96.7%; 942), 0.25 (97.6%; 673), and 0.06 (96.7%; 849) for Candida albicans; 4 (86.1%; 642), 0.5 (99.4%; 642), 0.12 (93.9%; 392), and 0.06 (86.9%; 559) for C. parapsilosis; 8 (94.9%; 175), 1 (93.7%; 175), 2 (93.6%; 125), and 0.25 (90.4%; 167) for C. tropicalis; 128 (98.6%; 212), 4 (95.8%; 212), 4 (96.0%; 173), and 2 (98.5; 205) for C. glabrata; 256 (100%; 53), 1 (98.1%; 53), 1 (100%; 33), and 1 (97.9%; 48) for C. krusei; 4 (89.2%; 93), 0.5 (100%; 93), 0.25 (100%; 33), and 0.06 (87.7%; 73) for C. orthopsilosis. All methods included ≥94% of isolates and yielded similar ECVs (within 1 dilution). These ECVs would be suitable for monitoring emergence of isolates with reduced susceptibility by using the SYO method. PMID:23761155

  5. How to assess epidemiological studies

    PubMed Central

    Zaccai, J

    2004-01-01

    Assessing the quality of an epidemiological study equates to assessing whether the inferences drawn from it are warranted when account is taken of the methods, the representativeness of the study sample, and the nature of the population from which it is drawn. Bias, confounding, and chance can threaten the quality of an epidemiological study at all its phases. Nevertheless, their presence does not necessarily imply that a study should be disregarded. The reader must first balance any of these threats or missing information with their potential impact on the conclusions of the report. PMID:15016934

  6. SU-D-16A-01: A Novel Method to Estimate Normal Tissue Dose for Radiotherapy Patients to Support Epidemiologic Studies of Second Cancer Risk

    SciTech Connect

    Lee, C; Jung, J; Pelletier, C; Kim, J; Lee, C

    2014-06-01

    Purpose: Patient cohort of second cancer study often involves radiotherapy patients with no radiological images available: We developed methods to construct a realistic surrogate anatomy by using computational human phantoms. We tested this phantom images both in a commercial treatment planning system (Eclipse) and a custom Monte Carlo (MC) transport code. Methods: We used a reference adult male phantom defined by International Commission on Radiological Protection (ICRP). The hybrid phantom which was originally developed in Non-Uniform Rational B-Spline (NURBS) and polygon mesh format was converted into more common medical imaging format. Electron density was calculated from the material composition of the organs and tissues and then converted into DICOM format. The DICOM images were imported into the Eclipse system for treatment planning, and then the resulting DICOM-RT files were imported into the MC code for MC-based dose calculation. Normal tissue doses were calculation in Eclipse and MC code for an illustrative prostate treatment case and compared to each other. Results: DICOM images were generated from the adult male reference phantom. Densities and volumes of selected organs between the original phantom and ones represented within Eclipse showed good agreements, less than 0.6%. Mean dose from Eclipse and MC code match less than 7%, whereas maximum and minimum doses were different up to 45%. Conclusion: The methods established in this study will be useful for the reconstruction of organ dose to support epidemiological studies of second cancer in cancer survivors treated by radiotherapy. We also work on implementing body size-dependent computational phantoms to better represent patient's anatomy when the height and weight of patients are available.

  7. Assessing health impacts in complex eco-epidemiological settings in the humid tropics: Advancing tools and methods

    SciTech Connect

    Winkler, Mirko S.; Divall, Mark J.; Krieger, Gary R.; Balge, Marci Z.; Singer, Burton H.; Utzinger, Juerg

    2010-01-15

    In the developing world, large-scale projects in the extractive industry and natural resources sectors are often controversial and associated with long-term adverse health consequences to local communities. In many industrialised countries, health impact assessment (HIA) has been institutionalized for the mitigation of anticipated negative health effects while enhancing the benefits of projects, programmes and policies. However, in developing country settings, relatively few HIAs have been performed. Hence, more HIAs with a focus on low- and middle-income countries are needed to advance and refine tools and methods for impact assessment and subsequent mitigation measures. We present a promising HIA approach, developed within the frame of a large gold-mining project in the Democratic Republic of the Congo. The articulation of environmental health areas, the spatial delineation of potentially affected communities and the use of a diversity of sources to obtain quality baseline health data are utilized for risk profiling. We demonstrate how these tools and data are fed into a risk analysis matrix, which facilitates ranking of potential health impacts for subsequent prioritization of mitigation strategies. The outcomes encapsulate a multitude of environmental and health determinants in a systematic manner, and will assist decision-makers in the development of mitigation measures that minimize potential adverse health effects and enhance positive ones.

  8. Molecular Epidemiology of Leptospirosis in Northern Iran by Nested Polymerase Chain Reaction/Restriction Fragment Length Polymorphism and Sequencing Methods

    PubMed Central

    Zakeri, Sedigheh; Sepahian, Neda; Afsharpad, Mandana; Esfandiari, Behzad; Ziapour, Peyman; Djadid, Navid D.

    2010-01-01

    This study was conducted to investigate the prevalence of Leptospira species in Mazandaran Province of Iran by using nested polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) methods and sequencing analysis. Blood samples (n = 119) were collected from humans suspected of having leptospirosis from different parts of the province in 2007. By using an indirect immunofluorescent antibody test (IFAT), we determined that 35 (29.4%) of 119 suspected cases had leptospiral antibody titers ≥ 1:80, which confirmed the diagnosis of leptospirosis. Nested PCR assay also determined that 60 (50.4%) of 119 samples showed Leptospira infection. Furthermore, 44 (73.3%) of 60 confirmed leptospirosis amplified products were subjected to sequencing analysis. Sequence alignment identified L. interrogans, L. kirschneri, and L. wolffii species. All positive cases diagnosed by IFAT or PCR were in patients who reported contact with animals, high-risk occupational activities, and exposure to contaminated water. Therefore, it is important to increase attention about this disease among physicians and to strengthen laboratory capacity for its diagnosis in infected patients in Iran. PMID:20439973

  9. Aims, methods and preliminary findings of the Physical Activity, Nutrition and Allergies in Children Examined in Athens (PANACEA) epidemiological study

    PubMed Central

    Priftis, Kostas N; Panagiotakos, Demosthenes B; Anthracopoulos, Michael B; Papadimitriou, Anastasios; Nicolaidou, Polyxeni

    2007-01-01

    Background To determine the prevalence of asthma symptoms in a sample of Greek children aged 10–12 years, and to evaluate these rates in relation to anthropometric, lifestyle characteristics and dietary habits. Methods During 2006, 700 schoolchildren (323 male and 377 female), aged 10–12 years (4th to 6th school grade), were selected from 18 schools located in the greater Athens area. The schools were randomly selected from a list provided by the regional educational offices. To achieve a representative sample the schools enrolled were selected from various region of the Athens area. For each child a questionnaire was completed that was developed for the purposes of the study to retrieve information on: age, sex, school class, other socio-demographic characteristics, anthropometric measurements, dietary habits (through a semi-quantitative Food Frequency Questionnaire) and physical activity status; the presence of asthma and allergies was assessed by the standard ISAAC questionnaire. Results The prevalence of wheezing in the past was 25% in boys and 19% in girls, while the prevalence of current wheezing was 9.0% in boys and 5.8% in girls. The prevalence of any asthma symptoms was 27.6% in boys and 20.4% in girls. Multiple logistic regression analysis revealed that increased body weight and sedentary lifestyle is associated with asthma symptoms only in boys. Conclusion The present cross-sectional study cannot establish causal relationships between asthma and increased body weight of schoolchildren; however, our findings underline the associations between asthma, increased body weight, and physical activity at population level, and urge for actions that should be taken by public health policy makers in order to prevent these conditions among children. PMID:17610743

  10. Assessing the Epidemiological Data and Management Methods of Body Packers Admitted to a Referral Center in Iran.

    PubMed

    Alipour-Faz, Athena; Shadnia, Shahin; Mirhashemi, Seyyed Hadi; Peyvandi, Maryam; Oroei, Mahbobeh; Shafagh, Omid; Peyvandi, Hassan; Peyvandi, Ali Asghar

    2016-05-01

    The incidence of smuggling and transporting illegal substances by internal concealment, also known as body packing, is on the rise. The clinical approach to such patients has been changed significantly over the past 2 decades. However, despite a recorded increase in body packing in general, there are controversies in the management of these patients. We aimed to gather data regarding the demographic characteristics, treatment, and outcome of body packers, which were that referred to Loghman Hakim Hospital, Tehran, Iran.The data of all body packers admitted to Loghman Hakim Hospital during 2010 to 2014 were evaluated retrospectively. Data regarding the demographic characteristics of the patients, findings of clinical imaging, treatment, and outcome were recorded.In this study, 175 individuals with a mean age of 31 ± 10 years were assessed. The most common concealed substances were crack (37%), crystal (17%), opium (13%), and heroin (6%). According to the results of surgery and imaging (abdominal radiography or computed tomography), the most common place for concealment was stomach in 33.3% and 12% of cases, respectively. Imaging findings were normal in 18% of the individuals. Forty-eight (27%) patients underwent surgery. The main indications for surgery were clinical manifestations of toxicity (79%) and obstruction of the gastro-intestinal tract (17%). The most common surgical techniques were laparotomy and gastrotomy (50%). The mean duration of hospitalization was 3.8 ± 4 days. The mortality rate was 3%.Conservative treatment of body packers seems to be the best treatment method. Careful monitoring of the patients for possible signs and symptoms of intoxication and gastro-intestinal obstruction is strongly recommended. PMID:27175693

  11. Assessing the Epidemiological Data and Management Methods of Body Packers Admitted to a Referral Center in Iran

    PubMed Central

    Alipour-faz, Athena; Shadnia, Shahin; Mirhashemi, Seyyed Hadi; Peyvandi, Maryam; Oroei, Mahbobeh; Shafagh, Omid; Peyvandi, Hassan; Peyvandi, Ali Asghar

    2016-01-01

    Abstract The incidence of smuggling and transporting illegal substances by internal concealment, also known as body packing, is on the rise. The clinical approach to such patients has been changed significantly over the past 2 decades. However, despite a recorded increase in body packing in general, there are controversies in the management of these patients. We aimed to gather data regarding the demographic characteristics, treatment, and outcome of body packers, which were that referred to Loghman Hakim Hospital, Tehran, Iran. The data of all body packers admitted to Loghman Hakim Hospital during 2010 to 2014 were evaluated retrospectively. Data regarding the demographic characteristics of the patients, findings of clinical imaging, treatment, and outcome were recorded. In this study, 175 individuals with a mean age of 31 ± 10 years were assessed. The most common concealed substances were crack (37%), crystal (17%), opium (13%), and heroin (6%). According to the results of surgery and imaging (abdominal radiography or computed tomography), the most common place for concealment was stomach in 33.3% and 12% of cases, respectively. Imaging findings were normal in 18% of the individuals. Forty-eight (27%) patients underwent surgery. The main indications for surgery were clinical manifestations of toxicity (79%) and obstruction of the gastro-intestinal tract (17%). The most common surgical techniques were laparotomy and gastrotomy (50%). The mean duration of hospitalization was 3.8 ± 4 days. The mortality rate was 3%. Conservative treatment of body packers seems to be the best treatment method. Careful monitoring of the patients for possible signs and symptoms of intoxication and gastro-intestinal obstruction is strongly recommended. PMID:27175693

  12. ADHD in the Arab World: A Review of Epidemiologic Studies

    ERIC Educational Resources Information Center

    Farah, Lynn G.; Fayyad, John A.; Eapen, Valsamma; Cassir,Youmna; Salamoun, Mariana M.; Tabet, Caroline C.; Mneimneh, Zeina N.; Karam, Elie G.

    2009-01-01

    Objective: Epidemiological studies on psychiatric disorders are quite rare in the Arab World. This article reviews epidemiological studies on ADHD in all the Arab countries. Method: All epidemiological studies on ADHD conducted from 1966 through th present were reviewed. Samples were drawn from the general community, primary care clinical…

  13. [Epidemiology of "sick buildings"].

    PubMed

    Sterling, T D; Collett, C; Rumel, D

    1991-02-01

    The indoor environment of modern buildings, especially those designed for commercial and administrative purposes, constitutes a unique ecological niche with its own biochemical environment, fauna and flora. Sophisticated construction methods and the new materials and machinery required to maintain the indoor environment of these enclosed structures produce a large number of chemical by-products and permit the growth of many different microorganisms. Because modern office buildings are sealed, the regulation of humidification and temperature of ducted air presents a dilemma, since difference species of microorganisms flourish at different combinations of humidity and temperature. If the indoor environment of modern office buildings is not properly maintained, the environment may become harmful to its occupants' health. Such buildings are classified as "Sick Buildings". A review of the epidemiology of building illness is presented. The etiology of occupant illnesses, sources of toxic substances, and possible methods of maintaining a safe indoor environment are described. PMID:1784964

  14. Ecogeographic Genetic Epidemiology

    PubMed Central

    Sloan, Chantel D.; Duell, Eric J.; Shi, Xun; Irwin, Rebecca; Andrew, Angeline S.; Williams, Scott M.; Moore, Jason H.

    2009-01-01

    Complex diseases such as cancer and heart disease result from interactions between an individual's genetics and environment, i.e. their human ecology. Rates of complex diseases have consistently demonstrated geographic patterns of incidence, or spatial “clusters” of increased incidence relative to the general population. Likewise, genetic subpopulations and environmental influences are not evenly distributed across space. Merging appropriate methods from genetic epidemiology, ecology and geography will provide a more complete understanding of the spatial interactions between genetics and environment that result in spatial patterning of disease rates. Geographic Information Systems (GIS), which are tools designed specifically for dealing with geographic data and performing spatial analyses to determine their relationship, are key to this kind of data integration. Here the authors introduce a new interdisciplinary paradigm, ecogeographic genetic epidemiology, which uses GIS and spatial statistical analyses to layer genetic subpopulation and environmental data with disease rates and thereby discern the complex gene-environment interactions which result in spatial patterns of incidence. PMID:19025788

  15. Quantifying Uncertainty in Epidemiological Models

    SciTech Connect

    Ramanathan, Arvind; Jha, Sumit Kumar

    2012-01-01

    Modern epidemiology has made use of a number of mathematical models, including ordinary differential equation (ODE) based models and agent based models (ABMs) to describe the dynamics of how a disease may spread within a population and enable the rational design of strategies for intervention that effectively contain the spread of the disease. Although such predictions are of fundamental importance in preventing the next global pandemic, there is a significant gap in trusting the outcomes/predictions solely based on such models. Hence, there is a need to develop approaches such that mathematical models can be calibrated against historical data. In addition, there is a need to develop rigorous uncertainty quantification approaches that can provide insights into when a model will fail and characterize the confidence in the (possibly multiple) model outcomes/predictions, when such retrospective analysis cannot be performed. In this paper, we outline an approach to develop uncertainty quantification approaches for epidemiological models using formal methods and model checking. By specifying the outcomes expected from a model in a suitable spatio-temporal logic, we use probabilistic model checking methods to quantify the probability with which the epidemiological model satisfies the specification. We argue that statistical model checking methods can solve the uncertainty quantification problem for complex epidemiological models.

  16. [METHODS AND TECHNOLOGIES OF HEALTH RISK ANALYSIS IN THE SYSTEM OF THE STATE MANAGEMENT UNDER ASSURANCE OF THE SANITATION AND EPIDEMIOLOGICAL WELFARE OF POPULATION].

    PubMed

    Zaĭtseva, N V; Popova, A Iu; Maĭ, I V; Shur, P Z

    2015-01-01

    The methodology of the analysis of health risk at the present stage of development of Russian society is in-demand at all levels of government management. In conjunction with the methods of mathematical modeling, spatial-temporal analysis and economic tools the risk assessment in the analysis of the situation makes it possible to determine the level of safety of the population, workers and consumers, to select prior resources, and threat factors as a point for exertion efforts. At the planning stage risk assessment is a basis for the establishment of most effective measures for the minimization of hazard and dangers. At the realization stage the methodology allows to estimate the efficiency of measures; at the control and supervision phase it permits to select out priorities for the concentration of efforts on the objects of maximal health risk for population. Risk assessments, including the elements of evolutionary modeling, are incorporated in the system of state hygienic regulation, the formation of evidence base of harm to health, the organization of control and supervisory activities. This allows you to harmonize the domestic legal framework with ternational legal requirements and ultimately enhances the credibility of the Russian data on the safety of the environment products and services. There is seemed to be actual the further assignment of enforcement of methodology of health risk analysis in the field of assurance of sanitary and epidemiological well-being and health of employers; he development of informational and analytical base in the part of the establishment of models of dependencies "exposure-response" for different types and levels of exposure and risk contingents; the accuracy enhancement of estimations of exposure; improvement of the economic aspects of health risk analysis and forecasting of measures aimed at mitigation of the losses associated with the negative impact of manifold factors on the health of citizens. PMID:26155657

  17. [The contribution of epidemiology to disease control: malaria].

    PubMed

    Osorio, Lyda E

    2013-01-01

    Despite the number of cases and attributable mortality having become reduced, malaria continues to be an important public health problem. This report presents some examples of epidemiology's contribution to malaria control; it also motivates reflexion to the contrary, i.e. malaria's contribution to the development of epidemiology. Attempting to identify methods for measuring epidemiology's contribution to malaria control led to an in-depth analysis of what exactly does epidemiology consist of, whether all its contributions could be considered positive and to what extent they might have been due just to epidemiology. PMID:25124242

  18. Multicenter Study of Epidemiological Cutoff Values and Detection of Resistance in Candida spp. to Anidulafungin, Caspofungin, and Micafungin Using the Sensititre YeastOne Colorimetric Method

    PubMed Central

    Alvarez-Fernandez, M.; Cantón, E.; Carver, P. L.; Chen, S. C.-A.; Eschenauer, G.; Getsinger, D. L.; Gonzalez, G. M.; Govender, N. P.; Grancini, A.; Hanson, K. E.; Kidd, S. E.; Klinker, K.; Kubin, C. J.; Kus, J. V.; Lockhart, S. R.; Meletiadis, J.; Morris, A. J.; Pelaez, T.; Quindós, G.; Rodriguez-Iglesias, M.; Sánchez-Reus, F.; Shoham, S.; Wengenack, N. L.; Borrell Solé, N.; Echeverria, J.; Esperalba, J.; Gómez-G. de la Pedrosa, E.; García García, I.; Linares, M. J.; Marco, F.; Merino, P.; Pemán, J.; Pérez del Molino, L.; Roselló Mayans, E.; Rubio Calvo, C.; Ruiz Pérez de Pipaon, M.; Yagüe, G.; Garcia-Effron, G.; Guinea, J.; Perlin, D. S.; Sanguinetti, M.; Shields, R.; Turnidge, J.

    2015-01-01

    Neither breakpoints (BPs) nor epidemiological cutoff values (ECVs) have been established for Candida spp. with anidulafungin, caspofungin, and micafungin when using the Sensititre YeastOne (SYO) broth dilution colorimetric method. In addition, reference caspofungin MICs have so far proven to be unreliable. Candida species wild-type (WT) MIC distributions (for microorganisms in a species/drug combination with no detectable phenotypic resistance) were established for 6,007 Candida albicans, 186 C. dubliniensis, 3,188 C. glabrata complex, 119 C. guilliermondii, 493 C. krusei, 205 C. lusitaniae, 3,136 C. parapsilosis complex, and 1,016 C. tropicalis isolates. SYO MIC data gathered from 38 laboratories in Australia, Canada, Europe, Mexico, New Zealand, South Africa, and the United States were pooled to statistically define SYO ECVs. ECVs for anidulafungin, caspofungin, and micafungin encompassing ≥97.5% of the statistically modeled population were, respectively, 0.12, 0.25, and 0.06 μg/ml for C. albicans, 0.12, 0.25, and 0.03 μg/ml for C. glabrata complex, 4, 2, and 4 μg/ml for C. parapsilosis complex, 0.5, 0.25, and 0.06 μg/ml for C. tropicalis, 0.25, 1, and 0.25 μg/ml for C. krusei, 0.25, 1, and 0.12 μg/ml for C. lusitaniae, 4, 2, and 2 μg/ml for C. guilliermondii, and 0.25, 0.25, and 0.12 μg/ml for C. dubliniensis. Species-specific SYO ECVs for anidulafungin, caspofungin, and micafungin correctly classified 72 (88.9%), 74 (91.4%), 76 (93.8%), respectively, of 81 Candida isolates with identified fks mutations. SYO ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin, micafungin, and especially caspofungin, since testing the susceptibilities of Candida spp. to caspofungin by reference methodologies is not recommended. PMID:26282428

  19. Multicenter study of epidemiological cutoff values and detection of resistance in Candida spp. to anidulafungin, caspofungin, and micafungin using the Sensititre YeastOne colorimetric method.

    PubMed

    Espinel-Ingroff, A; Alvarez-Fernandez, M; Cantón, E; Carver, P L; Chen, S C-A; Eschenauer, G; Getsinger, D L; Gonzalez, G M; Govender, N P; Grancini, A; Hanson, K E; Kidd, S E; Klinker, K; Kubin, C J; Kus, J V; Lockhart, S R; Meletiadis, J; Morris, A J; Pelaez, T; Quindós, G; Rodriguez-Iglesias, M; Sánchez-Reus, F; Shoham, S; Wengenack, N L; Borrell Solé, N; Echeverria, J; Esperalba, J; Gómez-G de la Pedrosa, E; García García, I; Linares, M J; Marco, F; Merino, P; Pemán, J; Pérez Del Molino, L; Roselló Mayans, E; Rubio Calvo, C; Ruiz Pérez de Pipaon, M; Yagüe, G; Garcia-Effron, G; Guinea, J; Perlin, D S; Sanguinetti, M; Shields, R; Turnidge, J

    2015-11-01

    Neither breakpoints (BPs) nor epidemiological cutoff values (ECVs) have been established for Candida spp. with anidulafungin, caspofungin, and micafungin when using the Sensititre YeastOne (SYO) broth dilution colorimetric method. In addition, reference caspofungin MICs have so far proven to be unreliable. Candida species wild-type (WT) MIC distributions (for microorganisms in a species/drug combination with no detectable phenotypic resistance) were established for 6,007 Candida albicans, 186 C. dubliniensis, 3,188 C. glabrata complex, 119 C. guilliermondii, 493 C. krusei, 205 C. lusitaniae, 3,136 C. parapsilosis complex, and 1,016 C. tropicalis isolates. SYO MIC data gathered from 38 laboratories in Australia, Canada, Europe, Mexico, New Zealand, South Africa, and the United States were pooled to statistically define SYO ECVs. ECVs for anidulafungin, caspofungin, and micafungin encompassing ≥97.5% of the statistically modeled population were, respectively, 0.12, 0.25, and 0.06 μg/ml for C. albicans, 0.12, 0.25, and 0.03 μg/ml for C. glabrata complex, 4, 2, and 4 μg/ml for C. parapsilosis complex, 0.5, 0.25, and 0.06 μg/ml for C. tropicalis, 0.25, 1, and 0.25 μg/ml for C. krusei, 0.25, 1, and 0.12 μg/ml for C. lusitaniae, 4, 2, and 2 μg/ml for C. guilliermondii, and 0.25, 0.25, and 0.12 μg/ml for C. dubliniensis. Species-specific SYO ECVs for anidulafungin, caspofungin, and micafungin correctly classified 72 (88.9%), 74 (91.4%), 76 (93.8%), respectively, of 81 Candida isolates with identified fks mutations. SYO ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin, micafungin, and especially caspofungin, since testing the susceptibilities of Candida spp. to caspofungin by reference methodologies is not recommended. PMID:26282428

  20. Vaccine epidemiology: A review

    PubMed Central

    Lahariya, Chandrakant

    2016-01-01

    This review article outlines the key concepts in vaccine epidemiology, such as basic reproductive numbers, force of infection, vaccine efficacy and effectiveness, vaccine failure, herd immunity, herd effect, epidemiological shift, disease modeling, and describes the application of this knowledge both at program levels and in the practice by family physicians, epidemiologists, and pediatricians. A case has been made for increased knowledge and understanding of vaccine epidemiology among key stakeholders including policy makers, immunization program managers, public health experts, pediatricians, family physicians, and other experts/individuals involved in immunization service delivery. It has been argued that knowledge of vaccine epidemiology which is likely to benefit the society through contributions to the informed decision-making and improving vaccination coverage in the low and middle income countries (LMICs). The article ends with suggestions for the provision of systematic training and learning platforms in vaccine epidemiology to save millions of preventable deaths and improve health outcomes through life-course. PMID:27453836

  1. [Epidemiological research in Brazil].

    PubMed

    Guimarães, R; Lourenço-De-Oliveira, R; Cosac, S

    2001-08-01

    The current epidemiological research in Brazil is described. Secondary data sources were consulted, such as the year 2000 database of the Brazilian Directory of Research Groups and the National Board of Scientific and Technological Development (CNPq). The criterion to identify a group as a research one relies on the existence of at least one research line in the field of epidemiology, as defined by the group leader. After identifying the defined universe of epidemiological research, which included 176 groups and 320 different research lines, the following issues were presented and discussed: the relationships between research financing and health research, focusing on CAPES (Coordination Center for the Advance of University Professionals) graduation programs, public health research and epidemiological research, geographic and institutional distribution and outreach of the current epidemiological research, the researchers and students directly participating in epidemiological research, research topics and patterns of disseminating research findings; the journals where papers in its fullness were published; the financial support of the epidemiological research focusing on the 23 officially recognized graduate programs in public health field. PMID:11600921

  2. Networks and the Epidemiology of Infectious Disease

    PubMed Central

    Danon, Leon; Ford, Ashley P.; House, Thomas; Jewell, Chris P.; Keeling, Matt J.; Roberts, Gareth O.; Ross, Joshua V.; Vernon, Matthew C.

    2011-01-01

    The science of networks has revolutionised research into the dynamics of interacting elements. It could be argued that epidemiology in particular has embraced the potential of network theory more than any other discipline. Here we review the growing body of research concerning the spread of infectious diseases on networks, focusing on the interplay between network theory and epidemiology. The review is split into four main sections, which examine: the types of network relevant to epidemiology; the multitude of ways these networks can be characterised; the statistical methods that can be applied to infer the epidemiological parameters on a realised network; and finally simulation and analytical methods to determine epidemic dynamics on a given network. Given the breadth of areas covered and the ever-expanding number of publications, a comprehensive review of all work is impossible. Instead, we provide a personalised overview into the areas of network epidemiology that have seen the greatest progress in recent years or have the greatest potential to provide novel insights. As such, considerable importance is placed on analytical approaches and statistical methods which are both rapidly expanding fields. Throughout this review we restrict our attention to epidemiological issues. PMID:21437001

  3. Evolution and social epidemiology.

    PubMed

    Nishi, Akihiro

    2015-11-01

    Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology. PMID:26319950

  4. Comparison of Three Statistical Methods for Establishing Tentative Wild-Type Population and Epidemiological Cutoff Values for Echinocandins, Amphotericin B, Flucytosine, and Six Candida Species as Determined by the Colorimetric Sensititre YeastOne Method

    PubMed Central

    Pemán, Javier; Hervás, David; Iñiguez, Carmen; Navarro, David; Echeverría, Julia; Martínez-Alarcón, José; Fontanals, Dionisia; Gomila-Sard, Bárbara; Buendía, Buenaventura; Torroba, Luis; Ayats, Josefina; Bratos, Angel; Sánchez-Reus, Ferran; Fernández-Natal, Isabel

    2012-01-01

    The Sensititre YeastOne (SYO) method is a widely used method to determine the susceptibility of Candida spp. to antifungal agents. CLSI clinical breakpoints (CBP) have been reported for antifungals, but not using this method. In the absence of CBP, epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (those without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of any susceptibility test. The ECVs for five agents, obtained using the MIC distributions determined by the SYO test, were calculated and contrasted with those for three statistical methods and the MIC50 and modal MIC, both plus 2-fold dilutions. The median ECVs (in mg/liter) (% of isolates inhibited by MICs equal to or less than the ECV; number of isolates tested) of the five methods for anidulafungin, micafungin, caspofungin, amphotericin B, and flucytosine, respectively, were as follows: 0.25 (98.5%; 656), 0.06 (95.1%; 659), 0.25 (98.7%; 747), 2 (100%; 923), and 1 (98.5%; 915) for Candida albicans; 8 (100%; 352), 4 (99.2%; 392), 2 (99.2%; 480), 1 (99.8%; 603), and 0.5 (97.9%; 635) for C. parapsilosis; 1 (99.2%; 123), 0.12 (99.2%; 121), 0.25 (99.2%; 138), 2 (100%; 171), and 0.5 (97.2%; 175) for C. tropicalis; 0.12 (96.6%; 174), 0.06 (96%; 176), 0.25 (98.4%; 188), 2 (100%; 209), and 0.25 (97.6%; 208) for C. glabrata; 0.25 (97%; 33), 0.5 (93.9%; 33), 1 (91.9%; 37), 4 (100%; 51), and 32 (100%; 53) for C. krusei; and 4 (100%; 33), 2 (100%; 33), 2 (100%; 54), 1 (100%; 90), and 0.25 (93.4%; 91) for C. orthopsilosis. The three statistical methods gave similar ECVs (within one dilution) and included ≥95% of isolates. These tentative ECVs would be useful for monitoring the emergence of isolates with reduced susceptibility by use of the SYO method. PMID:23015676

  5. Epidemiology of Enterocytozoon bieneusi Infection in Humans

    PubMed Central

    Matos, Olga; Lobo, Maria Luisa; Xiao, Lihua

    2012-01-01

    A review was conducted to examine published works that focus on the complex epidemiology of Enterocytozoon bieneusi infection in humans. Studies on the prevalence of these emerging microsporidian pathogens in humans, in developed and developing countries, the different clinical spectra of E. bieneusi intestinal infection in children, in different settings, and the risk factors associated with E. bieneusi infection have been reviewed. This paper also analyses the impact of the recent application of PCR-based molecular methods for species-specific identification and genotype differentiation has had in increasing the knowledge of the molecular epidemiology of E. bieneusi in humans. The advances in the epidemiology of E. bieneusi, in the last two decades, emphasize the importance of epidemiological control and prevention of E. bieneusi infections, from both the veterinary and human medical perspectives. PMID:23091702

  6. Epidemiology of Substance Use Disorders

    PubMed Central

    Merikangas, Kathleen R.; McClair, Vetisha L.

    2013-01-01

    Epidemiological studies of substance use and substance use disorders (SUDs) have provided an abundance of data on the patterns of substance use in nationally representative samples across the world (Degenhardt et al. 2008; Johnston et al. 2011; SAMHSA 2011). This paper presents a summary of the goals, methods and recent findings on the epidemiology of substance use and disorders in the general population of adults and adolescents and describes the methods and findings on the genetic epidemiology of drug use disorders. The high 12 month prevalence rates of substance dependence in U.S. adults (about 12% for alcohol and 2–3% for illicit drugs) approximate those of other mental disorders as well as chronic physical disorders with major public health impact. New findings from the nationally representative samples of U.S. youth reveal that the lifetime prevalence of alcohol use disorders is approximately 8% and illicit drug use disorders is 2–3% (Merikangas et al. 2010; Swendsen et al. in press, SAMSHA, 2011). The striking increase in prevalence rates from ages 13 to 18 highlight adolescence as the key period of development of substance use disorders. The application of genetic epidemiological studies has consistently demonstrated that genetic factors have a major influence on progression of substance use to dependence, whereas environmental factors unique to the individual play an important role in exposure and initial use of substances. Identification of specific susceptibility genes and environmental factors that influence exposure and progression of drug use may enhance our ability to prevent and treat substance use disorders. PMID:22543841

  7. Epidemiology of Lice

    ERIC Educational Resources Information Center

    Juranek, Dennis D.

    1977-01-01

    Research into the epidemiology of lice indicates that infestation is uncommon in blacks, more common in females than males, significantly higher in low income groups, and transmission is by way of articles of clothing. (JD)

  8. Cancer Epidemiology Cohorts

    Cancer.gov

    Cohort studies are fundamental for epidemiological research by helping researchers better understand the etiology of cancer and provide insights into the key determinants of this disease and its outcomes.

  9. Epidemiology of varicocele

    PubMed Central

    Alsaikhan, Bader; Alrabeeah, Khalid; Delouya, Guila; Zini, Armand

    2016-01-01

    Varicocele is a common problem in reproductive medicine practice. A varicocele is identified in 15% of healthy men and up to 35% of men with primary infertility. The exact pathophysiology of varicoceles is not very well understood, especially regarding its effect on male infertility. We have conducted a systematic review of studies evaluating the epidemiology of varicocele in the general population and in men presenting with infertility. In this article, we have identified some of the factors that can influence the epidemiological aspects of varicoceles. We also recognize that varicocele epidemiology remains incompletely understood, and there is a need for well-designed, large-scale studies to fully define the epidemiological aspects of this condition. PMID:26763551

  10. EPIDEMIOLOGY AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    Research collaborations between the National Health and Environmental Effects Research Laboratory (NHEERL) and the National Exposure Research Laboratory (NERL) centered on the development and application of exposure analysis tools in environmental epidemiology include the El Paso...

  11. Epidemiology & Genomics Research Program

    Cancer.gov

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  12. Molecular Epidemiology of Tuberculosis: Current Insights

    PubMed Central

    Mathema, Barun; Kurepina, Natalia E.; Bifani, Pablo J.; Kreiswirth, Barry N.

    2006-01-01

    Molecular epidemiologic studies of tuberculosis (TB) have focused largely on utilizing molecular techniques to address short- and long-term epidemiologic questions, such as in outbreak investigations and in assessing the global dissemination of strains, respectively. This is done primarily by examining the extent of genetic diversity of clinical strains of Mycobacterium tuberculosis. When molecular methods are used in conjunction with classical epidemiology, their utility for TB control has been realized. For instance, molecular epidemiologic studies have added much-needed accuracy and precision in describing transmission dynamics, and they have facilitated investigation of previously unresolved issues, such as estimates of recent-versus-reactive disease and the extent of exogenous reinfection. In addition, there is mounting evidence to suggest that specific strains of M. tuberculosis belonging to discrete phylogenetic clusters (lineages) may differ in virulence, pathogenesis, and epidemiologic characteristics, all of which may significantly impact TB control and vaccine development strategies. Here, we review the current methods, concepts, and applications of molecular approaches used to better understand the epidemiology of TB. PMID:17041139

  13. Epidemiology of Lung Cancer

    PubMed Central

    Brock, Malcolm V.; Ford, Jean G.; Samet, Jonathan M.; Spivack, Simon D.

    2013-01-01

    Background: Ever since a lung cancer epidemic emerged in the mid-1900s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research. Methods: A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk. Results: Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application. Conclusions: Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers. PMID:23649439

  14. Causal diagrams in systems epidemiology

    PubMed Central

    2012-01-01

    Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s). Transmitted causes ("causes of causes") tend not to be systematically analysed. The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties. The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets. Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback. PMID:22429606

  15. Shifting epidemiology of Flaviviridae.

    PubMed

    Petersen, Lyle R; Marfin, Anthony A

    2005-04-01

    The dengue, West Nile, Japanese encephalitis and yellow fever viruses are important mosquito-borne viruses whose epidemiology is shifting in response to changing societal factors, such as increasing commerce, urbanization of rural areas, and population growth. All four viruses are expanding geographically, as exemplified by the emergence of West Nile virus in the Americas and Japanese encephalitis virus in Australasia. The large, recent global outbreaks of severe neurological disease caused by West Nile virus, the increasing frequency of dengue hemorrhagic fever outbreaks in the Americas, and the emergence of yellow fever virus vaccination-associated viscerotropic disease, are new clinical epidemiologic trends. These worrisome epidemiologic trends will probably continue in coming decades, as a reversal of their societal and biological drivers is not in sight. Nevertheless, the substantial reductions in Japanese encephalitis virus incidence resulting from vaccination programs and economic development in some Asian countries provide some encouragement within this overall guarded outlook. PMID:16225801

  16. Navigating the future of bacterial molecular epidemiology

    PubMed Central

    Baker, Stephen; Hanage, William P; Holt, Kathryn E

    2010-01-01

    Technological advances in high-throughput genome sequencing have led to an enhanced appreciation of the genetic diversity found within populations of pathogenic bacteria. Methods based on single nucleotide polymorphisms (SNPs) and insertions or deletions (indels) build upon the framework established by multi-locus sequence typing (MLST) and permit a detailed, targeted analysis of variation within related organisms. Robust phylogenetics, when combined with epidemiologically informative data, can be applied to study ongoing temporal and geographical fluctuations in bacterial pathogens. As genome sequencing, SNP detection and geospatial information become more accessible these methods will continue to transform the way molecular epidemiology is used to study populations of bacterial pathogens. PMID:20846899

  17. Epidemiology of Lung Cancer.

    PubMed

    Mao, Yousheng; Yang, Ding; He, Jie; Krasna, Mark J

    2016-07-01

    Lung cancer has been transformed from a rare disease into a global problem and public health issue. The etiologic factors of lung cancer become more complex along with industrialization, urbanization, and environmental pollution around the world. Currently, the control of lung cancer has attracted worldwide attention. Studies on the epidemiologic characteristics of lung cancer and its relative risk factors have played an important role in the tertiary prevention of lung cancer and in exploring new ways of diagnosis and treatment. This article reviews the current evolution of the epidemiology of lung cancer. PMID:27261907

  18. [Future prospects of molecular epidemiology in tuberculosis].

    PubMed

    Matsumoto, Tomoshige; Iwamoto, Tomotada

    2009-12-01

    Before the availability of high-resolution genotyping tools in 1990s, there was a prevailing dogma of little genomic sequence diversity in Mycobacterium tuberculosis. Due to the low levels of genetic variation, it was assumed that M. tuberculosis exhibit very little phenotypic variation in immunologic and virulence factors. The fingerprinting method based on restriction fragment length polymorphisms (RFLP) of IS6110 insertion sequences had unveiled the underestimation of the sequence variation in M. tuberculosis and the importance of strain-to-strain variation for understanding pathogenesis, immune mechanisms, bacterial evolution, and host adaptation. This method became a gold standard for strain differentiation in the molecular epidemiological study. It had lead to a profusion of studies in molecular epidemiology such as the detection of unsuspected transmission, the estimation of the extent of recent transmission, the identification of laboratory cross-contamination, the identification of outbreaks, and distinction between reinfection and relapse. This, in 1990s, is the opening of the molecular epidemiology of tuberculosis. After the completion of genome project of the M. tuberculosis laboratory strain H37Rv, some of the clinical isolates were completely sequenced. This prompted the in silico genome comparison and identified various genomic markers which can give a unifying framework for both epidemiology and evolutionary analysis of M. tuberculosis population. Of them, variable numbers of tandem repeats (VNTR) was found as the most promising PCR-based method which can provide adequate discrimination of M. tuberculosis strains in many cases, including the estimation of M. tuberculosis transmission and the identification of genetic lineages. PCR-based VNTR analysis is easy, rapid, and highly specific and can generate portable digit-based data, unlike the analog information obtained from IS6110 RFLP which is labor intensive. In this regards, investigators can

  19. WHO activities in oral epidemiology.

    PubMed

    Barmes, D E; Infirri, J S

    1977-01-01

    Standard methods to facilitate the collection of data on a global basis have been developed by WHO. Data collection in accordance with criteria proposed by WHO began in 1969 from existing sources and was subsequently supplemented by new data collected using the standard methods. Associated with these methods developments, a WHO Global Oral Epidemiology program was begun with the objective of facilitating comparison of data and their use in planning, replanning, and evaluating oral health services according to needs and economic possibilities. That program provides an orderly storage and retrieval system and a visual representation of contrasts in prevalence of those oral diseases which are among the most common known to man. In selecting data for inclusion in the WHO oral epidemiology data bank, a liberal policy has been pursued to make maximum use of available material. The system of classification allows for data retrieval at various levels and for specific ages. Data on caries are available for 95 countries and on periodontal diseases for 50 countries. PMID:264415

  20. Epidemiology of juvenile violence.

    PubMed

    Farrington, D P; Loeber, R

    2000-10-01

    , and especially on interactions between biologic and psychosocial risk factors. Important short-term situational factors include motives of potential offenders (e.g., anger, a desire to hurt), alcohol consumption, and actions leading to violent events (e.g., the escalation of a trivial altercation). More specific research is needed on protective factors against youth violence, for example, by investigating why aggressive children do not become violent juveniles. More research is also needed on the development and validation of risk assessment instruments. To investigate developmental and risk factors for juvenile violence, longitudinal studies are needed. Such studies should include multiple cohorts, to draw conclusions about different age groups, and should include both boys and girls and the major racial and ethnic groups. They should measure a wide range of risk and especially protective factors. They should be based on large, high-risk samples, especially in inner-city areas, incorporating screening methods to maximize the yield of violent offenders while simultaneously making it possible to draw conclusions about the total population. They should include long-term follow-up studies to permit conclusions about developmental pathways. They should make a special effort to study careers of violence and to link developmental and situational data. It will not be easy to mount new longitudinal studies focusing specifically on juvenile violence, but such studies are needed to advance knowledge about the epidemiology of juvenile violence, including risk factors and developmental pathways. PMID:11005003

  1. Corporate influences on epidemiology.

    PubMed

    Pearce, Neil

    2008-02-01

    Corporate influences on epidemiology have become stronger and more pervasive in the last few decades, particularly in the contentious fields of pharmacoepidemiology and occupational epidemiology. For every independent epidemiologist studying the side effects of medicines and the hazardous effects of industrial chemicals, there are several other epidemiologists hired by industry to attack the research and to debunk it as 'junk science'. In some instances these activities have gone as far as efforts to block publication. In many instances, academics have accepted industry funding which has not been acknowledged, and only the academic affiliations of the company-funded consultants have been listed. These activities are major threats to the integrity of the field, and its survival as a scientific discipline. There is no simple solution to these problems. However, for the last two decades there has been substantial discussion on ethics in epidemiology, partly in response to the unethical conduct of many industry-funded consultants. Professional organizations, such as the International Epidemiological Association, can play a major role in encouraging and supporting epidemiologists to assert positive principles of how science should work, and how it should be applied to public policy decisions, rather than simply having a list of what not to do. PMID:18245050

  2. Epidemiology of Down Syndrome

    ERIC Educational Resources Information Center

    Sherman, Stephanie L.; Allen, Emily G.; Bean, Lora H.; Freeman, Sallie B.

    2007-01-01

    Down syndrome (DS) is the most commonly identified genetic form of mental retardation and the leading cause of specific birth defects and medical conditions. Traditional epidemiological studies to determine the prevalence, cause, and clinical significance of the syndrome have been conducted over the last 100 years. DS has been estimated to occur…

  3. Phylogenetically resolving epidemiologic linkage

    PubMed Central

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-01-01

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results. PMID:26903617

  4. Phylogenetically resolving epidemiologic linkage

    DOE PAGESBeta

    Romero-Severson, Ethan O.; Bulla, Ingo; Leitner, Thomas

    2016-02-22

    The use of phylogenetic trees in epidemiological investigations has become commonplace, but their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the truemore » transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals’ HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. Moreover, we confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.« less

  5. Epidemiology of Cardiovascular Diseases.

    ERIC Educational Resources Information Center

    Jenkins, C. David

    1988-01-01

    Reviews epidemiological studies of cardiovascular diseases especially coronary heart disease (CHD), to document their major public health importance, changes in mortality during this century, and international comparisons of trends. Finds major risk factors for CHD are determined in large part by psychosocial and behavioral mechanisms. Asserts…

  6. Phylogenetically resolving epidemiologic linkage.

    PubMed

    Romero-Severson, Ethan O; Bulla, Ingo; Leitner, Thomas

    2016-03-01

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals' HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results. PMID:26903617

  7. Concepts in Huanglongbing Epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB) was discovered in Brazil and Florida in 2004 and 2005 respectively. Previously, very few quantitative epidemiological studies had been conducted, and thus the increase and spread of the disease remains incompletely characterized. The perennial nature of the disease necessitates...

  8. Translational Epidemiology in Psychiatry

    PubMed Central

    Weissman, Myrna M.; Brown, Alan S.; Talati, Ardesheer

    2012-01-01

    Translational research generally refers to the application of knowledge generated by advances in basic sciences research translated into new approaches for diagnosis, prevention, and treatment of disease. This direction is called bench-to-bedside. Psychiatry has similarly emphasized the basic sciences as the starting point of translational research. This article introduces the term translational epidemiology for psychiatry research as a bidirectional concept in which the knowledge generated from the bedside or the population can also be translated to the benches of laboratory science. Epidemiologic studies are primarily observational but can generate representative samples, novel designs, and hypotheses that can be translated into more tractable experimental approaches in the clinical and basic sciences. This bedside-to-bench concept has not been explicated in psychiatry, although there are an increasing number of examples in the research literature. This article describes selected epidemiologic designs, providing examples and opportunities for translational research from community surveys and prospective, birth cohort, and family-based designs. Rapid developments in informatics, emphases on large sample collection for genetic and biomarker studies, and interest in personalized medicine—which requires information on relative and absolute risk factors—make this topic timely. The approach described has implications for providing fresh metaphors to communicate complex issues in interdisciplinary collaborations and for training in epidemiology and other sciences in psychiatry. PMID:21646577

  9. Understanding epidemiological transition in India

    PubMed Central

    Yadav, Suryakant; Arokiasamy, Perianayagam

    2014-01-01

    Background Omran's theory explains changing disease patterns over time predominantly from infectious to chronic noncommunicable diseases (NCDs). India's epidemiological transition is characterized by dual burden of diseases. Kumar addressed low mortality and high morbidity in Kerala, which seems also to be true for India as a country in the current demographic scenario. Methods NSS data (1986–1987, 1995–1996, 2004) and aggregated data on causes of death provided by Registrar General India (RGI) were used to examine the structural changes in morbidity and causes of death. A zero-inflated poisson (ZIP) regression model and a beta-binomial model were used to corroborate the mounting age pattern of morbidity. Measures, namely the 25th and 75th percentiles of age-at-death and modal age-at-death, were used to examine the advances in mortality transition. Objective This study addressed the advances in epidemiological transition via exploring the structural changes in pattern of diseases and progress in mortality transition. Results The burden of NCDs has been increasing in old age without replacing the burden of communicable diseases. The manifold rise of chronic diseases in recent decades justifies the death toll and is responsible for transformation in the age pattern of morbidity. Over time, deaths have been concentrated near the modal age-at-death. Modal age-at-death increased linearly by 5 years for females (r2=0.9515) and males (r2=0.9020). Significant increase in modal age-at-death ascertained the dominance of old age mortality over the childhood/adult age mortality. Conclusions India experiences a dual burden of diseases associated with a remarkable transformation in the age pattern of morbidity and mortality, contemporaneous with structural changes in disease patterns. Continued progress in the pattern of diseases and mortality transition, accompanied by a linear rise in ex, unravels a compelling variation in advances found so far in epidemiological

  10. Causation: the elusive grail of epidemiology.

    PubMed

    Karhausen, L R

    2000-01-01

    The paper discusses the evolving concept of causation in epidemiology and its potential interaction with logic and scientific philosophy. Causes are contingent but the necessity which binds them to their effects relies on contrary-to-fact conditionals, i.e. conditional statements whose antecedent is false. Chance instead of determinism plays a growing role in science and, although rarely acknowledged yet, in epidemiology: causes are multiple and chancy; a prior event causes a subsequent event if the probability distribution of the subsequent event changes conditionally upon the probability of the prior event. There are no known sufficient causes in epidemiology. We merely observe tendencies toward sufficiency or tendencies toward necessity: cohort studies evaluate the first tendencies, and case-control studies the latter. In applied sciences, such as medicine and epidemiology, causes are intrinsically connected with goals and effective strategies: they are recipe which have a potential harmful or successful use; they are contrastive since they make a difference between circumstances in which they are present and those in which they are absent: causes do not explain event E but event E rather than even F. Causation is intrinsically linked with the notion of "what is pathological". Any definition of causation will inevitably collapse into the use made of epidemiologic methods. The progressive methodological sophistication of the last forty years is in perfect alignment with a gradual implicit overhaul of our concept of causation. PMID:11080970

  11. An argument for a consequentialist epidemiology.

    PubMed

    Galea, Sandro

    2013-10-15

    Epidemiology is the study of the causes and distributions of diseases in human populations so that we may identify ways to prevent and control disease. Although this definition broadly serves us well, I suggest that in recent decades, our discipline's robust interest in identifying causes has come at the expense of a more rigorous engagement with the second part of our vision for ourselves-the intent for us to intervene-and that this approach threatens to diminish our field's relevance. I argue here for a consequentialist epidemiology, a formalization and recalibration of the philosophical foundations of our discipline. I discuss how epidemiology is, at its core, more comfortably a consequentialist, as opposed to a deontological, discipline. A more consequentialist approach to epidemiology has several implications. It clarifies our research priorities, offers a perspective on the place of novel epidemiologic approaches and a metric to evaluate the utility of new methods, elevates the importance of global health and considerations about equity to the discipline, brings into sharp focus our engagement in implementation and translational science, and has implications for how we teach our students. I intend this article to be a provocation that can help clarify our disciplinary intentions. PMID:24022890

  12. Epidemiology of the leishmaniases: general considerations

    PubMed Central

    Moškovskij, Š. D.; Duhanina, N. N.

    1971-01-01

    Recent information from various countries shows that the distribution of the leishmaniases is rapidly changing, as are our concepts of the diverse noso-geographical forms of infection. Concerted efforts should be made to improve our knowledge in these fields to enable the preparation of charts forecasting the spread of the disease. The basic considerations, objectives, and methods of epidemiological investigations carried out in the USSR in natural foci, as well as the classifications used for typing foci, are discussed. The need to use clear-cut epidemiological concepts is particularly stressed. PMID:5316254

  13. Principles of study design in environmental epidemiology.

    PubMed Central

    Morgenstern, H; Thomas, D

    1993-01-01

    This paper discusses the principles of study design and related methodologic issues in environmental epidemiology. Emphasis is given to studies aimed at evaluating causal hypotheses regarding exposures to suspected health hazards. Following background sections on the quantitative objectives and methods of population-based research, we present the major types of observational designs used in environmental epidemiology: first, the three basic designs involving the individual as the unit of analysis (i.e., cohort, cross-sectional, and case-control studies) and a brief discussion of genetic studies for assessing gene-environment interactions; second, various ecologic designs involving the group or region as the unit of analysis. Ecologic designs are given special emphasis in this paper because of our lack of resources or inability to accurately measure environmental exposures in large numbers of individuals. The paper concludes with a section highlighting current design issues in environmental epidemiology and several recommendations for future work. PMID:8206038

  14. History and Impact of Nutritional Epidemiology123

    PubMed Central

    Alpers, David H.; Bier, Dennis M.; Carpenter, Kenneth J.; McCormick, Donald B.; Miller, Anthony B.; Jacques, Paul F.

    2014-01-01

    The real and important role of epidemiology was discussed, noting heretofore unknown associations that led to improved understanding of the cause and prevention of individual nutritional deficiencies. However, epidemiology has been less successful in linking individual nutrients to the cause of chronic diseases, such as cancer and cardiovascular disease. Dietary changes, such as decreasing caloric intake to prevent cancer and the Mediterranean diet to prevent diabetes, were confirmed as successful approaches to modifying the incidence of chronic diseases. The role of the epidemiologist was confirmed as a collaborator, not an isolated expert of last resort. The challenge for the future is to decide which epidemiologic methods and study designs are most useful in studying chronic disease, then to determine which associations and the hypotheses derived from them are especially strong and worthy of pursuit, and finally to design randomized studies that are feasible, affordable, and likely to result in confirmation or refutation of these hypotheses. PMID:25469385

  15. The Epidemiology of Peace and War.

    ERIC Educational Resources Information Center

    Beer, Francis A.

    Health science (epidemiology) is a relatively advanced discipline which offers theories and methods which could be useful in peace science (polemology). Similarities between war and disease, peace and health, center around concern with prevention of physical damage and death on the one hand and preservation and extension of human life on the…

  16. GIS ANALYSIS FOR EPIDEMIOLOGIC RECREATIONAL WATER SUTDIES

    EPA Science Inventory

    Introduction: The Beaches Act of 2000 requires that the Agency develop new rapid method water quality indicators (2 hours or less) that predict whether or not coastal water is safe for swimming. This new set of water quality indicators must be validated through the epidemiologi...

  17. [Epidemiology of osteoporosis].

    PubMed

    Scheidt-Nave, C; Ziegler, R; Raspe, H

    1998-03-15

    Epidemiological studies have identified osteoporosis as a disease of significant public health impact and have delineated numerous potential risk factors. Nevertheless, it has proven difficult to establish preventive strategies for several reasons. First, there has been no final agreement on the definition of osteoporosis, which has hampered efforts to characterize the magnitude of the problem as a whole. Secondly, as osteoporosis is a multifactorial chronic disorder, effective programs for risk assessment and intervention depend on the development of complex disease models. In summarizing the contributions of epidemiological studies to the current understanding of osteoporosis this review intends to outline the scientific background for the European Vertebral Osteoporosis Study (EVOS) and its successors. PMID:9564151

  18. [Rickettsioses: the epidemiological assessment].

    PubMed

    Lukin, E P; Makhlaĭ, A A; Perepelkin, V S

    1997-08-01

    Microbe of taxonomical families Rickettsiaceae aceal and Bartonellaceae of Rickettsiales order have caused not less than 14 nosological forms of disease among people in different parts of the world. About 8 of them--in Russia and in the former Soviet Republics. These diseases are not unequivocal from epidemiological point of view. Trench, Marseilles and other forms of fever, murine typhus, vesicules rickettsia, etc. have been liquidated and never recurred for 30-40 years. Prowazek's [correction of Provachek's] rickettsia in its two forms has lost its epidemiological meaning in Russia and is next to full disappearance. However, some types of fever still represent a definite threat to public health. Some diseases, like ehrlichiosis, Bartonella, tsutsugamushi fever have not yet been studied to the end in Russia. PMID:9424811

  19. Prospects for Epigenetic Epidemiology

    PubMed Central

    Foley, Debra L.; Craig, Jeffrey M.; Morley, Ruth; Olsson, Craig J.; Dwyer, Terence; Smith, Katherine

    2009-01-01

    Epigenetic modification can mediate environmental influences on gene expression and can modulate the disease risk associated with genetic variation. Epigenetic analysis therefore holds substantial promise for identifying mechanisms through which genetic and environmental factors jointly contribute to disease risk. The spatial and temporal variance in epigenetic profile is of particular relevance for developmental epidemiology and the study of aging, including the variable age at onset for many common diseases. This review serves as a general introduction to the topic by describing epigenetic mechanisms, with a focus on DNA methylation; genetic and environmental factors that influence DNA methylation; epigenetic influences on development, aging, and disease; and current methodology for measuring epigenetic profile. Methodological considerations for epidemiologic studies that seek to include epigenetic analysis are also discussed. PMID:19139055

  20. Measurement issues in environmental epidemiology.

    PubMed Central

    Hatch, M; Thomas, D

    1993-01-01

    This paper deals with the area of environmental epidemiology involving measurement of exposure and dose, health outcomes, and important confounding and modifying variables (including genotype and psychosocial factors). Using examples, we illustrate strategies for increasing the accuracy of exposure and dose measurement that include dosimetry algorithms, pharmacokinetic models, biologic markers, and use of multiple measures. Some limitations of these methods are described and suggestions are made about where formal evaluation might be helpful. We go on to discuss methods for assessing the inaccuracies in exposure or dose measurements, including sensitivity analysis and validation studies. In relation to measurement of health outcomes, we discuss some definitional issues and cover, among other topics, biologic effect markers and other early indicators of disease. Because measurement error in covariates is also important, we consider the problems in measurement of common confounders and effect modifiers. Finally, we cite some general methodologic research needs. PMID:8206042

  1. [Epidemiology of myopia].

    PubMed

    Pechmann, A; Czepita, D

    2000-01-01

    The present state of knowledge on the epidemiology of myopia is discussed. The history of myopia investigations is described. The prevalence of myopia in different ages, races and populations is presented. The factors influencing myopia occurrence are characterized. Special attention is focused on the results of studies indicating environmental and genetic reasons of myopia. Most recent investigations concerning the influence of light on myopia occurrence as well as concerning a genetic locus for high myopia are described. PMID:11291303

  2. Epidemiology of venous thromboembolism.

    PubMed Central

    Coon, W W

    1977-01-01

    This review of the epidemiology of venous thromboembolism includes estimates of incidence and prevalence of venous thrombosis and its sequelae, a discussion geographical, annual and seasonal variations and data concerning possible risk factors. Selection of patients at increased risk for development of deep venous thrombosis or pulmonary embolism for specific diagnostic screening or for prophylactic therapy with low-dose heparin may be a more effective approach to lowering morbidity and mortality from this disease. PMID:329779

  3. The leukemias: Epidemiologic aspects

    SciTech Connect

    Linet, M.S.

    1984-01-01

    Particularly geared to physicians and cancer researchers, this study of the epidemiology and etiology of leukemia analyzes the four major leukemia subtypes in terms of genetic and familial determinant factors and examines the incidence, distribution and frequency of reported leukemia clusters. Linet discusses the connection between other types of malignancies, their treatments, and the subsequent development of leukemia and evaluates the impact on leukemia onset of such environmental factors as radiation therapy, drugs, and occupational hazards.

  4. Epidemiology of Cystic Fibrosis.

    PubMed

    Spoonhower, Kimberly A; Davis, Pamela B

    2016-03-01

    Improved quality of care and rapidly emerging therapeutic strategies to restore chloride transport profoundly impact the epidemiology and pathobiology of cystic fibrosis (CF) in the twenty-first century. CF now serves as a model for chronic illness management, continuous quality improvement via registry data, and a seamless link between basic science research, translational studies, clinical trials, and outcomes research to enable rapid expansion of treatment options. PMID:26857763

  5. [Acute coronary syndromes: epidemiology].

    PubMed

    Ozkan, Alev Arat

    2013-04-01

    Coronary heart disease is the main cause of death in the world as well as in Turkey. It's not only a health issue but also a social problem with a high economic burden and negative impact on quality of life. The majority of deaths are attributable to acute coronary syndromes (ACS) and their complications.This review summarizes some important facts regarding ACS epidemiology in the world and in Turkey. PMID:27323430

  6. Epidemiology of Itch.

    PubMed

    Weisshaar, Elke

    2016-01-01

    Epidemiology is the study of disease frequency and the associations between risk factors and outcome in a population. Clinical populations are highly selective and depend for instance on perceived severity of symptoms and access to health services. Assessment of a disease in the community and in specific populations is an important measure for the purpose of health planning as well as for the understanding of associations between disease and factors in the environment. Itch is definitely the most frequent symptom of the skin and can occur in acute and chronic skin diseases and other diseases like end-stage renal disease, cholestasis, and hematological, neurological, and psychiatric diseases. This diversity may explain why research on the epidemiology of itch was disregarded for a long time. A recent European study demonstrated that the prevalence of itch among dermatological patients is 54.4%. The prevalence of acute itch in the general population is 8.4% and for chronic itch it is 13.5%; however, with a recurrent symptom it is important to consider different prevalence estimates (point, 12-month, and lifetime prevalence). The lifetime prevalence of chronic itch in the general populations is 22%, demonstrating that more than 1 in 5 people experience chronic itch once in their life. This shows that research in this field should not only focus on patients. This chapter briefly summarizes major facts on the epidemiology of itch in the general population and in some patient populations. PMID:27578064

  7. [Occupational epidemiology in Italy].

    PubMed

    Assennato, G; Bisceglia, L

    2003-01-01

    The development of Occupational Epidemiology in Italy is closely correlated with the political and social awareness of the needs of preventive strategies in the workplace. In the late '60s the Trade Unions supported a model of intervention based on the involvement of the so-called "Homogeneous group of workers" in the validation of the preventive measures taken on the workplace. In spite of the shortcomings of the model, it was extremely effective resulting in enhanced perception of the priority of preventive strategies and in the formation within the National Health Service of the Occupational Health Services. In Italy over the period 1973-2002 there has been an impressive trend of research in field of occupational epidemiology (a search on Medline shows an increasing trend over the years and, in terms of international comparison, higher figures than in Germany, France and Spain). Occupational Epidemiology is now present in the activities of the local Occupational Health Services and in the teaching activities of the Medical Schools throughout the country. PMID:14582235

  8. What matters most: quantifying an epidemiology of consequence

    PubMed Central

    Keyes, Katherine; Galea, Sandro

    2015-01-01

    Risk factor epidemiology has contributed to substantial public health success. In this essay, we argue, however, that the focus on risk factor epidemiology has led epidemiology to ever increasing focus on the estimation of precise causal effects of exposures on an outcome at the expense of engagement with the broader causal architecture that produces population health. To conduct an epidemiology of consequence, a systematic effort is needed to engage our science in a critical reflection both about how well and under what conditions or assumptions we can assess causal effects and also on what will truly matter most for changing population health. Such an approach changes the priorities and values of the discipline and requires reorientation of how we structure the questions we ask and the methods we use, as well as how we teach epidemiology to our emerging scholars. PMID:25749559

  9. myEpi. Epidemiology of One

    PubMed Central

    Bobashev, Georgiy

    2014-01-01

    A new concept of within-individual epidemiology termed “myEpi” is introduced. It is argued that traditional epidemiological methods, which are usually applied to populations of humans, can be applicable to a single individual and thus used for self-monitoring and forecasting of “epidemic” outbreaks within an individual. Traditional epidemiology requires that results be generalizable to a predefined population. The key component of myEpi is that a single individual may be viewed as an entire population of events and thus, the analysis should be generalizable to this population. Applications of myEpi are aimed for, but not limited to, the analysis of data collected by individuals with the help of wearable sensors and digital diaries. These data can include physiological measures and records of healthy and risky behaviors (e.g., exercise, sleep, smoking, food consumption, alcohol, and drug use). Although many examples of within-individual epidemiology exist, there is a pressing need for systematic guidance to the analysis and interpretation of intensive individual-level data. myEpi serves this need by adapting statistical methods (e.g., regressions, hierarchical models, survival analysis, agent-based models) to individual-level data. PMID:25161995

  10. myEpi. Epidemiology of One.

    PubMed

    Bobashev, Georgiy

    2014-01-01

    A new concept of within-individual epidemiology termed "myEpi" is introduced. It is argued that traditional epidemiological methods, which are usually applied to populations of humans, can be applicable to a single individual and thus used for self-monitoring and forecasting of "epidemic" outbreaks within an individual. Traditional epidemiology requires that results be generalizable to a predefined population. The key component of myEpi is that a single individual may be viewed as an entire population of events and thus, the analysis should be generalizable to this population. Applications of myEpi are aimed for, but not limited to, the analysis of data collected by individuals with the help of wearable sensors and digital diaries. These data can include physiological measures and records of healthy and risky behaviors (e.g., exercise, sleep, smoking, food consumption, alcohol, and drug use). Although many examples of within-individual epidemiology exist, there is a pressing need for systematic guidance to the analysis and interpretation of intensive individual-level data. myEpi serves this need by adapting statistical methods (e.g., regressions, hierarchical models, survival analysis, agent-based models) to individual-level data. PMID:25161995

  11. DESIGN STRATEGIES FOR EPIDEMIOLOGIC STUDIES OF ENVIRONMENTAL IMPACTS ON HEALTH

    EPA Science Inventory

    The papers describes epidemiologic designs and methods in studies of health effects of air pollution, whose implications, however, can be extended to the detection of health effects of other environmental exposures. Recent advances in measurement technology for the assessment of ...

  12. Abortion: epidemiology, safety, and technique.

    PubMed

    Blumenthal, P D

    1992-08-01

    In 1991, the abortion literature was characterized by articles relating to 1) epidemiologic issues in abortion care, 2) advances in knowledge and experience with medical abortifacients such as mifepristone (RU 486), and 3) cervical ripening prior to abortion with the use of both mifepristone and prostaglandins. Technical methods of achieving termination of pregnancy continue to be similar in the United States, the United Kingdom, and Europe, although induction-abortion times are generally slower in Europe than in the United States. Surgically, dilatation and evacuation procedures continue to be more common in the United States than in other countries. The effectiveness of mifepristone is undisputed, and the recommended dose for early first-trimester termination is being compared with lower dose alternative regimens. There is additional evidence that at least in the short term, the negative psychological sequelae of abortion are infrequent and are inconsequential as a public health issue. PMID:1504270

  13. [Suicide - background, epidemiology, risk factors].

    PubMed

    Ajdacic-Gross, Vladeta

    2015-10-01

    Suicide research, in particular epidemiology, comprises a huge amount of data. However, the theoretical understanding clearly lags behind the empirical knowledge. Suicide, suicide attempts and other suicidal behaviors are more heterogeneous than most explanatory approaches would assume. The most important recent contributions to a better understanding have come from selected epidemiological findings and, interestingly, prevention. This article provides an overview of epidemiological findings, the most relevant risk factors and conclusions related to successful preventive efforts. PMID:26423878

  14. Trichinosis: Epidemiology in Thailand

    PubMed Central

    Kaewpitoon, Natthawut; Kaewpitoon, Soraya Jatesadapattaya; Philasri, Chutikan; Leksomboon, Ratana; Maneenin, Chanvit; Sirilaph, Samaporn; Pengsaa, Prasit

    2006-01-01

    Trichinosis is one of the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. This paper reviews the history, species, and epidemiology of the disease and food habits of the people with an emphasis on the north, northeast, central and south regions of Thailand. The earliest record of trichinosis in Thailand was in 1962 in the Mae Sariang District, Mae Hong Son Province. Since then, about 130 outbreaks have been reported involving 7392 patients and 97 deaths (1962-2005). The highest number of cases, 557, was recorded in 1983. The annual epidemiological surveillance reports of the Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health, Thailand, show that trichinosis cases increased from 61 in 1997 to 351 in 1998. In contrast to these figures, the number of reported cases decreased to 16 in 1999 and 128 cases in 2000. There was no record of trichinosis in 2001, but then the figures for 2002, 2003 and 2004 were 289, 126 and 212 respectively. The infected patients were mostly in the 35-44 years age group and the disease occurred more frequently in men than women at a ratio of 1.7-2.0:1. There were 84 reported cases of trichinosis in Chiang Rai, Nan, Chiang Mai, Si Sa ket, Nakhon Phanom, Kalasin, Nakhon Ratchasima, Nakhon Nayok, Nakhon Pathom and Surat Thani, provinces located in different parts of Thailand in 2005. The outbreaks were more common in the northern areas, especially in rural areas where people ate raw or under-cooked pork and/or wild animals. This indicates the need for health education programs to prevent and control trichinosis as soon as possible in the high-risk areas. PMID:17072975

  15. Epidemiological Perspectives of Diabetes.

    PubMed

    Tao, Ziqi; Shi, Aimin; Zhao, Jing

    2015-09-01

    The global statistics of diabetes mellitus in year 2013 indicated, about 382 million people had this disease worldwide, with type 2 diabetes making up about 90 % of the cases. This is equal to 8.3 % of the adult population with equal rates in both women and men. In year 2012 and 2013 diabetes resulted in mortality of 1.5-5.1 million people per year, making it the 8th leading cause of death in the world. It is predicted that by year 2035 about 592 million people will die of diabetes. The economic cost of diabetes seems to have increased worldwide. An average age of onset of diabetes is 42.5 years and could be due to consumption of high sugar and high-calorie diet, low physical activity, genetic susceptibility, and lifestyle. Approximately 8 % children and about 26 % young adults have diabetes mellitus in the world. The results of epidemiological study of type 1 diabetes mellitus (T1D) are presented by demographic, geographic, biologic, cultural, and other factors in human populations. The prevalence of T1D has been increased by 2-5 % worldwide and its prevalence is approximately one in 300 in US by 18 years of age. The epidemiological studies are important to study the role, causes, clinical care, prevention, and treatment of type1 diabetes in pregnant women and their children before and after birth. In this article, causes, diagnosis, symptoms, treatment and medications, and epidemiology of diabetes will be described. PMID:25711186

  16. Epidemiologic research in Antarctica

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A study of epidemiology of respiratory viruses that was begun in the early 1960's is described. Locations selected for the study included a Wisconsin University housing village, a second grade school population, individual volunteers who associated socially, married couples, and the winter-over population at McMurdo Bay and at Scott Base in the Antarctic. It was concluded that most rhinovirus transmission is through aerosolized particles. Air filtration and careful nasal sanitation with virucidal tissues are determined to be effective in blocking rhinovirus transmission and should be useful in both isolated space colonies and in ordinary earth-bound populations.

  17. Epidemiology of urethral strictures

    PubMed Central

    Blaschko, Sarah D.; McAninch, Jack W.; Breyer, Benjamin N.

    2014-01-01

    Urethral stricture disease is relatively common and is associated with a significant financial cost and potentially debilitating outcomes. Understanding urethral stricture epidemiology is important to identify risk factors associated with the etiology or progression of the disease. This understanding may lead to better treatments and preventative measures that could ameliorate disease severity, produce better health outcomes, and reduce expenditures. We performed a comprehensive review of urethral stricture disease based on available published case series, identified gaps in knowledge of this disease, and recommend future directions for research. PMID:26813256

  18. Background and Epidemiology.

    PubMed

    Sanders, Don B; Fink, Aliza K

    2016-08-01

    Cystic fibrosis (CF) is the most common autosomal-recessive disease in white persons. Significant advances in therapies and outcomes have occurred for people with CF over the past 30 years. Many of these improvements have come about through the concerted efforts of the CF Foundation and international CF societies; networks of CF care centers; and the worldwide community of care providers, researchers, and patients and families. There are still hurdles to overcome to continue to improve the quality of life, reduce CF complications, prolong survival, and ultimately cure CF. This article reviews the epidemiology of CF, including trends in incidence and prevalence, clinical characteristics, common complications, and survival. PMID:27469176

  19. Migraine headache: epidemiologic perspectives.

    PubMed

    Linet, M S; Stewart, W F

    1984-01-01

    Clinical and epidemiologic studies suggest that a number of factors are associated with the risk of migraine and precipitation of an attack. However, the degree to which causal associations can be inferred from reported studies is very limited and is a result of the methodological problems discussed throughout this review. The study of migraine in many ways parallels the pattern seen in early investigations of other conditions, such as rheumatoid arthritis and systemic lupus erythematosus, because a number of methodological problems had to be resolved in the study of these conditions before significant progress could be made. To achieve significant advances in the improvement of our understanding of the causes of migraine, a number of related issues must be addressed and resolved in future studies. Most noteworthy among these are Recognition of the probable heterogeneity of migraine, not merely in the manifestation of symptoms but, more importantly, in the existence of distinct etiologic subtypes. A number of findings suggest that some migraine subtypes are sensitive to certain precipitants, some appear to be a part of a more generalized constitutional disorder, and some are accompanied by a higher prevalence of migraine among family members. Efforts should be made in understanding the relationship between specific biochemical markers and traits (such as monoamine oxidase deficiency and tyramine sensitivity); precipitants related to the migraine attack; and epidemiologic characteristics such as age at onset and sex. Creation of a more precise, reliable, and practically useful definition of migraine. Without such a definition, it is difficult, if not impossible, to compare results between studies, to understand the relationship between risk factors and migraine subtypes, to understand properly associations identified in selected clinic populations, and, in general, to understand the epidemiology of migraine. More accurate characterization of the case group under

  20. Epidemiology--Teaching the Fundamentals.

    ERIC Educational Resources Information Center

    McEachron, Donald L.; Finegold, Leonard

    2000-01-01

    Discusses the use of epidemiology as an introduction to useful aspects of biology, mathematics, and simulation skills for kindergarten through university undergraduate students. (Contains 20 references.) (ASK)

  1. The Epidemiology of Sarcopenia.

    PubMed

    Dodds, Richard Matthew; Roberts, Helen Clare; Cooper, Cyrus; Sayer, Avan Aihie

    2015-01-01

    The aim of this review is to describe the epidemiology of sarcopenia, specifically prevalence, health outcomes, and factors across the life course that have been linked to its development. Sarcopenia definitions involve a range of measures (muscle mass, strength, and physical performance), which tend to decline with age, and hence sarcopenia becomes increasingly prevalent with age. Less is known about prevalence in older people in hospital and care homes, although it is likely to be higher than in community settings. The range of measures used, and the cutpoints suggested for each, presents a challenge for comparing prevalence estimates between studies. The importance of sarcopenia is highlighted by the range of adverse health outcomes that strength and physical performance (and to a lesser extent, muscle mass) have been linked to. This is shown most strikingly by the finding of increased all-cause mortality rates among those with weaker grip strength and slower gait speed. A life course approach broadens the window for our understanding of the etiology of sarcopenia and hence the potential intervention. An example is physical activity, with increased levels across midadulthood appearing to increase muscle mass and strength in early old age. Epidemiologic studies will continue to make an important contribution to our understanding of sarcopenia and possible avenues for intervention and prevention. PMID:26073423

  2. Epidemiology of bronchioloalveolar carcinoma.

    PubMed

    Falk, R T; Pickle, L W; Fontham, E T; Greenberg, S D; Jacobs, H L; Correa, P; Fraumeni, J F

    1992-01-01

    Descriptive features of bronchioloalveolar carcinoma (BAC) are presented using Surveillance, Epidemiology and End Results Program population-based incidence data from 1973 through 1987, along with risk factors from histologically confirmed cases of BAC identified in a hospital-based case-control study conducted in Louisiana between 1979 and 1982. Compared to the rising incidence of lung cancer overall, BAC rates have remained relatively constant, accounting for less than 3% of all lung cancer. BAC incidence rates were higher in males, yet it explained proportionately more of the total lung cancer incidence in females. In the case-control study, 21 of the 33 cases originally ascertained from hospital pathology records were histologically confirmed as BAC. Most cases smoked cigarettes, with a 4-fold risk for ever smoking. Risks tended to increase with smoking intensity (reaching 10-fold for more than 1.5 packs/day) and duration (reaching 5-fold for more than 45 years of smoking). Following 10 or more years of employment, there was a 4-fold risk associated with motor freight occupations, along with nonsignificant excesses among construction workers, petroleum manufacturers, and sugar cane farmers. Cases were more likely than controls to have had emphysema or to have had a close family member with lung cancer. Although based on small numbers, this study suggests that BAC shares many of the epidemiological characteristics of lung adenocarcinoma. PMID:1339048

  3. Global epidemiology of sporotrichosis.

    PubMed

    Chakrabarti, Arunaloke; Bonifaz, Alexandro; Gutierrez-Galhardo, Maria Clara; Mochizuki, Takashi; Li, Shanshan

    2015-01-01

    Sporotrichosis is an endemic mycosis caused by the dimorphic fungus Sporothrix schenckii sensu lato. It has gained importance in recent years due to its worldwide prevalence, recognition of multiple cryptic species within the originally described species, and its distinctive ecology, distribution, and epidemiology across the globe. In this review, we describe the current knowledge of the taxonomy, ecology, prevalence, molecular epidemiology, and outbreaks due to S. schenckii sensu lato. Despite its omnipresence in the environment, this fungus has remarkably diverse modes of infection and distribution patterns across the world. We have delved into the nuances of how sporotrichosis is intimately linked to different forms of human activities, habitats, lifestyles, and environmental and zoonotic interactions. The purpose of this review is to stimulate discussion about the peculiarities of this unique fungal pathogen and increase the awareness of clinicians and microbiologists, especially in regions of high endemicity, to its emergence and evolving presentations and to kindle further research into understanding the unorthodox mechanisms by which this fungus afflicts different human populations. PMID:25526781

  4. Molecular Epidemiology of Amebiasis

    PubMed Central

    Ali, Ibne Karim M.; Clark, C. Graham; Petri, William A.

    2008-01-01

    Entamoeba histolytica, the causative agent of human amebiasis, remains a significant cause of morbidity and mortality in developing countries and is responsible for up to 100,000 deaths worldwide each year. Entamoeba dispar, morphologically indistinguishable from E. histolytica, is more common in humans in many parts of the world. Similarly Entamoeba moshkovskii, which was long considered to be a free-living ameba, is also morphologically identical to E. histolytica and E. dispar, and is highly prevalent in some E. histolytica endemic countries. However, the only species to cause disease in humans is E. histolytica. Most old epidemiological data on E. histolytica are unusable as the techniques employed do not differentiate between the above three Entamoeba species. Molecular tools are now available not only to diagnose these species accurately but also to study intra-species genetic diversity. Recent studies suggest that only a minority of all E. histolytica infections progress to development of clinical symptoms in the host and there exist population level differences between the E. histolytica strains isolated from the asymptomatic and symptomatic individuals. Nevertheless the underlying factors responsible for variable clinical outcome of infection by E. histolytica remain largely unknown. We anticipate that the recently completed E. histolytica genome sequence and new molecular techniques will rapidly advance our understanding of the epidemiology and pathogenicity of amebiasis. PMID:18571478

  5. Epidemiology of rickettsial diseases.

    PubMed

    Walker, D H; Fishbein, D B

    1991-05-01

    Rickettsial diseases have a diversity of epidemiologic characteristics reflective of the variety of ecologic situations in which the obligate intracellular bacteria are transmitted to humans. For the spotted fever group (SFG) rickettsiae, Rickettsia typhi, R. tsutsugamushi, Coxiella burnetii, and the human ehrlichial agent, humans are a dead-end host who plays no role in the maintenance of the organism in nature. All rickettsioses exist as zoonoses. Moreover, all rickettsiae are found in infected arthopods, which generally serve as the natural hosts and can transmit the infection to the next generation of ticks, mites, chiggers, or fleas. From our anthropocentric viewpoint, Q fever aerosol infection from parturient animals and Brill-Zinsser disease ignited epidemics of louse-borne epidemic typhus are exceptions. However, silent cycles of C. burnetii in ticks and R. prowazekii in the flying squirrel flea may have maintained these agents in transovarial or enzootic cycles for eons before humans and their domestic animals arrived on the scene. Thus, the epidemiology of rickettsial diseases must be recognized as an unfortunate aberration of the rickettsial economy. Several excellent reviews of rickettsial ecology contain a wealth of useful information. PMID:1884775

  6. The new epidemiology of nephrolithiasis.

    PubMed

    Shoag, Jonathan; Tasian, Greg E; Goldfarb, David S; Eisner, Brian H

    2015-07-01

    Historically nephrolithiasis was considered a disease of dehydration and abnormal urine composition. However, over the past several decades, much has been learned about the epidemiology of this disease and its relation to patient demographic characteristics and common systemic diseases. Here we review the latest epidemiologic studies in the field. PMID:26088071

  7. Epidemiology in Early Childhood Education.

    ERIC Educational Resources Information Center

    Gratz, Rene R.

    1994-01-01

    Describes the importance of early childhood education as a source of information about health and safety of young children. Discusses the significance of early childhood programs adopting an epidemiological approach to document this information. Outlines a five-step plan to conduct an epidemiological study, using examples from epidemiological…

  8. CEDR: Comprehensive Epidemiologic Data Resource

    SciTech Connect

    Not Available

    1993-08-01

    The Department of Energy (DOE) and its predecessor agencies have a long history of epidemiologic research programs. The main focus of these programs has been the Health and Mortality Study of the DOE work force. This epidemiologic study began in 1964 with a feasibility study of workers at the Hanford facility. Studies of other populations exposed to radiation have also been supported, including the classic epidemiologic study of radium dial painters and studies of atomic bomb survivors. From a scientific perspective, these epidemiologic research program have been productive, highly credible, and formed the bases for many radiological protection standards. Recently, there has been concern that, although research results were available, the data on which these results were based were not easily obtained by interested investigators outside DOE. Therefore, as part of an effort to integrate and broaden access to its epidemiologic information, the DOE has developed the Comprehensive Epidemiologic Data Resource (CEDR) Program. Included in this effort is the development of a computer information system for accessing the collection of CEDR data and its related descriptive information. The epidemiologic data currently available through the CEDAR Program consist of analytic data sets, working data sets, and their associated documentation files. In general, data sets are the result of epidemiologic studies that have been conducted on various groups of workers at different DOE facilities during the past 30 years.

  9. Epidemiology of Depression for Clinicians.

    ERIC Educational Resources Information Center

    Bromberger, Joyce T.; Costello, Elizabeth Jane

    1992-01-01

    Reviews epidemiology of depression and ways this information can be useful for clinicians. Defines frequently used epidemiological terms; presents prevalence rates and risk factors; discusses impact and consequences of depression; and suggests arenas for prevention, early intervention, and treatment that can help clinicians in their everyday work.…

  10. [Descriptive epidemiology of urolithiasis].

    PubMed

    Kodama, H; Ohno, Y

    1989-06-01

    In this paper, urolithiasis is remarked from the standpoint of descriptive epidemiology, which examines the frequency distribution of a given disease in a population in terms of time, place and personal characteristics with an aim of identifying risk factors or some clues to the etiology. Some descriptive epidemiological features of urolithiasis are summarized. Prevalence rate is around 4% (4-15% in males and 4-8% in females), and incidence rate varies from area to area: 53.2 per 100,000 population in 1975 in Japan, 364 in 1976 in Malaysia, and 540 in 1979 in West Germany. Prevalence and/or incidence rates have, in general, increased in the developed countries since World War II and in the developing countries as well, where upward trends are quite analogous to the trends observed in the nineteenth century in Europe. Recurrence rate, which is much higher in males than in females, ranges from 31% to 75%, depending on the follow-up periods. In the industrialized countries, upper urinary (renal and ureteral) stones account for more than 90% of total stones, which are ordinarily calcium complexes in composition. More common in the developing countries are lower urinary (bladder and urethral) stones, frequently composed of magnesium ammonium phosphate, which indicates a close association with urinary tract infections. Variations in frequency are evident by season and by region within a country. Age and sex differentials in urinary stone formers are substantial: more common in males 30-40 years old in the industrialized countries and in children under 10 years old in the developing countries. Racial differentials are also noted; blacks appear to suffer less frequently than whites. Stone formers experience more frequent episodes of stone formation in their family members, particularly father and brothers, than non-stone formers. These findings on racial differentials and family preponderance suggest the possible relevance of genetic factors in stone formation. Stone

  11. The Epidemiology of Sarcoma

    PubMed Central

    2012-01-01

    Sarcomas account for over 20% of all pediatric solid malignant cancers and less than 1% of all adult solid malignant cancers. The vast majority of diagnosed sarcomas will be soft tissue sarcomas, while malignant bone tumors make up just over 10% of sarcomas. The risks for sarcoma are not well-understood. We evaluated the existing literature on the epidemiology and etiology of sarcoma. Risks for sarcoma development can be divided into environmental exposures, genetic susceptibility, and an interaction between the two. HIV-positive individuals are at an increased risk for Kaposi’s sarcoma, even though HHV8 is the causative virus. Radiation exposure from radiotherapy has been strongly associated with secondary sarcoma development in certain cancer patients. In fact, the risk of malignant bone tumors increases as the cumulative dose of radiation to the bone increases (p for trend <0.001). A recent meta-analysis reported that children with a history of hernias have a greater risk of developing Ewing’s sarcoma (adjusted OR 3.2, 95% CI 1.9, 5.7). Bone development during pubertal growth spurts has been associated with osteosarcoma development. Occupational factors such as job type, industry, and exposures to chemicals such as herbicides and chlorophenols have been suggested as risk factors for sarcomas. A case-control study found a significant increase in soft tissue sarcoma risk among gardeners (adjusted OR 4.1, 95% CI 1.00, 14.00), but not among those strictly involved in farming. A European-based study reported an increased risk in bone tumors among blacksmiths, toolmakers, or machine-tool operators (adjusted OR 2.14, 95% CI 1.08, 4.26). Maternal and paternal characteristics such as occupation, age, smoking status, and health conditions experienced during pregnancy also have been suggested as sarcoma risk factors and would be important to assess in future studies. The limited studies we identified demonstrate significant relationships with sarcoma risk, but many of

  12. 6) Epidemiology and Control of Guatemalan Onchocerciasis

    PubMed Central

    Takaoka, Hiroyuki; Suzuki, Takeshi

    2015-01-01

    Recent studies on the epidemiology and control of Guatemalan onchocerciasis, chiefly made by the Guatemala–Japan Cooperative Project on Onchocerciasis Research and Control, are reviewed. Epidemiological features of Guatemalan onchocerciasis are summarized as to characteristic altitudinal distribution of endemic areas, disease manifestation, vector taxonomy, biology and transmission dynamic of the disease. Extensive insecticide studies in the field and laboratory demonstrate that the characteristic situations of Guatemalan streams where Simulium ochraceum, the main vector of onchocerciasis, breeds require ingenious methods of larviciding. Finally, the feasibility of an area vector control is indicated by the successful control operation in the San Vicente Pacaya Pilot Area, in which a new fixed-dose larviciding method was applied. PMID:26744576

  13. Genetic Epidemiology of Psoriasis

    PubMed Central

    Gupta, Rashmi; Debbaneh, Maya G.; Liao, Wilson

    2014-01-01

    Psoriasis is a chronic, inflammatory, immune-mediated skin condition with a prevalence of 0-11.8% across the world. It is associated with a number of cardiovascular, metabolic, and autoimmune disease co-morbidities. Psoriasis is a multifactorial disorder, influenced by both genetic and environmental factors. Its genetic basis has long been established through twin studies and familial clustering. The association of psoriasis with the HLA-Cw6 allele has been shown in many studies. Recent genome-wide association studies have identified a large number of other genes associated with psoriasis. Many of these genes regulate the innate and adaptive immune system. These findings indicate that a dysregulated immune system may play a major role in the pathogenesis of psoriasis. In this article, we review the clinical and genetic epidemiology of psoriasis with a brief description of the pathogenesis of disease. PMID:25580373

  14. Melanoma Epidemiology and Prevention.

    PubMed

    Berwick, Marianne; Buller, David B; Cust, Anne; Gallagher, Richard; Lee, Tim K; Meyskens, Frank; Pandey, Shaily; Thomas, Nancy E; Veierød, Marit B; Ward, Sarah

    2016-01-01

    The epidemiology of melanoma is complex, and individual risk depends on sun exposure, host factors, and genetic factors, and in their interactions as well. Sun exposure can be classified as intermittent, chronic, or cumulative (overall) exposure, and each appears to have a different effect on type of melanoma. Other environmental factors, such as chemical exposures-either through occupation, atmosphere, or food-may increase risk for melanoma, and this area warrants further study. Host factors that are well known to be important are the numbers and types of nevi and the skin phenotype. Genetic factors are classified as high-penetrant genes, moderate-risk genes, or low-risk genetic polymorphisms. Subtypes of tumors, such as BRAF-mutated tumors, have different risk factors as well as different therapies. Prevention of melanoma has been attempted using various strategies in specific subpopulations, but to date optimal interventions to reduce incidence have not emerged. PMID:26601858

  15. [Epidemiology of osteoporosis].

    PubMed

    Grazio, Simeon

    2006-01-01

    Osteoporosis represents a major and increasing public health problem with the aging of population. Major clinical consequences and economic burden of the disease are fractures. Many risk factors are associated with the fractures including low bone mass, hormonal disorders, personal and family history of fractures, low body weight, use of certain drugs (e.g. glucocorticoids), cigarette smoking, elevated intake of alchohol, low physical activity, insufficient level of vitamin D and low intake of calcium. This epidemiological review describes frequency, importance of risk factors and impact of osteoporosis and osteoporotic fractures. Objective measures of bone mineral density along with clinical assessment of risk factors can help identify patients who will benefit from prevention and intervention efforts and eventually reduce the morbidity and mortality associated with osteoporosis-related fractures. PMID:17580550

  16. EPIDEMIOLOGY OF PARACOCCIDIOIDOMYCOSIS

    PubMed Central

    MARTINEZ, Roberto

    2015-01-01

    SUMMARY The epidemiological characteristics of paracoccidioidomycosis were reviewed and updated. The new endemic areas in Brazil were discussed in the section regarding the geographic distribution of the mycosis. Subclinical infection with Paracoccidioides brasiliensis was discussed on the basis of skin test surveys with antigens of the fungus, seroepidemiological studies, and disease cases outside Latin America. Large case series permitted a comparison of the prevalence of the mycosis in different regions, its estimated incidence and risk factors for the development of the disease. Aspects modulating the expression of the clinical forms of paracoccidioidomycosis are also presented. This review also deals with diseases associated with the mycosis, opportunistic paracoccidioidomycosis, lethality, mortality and infection and disease in animals. PMID:26465364

  17. Epidemiology of HCV infection.

    PubMed

    Baldo, V; Baldovin, T; Trivello, R; Floreani, A

    2008-01-01

    It is estimated that approximately 130-170 million people worldwide are infected with hepatitis C virus (HCV). According to data from WHO community and blood donor surveys, the African and Eastern Mediterranean countries report the highest prevalence rates (>10%). The rates of infection in the general population and the incidence of newly-acquired cases indicate an appreciable change in the epidemiology of the infection in recent years. Prior to the widespread screening of blood donations, infected blood and blood products represented a common source of infection. On the other hand, the high peak in HCV antibodies among the elderly in Italian epidemiological studies on the population at large reflects a cohort effect due to an epidemic of HCV infection occurring after the Second World War. According to data reported by the CDC Surveillance System, the incidence of acute hepatitis C has declined since the late 1980s. In 2005, as in previous years, the majority of such cases in North America and Northern Europe occurred among young adults and injected drug use was the most common risk factor. Other, less commonly reported modes of HCV acquisition are occupational exposure to blood, high-risk sexual activity, tattooing, body piercing and other forms of skin penetration. Finally, the overall rate of mother-to-child transmission from HCV-infected, HIV-negative mothers has been estimated at around 5% (coinfection with HIV raises this figure to 19.4%). HCV prevention relies on identifying and counseling uninfected persons at risk of contracting hepatitis C. PMID:18673187

  18. Epidemiology of acne vulgaris.

    PubMed

    Bhate, K; Williams, H C

    2013-03-01

    Despite acne being an almost universal condition in younger people, relatively little is known about its epidemiology. We sought to review what is known about the distribution and causes of acne by conducting a systematic review of relevant epidemiological studies. We searched Medline and Embase to the end of November 2011. The role of Propionibacterium acnes in pathogenesis is unclear: antibiotics have a direct antimicrobial as well as an anti-inflammatory effect. Moderate-to-severe acne affects around 20% of young people and severity correlates with pubertal maturity. Acne may be presenting at a younger age because of earlier puberty. It is unclear if ethnicity is truly associated with acne. Black individuals are more prone to postinflammatory hyperpigmentation and specific subtypes such as 'pomade acne'. Acne persists into the 20s and 30s in around 64% and 43% of individuals, respectively. The heritability of acne is almost 80% in first-degree relatives. Acne occurs earlier and is more severe in those with a positive family history. Suicidal ideation is more common in those with severe compared with mild acne. In the U.S.A., the cost of acne is over 3 billion dollars per year in terms of treatment and loss of productivity. A systematic review in 2005 found no clear evidence of dietary components increasing acne risk. One small randomized controlled trial showed that low glycaemic index (GI) diets can lower acne severity. A possible association between dairy food intake and acne requires closer scrutiny. Natural sunlight or poor hygiene are not associated. The association between smoking and acne is probably due to confounding. Validated core outcomes in future studies will help in combining future evidence. PMID:23210645

  19. Myeloma aetiology and epidemiology.

    PubMed

    Morgan, G J; Davies, F E; Linet, M

    2002-07-01

    Recently there have been substantial improvements in our understanding of the biology of myeloma. These findings have important implications for aetiological studies aimed at defining the causative factors for myeloma. Myeloma is closely related to monoclonal gammopathy of unknown significance (MGUS), which is now recognized to be very common in the older population. The epidemiology of these conditions is presented and discussed in the context of the genetic factors governing both the risk of developing MGUS or of transformation to myeloma. Biological studies support a role for aberrant class switch recombination early in the natural history of myeloma suggesting that factors in the environment may interact with this mechanism to increase myeloma risk. Case-control and cohort studies have identified several known and suspected environmental exposures. These exposures include high doses of ionizing radiation, and occupational exposure in the farming and petrochemical industries. The data supporting these associations are presented and discussed in the context of the molecular mechanisms underlying these exposures. In particular DNA damage occurring as a consequence could readily interact with the class switch recombination process to increase the risk of chromosomal translocations, oncogene deregulation and malignant transformation. A further hypothesis, which has been extensively investigated, is the role of chronic immune/antigenic stimulation and the risk of myeloma. This concept is difficult to explain in the context of our current immunological concepts. The data supporting the association and how molecular epidemiological studies using genetic variants in cytokine genes are allowing us to revisit this concept are discussed in detail. PMID:12199621

  20. Snippets From the Past: The Evolution of Wade Hampton Frost's Epidemiology as Viewed From the American Journal of Hygiene/Epidemiology

    PubMed Central

    Morabia, Alfredo

    2013-01-01

    Wade Hampton Frost, who was a Professor of Epidemiology at Johns Hopkins University from 1919 to 1938, spurred the development of epidemiologic methods. His 6 publications in the American Journal of Hygiene, which later became the American Journal of Epidemiology, comprise a 1928 Cutter lecture on a theory of epidemics, a survey-based study of tonsillectomy and immunity to Corynebacterium diphtheriae (1931), 2 papers from a longitudinal study of the incidence of minor respiratory diseases (1933 and 1935), an attack rate ratio analysis of the decline of diphtheria in Baltimore (1936), and a 1936 lecture on the age, time, and cohort analysis of tuberculosis mortality. These 6 American Journal of Hygiene /American Journal of Epidemiology papers attest that Frost's personal evolution mirrored that of the emerging “early” epidemiology: The scope of epidemiology extended beyond the study of epidemics of acute infectious diseases, and rigorous comparative study designs and their associated quantitative methods came to light. PMID:24022889

  1. Innovative multidisciplinary research in environmental epidemiology: the challenges and needs.

    PubMed

    Vena, J E; Weiner, J M

    1999-01-01

    The ability of epidemiology to determine the relationships between health and environmental insults has become exceedingly difficult. The multifactorial nature of disease and the diversity of the insults, which include biologic, physical, social and cultural factors, combined with genetic susceptibility, suggest the need to develop better models of multidisciplinary epidemiologic investigation. This paper highlights the needs of an environmental epidemiologic team, discusses ways to incorporate new ideas across disciplines and to integrate constructs and paradigms of social, ecological, cultural and population determinants with individual-based exposure assessments. Innovation will be the key to the survival and increasing importance of epidemiology in addressing the public health needs of the future, but what are the ways to enhance and encourage creativity in environmental epidemiology? The process of self-renewal and continuing education will be highlighted. Additionally, the complexity of the problems and the need for clear supervision and control of multidisciplinary research efforts require a forum of communication and an 'information-processing approach' beyond those in traditional epidemiologic studies. New approaches in data management and medical informatics must be incorporated into the epidemiologic investigative framework. Methods to be included should focus on opportunities for computer-supported sharing of ideas. Such capabilities minimise the geographic distances and the disparate knowledge and training of the investigators and bring the team closer to the objectives and functions inherent in multidisciplinary investigation. PMID:10703183

  2. Transforming Epidemiology for 21st Century Medicine and Public Health

    PubMed Central

    Khoury, Muin J.; Lam, Tram Kim; Ioannidis, John P.A.; Hartge, Patricia; Spitz, Margaret R.; Buring, Julie E.; Chanock, Stephen J.; Croyle, Robert T.; Goddard, Katrina A.; Ginsburg, Geoffrey S.; Herceg, Zdenko; Hiatt, Robert A.; Hoover, Robert N.; Hunter, David J.; Kramer, Barnet S.; Lauer, Michael S.; Meyerhardt, Jeffrey A.; Olopade, Olufunmilayo I.; Palmer, Julie R.; Sellers, Thomas A.; Seminara, Daniela; Ransohoff, David F.; Rebbeck, Timothy R.; Tourassi, Georgia; Winn, Deborah M.; Zauber, Ann; Schully, Sheri D.

    2013-01-01

    In 2012, the National Cancer Institute (NCI) engaged the scientific community to provide a vision for cancer epidemiology in the 21st century. Eight overarching thematic recommendations, with proposed corresponding actions for consideration by funding agencies, professional societies, and the research community emerged from the collective intellectual discourse. The themes are (i) extending the reach of epidemiology beyond discovery and etiologic research to include multilevel analysis, intervention evaluation, implementation, and outcomes research; (ii) transforming the practice of epidemiology by moving towards more access and sharing of protocols, data, metadata, and specimens to foster collaboration, to ensure reproducibility and replication, and accelerate translation; (iii) expanding cohort studies to collect exposure, clinical and other information across the life course and examining multiple health-related endpoints; (iv) developing and validating reliable methods and technologies to quantify exposures and outcomes on a massive scale, and to assess concomitantly the role of multiple factors in complex diseases; (v) integrating “big data” science into the practice of epidemiology; (vi) expanding knowledge integration to drive research, policy and practice; (vii) transforming training of 21st century epidemiologists to address interdisciplinary and translational research; and (viii) optimizing the use of resources and infrastructure for epidemiologic studies. These recommendations can transform cancer epidemiology and the field of epidemiology in general, by enhancing transparency, interdisciplinary collaboration, and strategic applications of new technologies. They should lay a strong scientific foundation for accelerated translation of scientific discoveries into individual and population health benefits. PMID:23462917

  3. Transforming Epidemiology for 21st Century Medicine and Public Health

    SciTech Connect

    Khoury, Muin J; Lam, Tram Kim; Ioannidis, John; Hartge, Patricia; Spitz, Margaret R.; Buring, Julie E.; Chanock, Stephen J.; Tourassi, Georgia; Zauber, Ann; Schully, Sheri D

    2013-01-01

    n 2012, the National Cancer Institute (NCI) engaged the scientific community to provide a vision for cancer epidemiology in the 21st century. Eight overarching thematic recommendations, with proposed corresponding actions for consideration by funding agencies, professional societies, and the research community emerged from the collective intellectual discourse. The themes are (i) extending the reach of epidemiology beyond discovery and etiologic research to include multilevel analysis, intervention evaluation, implementation, and outcomes research; (ii) transforming the practice of epidemiology by moving toward more access and sharing of protocols, data, metadata, and specimens to foster collaboration, to ensure reproducibility and replication, and accelerate translation; (iii) expanding cohort studies to collect exposure, clinical, and other information across the life course and examining multiple health-related endpoints; (iv) developing and validating reliable methods and technologies to quantify exposures and outcomes on a massive scale, and to assess concomitantly the role of multiple factors in complex diseases; (v) integrating big data science into the practice of epidemiology; (vi) expanding knowledge integration to drive research, policy, and practice; (vii) transforming training of 21st century epidemiologists to address interdisciplinary and translational research; and (viii) optimizing the use of resources and infrastructure for epidemiologic studies. These recommendations can transform cancer epidemiology and the field of epidemiology, in general, by enhancing transparency, interdisciplinary collaboration, and strategic applications of new technologies. They should lay a strong scientific foundation for accelerated translation of scientific discoveries into individual and population health benefits.

  4. Evaluation of primary HPV-DNA testing in relation to visual inspection methods for cervical cancer screening in rural China: an epidemiologic and cost-effectiveness modelling study

    PubMed Central

    2011-01-01

    Background A new lower-cost rapid-throughput human papillomavirus (HPV) test (careHPV, Qiagen, Gaithersburg, USA) has been shown to have high sensitivity for the detection of high grade cervical intraepithelial neoplasia. Methods We assessed the outcomes and cost-effectiveness of careHPV screening in rural China, compared to visual inspection with acetic acid, when used alone (VIA) or in combination with Lugol's iodine (VIA/VILI). Using data on sexual behaviour, test accuracy, diagnostic practices and costs from studies performed in rural China, we estimated the cost-effectiveness ratio (CER) and associated lifetime outcomes for once-lifetime and twice-lifetime screening strategies, and for routine screening at 5-yearly, 10-yearly and IARC-recommended intervals. The optimal age range for once-lifetime screening was also assessed. Results For all strategies, the relative ordering of test technologies in reducing cervical cancer incidence and mortality was VIA (least effective); VIA/VILI; careHPV@1.0 pg/ml and careHPV@0.5 pg/ml (most effective). For once-lifetime strategies, maximum effectiveness was achieved if screening occurred between 35-50 years. Assuming a participation rate of ~70%, once-lifetime screening at age 35 years would reduce cancer mortality by 8% (for VIA) to 12% (for careHPV@0.5) over the long term, with a CER of US$557 (for VIA) to $959 (for careHPV@1.0) per life year saved (LYS) compared to no intervention; referenced to a 2008 GDP per capita in Shanxi Province of $2,975. Correspondingly, regular screening with an age-standardised participation rate of 62% (which has been shown to be achievable in this setting) would reduce cervical cancer mortality by 19-28% (for 10-yearly screening) to 43-54% (using IARC-recommended intervals), with corresponding CERs ranging from $665 (for 10-yearly VIA) to $2,269 (for IARC-recommended intervals using careHPV@1.0) per LYS. Conclusions This modelled analysis suggests that primary careHPV screening compares

  5. [Epidemiology's and epidemiologists' vices and virtues].

    PubMed

    Gennaro, Valerio; Ricci, Paolo; Levis, Angelo Gino; Crosignani, Paolo

    2009-01-01

    Epidemiology is a public health oriented discipline and is aimed to detect the spatial, temporal, social and causal distribution of diseases in the human population, in order to promote timely and effective preventive solutions. This paper highlights some gold standard of the epidemiological method and suggests some considerations for a critical comprehension of epidemiological studies, in particular those that deny or minimize the existence of public health risks. This paper will focus on some crucial elements such as definition, attribution, misclassification and underestimation of the harmful exposures caused by a multitude of factors, undervaluation of the possible interactions among harmful agents (even when law limits are respected), selection of exposed populations, insufficient number of studied diseases, importance of the right comparisons between similar groups when the reference population is used, disproportion between shortness of follow-up in respect with long latency period of the studied diseases, including cancer. This paper also observes that many epidemiologists carry out confirmative studies rather than exploratory ones, and they end to both underestimate and underevaluate the multiplicity of the causal associations in favour of a reductive and a critical approach to the statistics which, in final analysis, wants to replace epidemiology. It points out, moreover, that neglecting primary prevention as well as precautionary principles in the interpretation of public health studies, arises the suspicion of professional limitation or strong conflict of interests (business bias). Epidemiology is naturally oriented to both primary prevention and public health defense, and today, more than ever before, for many reasons, among which the overwhelming market power that is first and foremost the cause of the general increase of populations affected by avoidable pathologies, a systematic, correct and timely application of this precious discipline seems to be

  6. Intelligent management of epidemiologic data.

    PubMed Central

    Ferri, F.; Evoli, L. M.; Pisanelli, D. M.; Ricci, F. L.

    1991-01-01

    In the lifecycle of epidemiologic data three steps can be identified: production, interpretation and exploitation for decision. Computerized support can be precious, if not indispensable, at any of the three levels, therefore several epidemiologic data management systems were developed. In this paper we focus on intelligent management of epidemiologic data, where intelligence is needed in order to analyze trends or to compare observed with reference value and possibly detect abnormalities. After having outlined the problems involved in such a task, we show the features of ADAMS, a system realized to manage aggregated data and implemented in a personal computer environment. PMID:1807619

  7. Role of data warehousing in healthcare epidemiology.

    PubMed

    Wyllie, D; Davies, J

    2015-04-01

    Electronic storage of healthcare data, including individual-level risk factors for both infectious and other diseases, is increasing. These data can be integrated at hospital, regional and national levels. Data sources that contain risk factor and outcome information for a wide range of conditions offer the potential for efficient epidemiological analysis of multiple diseases. Opportunities may also arise for monitoring healthcare processes. Integrating diverse data sources presents epidemiological, practical, and ethical challenges. For example, diagnostic criteria, outcome definitions, and ascertainment methods may differ across the data sources. Data volumes may be very large, requiring sophisticated computing technology. Given the large populations involved, perhaps the most challenging aspect is how informed consent can be obtained for the development of integrated databases, particularly when it is not easy to demonstrate their potential. In this article, we discuss some of the ups and downs of recent projects as well as the potential of data warehousing for antimicrobial resistance monitoring. PMID:25737091

  8. The epidemiology and economic consequences of pain.

    PubMed

    Henschke, Nicholas; Kamper, Steven J; Maher, Chris G

    2015-01-01

    Pain is considered a major clinical, social, and economic problem in communities around the world. In this review, we describe the incidence, prevalence, and economic burden of pain conditions in children, adolescents, and adults based on an electronic search of the MEDLINE and EMBASE databases for articles published from January 1, 2000, through August 1, 2014, using the keywords pain, epidemiology, burden, prevalence, and incidence. The impact of pain on individuals and potential risk factors are also discussed. Differences in the methodology and conduct of epidemiological studies make it difficult to provide precise estimates of prevalence and incidence; however, the burden of pain is unquestionably large. Improved concepts and methods are needed in order to study pain from a population perspective and further the development of pain prevention and management strategies. PMID:25572198

  9. Epidemiology of actinic keratoses.

    PubMed

    Green, Adèle C

    2015-01-01

    The epidemiology of actinic keratoses (AKs) reflects their causation by cumulative sun exposure, with the highest prevalence seen in pale-skinned people living at low latitudes and on the most sun-exposed body sites, namely the hands, forearms and face. AKs are markers of increased risk of basal cell carcinoma, squamous cell carcinoma and melanoma, especially when they are numerous and have coalesced into an area of 'field cancerisation'. The major risk factors are male sex, advanced age, sun-sensitive complexion, high lifetime sun exposure and prolonged immunosuppression. Clinical counts of AKs enable the assessment and monitoring of AK burden, but accurate counting is notoriously difficult, especially when skin is severely sun damaged. AK counting has been repeatedly shown to be unreliable, even among expert dermatologists. Notwithstanding these challenges, qualitative assessment of the natural history of AKs shows a high turnover, with new lesions developing and with other lesions regressing. A very small proportion of AKs undergo malignant transformation, but the precise rate of transformation is unknown due to the inaccuracies in monitoring AK lesions over time. Primary prevention of AKs is achieved by limiting intense sun exposure through sun-protective behaviour, including seeking deep shade, wearing sun-protective clothing and applying sunscreen regularly to exposed skin, from an early age. PMID:25561199

  10. Epidemiology of severe trauma.

    PubMed

    Alberdi, F; García, I; Atutxa, L; Zabarte, M

    2014-12-01

    Major injury is the sixth leading cause of death worldwide. Among those under 35 years of age, it is the leading cause of death and disability. Traffic accidents alone are the main cause, fundamentally in low- and middle-income countries. Patients over 65 years of age are an increasingly affected group. For similar levels of injury, these patients have twice the mortality rate of young individuals, due to the existence of important comorbidities and associated treatments, and are more likely to die of medical complications late during hospital admission. No worldwide, standardized definitions exist for documenting, reporting and comparing data on severely injured trauma patients. The most common trauma scores are the Abbreviated Injury Scale (AIS), the Injury Severity Score (ISS) and the Trauma and Injury severity Score (TRISS). Documenting the burden of injury also requires evaluation of the impact of post-trauma impairments, disabilities and handicaps. Trauma epidemiology helps define health service and research priorities, contributes to identify disadvantaged groups, and also facilitates the elaboration of comparable measures for outcome predictions. PMID:25241267

  11. Shigellosis: Epidemiology in India

    PubMed Central

    Taneja, Neelam; Mewara, Abhishek

    2016-01-01

    Shigellosis is one of the major causes of diarrhoea in India. The accurate estimates of morbidity and mortality due to shigellosis are lacking, though it is endemic in the country and has been reported to cause many outbreaks. The limited information available indicates Shigella to be an important food-borne pathogen in India. S. flexneri is the most common species, S. sonnei and non-agglutinable shigellae seem to be steadily surfacing, while S. dysenteriae has temporarily disappeared from the northern and eastern regions. Antibiotic-resistant strains of different Shigella species and serotypes have emerged all over the world. Especially important is the global emergence of multidrug resistant shigellae, notably the increasing resistance to third generation cephalosporins and fluoroquinolones, and also azithromycin. This calls for a continuous and strong surveillance of antibiotic resistance across the country for periodic updation of the local antibiograms. The prevention of shigellosis is desirable as it will substantially reduce the morbidity associated with diarrhoea in the country. Public health measures like provision of safe water and adequate sanitation are of immense importance to reduce the burden of shigellosis, however, the provision of resources to develop such an infrastructure in India is a complex issue and will take time to resolve. Thus, the scientific thrust should be focused towards development of a safe and affordable multivalent vaccine. This review is focused upon the epidemiology, disease burden and the therapeutic challenges of shigellosis in Indian perspective. PMID:27487999

  12. Shigellosis: Epidemiology in India.

    PubMed

    Taneja, Neelam; Mewara, Abhishek

    2016-05-01

    Shigellosis is one of the major causes of diarrhoea in India. The accurate estimates of morbidity and mortality due to shigellosis are lacking, though it is endemic in the country and has been reported to cause many outbreaks. The limited information available indicates Shigella to be an important food- borne pathogen in India. S. flexneri is the most common species, S. sonnei and non-agglutinable Shigellae seem to be steadily surfacing, while S. dysenteriae has temporarily disappeared from the northern and eastern regions. Antibiotic-resistant strains of different Shigella species and serotypes have emerged all over the world. Especially important is the global emergence of multidrug resistant Shigellae, notably the increasing resistance to third generation cephalosporins and fluoroquinolones, and also azithromycin. This calls for a continuous and strong surveillance of antibiotic resistance across the country for periodic updation of the local antibiograms. The prevention of shigellosis is desirable as it will substantially reduce the morbidity associated with diarrhoea in the country. Public health measures like provision of safe water and adequate sanitation are of immense importance to reduce the burden of shigellosis, however, the provision of resources to develop such an infrastructure in India is a complex issue and will take time to resolve. Thus, the scientific thrust should be focused towards development of a safe and affordable multivalent vaccine. this review is focused upon the epidemiology, disease burden and the therapeutic challenges of shigellosis in Indian perspective. PMID:27487999

  13. [Epidemiology of brain metastases].

    PubMed

    Taillibert, S; Le Rhun, É

    2015-02-01

    The most frequent intracranial brain tumours are brain metastases. All types of cancer can develop brain metastases but two thirds of brain metastases occurring in adult patients are secondary to one of these three cancers: lung cancer, breast cancer and melanoma. In accordance with these data, this review is focusing on the epidemiology of these three types of cancer. We report here the incidence, risk factors, median time of brain metastases occurrence after diagnosis of the primary cancer, prognosis and median survival for these three types of cancer. We also discuss the clinical implications of these data. The second part of this review is focusing on the Graded Prognostic Assessment scores in all types of primary cancer with brain metastases, how they can be applied in clinical research for a better stratification of patients, and to some extent in clinical practice to guide decisions for personalized treatments. These scores provide a better understanding of the different profiles of clinical evolution that can be observed amongst patients suffering from brain metastases according to the type of primary cancer. We highlighted the most remarkable and useful clinical implications of these data. PMID:25636729

  14. [Epidemiology of teeth hypersensitivity].

    PubMed

    Lutskaia, I K; Zinovenko, O G; Kovalenko, I P

    2015-01-01

    A clinical examination of 98 patients aged 20 to 75 years was carried out to identifyclinical and epidemiological features of hard tooth tissueshypersensitivity. The survey found out what stimuli (cold, hot, sour, mechanical, chemical) cause the appearance of dental hyperesthesia. The detailed survey of the affected area aimed to determine the presence of dental caries, gingival recession, wedge-shaped defects, erosions, microcracks and chipped enamel, as well as wear of the tooth crown. Forty-threepatients of 98 (43.88%) had tooth sensitivity. Most affected age group was 25-34 years (33%). Among patients studied with hyperesthesia 86% complained of pain. It was establishedthat dental hyperesthesia most often causes an intense, but quickly passing pain response, wherein upon exposure of several types of stimuli. Teeth with high sensitivity showed signs of abrasion (74.1%), most often--on the vestibular surface (44.4%). Patients under 45 years had notable cracks and wedge-shaped defects. In patients 45 years and older cracks and increased abrasion of hard dental tissues was seen. PMID:26271696

  15. Tuberculosis: Epidemiology and Control

    PubMed Central

    Sulis, Giorgia; Roggi, Alberto; Matteelli, Alberto; Raviglione, Mario C.

    2014-01-01

    Tuberculosis (TB) is a major public health concern worldwide: despite a regular, although slow, decline in incidence over the last decade, as many as 8.6 million new cases and 1.3 million deaths were estimated to have occurred in 2012. TB is by all means a poverty-related disease, mainly affecting the most vulnerable populations in the poorest countries. The presence of multidrug-resistant strains of M. tuberculosis in most countries, with somewhere prevalence is high, is among the major challenges for TB control, which may hinder recent achievements especially in some settings. Early TB case detection especially in resource-constrained settings and in marginalized groups remains a challenge, and about 3 million people are estimated to remain undiagnosed or not notified and untreated. The World Health Organization (WHO) has recently launched a new global TB strategy for the “post-2015 era” aimed at “ending the global TB epidemic” by 2035. This strategy is based on the three pillars that emphasize patient-centred TB care and prevention, bold policies and supportive systems, and intensified research and innovation. This paper aims to provide an overview of the global TB epidemiology as well as of the main challenges that must be faced to eliminate the disease as a public health problem everywhere. PMID:25408856

  16. Epidemiology of clavicle fractures.

    PubMed

    Postacchini, Franco; Gumina, Stefano; De Santis, Pierfrancesco; Albo, Francesco

    2002-01-01

    An epidemiologic study of 535 isolated clavicle fractures treated in a hospital of a large metropolis during an 11-year period was performed. Data regarding patient's age and sex, side involved, mechanism of injury, and season in which the fracture occurred were obtained from the clinical records. Radiographic classification was performed with the Allman system. Clavicle fractures represented 2.6% of all fractures and 44% of those in the shoulder girdle. Most patients were men (68%), and the left side was involved in 61% of cases. Fractures of the middle third of the clavicle, which were the most common (81%), were displaced in 48% of cases and comminuted in 19%. Fractures of the medial third were the least common (2%). The prevalence of midclavicular fractures was found to decrease progressively with age, starting from the first decade of life when they represented 88.2% of all clavicle fractures and were undisplaced in 55.5% of cases. In adults, the incidence of displaced fractures, independent of location, was higher than that of undisplaced fractures. Traffic accidents were the most common cause of the injury. In the period under study, the incidence of fractures showed no significant change over time and no seasonal variation. PMID:12378163

  17. Epidemiology of malignant melanoma.

    PubMed

    Liu, T; Soong, S J

    1996-12-01

    Descriptive epidemiology of melanoma indicates increases in both incidence and mortality over the past two to three decades. A moderation in both rates began to emerge in several regions after the 1980s, especially in younger age groups. Recent improvement in survival rates is more likely due to earlier diagnosis than to real improvement in treatment. This suggests the potential effectiveness of secondary prevention. Continued health education efforts to improve awareness about signs and symptoms of melanoma should lead to earlier diagnosis and may increase incidence for a certain period of time. However, reduction in mortality will eventually be achieved owing to thinner melanoma at time of diagnosis. Etiologic studies indicate that the most important environmental risk factor for melanoma is extensive exposure to the sun. Primary prevention efforts should target public education about the risk of sun exposure and the benefit of wearing hats and adequate clothing. Specific prevention and control programs should be implemented among high-risk groups, such as those with light complexions and those sensitive to sunburn. In view of the long latency of melanoma, as much as 10 years, past exposure to the risk factors continues to cause melanoma, and any benefits of preventive efforts do not appear for some time. Although a dramatic decline is not expected in melanoma rates immediately, continuous preventive efforts ultimately should lead to a reduction in incidence and mortality. PMID:8977547

  18. The People's Library of Epidemiology.

    PubMed

    Last, John M

    2012-03-01

    The People's Library of Epidemiology is in the process of development. It consists of a website (http://www.jameslindlibrary.org) with links to online excerpts of papers and monographs of historical and scientific importance in epidemiology and related public health sciences that are held by the library of the Royal College of Physicians of Edinburgh. This paper reflects the lively panel discussion which took place on 9 August 2011. The panel members who opened the discussion were Alfredo Morabia, Anne Hardy, Roger Bernier, Jan Vandenbroucke, George Davey Smith, Esther Villalonga and Stephen Walter, who had won the prize awarded by Epidemiology Monitor for an essay on the People's Library of Epidemiology. PMID:22326598

  19. Rosacea: current state of epidemiology.

    PubMed

    Tan, Jerry; Berg, Mats

    2013-12-01

    Case definitions are critical in epidemiologic research. However, modern disease indicators must now consider complex data from gene-based research along with traditional clinical parameters. Rosacea is a skin disorder with multiple signs and symptoms. In individuals, these features may be multiple or one may predominate. While studies on the epidemiology of rosacea have previously been sparse, there has been a recent increase in research activity. A broader body of epidemiological information that includes a greater variety of countries beyond Northern Europe and general population-based demographics is needed. As there are operational issues in current case definitions of rosacea subtypes--rationalization and standardization--universal consistent applications in future research is also imperative. Further improvement in disease definition combining new research information along with clinical pragmatism should increase the accuracy of rosacea case ascertainment and facilitate further epidemiological research. PMID:24229634

  20. Sample Cancer Epidemiology Grant Applications

    Cancer.gov

    The National Cancer Institute frequently receives questions from investigators for examples of successfully funded grant applications. Several investigators agreed to let the Epidemiology and Genomics Research Program post excerpts of their grant applications online.

  1. Metabolomics and Epidemiology Working Group

    Cancer.gov

    The Metabolomics and Epidemiology (MetEpi) Working Group promotes metabolomics analyses in population-based studies, as well as advancement in the field of metabolomics for broader biomedical and public health research.

  2. Genomic Resources for Cancer Epidemiology

    Cancer.gov

    This page provides links to research resources, complied by the Epidemiology and Genomics Research Program, that may be of interest to genetic epidemiologists conducting cancer research, but is not exhaustive.

  3. [Etiological epidemiology of colorectal tumors].

    PubMed

    Cipriani, F; Geddes, M

    1996-01-01

    We reviewed the main results of colon cancer (CC) epidemiologic studies, according to data published in the 1973-1994 period, with a particular mention to dietary factors and to differences with Italian findings. Meat (mostly, red meat), animal fats and high energy intake not counterbalanced by sufficient physical activity seem to be the most consistent risk factors for CC. On the contrary, the vegetarian based diet seems to reduce the risk of CC. Although interestingly, the relevance to CC of other life-style and diet-related factors (alcohol intake, smoking habits, processing and cooking methods, occupation, drugs, personal medical and reproductive history) must be better defined and requests further investigations. More recently, genetic studies are clarifying the hereditary risk of CC. Several colon carcinogenesis hypotheses have been proposed, but general agreement on the most reliable is still lacking. Authors argue that in the next future, new acquirements could emerge from metabolic polymorphism studies, possibly reconciling the biological significance of individual susceptibility and environmental factors to CC incidence. PMID:9382427

  4. [Epidemiology of rosacea: updated data].

    PubMed

    Chosidow, O; Cribier, B

    2011-09-01

    The epidemiological data on rosacea remain fragmentary and the methodological quality debatable. Rosacea affects mainly adults around the age of 30 years and classically predominates in females. Recent Estonian and Irish studies suggest that the female predominance may not be as high as previously believed. However, prevalence does increase with age. The prevalence statistics published in Europe and the United States are highly variable, ranging from less than 1% to more than 20% of the adult population; actually, the methods used and the populations studied vary greatly from one study to another; consequently, they cannot be compared. A family history of the disease is a risk factor, as is the very light skin phototype (Celtic skin type). Alcohol and coffee, classically blamed, are not risk factors; however, tobacco may have a protective effect. New studies are undoubtedly necessary: they should use the diagnostic and severity criteria established in 2002 and 2004. Rosacea has a strong impact on quality of life and can be associated with depressive symptoms. A specific quality-of-life scale, the RosaQol, has been established and validated in the United States, by the same group that elaborated the Skindex scale. Translations of this scale into French, Italian, German, and Spanish have been validated, which may allow future intercultural comparisons. PMID:21907871

  5. Epidemiology of rosacea: updated data.

    PubMed

    Chosidow, O; Cribier, B

    2011-11-01

    The epidemiological data on rosacea remain fragmentary and the methodological quality debatable. Rosacea affects mainly adults around the age of 30 years and classically predominates in females. Recent Estonian and Irish studies suggest that the female predominance may not be as high as previously believed. However, prevalence does increase with age. The prevalence statistics published in Europe and the United States are highly variable, ranging from less than 1% to more than 20% of the adult population; actually, the methods used and the populations studied vary greatly from one study to another; consequently, they cannot be compared. A family history of the disease is a risk factor, as is the very light skin phototype (Celtic skin type). Alcohol and coffee, classically blamed, are not risk factors; however, tobacco may have a protective effect. New studies are undoubtedly necessary: they should use the diagnostic and severity criteria established in 2002 and 2004. Rosacea has a strong impact on quality of life and can be associated with depressive symptoms. A specific quality-of-life scale, the RosaQol, has been established and validated in the United States, by the same group that elaborated the Skindex scale. Translations of this scale into French, Italian, German, and Spanish have been validated, which may allow future intercultural comparisons. PMID:22183096

  6. Molecular epidemiology in environmental carcinogenesis.

    PubMed Central

    Perera, F P; Mooney, L A; Dickey, C P; Santella, R M; Bell, D; Blaner, W; Tang, D; Whyatt, R M

    1996-01-01

    Molecular epidemiology has significant potential in preventing cancer and other diseases caused by environmental exposures (related to lifestyle, occupation, or ambient pollution). This approach attempts to prevent cancer by incorporating laboratory methods to document the molecular dose and preclinical effects of carcinogens, as well as factors that increases individual susceptibility to carcinogens. Recently we have carried out validation studies of biologic markers such as carcinogen--DNA and carcinogen--protein adducts, gene and chromosomal mutations, alterations in target oncogenes or tumor suppressor genes, polymorphisms in putative susceptibility genes (individual P450s, glutathione transferase M1), and serum levels of micronutrients. This research involves adults, infants, and children exposed to varying levels of carcinogens, as well as cancer cases and controls. On a group level, dose-response relationships have frequently been seen between various biomarkers and environmental exposures such as polycyclic aromatic hydrocarbons, cigarette smoke (active and passive), and ambient indoor and workplace air pollution. However, there is significant interindividual variation in biomarkers that appears to reflect a modulating effect on biomarkers (hence potential risk) by genetic and acquired susceptibility factors. Ongoing retrospective and nested case-control studies of lung and breast cancer are examining the association between biomarkers and cancer risk. Results of these studies are encouraging; they suggest that biomarkers, once validated, can be useful in identifying populations and individuals at risk in time to intervene effectively. PMID:8781360

  7. The emergence of translational epidemiology: from scientific discovery to population health impact.

    PubMed

    Khoury, Muin J; Gwinn, Marta; Ioannidis, John P A

    2010-09-01

    Recent emphasis on translational research (TR) is highlighting the role of epidemiology in translating scientific discoveries into population health impact. The authors present applications of epidemiology in TR through 4 phases designated T1-T4, illustrated by examples from human genomics. In T1, epidemiology explores the role of a basic scientific discovery (e.g., a disease risk factor or biomarker) in developing a "candidate application" for use in practice (e.g., a test used to guide interventions). In T2, epidemiology can help to evaluate the efficacy of a candidate application by using observational studies and randomized controlled trials. In T3, epidemiology can help to assess facilitators and barriers for uptake and implementation of candidate applications in practice. In T4, epidemiology can help to assess the impact of using candidate applications on population health outcomes. Epidemiology also has a leading role in knowledge synthesis, especially using quantitative methods (e.g., meta-analysis). To explore the emergence of TR in epidemiology, the authors compared articles published in selected issues of the Journal in 1999 and 2009. The proportion of articles identified as translational doubled from 16% (11/69) in 1999 to 33% (22/66) in 2009 (P = 0.02). Epidemiology is increasingly recognized as an important component of TR. By quantifying and integrating knowledge across disciplines, epidemiology provides crucial methods and tools for TR. PMID:20688899

  8. Epidemiology in a changing world: implications for population-based research on mental disorders.

    PubMed

    Cooper, B

    2014-06-01

    Introduction and objectives. Population-based research on mental disorders needs to keep pace with trends in general epidemiology. At present, this requirement is complicated by uncertainty within the parent discipline about its future development. The present study examines proposals for new directions in strategy and methods and considers their significance for psychiatric epidemiology. Method. Narrative review, cross-checked by search of English-language journals of epidemiology for new trends and developments reported in the years from 2000 onwards. Results. The proposals reviewed here are divided into three groups: 1. A new research paradigm of 'eco-epidemiology', which includes both individual risk factors and macro-environmental systems that mediate population levels of health and sickness. 2. Improved 'translation' of research findings - i.e. more rapid and effective implementation of epidemiological evidence into health policy and practice. 3. Adaptation of epidemiology to a globalised economy, with firmer regulation of funding and resources. Conclusions. Each of these proposals has implications for psychiatric epidemiology. Workers in this field, however, are still preoccupied by relatively specific problems of definition, measurement and classification, and so far the current debates in general epidemiology are scarcely reflected. The proposals outlined above call for: • a working model of eco-epidemiology as it relates to psychiatric disorders; • implementation strategies to encourage more active participation in epidemiological research by community health services and caregiver organisations; • international collaborative projects that offer practical benefits in training and service facilities for the countries taking part. PMID:24345606

  9. Malaria Molecular Epidemiology: Lessons from the International Centers of Excellence for Malaria Research Network

    PubMed Central

    Escalante, Ananias A.; Ferreira, Marcelo U.; Vinetz, Joseph M.; Volkman, Sarah K.; Cui, Liwang; Gamboa, Dionicia; Krogstad, Donald J.; Barry, Alyssa E.; Carlton, Jane M.; van Eijk, Anna Maria; Pradhan, Khageswar; Mueller, Ivo; Greenhouse, Bryan; Andreina Pacheco, M.; Vallejo, Andres F.; Herrera, Socrates; Felger, Ingrid

    2015-01-01

    Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts. PMID:26259945

  10. Clinical, epidemiological, and therapeutic profile of dermatophytosis*

    PubMed Central

    Pires, Carla Andréa Avelar; da Cruz, Natasha Ferreira Santos; Lobato, Amanda Monteiro; de Sousa, Priscila Oliveira; Carneiro, Francisca Regina Oliveira; Mendes, Alena Margareth Darwich

    2014-01-01

    BACKGROUND The cutaneous mycoses, mainly caused by dermatophyte fungi, are among the most common fungal infections worldwide. It is estimated that 10% to 15% of the population will be infected by a dermatophyte at some point in their lives, thus making this a group of diseases with great public health importance. OBJECTIVE To analyze the clinical, epidemiological, and therapeutic profile of dermatophytosis in patients enrolled at the Dermatology service of Universidade do Estado do Pará, Brazil, from July 2010 to September 2012. METHOD A total of 145 medical records of patients diagnosed with dermatophytosis were surveyed. Data were collected and subsequently recorded according to a protocol developed by the researchers. This protocol consisted of information regarding epidemiological and clinical aspects of the disease and the therapy employed. RESULTS The main clinical form of dermatophyte infection was onychomycosis, followed by tinea corporis, tinea pedis, and tinea capitis. Furthermore, the female population and the age group of 51 to 60 years were the most affected. Regarding therapy, there was a preference for treatments that combine topical and systemic drugs, and the most widely used drugs were fluconazole (systemic) and ciclopirox olamine (topical). CONCLUSION This study showed the importance of recurrent analysis of the epidemiological profile of dermatophytosis to enable correct therapeutic and preventive management of these conditions, which have significant clinical consequences, with chronic, difficult-totreat lesions that can decrease patient quality of life and cause disfigurement. PMID:24770502

  11. Charting a Future for Epidemiologic Training

    PubMed Central

    Samet, Jonathan M.; Chavez, Gilbert F.; Davies, Megan M.; Galea, Sandro; Hiatt, Robert A.; Hornung, Carlton A.; Khoury, Muin J.; Koo, Denise; Mays, Vickie M.; Remington, Patrick; Yarber, Laura

    2015-01-01

    Purpose To identify macro level trends that are changing the needs of epidemiologic research and practice and to develop and disseminate a set of competencies and recommendations for epidemiologic training that will be responsive to these changing needs. Methods There were three stages to the project: 1) assembly of a working group of senior epidemiologists from multiple sectors, 2) Identifying relevant literature, and 3) conducting key informant interviews with 15 experienced epidemiologists. Results Twelve macro trends were identified along with associated actions for the field and educational competencies. The macro trends include: 1) “Big Data”/ informatics, 2) the changing health communication environment, 3) the Affordable Care Act/health care system reform, 4) shifting demographics, 5) globalization, 6) emerging high throughput technologies (“omics”), 7) a greater focus on accountability, 8) privacy changes, 9) a greater focus on “upstream” causes of disease, 10) the emergence of translational sciences, 11) the growing centrality of team and trans-disciplinary science, and 12) the evolving funding environment. Conclusion Addressing these issues through curricular change is needed to allow the field of epidemiology to more fully reach and sustain its full potential to benefit population health and remain a scientific discipline that makes critical contributions to ensuring clinical, social, and population health. PMID:25976024

  12. Epidemiology of Spondyloarthritis

    PubMed Central

    Stolwijk, Carmen; van Tubergen, Astrid; Reveille, John D.

    2014-01-01

    Synopsis Spondyloarthritis (SpA) represents a group of interrelated diseases with common clinical features and a close association with HLA-B27. Figures on the incidence and prevalence of diseases vary highly dependent on methodological differences between studies, the case definition used to classify disease and on the prevalence of HLA-B27 in the population studied. When summarizing the available literature, incidence rates of SpA are mainly based on the ESSG criteria and range between 0.48 and 63/100.000 while prevalence rates vary between 0.01 and 2.5%. For ankylosing spondylitis (AS), the most widely recognized representative of the SpA group of diseases, incidence rates of 0.44-7.3/100.000 and prevalence rates of 0.007-1.7% have been described in studies that were based on the (modified) New York criteria to classify cases. The incidence of psoriatic arthritis (PsA) varied from 3.6 up to 23.1/100.000 in different studies and prevalence between <0.1% and 0.4%, using a variety of classification criteria. The incidence of ReA has been estimated between 0.6 up to 28/100.000 in studies based on different source populations and different case definitions. The newly proposed criteria for axial SpA and peripheral SpA present an attractive new approach to facilitate classification of the SpA into two main subtypes and the axial SpA criteria allow earlier detection of patents with inflammatory back pain. It should be emphasized that these criteria were developed for use in a (specialized) clinical setting and not for large epidemiological studies. PMID:23083748

  13. Epidemiological surveillance of infectious diseases in France.

    PubMed

    Dufour, B; La Vieille, S

    2000-01-01

    Epidemiological surveillance, namely the continuous monitoring of diseases and health determinants in a population, has developed over the past fifteen years, in the sphere of human health as well as in animal health. All epidemiological surveillance networks include the following four stages: data collection, data transmission, data processing and dissemination of information. However, despite this basic similarity, the very many networks existing in France are extremely varied in nature. At the national level, the bodies involved in epidemiological surveillance for infectious animal diseases are the Direction générale de l'alimentation, the Agence française de sécurité sanitaire des aliments and, to a lesser degree, the Institut français de recherche pour l'exploitation de la mer. In the field, the networks rely on the Direction des services vétérinaires, veterinary practitioners, laboratories in each département, and livestock producers' groups (especially animal health protection groups). Some twenty French networks currently in operation are presented in this article according to a classification based on published criteria. In the case of human infectious diseases, epidemiological surveillance is carried out almost entirely by the Direction générale de la santé and the Directions départementales d'action sanitaire et sociale, the Institut de veille sanitaire and the various Centres nationaux de référence (CNRs). Most human infectious diseases are monitored by one or more of the following broad categories of networks: reporting of notifiable diseases, the CNRs, the network of sentinel doctors, the network of hospital laboratories and departments, and medical causes of death. An example where surveillance is covered by several networks is also presented, namely surveillance for salmonellosis and Salmonella. Lastly, methods for evaluating networks are discussed. PMID:10779198

  14. Epidemiologic studies based on the Chernobyl accident

    SciTech Connect

    Beebe, G.

    1996-12-31

    There are great opportunities in the post-Chernobyl experience for significant epidemiologic research, perhaps even more in the area of disaster research than in the area of the human health effects of ionizing radiation. But the potential opportunity for learning the effects of radioiodine on the thyroid is very great and has aroused widespread national and international investigative interest. The opportunities for significant epidemiologic research are, however, severely limited currently by the worsening economic situation in Belarus and Ukraine, where the greatest exposure occurred, and by the lack of personnel trained in appropriate methods of study, the lack of modern equipment, the lack of supplies, the poor communication facilities, and the difficulties of accurate dose estimation. the disadvantages may or may not outweigh the obvious advantages of large numbers, the extensive direct thyroidal measurements made shortly after the accident in 1986, the magnitude of the releases of radioiodine, and the retention of the former Soviet system of universal medical care. Both the European Commission (EC) and the World Health Organization (WHO) have been working actively to strengthen the infrastructure of Russia, Belarus, and Ukraine. New scientific knowledge has yet to emerge from the extensive epidemiologic work but information of considerable public health significance has begun to accumulate. The bulk of the thyroid cancer has been shown to be valid by international pathology review; both EC and WHO representatives have declared the increase in thyroid cancer among children to have been caused in large part by Chernobyl. No increase in leukemia has been seen in the general population. The WHO pilot studies have shown no evidence of an increase in psychologic or neurologic complications among those exposed in utero. Ongoing epidemiologic work can be described by review of the inventory that the WHO has begun to maintain and publish. 20 refs., 7 tabs.

  15. Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

    DOE PAGESBeta

    Cologne, John; Grant, Eric J.; Nakashima, Eiji; Chen, Yun; Funamoto, Sachiyo; Katayama, Hiroaki

    2012-01-01

    Objective . Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying) the data, but overmasking can compromise utility (analysis potential). Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods . We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results . Masking by modest rounding did not adequately enhance security but rounding to remove several digits ofmore » relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions . When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs.« less

  16. Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

    PubMed Central

    Cologne, John; Grant, Eric J.; Nakashima, Eiji; Chen, Yun; Funamoto, Sachiyo; Katayama, Hiroaki

    2012-01-01

    Objective. Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying) the data, but overmasking can compromise utility (analysis potential). Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods. We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results. Masking by modest rounding did not adequately enhance security but rounding to remove several digits of relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions. When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs. PMID:22505949

  17. A Bayesian Ensemble Approach for Epidemiological Projections

    PubMed Central

    Lindström, Tom; Tildesley, Michael; Webb, Colleen

    2015-01-01

    Mathematical models are powerful tools for epidemiology and can be used to compare control actions. However, different models and model parameterizations may provide different prediction of outcomes. In other fields of research, ensemble modeling has been used to combine multiple projections. We explore the possibility of applying such methods to epidemiology by adapting Bayesian techniques developed for climate forecasting. We exemplify the implementation with single model ensembles based on different parameterizations of the Warwick model run for the 2001 United Kingdom foot and mouth disease outbreak and compare the efficacy of different control actions. This allows us to investigate the effect that discrepancy among projections based on different modeling assumptions has on the ensemble prediction. A sensitivity analysis showed that the choice of prior can have a pronounced effect on the posterior estimates of quantities of interest, in particular for ensembles with large discrepancy among projections. However, by using a hierarchical extension of the method we show that prior sensitivity can be circumvented. We further extend the method to include a priori beliefs about different modeling assumptions and demonstrate that the effect of this can have different consequences depending on the discrepancy among projections. We propose that the method is a promising analytical tool for ensemble modeling of disease outbreaks. PMID:25927892

  18. A Systematic Bayesian Integration of Epidemiological and Genetic Data

    PubMed Central

    Lau, Max S. Y.; Marion, Glenn; Streftaris, George; Gibson, Gavin

    2015-01-01

    Genetic sequence data on pathogens have great potential to inform inference of their transmission dynamics ultimately leading to better disease control. Where genetic change and disease transmission occur on comparable timescales additional information can be inferred via the joint analysis of such genetic sequence data and epidemiological observations based on clinical symptoms and diagnostic tests. Although recently introduced approaches represent substantial progress, for computational reasons they approximate genuine joint inference of disease dynamics and genetic change in the pathogen population, capturing partially the joint epidemiological-evolutionary dynamics. Improved methods are needed to fully integrate such genetic data with epidemiological observations, for achieving a more robust inference of the transmission tree and other key epidemiological parameters such as latent periods. Here, building on current literature, a novel Bayesian framework is proposed that infers simultaneously and explicitly the transmission tree and unobserved transmitted pathogen sequences. Our framework facilitates the use of realistic likelihood functions and enables systematic and genuine joint inference of the epidemiological-evolutionary process from partially observed outbreaks. Using simulated data it is shown that this approach is able to infer accurately joint epidemiological-evolutionary dynamics, even when pathogen sequences and epidemiological data are incomplete, and when sequences are available for only a fraction of exposures. These results also characterise and quantify the value of incomplete and partial sequence data, which has important implications for sampling design, and demonstrate the abilities of the introduced method to identify multiple clusters within an outbreak. The framework is used to analyse an outbreak of foot-and-mouth disease in the UK, enhancing current understanding of its transmission dynamics and evolutionary process. PMID:26599399

  19. Epidemiologic problems associated with exposure to several agents.

    PubMed Central

    Waxweiler, R J

    1981-01-01

    Simultaneous exposure to many potentially hazardous agents in the environment is the rule, yet there have been few studies that have addressed the issue of interactions of these agents in modifying disease outcomes, even though such interactions may potentially be important in terms of policy-making. Epidemiological methods may be an important way to identify interaction effects, especially for chronic disease outcomes. Some examples of epidemiologic investigations of this problem are given, and a matrix method used to evaluate the contribution of nineteen chemicals to the risk of liver angiosarcoma in vinyl chloride workers is discussed. PMID:7199433

  20. Genetic epidemiology, genetic maps and positional cloning.

    PubMed Central

    Morton, Newton E

    2003-01-01

    Genetic epidemiology developed in the middle of the last century, focused on inherited causes of disease but with methods and results applicable to other traits and even forensics. Early success with linkage led to the localization of genes contributing to disease, and ultimately to the Human Genome Project. The discovery of millions of DNA markers has encouraged more efficient positional cloning by linkage disequilibrium (LD), using LD maps and haplotypes in ways that are rapidly evolving. This has led to large international programmes, some promising and others alarming, with laws about DNA patenting and ethical guidelines for responsible research still struggling to be born. PMID:14561327

  1. AIR POLLUTION EPIDEMIOLOGY: CAN INFORMATION BE OBTAINED FROM THE VARIATIONS IN SIGNIFICANCE AND RISK AS A FUNCTION OF DAYS AFTER EXPOSURE (LAG STRUCTURE)?

    EPA Science Inventory

    Determine if analysis of lag structure from time series epidemiology, using gases, particles, and source factor time series, can contribute to understanding the relationships among various air pollution indicators. Methods: Analyze lag structure from an epidemiologic study of ca...

  2. Descriptive Epidemiology of Cervical Dystonia

    PubMed Central

    Defazio, Giovanni; Jankovic, Joseph; Giel, Jennifer L.; Papapetropoulos, Spyridon

    2013-01-01

    Background Cervical dystonia (CD), the most common form of adult-onset focal dystonia, has a heterogeneous clinical presentation with variable clinical features, leading to difficulties and delays in diagnosis. Owing to the lack of reviews specifically focusing on the frequency of primary CD in the general population, we performed a systematic literature search to examine its prevalence/incidence and analyze methodological differences among studies. Methods We performed a systematic literature search to examine the prevalence data of primary focal CD. Sixteen articles met our methodological criteria. Because the reported prevalence estimates were found to vary widely across studies, we analyzed methodological differences and other factors to determine whether true differences exist in prevalence rates among geographic areas (and by gender and age distributions), as well as to facilitate recommendations for future studies. Results Prevalence estimates ranged from 20–4,100 cases/million. Generally, studies that relied on service-based and record-linkage system data likely underestimated the prevalence of CD, whereas population-based studies suffered from over-ascertainment. The more methodologically robust studies yielded a range of estimates of 28–183 cases/million. Despite the varying prevalence estimates, an approximate 2:1 female:male ratio was consistent among many studies. Three studies estimated incidence, ranging from 8–12 cases/million person-years. Discussion Although several studies have attempted to estimate the prevalence and incidence of CD, there is a need for additional well-designed epidemiological studies on primary CD that include large populations; use defined CD diagnostic criteria; and stratify for factors such as age, gender, and ethnicity. PMID:24255801

  3. Epidemiology of Bluetongue in India.

    PubMed

    Rao, P P; Hegde, N R; Reddy, Y N; Krishnajyothi, Y; Reddy, Y V; Susmitha, B; Gollapalli, S R; Putty, K; Reddy, G H

    2016-04-01

    Bluetongue (BT) is an insectborne endemic disease in India. Although infections are observed in domestic and wild ruminants, the clinical disease and mortality are observed only in sheep, especially in the southern states of the country. The difference in disease patterns in different parts of the country could be due to varied climatic conditions, sheep population density and susceptibility of the sheep breeds to BT. Over the five decades after the first report of BT in 1964, most of the known serotypes of bluetongue virus (BTV) have been reported from India either by virus isolation or by detection of serotype-specific antibodies. There have been no structured longitudinal studies to identify the circulating serotypes throughout the country. At least ten serotypes were isolated between 1967 and 2000 (BTV-1-4, 6, 9, 16-18, 23). Since 2001, the All-India Network Programme on Bluetongue and other laboratories have isolated eight different serotypes (BTV-1-3, 9, 10, 12, 16, 21). Genetic analysis of these viruses has revealed that some of them vary substantially from reference viruses, and some show high sequence identity with modified live virus vaccines used in different parts of the world. These observations have highlighted the need to develop diagnostic capabilities, especially as BT outbreaks are still declared based on clinical signs. Although virus isolation and serotyping are the gold standards, rapid methods based on the detection of viral nucleic acid may be more suitable for India. The epidemiological investigations also have implications for vaccine design. Although only a handful serotypes may be involved in causing outbreaks every year, the combination of serotypes may change from year to year. For effective control of BT in India, it may be pertinent to introduce sentinel and vector traps systems for identification of the circulating serotypes and to evaluate herd immunity against different serotypes, so that relevant strains can be included in vaccine

  4. Epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia by PCR.

    PubMed Central

    Chatelut, M; Dournes, J L; Chabanon, G; Marty, N

    1995-01-01

    We used two PCR methods for epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia with either arbitrary primers (random amplified polymorphic DNA) or enterobacterial repetitive intergenic consensus sequences as primers (ERIC-PCR). The analysis was performed with 38 isolates of S. maltophilia, comprising 9 nosocomial isolates from a burn unit, 20 other clinical isolates epidemiologically unrelated, and 9 isolates from one cystic fibrosis patient. Both methods indicated that all of the nosocomial episodes were independent. In contrast, the nine isolates from the cystic fibrosis patient were assigned to very closely related profiles, especially by ERIC-PCR. We conclude that random amplified polymorphic DNA and ERIC-PCR have comparable reproducible and discriminatory powers for epidemiological typing of S. maltophilia, but ERIC-PCR profiles can be more easily evaluated. PMID:7790459

  5. Mitochondrial DNA and Cancer Epidemiology Workshop

    Cancer.gov

    A workshop to review the state-of-the science in the mitochondrial DNA field and its use in cancer epidemiology, and to develop a concept for a research initiative on mitochondrial DNA and cancer epidemiology.

  6. About the Epidemiology and Genomics Research Program

    Cancer.gov

    Epidemiology is the scientific study of the causes and distribution of disease in populations. NCI-funded epidemiology research is conducted through research at institutions in the United States and internationally.

  7. [Topical problems of sanitary and epidemiologic examination concerning projects of sanitary protection zones in airports].

    PubMed

    Isayeva, A M; Zibaryov, E V

    2015-01-01

    The article covers data on major errors in sanitary protection zones specification for civil airports, revealed through sanitary epidemiologic examination. The authors focus attention on necessity to develop unified methodic approach to evaluation of aviation noise effects, when justifying sanitary protection zone of airports and examining sanitary and epidemiologic project documents. PMID:25895251

  8. Epidemiology of hepatitis C virus exposure in Egypt: Opportunities for prevention and evaluation

    PubMed Central

    Miller, F DeWolfe; Elzalabany, Mahmoud S; Hassani, Sara; Cuadros, Diego F

    2015-01-01

    AIM: To critically evaluate the current epidemiology data on exposures, rather than infection, to hepatitis C virus (HCV) transmission and recommend epidemiologic strategies to fill gaps. METHODS: Standard methods for identifying and evaluating relevant epidemiologic literature and available data were used. RESULTS: There is a large body of literature on the epidemiology of HCV transmission in Egypt that collectively identifies ongoing iatrogenic exposures as the major driver for HCV transmission due to short comings in infection control and standard procedures. Additional epidemiologic studies on HCV transmission that requires the participation of human subject is unwarranted. Alternatively, very little literature was found on the epidemiology of exposure to HCV, infection control, and safe injection practices. The information that is available on patterns of HCV exposure shows high frequencies of inadequate infection control, problems in sterilization in health care facilities, low rates of hand washing, untrained personnel, lack of stated policies in facilities, HCV contamination of instruments and very large injection frequencies with low but very significant syringe and needle reuse. There is an important need to increase the number, size, and diversity of epidemiologic studies on HCV exposures, patterns of risk factors for infection, infection control, and safe injection practices. In addition to health care facilities evaluation, relevant knowledge attitude and practice studies are recommended. CONCLUSION: Epidemiologic methods on HCV exposure can be used to characterize the magnitude of exposures to HCV infection, target interventions to reduce exposures, and provide the best method for evaluating interventions by demonstrating the reduction of exposure to HCV infection. PMID:26668697

  9. EPIDEMIOLOGICAL WORK ON DBP EXPOSURES

    EPA Science Inventory

    This effort was based on several completed or existing projects where disinfection by-products ( or DBPs) have been the primary exposure of interest. Previous epidemiologic results on reproductive or developmental risks that may be associated with consumption of disinfected drink...

  10. Brain Tumor Epidemiology Consortium (BTEC)

    Cancer.gov

    The Brain Tumor Epidemiology Consortium is an open scientific forum organized to foster the development of multi-center, international and inter-disciplinary collaborations that will lead to a better understanding of the etiology, outcomes, and prevention of brain tumors.

  11. Radiation epidemiology: Past and present

    SciTech Connect

    Boice, J.D. Jr.

    1997-03-01

    Major advancements in radiation epidemiology have occurred during the last several years in studies of atomic bomb survivors, patients given medical radiation, and radiation workers, including underground miners. Risks associated with the Chernobyl accident, indoor radon and childhood exposure to I-131 have yet to be elucidated. Situations in the former Soviet Union around Chelyabinsk, a nuclear installation in the southern Urals, and in the Altai, which received radioactive fallout from weapons testing at Semipalatinsk, Kazakhstan, have the potential to provide information on the effects of chronic radiation exposure. Since Roentgen`s discovery of x-rays just 100 years ago, a tremendous amount of knowledge has been accumulated about human health effects following irradiation. The 1994 UNSCEAR report contains the latest compilation and synthesis of radiation epidemiology. This overview will cover epidemiology from a radiation perspective. The different types of study methodologies will be described, followed by a kaleidoscope coverage of past and present studies; ending with some remaining questions in radiation epidemiology. This should set the stage for future chapters, and stimulate thinking about implications of the new data on radiation cancer risks.

  12. Methodologic research needs in environmental epidemiology: data analysis.

    PubMed Central

    Prentice, R L; Thomas, D

    1993-01-01

    A brief review is given of data analysis methods for the identification and quantification of associations between environmental exposures and health events of interest. Data analysis methods are outlined for each of the study designs mentioned, with an emphasis on topics in need of further research. Particularly noted are the need for improved methods for accommodating exposure assessment measurement errors in analytic epidemiologic studies and for improved methods for the conduct and analysis of aggregate data (ecologic) studies. PMID:8206041

  13. Techniques for assessing teratogenic effects: epidemiology.

    PubMed Central

    Flynt, J W

    1976-01-01

    Epidemiologic studies of malformations can aid in the understanding of human teratogenesis. Employing a variety of approaches epidemiology can develop or test hypotheses concerning possible causes or through surveillance provide data useful for a variety of purposes. Drawing heavily upon our experiences at the Center for Disease Control, this paper reviews some concepts and uses of epidemiology in studies of human teratogenesis. PMID:1030396

  14. Cancer Epidemiology Matters Blog - 2013 Archive

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  15. Cancer Epidemiology Matters Blog - 2015 Archive

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  16. Cancer Epidemiology Matters Blog - 2012 Archive

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  17. Cancer Epidemiology Matters Blog - 2014 Archive

    Cancer.gov

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  18. Methods and Technologies Branch (MTB)

    Cancer.gov

    The Methods and Technologies Branch focuses on methods to address epidemiologic data collection, study design and analysis, and to modify technological approaches to better understand cancer susceptibility.

  19. Seasonal Variation in Epidemiology

    ERIC Educational Resources Information Center

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  20. Combining Epidemiologic Information Across Space Agencies

    NASA Technical Reports Server (NTRS)

    Minard, Charles G.; Clark, April L.; Wear, Mary L.; Mason, Sara; Van Baalen, Mary

    2010-01-01

    Space flight is a very unique occupational exposure with potential hazards that are not fully understood. A limited number of individuals have experienced the exposures incurred during space flight, and epidemiologic research would benefit from shared information across space agencies. However, data sharing can be problematic due to agency protection policies for personally identifiable information as well as medical records. Compliance with these protocols in the astronaut population is particularly difficult given the small, high-profile population under study. Creativity in combining data is necessary in order to overcome these difficulties and improve statistical power in research. This study presents methods in meta-analysis that may be used to combine non-attributable data across space agencies so that meaningful conclusions may be drawn about study interests. Methods for combining epidemiologic data across space agencies are presented, and the processes are demonstrated using life-time mortality data in U.S. astronauts and Russian cosmonauts. This proof of concept was found to be an acceptable way of sharing data across agencies, and will be used in the future as more relevant research interests are identified.

  1. The global epidemiology of waterpipe smoking

    PubMed Central

    Maziak, Wasim; Taleb, Ziyad Ben; Bahelah, Raed; Islam, Farahnaz; Jaber, Rana; Auf, Rehab; Salloum, Ramzi G

    2015-01-01

    Objectives In the past decade, waterpipe smoking (a.k.a. hookah, shisha, narghile) has become a global phenomenon. In this review, we provide an updated picture of the main epidemiological trends in waterpipe smoking globally. Data sources Peer-reviewed publications indexed in major biomedical databases between 2004 and 2014. Search keywords included a combination of: waterpipe, hookah, shisha along with epidemiology, patterns, prevalence and predictors. We also used different spellings of waterpipe terms commonly used. Study selection The focus was on studies with large representative samples, national data or high-quality reports that illuminated aspects of the epidemiology and trends in waterpipe smoking. Data extraction Multiple researchers extracted the data independently and collectively decided on the most important and pertinent studies to include in the review. Data synthesis Waterpipe smoking has become a global phenomenon among youth. The global waterpipe epidemic is likely driven by (1) the introduction of manufactured flavoured tobacco (Maassel); (2) the intersection between waterpipe's social dimension and thriving café culture; (3) the evolution of mass communication media; (4) the lack of regulatory/policy framework specific to the waterpipe. Waterpipe smoking is becoming the most popular tobacco use method among youth in the Middle East, and is quickly gaining popularity elsewhere. Important patterns of waterpipe smoking include the predominance among younger, male, high socioeconomic, and urban groups. Intermittent and social use are also noted patterns. Conclusions Waterpipe smoking has become a global public health problem. Developing surveillance, intervention and regulatory/policy frameworks specific to the waterpipe has become a public health priority. PMID:25298368

  2. Rethinking cumulative exposure in epidemiology, again.

    PubMed

    de Vocht, Frank; Burstyn, Igor; Sanguanchaiyakrit, Nuthchyawach

    2015-01-01

    The use of cumulative exposure, the product of intensity and duration, has enjoyed great popularity in epidemiology of chronic diseases despite numerous known caveats in its interpretation. We briefly review the history of use of cumulative exposure in epidemiology and propose an alternative method for relating time-integrated exposures to health risks. We argue, as others before us have, that cumulative exposure metrics obscures the interplay of exposure intensity and duration. We propose to use a computationally simple alternative in which duration and intensity of exposure are modelled as a main effect and their interaction, cumulative exposure, only be added if there is evidence of deviation from this additive model. We also consider the Lubin-Caporaso model of interplay of exposure intensity and duration. The impact of measurement error in intensity on model selection was also examined. The value of this conceptualization is demonstrated using a simulation study and further illustrated in the context of respiratory health and occupational exposure to latex dust. We demonstrate why cumulative exposure has been so popular because the cumulative exposure metric per se gives a robust answer to the existence of an association, regardless of the underlying true mechanism of disease. Treating cumulative exposure as the interaction of main effects of exposure duration and intensity enables epidemiologists to derive more information about mechanism of disease then fitting cumulative exposure metric by itself, and without the need to collect additional data. We propose that the practice of fitting duration, intensity and cumulative exposure separately to epidemiologic data should lead to conceptualization of cumulative exposure as interaction of main effects of duration and intensity of exposure. PMID:25138292

  3. Improving Concordance in Environmental Epidemiology: A Three-Part Proposal.

    PubMed

    LaKind, Judy S; Goodman, Michael; Makris, Susan L; Mattison, Donald R

    2015-01-01

    In observational research, evidence is usually derived from multiple studies, and any single result is rarely considered sufficient for public health decision making. Despite more than five decades of research and thousands of studies published, the ability to draw robust conclusions regarding the presence or absence of causal links between specific environmental exposures and human health remains limited. To develop policies that are protective of public health and can withstand scrutiny, agencies need to rely on investigations of satisfactory quality that follow sufficiently concordant protocols in terms of exposure assessment, outcome ascertainment, data analysis, and reporting of results. Absent such concordance, the ability of environmental epidemiology studies to inform decision making is greatly diminished. Systems and tools are proposed here to improve concordance among environmental epidemiology studies. Specifically, working systems in place in other fields of research are critically examined and used as guidelines to develop analogous policies and procedures for environmental epidemiology. A three-part path forward toward more concordant, transparent, and readily accessible environmental epidemiology evidence that parallels ongoing efforts in medical research is proposed. The three parts address methods for improving quality and accessibility of systematic reviews, access to information on ongoing and completed studies, and principles for reporting. The goals are to increase the value of epidemiological research in public health decision making and to stimulate discussions around solutions proposed herein. PMID:26158301

  4. Improving Concordance in Environmental Epidemiology: A Three-Part Proposal

    PubMed Central

    LaKind, Judy S.; Goodman, Michael; Makris, Susan L.; Mattison, Donald R.

    2015-01-01

    In observational research, evidence is usually derived from multiple studies, and any single result is rarely considered sufficient for public health decision making. Despite more than five decades of research and thousands of studies published, the ability to draw robust conclusions regarding the presence or absence of causal links between specific environmental exposures and human health remains limited. To develop policies that are protective of public health and can withstand scrutiny, agencies need to rely on investigations of satisfactory quality that follow sufficiently concordant protocols in terms of exposure assessment, outcome ascertainment, data analysis, and reporting of results. Absent such concordance, the ability of environmental epidemiology studies to inform decision making is greatly diminished. Systems and tools are proposed here to improve concordance among environmental epidemiology studies. Specifically, working systems in place in other fields of research are critically examined and used as guidelines to develop analogous policies and procedures for environmental epidemiology. A three-part path forward toward more concordant, transparent, and readily accessible environmental epidemiology evidence that parallels ongoing efforts in medical research is proposed. The three parts address methods for improving quality and accessibility of systematic reviews, access to information on ongoing and completed studies, and principles for reporting. The goals are to increase the value of epidemiological research in public health decision making and to stimulate discussions around solutions proposed herein. PMID:26158301

  5. Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement

    PubMed Central

    Hawwash, Dana; Ocké, Marga C.; Berg, Christina; Forsum, Elisabet; Sonestedt, Emily; Wirfält, Elisabet; Åkesson, Agneta; Kolsteren, Patrick; Byrnes, Graham; De Keyzer, Willem; Van Camp, John; Slimani, Nadia; Cevallos, Myriam; Egger, Matthias; Huybrechts, Inge

    2016-01-01

    Background Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology—Nutritional Epidemiology (STROBE-nut). Methods and Findings Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist. Conclusion When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health. PMID:27270749

  6. An Application of Epidemiological Modeling to Information Diffusion

    NASA Astrophysics Data System (ADS)

    McCormack, Robert; Salter, William

    Messages often spread within a population through unofficial - particularly web-based - media. Such ideas have been termed "memes." To impede the flow of terrorist messages and to promote counter messages within a population, intelligence analysts must understand how messages spread. We used statistical language processing technologies to operationalize "memes" as latent topics in electronic text and applied epidemiological techniques to describe and analyze patterns of message propagation. We developed our methods and applied them to English-language newspapers and blogs in the Arab world. We found that a relatively simple epidemiological model can reproduce some dynamics of observed empirical relationships.

  7. DNA typing of epidemiologically-related isolates of Aspergillus fumigatus.

    PubMed Central

    Birch, M.; Nolard, N.; Shankland, G. S.; Denning, D. W.

    1995-01-01

    Invasive aspergillosis is often nosocomially acquired and carries a high mortality. Molecular typing methods to discriminate isolates have now been developed. Using simple restriction endonuclease (Sal1 and Xho1) digestion of total genomic DNA, we have typed 25 epidemiologically-related isolates of A. fumigatus from six hospital episodes of invasive aspergillosis. Eight DNA types were found and in each case the DNA type matched precisely the epidemiological data. Thus DNA typing of A. fumigatus can provide the means to match isolates from linked sources and distinguish isolates from diverse origins. Images Fig. 1 PMID:7867735

  8. Childhood Brain Tumor Epidemiology: A Brain Tumor Epidemiology Consortium Review

    PubMed Central

    Johnson, Kimberly J.; Cullen, Jennifer; Barnholtz-Sloan, Jill S.; Ostrom, Quinn T.; Langer, Chelsea E.; Turner, Michelle C.; McKean-Cowdin, Roberta; Fisher, James L.; Lupo, Philip J.; Partap, Sonia; Schwartzbaum, Judith A.; Scheurer, Michael E.

    2014-01-01

    Childhood brain tumors are the most common pediatric solid tumor and include several histological subtypes. Although progress has been made in improving survival rates for some subtypes, understanding of risk factors for childhood brain tumors remains limited to a few genetic syndromes and ionizing radiation to the head and neck. In this report, we review descriptive and analytical epidemiology childhood brain tumor studies from the past decade and highlight priority areas for future epidemiology investigations and methodological work that is needed to advance our understanding of childhood brain tumor causes. Specifically, we summarize the results of a review of studies published since 2004 that have analyzed incidence and survival in different international regions and that have examined potential genetic, immune system, developmental and birth characteristics, and environmental risk factors. PMID:25192704

  9. Molecular epidemiology of tuberculosis: achievements and challenges to current knowledge.

    PubMed Central

    Murray, Megan; Nardell, Edward

    2002-01-01

    Over the past 10 years, molecular methods have become available with which to strain-type Mycobacterium tuberculosis. They have allowed researchers to study certain important but previously unresolved issues in the epidemiology of tuberculosis (TB). For example, some unsuspected microepidemics have been revealed and it has been shown that the relative contribution of recently acquired disease to the TB burden in many settings is far greater than had been thought. These findings have led to the strengthening of TB control. Other research has demonstrated the existence and described the frequency of exogenous reinfection in areas of high incidence. Much recent work has focused on the phenotypic variation among strains and has evaluated the relative transmissibility, virulence, and immunogenicity of different lineages of the organism. We summarize the recent achievements in TB epidemiology associated with the introduction of DNA fingerprinting techniques, and consider the implications of this technology for the design and analysis of epidemiological studies. PMID:12132006

  10. Epidemiology of Hospital-Treated Injuries Sustained by Fitness Participants

    ERIC Educational Resources Information Center

    Gray, Shannon E.; Finch, Caroline F.

    2015-01-01

    Purpose: The purpose of this study was to provide an epidemiological profile of injuries sustained by participants in fitness activities in Victoria, Australia, based on hospital admissions and emergency department (ED) presentations and to identify the most common types, causes, and sites of these injuries. Method: Hospital-treated fitness…

  11. A ROAD MAP FOR EFFICIENT AND RELIABLE HUMAN GENOME EPIDEMIOLOGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Network of investigators have begun sharing best practices, tools, and methods for analysis of associations between genetic variation and common diseases. A Network of Investigator Networks has been set up to drive the process, sponsored by the Human Genome Epidemiology Network. A workshop is planne...

  12. Epidemiology of idiopathic pulmonary fibrosis

    PubMed Central

    Ley, Brett; Collard, Harold R

    2013-01-01

    Idiopathic pulmonary fibrosis is a chronic fibrotic lung disease of unknown cause that occurs in adults and has a poor prognosis. Its epidemiology has been difficult to study because of its rarity and evolution in diagnostic and coding practices. Though uncommon, it is likely underappreciated both in terms of its occurrence (ie, incidence, prevalence) and public health impact (ie, health care costs and resource utilization). Incidence and mortality appear to be on the rise, and prevalence is expected to increase with the aging population. Potential risk factors include occupational and environmental exposures, tobacco smoking, gastroesophageal reflux, and genetic factors. An accurate understanding of its epidemiology is important, especially as novel therapies are emerging. PMID:24348069

  13. [The epidemiological transition in Chile].

    PubMed

    Albalá, C; Vio, F; Robledo, A; Icaza, G

    1993-12-01

    Aiming to describe the place that Chile has in the epidemiological transition, a descriptive study of the changes in demographic and epidemiological profiles of the country during the last 30 years is presented. The important decrease in general and child mortality rates, that has lead to an increase in life expectancy and ageing of the population, is emphasized. A 82% reduction in the proportion of deaths among less than one year old children and a 62% increase in mortality among people 65 years or older is observed. In agreement with these changes, non transmissible chronic diseases appear as the principal cause of mortality (65% of all deaths). However, regarding morbidity, an increase in digestive infectious and sexually transmitted diseases and a decrease in immuno-preventable diseases, excepting measles, is noted. It is concluded that, according to mortality, Chile is in a post transition stage, but there is persistence of some infectious diseases, typical of a pre-transition stage. PMID:8085073

  14. Uses of ecologic analysis in epidemiologic research.

    PubMed Central

    Morgenstern, H

    1982-01-01

    Despite the widespread use of ecologic analysis in epidemiologic research and health planning, little attention has been given by health scientists and practitioners to the methodological aspects of this approach. This paper reviews the major types of ecologic study designs, the analytic methods appropriate for each, the limitations of ecologic data for making causal inferences and what can be done to minimize these problems, and the relative advantages of ecologic analysis. Numerous examples are provided to illustrate the important principles and methods. A careful distinction is made between ecologic studies that generate or test etiologic hypotheses and those that evaluate the impact of intervention programs or policies (given adequate knowledge of disease etiology). Failure to recognize this difference in the conduct of ecologic studies can lead to results that are not very informative or that are misinterpreted by others. PMID:7137430

  15. Epidemiological investigation of trichinellosis in Switzerland.

    PubMed

    Gottstein, B; Pozio, E; Connolly, B; Gamble, H R; Eckert, J; Jakob, H P

    1997-10-01

    Domestic pigs in Switzerland have been considered Trichinella-free for decades, despite the occurrence of Trichinella in the wildlife cycle. In order to reevaluate the present epidemiological situation, tissue samples from 11226 domestic pigs, 356 wild boars and 452 foxes were examined using the standard artificial digestion method. A simultaneous serological study, extended to include 25239 sera from sows provided by a Swiss pig serum bank, was also undertaken. The results of both studies support the conclusion that Trichinella spp. do not occur within the domestic pig population in Switzerland. Among the fox population, Trichinella was detected in four (0.9%) of the animals tested using the digestion method, and Trichinella britovi was identified as the infecting species by RAPD fingerprint analyses. PMID:9404846

  16. Epidemiology of oral cancer in Arab countries

    PubMed Central

    Al-Jaber, Abeer; Al-Nasser, Lubna; El-Metwally, Ashraf

    2016-01-01

    Objectives: To review the oral cancer (OC) studies that were conducted in Arab countries with regard to epidemiology, risk factors, and prognosis. Methods: A computer-based PubMed literature search was performed to retrieve studies conducted in the Arab world on epidemiology of OC. After screening for exclusion criteria, cross-referencing, and searching local journals, a total of 19 articles were included. Results: Eight prevalence studies found an OC prevalence ranging from 1.8 to 2.13 per 100,000 persons. Oral cancer patients were mostly in their fifth to sixth decade of life, and the incidence in younger age was reported in some Arab countries. Yemenis have an alarming high prevalence of OC among people younger than 45 years. Eleven studies explored determinants or prognosis of OC. Behavioral determinants such as smokeless tobacco (Shamma and Qat), and cigarette smoking were strongly associated with OC. Alcohol drinking and solar radiation exposures were cited as possible risk factors. The most affected sites were tongue, floor of the mouth, and lower lip variations in the affected site were attributed to the socio-cultural behavior of the populations under study. Squamous cell carcinoma was the most frequently detected cancer, and usually patients were in late stages (III and IV) at the time of diagnosis. Conclusion: No solid evidence exists regarding the true OC prevalence/incidence in most Arab countries due to the lack of national cancer registries and population-based studies. PMID:26905345

  17. Path analysis in genetic epidemiology: a critique.

    PubMed Central

    Karlin, S; Cameron, E C; Chakraborty, R

    1983-01-01

    Path analysis, a form of general linear structural equation models, is used in studies of human genetics data to discern genetic, environmental, and cultural factors contributing to familial resemblance. It postulates a set of linear and additive parametric relationships between phenotypes and genetic and cultural variables and then essentially uses the assumption of multivariate normality to estimate and perform tests of hypothesis on parameters. Such an approach has been advocated for the analysis of genetic epidemiological data by D. C. Rao, N. Morton, C. R. Cloninger, L. J. Eaves, and W. E. Nance, among others. This paper reviews and evaluates the formulations, assumptions, methodological procedures, interpretations, and applications of path analysis. To give perspective, we begin with a discussion of path analysis as it occurs in the form of general linear causal models in several disciplines of the social sciences. Several specific path analysis models applied to lipoprotein concentrations, IQ, and twin data are then reviewed to keep the presentation self-contained. The bulk of the critical discussion that follows is directed toward the following four facets of path analysis: (1) coherence of model specification and applicability to data; (2) plausibility of modeling assumptions; (3) interpretability and utility of the model; and (4) validity of statistical and computational procedures. In the concluding section, a brief discussion of the problem of appropriate model selection is presented, followed by a number of suggestions of essentially model-free alternative methods of use in the treatment of complex structured data such as occurs in genetic epidemiology. PMID:6349335

  18. The renaissance of Hippocratic epidemiology.

    PubMed

    Hofman, A

    1996-11-01

    Epidemiology is a small but not unimportant field in medicine. It has a clear identity and special spirit. It is a science that has to avoid methodologic dogmatism. It is a science that is strongly dependent upon collaboration with medical practice and basic medical science. And it is a science that in the true spirit of Hippocrates tries to contribute to the conquering of diseases in patients and in populations. PMID:8987121

  19. Current Epidemiology of Genitourinary Trauma

    PubMed Central

    McGeady, James B.; Breyer, Benjamin N.

    2013-01-01

    Synopsis This article reviews recent publications evaluating the current epidemiology of urologic trauma. It begins by providing a brief explanation of databases that have been recently used to study this patient population, then proceeds to discuss each genitourinary organ individually, discussing the most relevant and up to date information published for each one. The conclusion of the article briefly discusses possible future research and development areas pertaining to the topic. PMID:23905930

  20. Standards for epidemiologic studies and surveillance of epilepsy.

    PubMed

    Thurman, David J; Beghi, Ettore; Begley, Charles E; Berg, Anne T; Buchhalter, Jeffrey R; Ding, Ding; Hesdorffer, Dale C; Hauser, W Allen; Kazis, Lewis; Kobau, Rosemarie; Kroner, Barbara; Labiner, David; Liow, Kore; Logroscino, Giancarlo; Medina, Marco T; Newton, Charles R; Parko, Karen; Paschal, Angelia; Preux, Pierre-Marie; Sander, Josemir W; Selassie, Anbesaw; Theodore, William; Tomson, Torbjörn; Wiebe, Samuel

    2011-09-01

    Worldwide, about 65 million people are estimated to have epilepsy. Epidemiologic studies are necessary to define the full public health burden of epilepsy; to set public health and health care priorities; to provide information needed for prevention, early detection, and treatment; to identify education and service needs; and to promote effective health care and support programs for people with epilepsy. However, different definitions and epidemiologic methods complicate the tasks of these studies and their interpretations and comparisons. The purpose of this document is to promote consistency in definitions and methods in an effort to enhance future population-based epidemiologic studies, facilitate comparison between populations, and encourage the collection of data useful for the promotion of public health. We discuss: (1) conceptual and operational definitions of epilepsy, (2) data resources and recommended data elements, and (3) methods and analyses appropriate for epidemiologic studies or the surveillance of epilepsy. Variations in these are considered, taking into account differing resource availability and needs among countries and differing purposes among studies. PMID:21899536

  1. Epidemiological studies in psychosomatic medicine.

    PubMed

    Eastwood, M R

    1975-01-01

    The epidemiological triad of host, agent and environment used conceptually in infectious disease may serve as a model for psychosomatic disorders, despite the involvement of many more variables. There are major problems with diagnosis and measurement, however, and the term "psychosomatic" has several meanings. The two main senses are "specific" psychosomatic disorders and an ecological view of illness. The association between psychiatric and physical disorder has been examined in a variety of settings and the findings have suggested that there is a positive relationship. Despite considerable methodological and sampling difficulties in epidemiological research into psychosomatic illness, recent efforts have been made to overcome these. The results of ecological studies appear to be more consistent that those dealing with "specific" psychosomatic disorders and suggest that man has a general psychophysical propensity to disease. Although physical and mental illness do seem to be intimately linked, the reasons for "vulnerability" to illness and "clustering" of illness are obscure. The clarification of these areas appears to be the main task ahead for epidemiology in the field of psychosomatic medicine. PMID:773850

  2. Biomarkers in Prostate Cancer Epidemiology

    PubMed Central

    Verma, Mukesh; Patel, Payal; Verma, Mudit

    2011-01-01

    Understanding the etiology of a disease such as prostate cancer may help in identifying populations at high risk, timely intervention of the disease, and proper treatment. Biomarkers, along with exposure history and clinical data, are useful tools to achieve these goals. Individual risk and population incidence of prostate cancer result from the intervention of genetic susceptibility and exposure. Biochemical, epigenetic, genetic, and imaging biomarkers are used to identify people at high risk for developing prostate cancer. In cancer epidemiology, epigenetic biomarkers offer advantages over other types of biomarkers because they are expressed against a person's genetic background and environmental exposure, and because abnormal events occur early in cancer development, which includes several epigenetic alterations in cancer cells. This article describes different biomarkers that have potential use in studying the epidemiology of prostate cancer. We also discuss the characteristics of an ideal biomarker for prostate cancer, and technologies utilized for biomarker assays. Among epigenetic biomarkers, most reports indicate GSTP1 hypermethylation as the diagnostic marker for prostate cancer; however, NKX2-5, CLSTN1, SPOCK2, SLC16A12, DPYS, and NSE1 also have been reported to be regulated by methylation mechanisms in prostate cancer. Current challenges in utilization of biomarkers in prostate cancer diagnosis and epidemiologic studies and potential solutions also are discussed. PMID:24213111

  3. Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014

    PubMed Central

    Nkwescheu, Armand Seraphin; Fokam, Joseph; Tchendjou, Patrice; Nji, Akindeh; Ngouakam, Hermann; Andre, Bita Fouda; Joelle, Sobngwi; Uzochukwu, Benjamin; Akinroye, Kingsley; Mbacham, Wilfred; Colizzi, Vittorio; Leke, Rose; Victora, Cesar

    2015-01-01

    As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3rd African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities. PMID:26523191

  4. Epidemiology of visceral leishmaniasis

    PubMed Central

    Ready, Paul D

    2014-01-01

    Leishmania species are the causative agents of leishmaniasis, a neglected tropical disease. These parasitic protozoans are usually transmitted between vertebrate hosts by the bite of blood sucking female phlebotomine sand flies. This review focuses on the two parasites causing most human visceral leishmaniasis (VL), which leads to substantial health problems or death for up to 400,000 people per year. Except for travel cases, Leishmania donovani infections are restricted to the (sub-)tropics of Asia and Africa, where transmission is mostly anthroponotic, while Leishmania infantum occurs in the drier parts of Latin America as well as in the Mediterranean climate regions of the Old World, with the domestic dog serving as the main reservoir host. The prevalence of VL caused by L. infantum has been declining where living standards have improved. In contrast, infections of L. donovani continue to cause VL epidemics in rural areas on the Indian subcontinent and in East Africa. The current review compares and contrasts these continental differences and suggests priorities for basic and applied research that might improve VL control. Transmission cycles, pathogenesis, diagnosis, treatment and prognosis, prevention (including vector control), surveillance, transmission modeling, and international control efforts are all reviewed. Most case detection is passive, and so routine surveillance does not usually permit accurate assessments of any changes in the incidence of VL. Also, it is not usually possible to estimate the human inoculation rate of parasites by the sand fly vectors because of the limitations of survey methods. Consequently, transmission modeling rarely passes beyond the proof of principle stage, and yet it is required to help develop risk factor analysis for control programs. Anthroponotic VL should be susceptible to elimination by rapid case detection and treatment combined with local vector control, and one of the most important interventions may well be

  5. Epidemiology of visceral leishmaniasis.

    PubMed

    Ready, Paul D

    2014-01-01

    Leishmania species are the causative agents of leishmaniasis, a neglected tropical disease. These parasitic protozoans are usually transmitted between vertebrate hosts by the bite of blood sucking female phlebotomine sand flies. This review focuses on the two parasites causing most human visceral leishmaniasis (VL), which leads to substantial health problems or death for up to 400,000 people per year. Except for travel cases, Leishmania donovani infections are restricted to the (sub-)tropics of Asia and Africa, where transmission is mostly anthroponotic, while Leishmania infantum occurs in the drier parts of Latin America as well as in the Mediterranean climate regions of the Old World, with the domestic dog serving as the main reservoir host. The prevalence of VL caused by L. infantum has been declining where living standards have improved. In contrast, infections of L. donovani continue to cause VL epidemics in rural areas on the Indian subcontinent and in East Africa. The current review compares and contrasts these continental differences and suggests priorities for basic and applied research that might improve VL control. Transmission cycles, pathogenesis, diagnosis, treatment and prognosis, prevention (including vector control), surveillance, transmission modeling, and international control efforts are all reviewed. Most case detection is passive, and so routine surveillance does not usually permit accurate assessments of any changes in the incidence of VL. Also, it is not usually possible to estimate the human inoculation rate of parasites by the sand fly vectors because of the limitations of survey methods. Consequently, transmission modeling rarely passes beyond the proof of principle stage, and yet it is required to help develop risk factor analysis for control programs. Anthroponotic VL should be susceptible to elimination by rapid case detection and treatment combined with local vector control, and one of the most important interventions may well be

  6. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    SciTech Connect

    Fabrikant, J.I.

    1982-08-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.

  7. Evaluation of endometrial cancer epidemiology in Romania

    PubMed Central

    Bohîlțea, RE; Furtunescu, F; Dosius, M; Cîrstoiu, M; Radoi, V; Baroș, A; Bohîlțea, LC

    2015-01-01

    Endometrial cancer represents the most frequent gynecological malignant affection in the developed countries, in which the incidence of cervical cancer has significantly decreased due to the rigorous application of screening methods and prophylaxis. According to its frequency, endometrial cancer is situated on the fourth place in the category of women’s genital-mammary malignant diseases, after breast, cervical and ovarian cancer in Romania. The incidence and mortality rates due to endometrial cancer have registered an increasing trend worldwide and also in Romania, a significant decrease of the age of appearance for the entire endometrial pathology sphere being noticed. At the national level, the maximum incidence is situated between 60 and 64 years old, the mortality rate of the women under 65 years old being high in Romania. The study evaluates endometrial cancer, from an epidemiologic point of view, at the national level compared to the international statistic data. PMID:25866582

  8. Epidemiology of and Diagnostic Strategies for Toxoplasmosis

    PubMed Central

    Dardé, Marie-Laure

    2012-01-01

    Summary: The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies. PMID:22491772

  9. Burns in childhood: an epidemiological survey.

    PubMed

    Pegg, S P; Gregory, J J; Hogan, P G; Mottarelly, I W; Walker, L F

    1978-08-01

    The epidemiology of 382 burns admitted to the Royal Children's Hospital, Brisbane, is reviewed. Accidents due to burn trauma are disproportionately common among children when compared with adults, and during childhood years make up a sizable proportion of all injuries. In addition to the immediate physical trauma, there can be severe psychological consequences as well as severe disturbances to family life. Seventy per cent of the children in this series were normal active children less than four years of age, who were too young to learn that certain things are dangerous, and for this group preventative measures must be directed towards the parents. Possible methods of prevention of burns in children are discussed, and it is tragic that the very traits that make young children so engaging also lead them to accidental burn injuries. Their only hope of prevention lies in increased parental concern. PMID:282865

  10. Evaluation of endometrial cancer epidemiology in Romania.

    PubMed

    Bohîlțea, R E; Furtunescu, F; Dosius, M; Cîrstoiu, M; Radoi, V; Baroș, A; Bohîlțea, L C

    2015-01-01

    Endometrial cancer represents the most frequent gynecological malignant affection in the developed countries, in which the incidence of cervical cancer has significantly decreased due to the rigorous application of screening methods and prophylaxis. According to its frequency, endometrial cancer is situated on the fourth place in the category of women's genital-mammary malignant diseases, after breast, cervical and ovarian cancer in Romania. The incidence and mortality rates due to endometrial cancer have registered an increasing trend worldwide and also in Romania, a significant decrease of the age of appearance for the entire endometrial pathology sphere being noticed. At the national level, the maximum incidence is situated between 60 and 64 years old, the mortality rate of the women under 65 years old being high in Romania. The study evaluates endometrial cancer, from an epidemiologic point of view, at the national level compared to the international statistic data. PMID:25866582

  11. [Epidemiology of FGF23-related hypophosophatemic diseases].

    PubMed

    Endo, Itsuro

    2016-02-01

    Through the studies of patients with hypophosphatemic rickets/osteomalacia, fibroblast growth factor 23(FGF23)has emerged as a humoral factor that reduces serum phosphate. Discovery of FGF23 as an essential regulator of phosphate homeostasis has markedly improved our understanding of phosphate homeostasis and hypophosphatemic or hyperphosphatemic disorders. A nationwide epidemiologic survey of FGF23-related hypophosphatemic diseases indicated that the patients showed FGF23 levels of above 30 pg/mL by intact assay in the presence of hypophosphatemia. The survey also showed that prevalence and biochemical data before and after treatment of the diseases. Novel therapeutic methods for these disorders may be developed by elucidation of the mechanism of action of FGF23. PMID:26813502

  12. Epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews the incidence of Listeria species in environments, food product and facility, animals and human population; and examines the mechanisms of survival and control measures for listerial bacteria....

  13. Pulmonary embolism: Epidemiology and registries.

    PubMed

    Monreal, Manuel; Mahé, Isabelle; Bura-Riviere, Alessandra; Prandoni, Paolo; Verhamme, Peter; Brenner, Benjamin; Wells, Phil S; Di Micco, Pierpaolo; Bertoletti, Laurent

    2015-12-01

    Real-life data is important in understanding the needs of patients in routine clinical practice, particularly owing to the fact that almost a quarter of patients with venous thromoboembolism (VTE) have at least one exclusion criterion preventing their recruitment into randomized clinical trials. The Registro Informatizado de Enfermedad Trombo Embólica (RIETE) registry is an ongoing, international, multicentre, prospective registry of consecutive patients presenting with acute VTE. In this chapter, we summarized some of the most relevant data concerning the epidemiology of VTE in the RIETE registry. PMID:26547675

  14. Intrathoracic neoplasia: Epidemiology and etiology

    SciTech Connect

    Weller, R.E.

    1992-05-01

    Neoplasms of the thorax encompass those derived from the thoracic wall, trachea, mediastinum, lungs and pleura. They represent a wide variety of lesions including benign and malignant tumors arising from many tissues. The large surface area, 60 to 90 m{sup 2} in man, represented by the respiratory epithelium and associated thoracic structures are ideal targets for carcinogens carried by inspired air. The topic of discussion in this report is the epidemiology, etiology, and mechanisms of spontaneous intrathoracic neoplasia in animals and man. Much of what we know or suspect about thoracic neoplasia in animals has been extrapolated from experimentally-induced neoplasms.

  15. Some aspects of cancer epidemiology

    SciTech Connect

    Lilienfeld, A.M.

    1982-03-01

    Epidemiolgic studies have strongly suggested that a vast majority (80-90%) of cancers are caused by radiation, chemical and biologic agents; the remainder result from endogenous or genetic factors. Biologically, cancer is most probably the end result of a complex multistage process and therefore may be due to a sequence of exposures to different agents at each of these stages. This emphasizes the need to stress the study of interactions in epidemiologic studies to a greater extent than has been done thus far. Examples of the importance of interactions in several types of cancer are presented.

  16. Clinical Epidemiology Unit - overview of research areas

    Cancer.gov

    Clinical Epidemiology Unit (CEU) conducts etiologic research with potential clinical and public health applications, and leads studies evaluating population-based early detection and cancer prevention strategies

  17. Clinical and Translational Epidemiology Branch (CTEB)

    Cancer.gov

    The Clinical and Translational Epidemiology Branch focuses on factors that influence cancer progression, recurrence, survival, and other treatment outcomes, and factors associated with cancer development.

  18. Epidemiologic surveillance program for evaluating occupational reproductive hazards

    SciTech Connect

    Wong, O.; Morgan, R.W.; Whorton, M.D.

    1985-01-01

    A noninvasive and inexpensive epidemiologic program for evaluating the possible effects of occupational exposures on fertility is proposed. This surveillance program utilizes reproductive information obtainable from a short questionnaire (1-2 pages in length) or directly from existing medical, employment, or insurance records, and results can be generated readily on a routine basis. The proposed method should be viewed as a mechanism to provide an early signal for any potential hazard and to direct priority for other more in-depth epidemiologic or physiologic studies. The procedure is illustrated with data from individuals exposed to EDB, DBCP, and waste-water treatment plant processes. The method can be modified to compare the reproductive performance of an exposed group to that of an internal control group. With an internal control group, additional confounding factors can be taken into consideration. The relative merits of this approach compared to another method of fertility evaluation, semen analysis, are discussed.

  19. Competing Risk Regression Models for Epidemiologic Data

    PubMed Central

    Cole, Stephen R.; Gange, Stephen J.

    2009-01-01

    Competing events can preclude the event of interest from occurring in epidemiologic data and can be analyzed by using extensions of survival analysis methods. In this paper, the authors outline 3 regression approaches for estimating 2 key quantities in competing risks analysis: the cause-specific relative hazard (csRH) and the subdistribution relative hazard (sdRH). They compare and contrast the structure of the risk sets and the interpretation of parameters obtained with these methods. They also demonstrate the use of these methods with data from the Women's Interagency HIV Study established in 1993, treating time to initiation of highly active antiretroviral therapy or to clinical disease progression as competing events. In our example, women with an injection drug use history were less likely than those without a history of injection drug use to initiate therapy prior to progression to acquired immunodeficiency syndrome or death by both measures of association (csRH = 0.67, 95% confidence interval: 0.57, 0.80 and sdRH = 0.60, 95% confidence interval: 0.50, 0.71). Moreover, the relative hazards for disease progression prior to treatment were elevated (csRH = 1.71, 95% confidence interval: 1.37, 2.13 and sdRH = 2.01, 95% confidence interval: 1.62, 2.51). Methods for competing risks should be used by epidemiologists, with the choice of method guided by the scientific question. PMID:19494242

  20. The New Epidemiology--A Challenge to Health Administration. Issues in Epidemiology for Administration.

    ERIC Educational Resources Information Center

    Crichton, Anne, Ed.; Neuhauser, Duncan, Ed.

    The role of epidemiology in health administration is considered in 11 articles, and three course descriptions and a bibliography are provided. Titles and authors include the following: "The Need for Creative Managerial Epidemiology" (Gary L. Filerman); "The Growing Role of Epidemiology in Health Administration" (Maureen M. Henderson, Robin E.…

  1. Epidemiologic surveillance to detect false-positive Mycobacterium tuberculosis cultures.

    PubMed

    Lee, Meng-Rui; Chung, Kuei-Pin; Chen, Wei-Ting; Huang, Yu-Tsung; Lee, Li-Na; Yu, Chong-Jen; Teng, Lee-Jene; Hsueh, Po-Ren; Yang, Pan-Chyr; Luh, Kwen-Tay

    2012-08-01

    This study was aimed to investigate the ability of potential indices from epidemiologic surveillance to detect false-positive cultures of Mycobacterium tuberculosis (MTB). All clinical specimens for mycobacterial culture from April 1 to August 31, 2010, were reviewed. Single-positive cultures without relevant clinical and pathologic information were categorized as suspected false-positive cultures. Genotyping methods were used to confirm false-positive cultures. The performance of epidemiologic surveillance indices to detect potential false-positive cultures was evaluated. A total of 14,462 specimens were sent to the laboratory and 214 batches were processed in 107 work days (average 67.6 specimens per batch, ranging from 21 to 130 specimens per batch). Seventy-one single-positive cultures were identified, among which 5 cultures of multidrug-resistant MTB in 1 batch were false-positive, confirmed by genotyping methods. Epidemiologic surveillance with statistical process control charts for single-positive cultures per day showed good performance in epidemiologic surveillance. The false-positive rate was 38.5% in the 13 potential false-positive cultures according to the statistical process control chart for single-positive cultures per day. Although the incidence of tuberculous disease is high in Taiwan, clustering of multidrug-resistant MTB in 1 batch or clustering of single-positive cultures still suggested the occurrence of false-positive MTB cultures. Therefore, epidemiologic surveillance for the clustering of single-positive cultures with the statistical process control chart could be used to monitor the occurrence of false-positive results. PMID:22705229

  2. Contrasting the epidemiological and evolutionary dynamics of influenza spatial transmission

    PubMed Central

    Viboud, Cécile; Nelson, Martha I.; Tan, Yi; Holmes, Edward C.

    2013-01-01

    In the past decade, rapid increases in the availability of high-resolution molecular and epidemiological data, combined with developments in statistical and computational methods to simulate and infer migration patterns, have provided key insights into the spatial dynamics of influenza A viruses in humans. In this review, we contrast findings from epidemiological and molecular studies of influenza virus transmission at different spatial scales. We show that findings are broadly consistent in large-scale studies of inter-regional or inter-hemispheric spread in temperate regions, revealing intense epidemics associated with multiple viral introductions, followed by deep troughs driven by seasonal bottlenecks. However, aspects of the global transmission dynamics of influenza viruses are still debated, especially with respect to the existence of tropical source populations experiencing high levels of genetic diversity and the extent of prolonged viral persistence between epidemics. At the scale of a country or community, epidemiological studies have revealed spatially structured diffusion patterns in seasonal and pandemic outbreaks, which were not identified in molecular studies. We discuss the role of sampling issues in generating these conflicting results, and suggest strategies for future research that may help to fully integrate the epidemiological and evolutionary dynamics of influenza virus over space and time. PMID:23382422

  3. Epidemiology of Enterovirus D68 in Ontario

    PubMed Central

    Peci, Adriana; Winter, Anne-Luise; Warshawsky, Bryna; Booth, Tim F.; Eshaghi, AliReza; Li, Aimin; Perusini, Stephen; Olsha, Romy; Marchand-Austin, Alex; Kristjanson, Erik; Gubbay, Jonathan B.

    2015-01-01

    In August 2014, children’s hospitals in Kansas City, Missouri and Chicago, Illinois notified the Centers for Disease Control and Prevention (CDC) about increased numbers of pediatric patients hospitalized with severe respiratory illness (SRI). In response to CDC reports, Public Health Ontario Laboratories (PHOL) launched an investigation of patients being tested for enterovirus D-68 (EV-D68) in Ontario, Canada. The purpose of this investigation was to enhance our understanding of EV-D68 epidemiology and clinical features. Data for this study included specimens submitted for EV-D68 testing at PHOL from September 1, 2014 to October 31, 2014. Comparisons were made between patients who tested positive for the virus (cases) and those testing negative (controls). EV-D68 was identified in 153/907 (16.8%) of patients tested. In the logistic regression model adjusting for age, sex, setting and time to specimen collection, individuals younger than 20 years of age were more likely to be diagnosed with EV-D68 compared to those 20 and over, with peak positivity at ages 5–9 years. Cases were not more likely to be hospitalized than controls. Cases were more likely to be identified in September than October (OR 8.07; 95% CI 5.15 to 12.64). Routine viral culture and multiplex PCR were inadequate methods to identify EV-D68 due to poor sensitivity and inability to differentiate EV-D68 from other enterovirus serotypes or rhinovirus. Testing for EV-D68 in Ontario from July to December, 2014 detected the presence of EV-D68 virus among young children during September-October, 2014, with most cases detected in September. There was no difference in hospitalization status between cases and controls. In order to better understand the epidemiology of this virus, surveillance for EV-D68 should include testing of symptomatic individuals from all treatment settings and patient age groups, with collection and analysis of comprehensive clinical and epidemiological data. PMID:26599365

  4. Epidemiology of Enterovirus D68 in Ontario.

    PubMed

    Peci, Adriana; Winter, Anne-Luise; Warshawsky, Bryna; Booth, Tim F; Eshaghi, AliReza; Li, Aimin; Perusini, Stephen; Olsha, Romy; Marchand-Austin, Alex; Kristjanson, Erik; Gubbay, Jonathan B

    2015-01-01

    In August 2014, children's hospitals in Kansas City, Missouri and Chicago, Illinois notified the Centers for Disease Control and Prevention (CDC) about increased numbers of pediatric patients hospitalized with severe respiratory illness (SRI). In response to CDC reports, Public Health Ontario Laboratories (PHOL) launched an investigation of patients being tested for enterovirus D-68 (EV-D68) in Ontario, Canada. The purpose of this investigation was to enhance our understanding of EV-D68 epidemiology and clinical features. Data for this study included specimens submitted for EV-D68 testing at PHOL from September 1, 2014 to October 31, 2014. Comparisons were made between patients who tested positive for the virus (cases) and those testing negative (controls). EV-D68 was identified in 153/907 (16.8%) of patients tested. In the logistic regression model adjusting for age, sex, setting and time to specimen collection, individuals younger than 20 years of age were more likely to be diagnosed with EV-D68 compared to those 20 and over, with peak positivity at ages 5-9 years. Cases were not more likely to be hospitalized than controls. Cases were more likely to be identified in September than October (OR 8.07; 95% CI 5.15 to 12.64). Routine viral culture and multiplex PCR were inadequate methods to identify EV-D68 due to poor sensitivity and inability to differentiate EV-D68 from other enterovirus serotypes or rhinovirus. Testing for EV-D68 in Ontario from July to December, 2014 detected the presence of EV-D68 virus among young children during September-October, 2014, with most cases detected in September. There was no difference in hospitalization status between cases and controls. In order to better understand the epidemiology of this virus, surveillance for EV-D68 should include testing of symptomatic individuals from all treatment settings and patient age groups, with collection and analysis of comprehensive clinical and epidemiological data. PMID:26599365

  5. Ophthalmic epidemiology in Europe: the "European Eye Epidemiology" (E3) consortium.

    PubMed

    Delcourt, Cécile; Korobelnik, Jean-François; Buitendijk, Gabriëlle H S; Foster, Paul J; Hammond, Christopher J; Piermarocchi, Stefano; Peto, Tunde; Jansonius, Nomdo; Mirshahi, Alireza; Hogg, Ruth E; Bretillon, Lionel; Topouzis, Fotis; Deak, Gabor; Grauslund, Jakob; Broe, Rebecca; Souied, Eric H; Creuzot-Garcher, Catherine; Sahel, José; Daien, Vincent; Lehtimäki, Terho; Hense, Hans-Werner; Prokofyeva, Elena; Oexle, Konrad; Rahi, Jugnoo S; Cumberland, Phillippa M; Schmitz-Valckenberg, Steffen; Fauser, Sascha; Bertelsen, Geir; Hoyng, Carel; Bergen, Arthur; Silva, Rufino; Wolf, Sebastian; Lotery, Andrew; Chakravarthy, Usha; Fletcher, Astrid; Klaver, Caroline C W

    2016-02-01

    The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 European participants. The aim of the consortium is to promote and sustain collaboration and sharing of data and knowledge in the field of ophthalmic epidemiology in Europe, with particular focus on the harmonization of methods for future research, estimation and projection of frequency and impact of visual outcomes in European populations (including temporal trends and European subregions), identification of risk factors and pathways for eye diseases (lifestyle, vascular and metabolic factors, genetics, epigenetics and biomarkers) and development and validation of prediction models for eye diseases. Coordinating these existing data will allow a detailed study of the risk factors and consequences of eye diseases and visual impairment, including study of international geographical variation which is not possible in individual studies. It is expected that collaborative work on these existing data will provide additional knowledge, despite the fact that the risk factors and the methods for collecting them differ somewhat among the participating studies. Most studies also include biobanks of various biological samples, which will enable identification of biomarkers to detect and predict occurrence and progression of eye diseases. This article outlines the rationale of the consortium, its design and presents a summary of the methodology. PMID:26686680

  6. Malaria epidemiological trends in Italy.

    PubMed

    Sabatinelli, G; Majori, G; D'Ancona, F; Romi, R

    1994-08-01

    Based on the official reports received from local health laboratories, an epidemiological analysis of malaria cases reported in Italy from 1989 to 1992 is presented. A total of 1,941 cases were reported, 1,287 among Italians and 654 among foreigners. The incidence of cases was on average 500 per year with a maximum in 1990. A slight, but constant decrease of incidence of malaria cases was recorded in this period among Italian citizens (-21.5%), while the incidence among foreigners increased (+80%). Plasmodium falciparum accounted for 74.2% of total infections, followed by P. vivax (19%). The highest number of cases was imported from Africa (86.5%), followed by Asia, South America, and Oceania. 11 cases were contracted in Europe (transfusion, airport and cryptic malaria). 26 people died from malaria during the four years, with a fatality rate of 2.3% among Italians. Other epidemiological features concerning incidence in the different categories of travellers, countries of infection, clinical and therapeutic aspects of cases, are also discussed. PMID:7843343

  7. Environmental Epidemiology of Essential Tremor

    PubMed Central

    Louis, Elan D.

    2008-01-01

    Background Essential tremor (ET) is one of the most common neurological disorders. Despite this, the disease mechanisms and etiology are not well understood. While susceptibility genotypes undoubtedly underlie many ET cases, no ET genes have been identified thus far. As with many other progressive, degenerative neurological disorders, it is likely that environmental factors contribute to the etiology of ET. Environmental epidemiology is the study in specific populations or communities of the effect on human health of physical, biologic and chemical factors in the external environment. The purpose of this article is to review current knowledge with regards to the environmental epidemiology of ET. Results As will be discussed, a series of preliminary case-control studies in recent years has begun to explore several candidate toxins/exposures, including harmane (1-methyl-9H-pyrido[3,4-b]indole), lead and agricultural exposures/pesticides. Conclusions While several initial results are promising, as will be discussed, additional studies are needed to more definitively establish whether these exposures are associated with ET and if they are of etiological importance. PMID:18716411

  8. Epidemiology: second-rate science?

    PubMed

    Parascandola, M

    1998-01-01

    In recent years epidemiology has come under increasing criticism in regulatory and public arenas for being "unscientific." The tobacco industry has taken advantage of this, insisting for decades that evidence linking cigarettes and lung cancer falls short of proof. Moreover, many epidemiologists remain unduly skeptical and self-conscious about the status of their own causal claims. This situation persists in part because of a widespread belief that only the laboratory can provide evidence sufficient for scientific proof. Adherents of this view erroneously believe that there is no element of uncertainty or inductive inference in the "direct observation" of the laboratory researcher and that epidemiology provides mere "circumstantial" evidence. The historical roots of this attitude can be traced to philosopher John Stuart Mill and physiologist Claude Bernard and their influence on modern experimental thinking. The author uses the debate over cigarettes and lung cancer to examine ideas of proof in medical science and public health, concluding that inductive inference from a limited sample to a larger population is an element in all empirical science. PMID:9672568

  9. Contemporary Renal Cell Cancer Epidemiology

    PubMed Central

    Chow, Wong-Ho; Devesa, Susan S.

    2010-01-01

    We analyzed renal cell cancer incidence patterns in the United States and reviewed recent epidemiologic evidence with regard to environmental and host genetic determinants of renal cell cancer risk. Renal cell cancer incidence rates continued to rise among all racial/ethnic groups in the United States, across all age groups, and for all tumor sizes, with the most rapid increases for localized stage disease and small tumors. Recent cohort studies confirmed the association of smoking, excess body weight, and hypertension with an elevated risk of renal cell cancer, and suggested that these factors can be modified to reduce the risk. There is increasing evidence for an inverse association between renal cell cancer risk and physical activity and moderate intake of alcohol. Occupational exposure to TCE has been positively associated with renal cell cancer risk in several recent studies, but its link with somatic mutations of the VHL gene has not been confirmed. Studies of genetic polymorphisms in relation to renal cell cancer risk have produced mixed results, but genome-wide association studies with larger sample size and a more comprehensive approach are underway. Few epidemiologic studies have evaluated risk factors by subtypes of renal cell cancer defined by somatic mutations and other tumor markers. PMID:18836333

  10. Epidemiology of yaws: an update

    PubMed Central

    Kazadi, Walter M; Asiedu, Kingsley B; Agana, Nsiire; Mitjà, Oriol

    2014-01-01

    Yaws, a neglected tropical disease, is targeted for eradication by 2020 through large-scale mass-treatment programs of endemic communities. A key determinant for the success of the eradication campaign is good understanding of the disease epidemiology. We did a review of historical trends and new information from endemic countries, with the aim of assessing the state of knowledge on yaws disease burden. Transmission of yaws is now present in Africa, Asia, and the South Pacific. At least 12 countries are known to harbor yaws cases and 21 to 42 million people live in endemic areas. Between 2008 and 2012 more than 300,000 new cases were reported to the World Health Organization. Yaws presented high geographical variation within a country or region, high seasonality for incidence of active disease, and evidence that low standards of hygiene predispose to suffering of the disease. Key data issues include low levels of reporting, potential misdiagnosis, and scarce documentation on prevalence of asymptomatic infections. Currently available data most likely underestimates the magnitude of the disease burden. More effort is needed in order to refine accuracy of data currently being reported. A better characterization of the epidemiology of yaws globally is likely to positively impact on planning and implementation of yaws eradication. PMID:24729728

  11. Epidemiology and Genetics of Hypertension.

    PubMed

    Sarkar, Taposh; Singh, Narinder Pal

    2015-09-01

    The prevalence of hypertension is increasing in India as well as in the world. The average prevalence of hypertension in India is 25-30%. The median prevalence of total hypertension in 2009 was 37.6% in men and 40.1% in women in U.S. Hypertension is a major risk factor for majority of patients with cardiovascular, cerebrovascular and renal morbidity and mortality. Environmental factors as well as genetic factors account for regulation of blood pressure and its control. Understanding of genetic factor may not only help in recognising those at risk but also help in treatment. Discovering hypertension susceptibility genes would help recognizing those at risk for developing the disease before the expression of clinical symptoms. Genetic and epidemiological studies have suggested that essential hypertension is a polygenic and multifactorial disorder that results from genetic and/or environmental factors. In India awareness, treatment and control status of hypertension is low, with only half of the urban and a quarter of the rural hypertensive individuals being aware of its presence. In this review we have discussed epidemiology and genetics of hypertension, both the monogenic and polygenic forms. PMID:27608868

  12. The epidemiology of mood disorders.

    PubMed

    Merikangas, Kathleen Ries; Low, Nancy C P

    2004-12-01

    This review provides an overview of the epidemiology, risk factors, and genetic epidemiology of mood disorders in adults and children. The magnitude and impact of mood disorders in the community outweighs that of most other chronic diseases. Although there is substantial knowledge regarding the sociodemographic risk factors for mood disorders, our understanding of the pathogenesis and classification still is evolving. Comorbidity of mood disorders with anxiety disorders and substance abuse has been documented widely. Whereas substance abuse and mood disorders seem to be independent etiologically, anxiety and mood disorders result from partially common etiologic factors. The results of family, twin, and adoption studies reveal that a positive family history is the most potent risk factor for mood disorders, particularly bipolar disorder. However, the specific factors that are transmitted in families still are unknown. The two areas that will inform future genetic research include phenomenologic studies that refine the validity of the current phenotypic classification of mood disorders, and application of study designs to elucidate specific factors that may explain the familial transmission of these disorders. PMID:15538988

  13. Epidemiology of nosocomial fungal infections.

    PubMed Central

    Fridkin, S K; Jarvis, W R

    1996-01-01

    This paper briefly reviews the current knowledge of the epidemiology and modes of transmission of nosocomial fungal infections and some of the therapeutic options for treating these diseases. In the mid-1980s, many institutions reported that fungi were common pathogens in nosocomial infections. Most, if not all, hospitals care for patients at risk for nosocomial fungal infections. The proportion in all nosocomial infections reportedly caused by Candida spp. increased from 2% in 1980 to 5% in 1986 to 1989. Numerous studies have identified common risk factors for acquiring these infections, most of which are very common among hospitalized patients; some factors act primarily by inducing immunosuppression (e.g., corticosteroids, chemotherapy, malnutrition, malignancy, and neutropenia), while others primarily provide a route of infection (e.g., extensive burns, indwelling catheter), and some act in combination. Non-albicans Candida spp., including fluconazole-resistant C. krusei and Torulopsis (C.) glabrata, have become more common pathogens. Newer molecular typing techniques can assist in the determination of a common source of infection caused by several fungal pathogens. Continued epidemiologic and laboratory research is needed to better characterize these pathogens and allow for improved diagnostic and therapeutic strategies. PMID:8894349

  14. The landscape epidemiology of echinococcoses.

    PubMed

    Cadavid Restrepo, Angela M; Yang, Yu Rong; McManus, Donald P; Gray, Darren J; Giraudoux, Patrick; Barnes, Tamsin S; Williams, Gail M; Soares Magalhães, Ricardo J; Hamm, Nicholas A S; Clements, Archie C A

    2016-01-01

    Echinococcoses are parasitic diseases of major public health importance globally. Human infection results in chronic disease with poor prognosis and serious medical, social and economic consequences for vulnerable populations. According to recent estimates, the geographical distribution of Echinococcus spp. infections is expanding and becoming an emerging and re-emerging problem in several regions of the world. Echinococcosis endemicity is geographically heterogeneous and over time it may be affected by global environmental change. Therefore, landscape epidemiology offers a unique opportunity to quantify and predict the ecological risk of infection at multiple spatial and temporal scales. Here, we review the most relevant environmental sources of spatial variation in human echinococcosis risk, and describe the potential applications of landscape epidemiological studies to characterise the current patterns of parasite transmission across natural and human-altered landscapes. We advocate future work promoting the use of this approach as a support tool for decision-making that facilitates the design, implementation and monitoring of spatially targeted interventions to reduce the burden of human echinococcoses in disease-endemic areas. PMID:26895758

  15. Epidemiology of yaws: an update.

    PubMed

    Kazadi, Walter M; Asiedu, Kingsley B; Agana, Nsiire; Mitjà, Oriol

    2014-01-01

    Yaws, a neglected tropical disease, is targeted for eradication by 2020 through large-scale mass-treatment programs of endemic communities. A key determinant for the success of the eradication campaign is good understanding of the disease epidemiology. We did a review of historical trends and new information from endemic countries, with the aim of assessing the state of knowledge on yaws disease burden. Transmission of yaws is now present in Africa, Asia, and the South Pacific. At least 12 countries are known to harbor yaws cases and 21 to 42 million people live in endemic areas. Between 2008 and 2012 more than 300,000 new cases were reported to the World Health Organization. Yaws presented high geographical variation within a country or region, high seasonality for incidence of active disease, and evidence that low standards of hygiene predispose to suffering of the disease. Key data issues include low levels of reporting, potential misdiagnosis, and scarce documentation on prevalence of asymptomatic infections. Currently available data most likely underestimates the magnitude of the disease burden. More effort is needed in order to refine accuracy of data currently being reported. A better characterization of the epidemiology of yaws globally is likely to positively impact on planning and implementation of yaws eradication. PMID:24729728

  16. Environmental pollutants and breast cancer: epidemiologic studies.

    PubMed

    Brody, Julia Green; Moysich, Kirsten B; Humblet, Olivier; Attfield, Kathleen R; Beehler, Gregory P; Rudel, Ruthann A

    2007-06-15

    Laboratory research has shown that numerous environmental pollutants cause mammary gland tumors in animals; are hormonally active, specifically mimicking estrogen, which is a breast cancer risk factor; or affect susceptibility of the mammary gland to carcinogenesis. An assessment of epidemiologic research on these pollutants identified in toxicologic studies can guide future research and exposure reduction aimed at prevention. The PubMed database was searched for relevant literature and systematic critical reviews were entered in a database available at URL: www.silentspring.org/sciencereview and URL: www.komen.org/environment (accessed April 10, 2007). Based on a relatively small number of studies, the evidence to date generally supports an association between breast cancer and polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in conjunction with certain genetic polymorphisms involved in carcinogen activation and steroid hormone metabolism. Evidence regarding dioxins and organic solvents is sparse and methodologically limited but suggestive of an association. Methodologic problems include inadequate exposure assessment, a lack of access to highly exposed and unexposed populations, and a lack of preclinical markers to identify associations that may be obscured by disease latency. Among chemicals identified in toxicologic research as relevant to breast cancer, many have not been investigated in humans. The development of better exposure assessment methods is needed to fill this gap. In the interim, weaknesses in the epidemiologic literature argue for greater reliance on toxicologic studies to develop national policies to reduce chemical exposures that may be associated with breast cancer. Substantial research progress in the last 5 years suggests that the investigation of environmental pollutants will lead to strategies to reduce breast cancer risk. PMID:17503436

  17. Epidemiology of Rhabdoid Tumors of Early Childhood

    PubMed Central

    Heck, Julia E; Lombardi, Christina A; Cockburn, Myles; Meyers, Travis J; Wilhelm, Michelle; Ritz, Beate

    2012-01-01

    Background Rhabdoid tumors are a rare and aggressive cancer subtype which is usually diagnosed in early childhood. Little is known about their etiology. The purpose of this study was to describe the epidemiology of rhabdoid tumors and examine their relation to perinatal characteristics. Methods We identified 44 atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system (CNS) and 61 rhabdoid sarcomas (renal and extra-renal non-CNS tumors) from California Cancer Registry records of diagnoses 1988-2007 among children <6 years of age. We randomly selected 208,178 controls from California birthrolls. Multivariable logistic regression was used to examine associations between rhabdoid tumors and perinatal characteristics. Results After adjustment for demographic characteristics, low birthweight (<2500g) strongly increased risk for developing both rhabdoid sarcomas (OR=2.43, 95% CI 1.09, 5.41) and AT/RT (OR=2.99, 95% CI 1.31, 6.84). Both preterm delivery (<37 weeks gestation, OR=2.63, 95% CI 1.34, 5.17) and late term delivery (>42 weeks, OR=3.66, 95% CI 1.54, 8.71) also increased risk of rhabdoid sarcomas. Rhabdoid sarcoma cases (OR=3.08, 95% CI 1.11, 8.55) and AT/RT cases (OR=3.16, 95% CI 1.23, 8.13) also were more likely to be multiple births. Conclusion The excess of twin pregnancies may suggest an association with infertility treatments. This is the first population-based epidemiologic study to examine these rare tumors. PMID:22434719

  18. Rabies Epidemiology and Control in Ecuador

    PubMed Central

    Ortiz-Prado, Esteban; Ponce-Zea, Jorge; Ramirez, Dario; Stewart-Ibarra, Anna M.; Armijos, Luciana; Yockteng, Jaime; Cárdenas, Washington B.

    2016-01-01

    Objective: Describe the epidemiology and the control effort for rabies in Ecuador. Methods: This observational study included data from the Ecuadorian National Institute of Census and Statistics (INEC), and mortality and morbidity data reported by the Ministry of Public Health and the National Institute for Social Security. We conducted a phylogeny analyses to compare the N gene from the Challenge Virus Standard (CVS) vaccine strain used in Ecuador with published Cosmopolitan, Asian and Sylvatic strains. Descriptive and inferential statistics were used to determine the significance of the data. Results: In 1996 Ecuador suffered the highest rate of rabies per capita in the Americas, with an incidence rate of 0.56 cases per 100 000 people per year. Human and canine rabies showed a sharp decline until 2012. Between 1994 and 2014, we found a correlation of 0.925 (p<0.01) between annual cases of dog and human rabies. In 2011, there was an epidemic of sylvatic rabies transmitted to people by vampire bats (Desmodus rotundus) in the Amazon region, specifically in Morona Santiago, leading to 11 fatalities. Phylogenetic analyses of the CVS vaccine N gene showed an association with urban canine rabies strains (the Cosmopolitan lineage and Asian strains), whereas sylvatic rabies, like those reported in the Amazon region, were found to be grouped in a different clade represented mainly by bat-derived strains. Conclusions: This study presents the first compilation of epidemiological data on rabies in Ecuador. The incidence of human and canine rabies, also known as urban rabies, has clearly decreased due to massive canine vaccination campaigns. Phylogenetic analysis of the prevailing vaccine used in the country showed a clear separation from bat-derived rabies, the source of recent rabies outbreaks. Efforts are ongoing to develop rabies vaccines that are highly specific to the rabies virus genotype circulating in the region, including sylvatic rabies. These efforts include the

  19. [Computerization of data collection in epidemiological studies].

    PubMed

    Galasso, R; Celentano, E

    1992-01-01

    Data collected in epidemiological studies on large cohorts need to be evaluated through the organization of a specific computer laboratory in order to make all procedures simple and fast. This paper describes the basic elements composing a computer laboratory and discusses its implementation in epidemiological investigations. PMID:1492737

  20. History of Epidemiological Aspects of Yellow Fever

    PubMed Central

    Downs, Wilbur G.

    1982-01-01

    This review attempts to follow the trail of the development of epidemiological aspects and concepts of yellow fever and yellow fever transmission (vectors, vertebrate hosts, spacing of epidemic outbreaks) with less emphasis on well-documented early history and more emphasis on epidemiological problems still remaining, plus discussion of possible means of resolving certain of these problems. PMID:6758368

  1. MEASURING RISKS IN HUMANS: THE PROMISE AND PRACTICE OF EPIDEMIOLOGY

    EPA Science Inventory


    Epidemiology has been considered the fundamental science of public health policy. The use of epidemiologic data in environmental health policy has been limited particularly in the environmental regulatory arena. Epidemiologic risk assessment (ERA) is different from risk ass...

  2. Epidemiological issues in mental retardation.

    PubMed

    Fryers, T

    1987-12-01

    The basic epidemiological issues have not changed fundamentally in 30 years but emphases are different. Clarity of concept and definition is essential; we need several definitions for different purposes, and should distinguish global criteria defining groups in some way specifically 'retarded' and partial criteria defining groups not exclusive to retardation. Of global definitions, we can distinguish Intellectual Impairment based on IQ, Learning Disability based on educational criteria, and Mental Handicap or Retardation based on service or administrative criteria. The first and second may be co-terminous for children. The first and third are usually co-terminous below a certain IQ level, conventionally 50, as SII and SMH/R. This is not so for higher ability groups: MII and MMR are conceived and defined differently, and suit different research purposes. There may be much unknown need because there have been so few studies of total IQ defined groups above 50. Although organic and psychological factors are very important, the study of MMR needs to recognize its primarily social nature, reflecting determinants of selection into MMR status in legal, organizational and professional structures, activities and attitudes characteristic of particular communities and cultures. If the primary focus is on aetiological factors, natural history, and preventive possibilities, study group should be aetiologically defined and preferably not limited to MR. The same applies to specific impairments, disabilities, diseases, behaviours and disadvantages. The services are also susceptible to epidemiological approaches, descriptive, analytic, interventionist and evaluative, but little is yet available on agency structure and function, professional activities, attitudes and training, legal contexts, and financial constraints. Rigorous outcome studies would greatly benefit rapidly developing services. We know quite a lot about the distribution and associations of SII/SMR, though more is

  3. [Epidemiology of age-related macular degeneration].

    PubMed

    Brandl, C; Stark, K J; Wintergerst, M; Heinemann, M; Heid, I M; Finger, R P

    2016-09-01

    Age-related macular degeneration (AMD) is the main cause of blindness in industrialized societies. Population-based epidemiological investigations generate important data on prevalence, incidence, risk factors, and future trends. This review summarizes the most important epidemiological studies on AMD with a focus on their transferability to Germany including existing evidence for the main risk factors for AMD development and progression. Future tasks, such as the standardization of grading systems and the use of recent retinal imaging technology in epidemiological studies are discussed. In Germany, epidemiological data on AMD are scarce. However, the need for epidemiological research in ophthalmology is currently being addressed by several recently started population-based studies. PMID:27541733

  4. Eco-epidemiology as anti-terrorism.

    PubMed

    Miller, Richard E

    Eco-epidemiology is a promising model for cross-disciplinary anti-terrorism. Derived from epidemiology's dominance of agents to illness and injury, the eco-epidemiological paradigm considers natural systems that generate causal pathways to disease and dynamic morbidity. Within this model is a hierarchy of systems interconnecting at biological, human, and social levels. Eco-epidemiology capitalizes on interacting components within and between system levels to identify contact patterns and apply mechanisms of control. Considering the complex and paradoxical nature of the threat-fear dynamic, a systematic, ecological approach would be more adaptive to terrorism's changing rules of engagement. To counter terrorism and nullify threat-fear, eco-epidemiology must be shared by public health researchers with threat assessment and harm reduction disciplines. PMID:17827097

  5. Improving estimates of exposures for epidemiologic studies of plutonium workers.

    PubMed

    Ruttenber, A J; Schonbeck, M; McCrea, J; McClure, D; Martyny, J

    2001-01-01

    Epidemiologic studies of nuclear facilities usually focus on relations between cancer and doses from external penetrating radiation, and describe these exposures with little detail on measurement error and missing data. We demonstrate ways to document complex exposures to nuclear workers with data on external and internal exposures to ionizing radiation and toxic chemicals. We describe methods for assessing internal exposures to plutonium and external doses from neutrons; the use of a job exposure matrix for estimating chemical exposures; and methods for imputing missing data for exposures and doses. For plutonium workers at Rocky Flats, errors in estimating neutron doses resulted in underestimating the total external dose for production workers by about 16%. Estimates of systemic deposition do not correlate well with estimates of organ doses. Only a small percentage of workers had exposures to toxic chemicals, making epidemiologic assessments of risk difficult. PMID:11319050

  6. Paper vs. electrons. Epidemiologic publishing in a changing world.

    PubMed

    Rothenberg; Frank; Fitzmaurice

    2000-10-01

    PURPOSE: To present the parallel histories of epidemiologic and electronic publishing and consider positive and negative factors that might affect their amalgam.METHODS: We performed a quantitative assessment of the arc of epidemiologic publication from 1966-1999, using major self-designated epidemiologic journals as a sample, and of scholarly electronic publication from 1991-1997, based on current literature review. We use an online, paperless journal as a case study, and review selected information-technology opinion in the area.RESULTS: By traditional standards, growth in epidemiologic publication has been considerable, with the addition of six new journals since 1966. In contrast, scholarly electronic publication for the period 1991-1997 grew from 27 to 2459 journals (not all exclusively online). Positive features of electronic publishing include flexibility, shortened time to publication, freedom from fixed publication date, diversity in presentation, and instant linkage to relevant material. A case study of a new online journal illustrates the substantive power of the medium. Negative factors include restriction (or unrestricted expansion) of the audience, the potential for hasty peer review, pitfalls in establishing credibility, an emphasis on style over content, technologic dependence, and additions to the information explosion. Relative cost and archiving are still debated. In assessing the pros and cons, it is important to distinguish electronic mechanisms that facilitate publication from electronic publishing, and to appreciate the difference between moving an existing journal to the electronic medium, and creating a new online journal.CONCLUSIONS: The movement from print to internet is probably inexorable, but a headlong rush may be ill-advised. Several models for dual publishing now exist, with the expectation that many, including the journals that serve epidemiology, will do so. The ultimate configuration is difficult to predict, but likely to be

  7. Epidemiology of Haemophilus ducreyi Infections

    PubMed Central

    González-Beiras, Camila; Marks, Michael; Chen, Cheng Y.; Roberts, Sally

    2016-01-01

    The global epidemiology of Haemophilus ducreyi infections is poorly documented because of difficulties in confirming microbiological diagnoses. We evaluated published data on the proportion of genital and nongenital skin ulcers caused by H. ducreyi before and after introduction of syndromic management for genital ulcer disease (GUD). Before 2000, the proportion of GUD caused by H. ducreyi ranged from 0.0% to 69.0% (35 studies in 25 countries). After 2000, the proportion ranged from 0.0% to 15.0% (14 studies in 13 countries). In contrast, H. ducreyi has been recently identified as a causative agent of skin ulcers in children in the tropical regions; proportions ranged from 9.0% to 60.0% (6 studies in 4 countries). We conclude that, although there has been a sustained reduction in the proportion of GUD caused by H. ducreyi, this bacterium is increasingly recognized as a major cause of nongenital cutaneous ulcers. PMID:26694983

  8. Epidemiological aspects of heart diseases

    PubMed Central

    Shi, Aimin; Tao, Ziqi; Wei, Peng; Zhao, Jing

    2016-01-01

    Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Coronary heart disease (CHD) is the main cause of mortality in heart patients following stroke, rheumatic heart disease and myocardial infarctions. Approximately 80% of individuals succumb to CVDs, due to poor living conditions in low and middle income families and malnutrition. Infectious diseases, human immunodeficiency, tuberculosis, malaria, high blood pressure or hypertension, obesity and overweight, and nutritional disorders including smoking, excessive alcohol consumption, high salt and sugar intake, as well as other factors are responsible for CVDs and CHDs in young as well as elderly individuals. The focus of the present review are recent epidemiological aspects of CVD and CHD as well as the usefulness of a Mediterranean diet for heart patients and the prevention of heart diseases. PMID:27602082

  9. [Epidemiologic factors in ovarian cancer].

    PubMed

    Curie, P; Sussmann, M; Treisser, A; Renaud, R

    1985-05-01

    Ovarian carcinoma is the most severe gynecological cancer with an overall incidence of 12 per 1000 Americans or Europeans developing it over 40 years of age. Only 3 of the 12 cases will receive efficient care because the diagnosis will be made too late. This study reveals the principal risk factors i.e. upper socioeconomic echelon, ovarian function uninterrupted by a pregnancy or usage of oral contraceptives, anamnestic evidence of ovarian carcinoma in the family, some hereditary disorders, external insults (talcum powder). The synthesis of these various risk factors permits a comprehensive review of the hypotheses of pathogenesis concerning recurrence of tumors. But corollary epidemiologic studies are still needed to try to define better the high risk groups whose follow-up systematic detection and testing is a priority. PMID:4023542

  10. A "big data" approach to HIV epidemiology and prevention.

    PubMed

    Young, Sean D

    2015-01-01

    The recent availability of "big data" from social media and mobile technologies provides promise for development of new tools and methods to address the HIV epidemic. This manuscript presents recent work in this growing area of bioinformatics, digital epidemiology, and disease modeling, describes how it can be applied to address HIV prevention, and presents issues that need to be addressed prior to implementing a mobile technology big-data approach to HIV prevention. PMID:25449693

  11. Epidemiology of violence and war.

    PubMed

    Cvjetanović, B

    2000-06-01

    The magnitude of the threat that violence and war pose to the health, the quality of life, and the very survival of humanity is obvious. A number of scientific disciplines have provided, each through its own methodology, insights into the causation, genesis, and dynamics of violence and war. Although epidemiological and psychological methodologies received priority, the multidisciplinary approach to this problem seems to be the most appropriate. This essay attempts to approach holistically the study of epidemiology of violence and war and the ways of preventing these severe problems of the contemporary society. Conceptual models of the causative mechanisms and dynamics of violence and war, mapping the various psychic, social, and environmental factors, are presented. These models, besides advancing abstract ideas, also provide a concrete framework for determining and exploring the interactions and dynamics of the factors and processes which lead to violence and war. The types of interventions outlined for control and prevention are intended to make an impact upon "critical points" within the dynamics of the process which produces violence and war, and are conceived to be implemented on both the national and international level. The importance of family, community, and school influences is considered, but the role of international organizations, including the United Nations, and other governmental and non-governmental organizations is also stressed. Discussion is focused on the factors which favour peace and hamper aggression, on "internationalization" and global society versus xenophobia and nationalism. The conclusions state that there is sufficient knowhow to devise and implement a reasonable and effective international programme for the control and prevention of violence and war, provided there is adequate public and political willingness and support. PMID:10895528

  12. Epidemiology's continuing contribution to public health: The power of "Then and Now".

    PubMed

    Buck Louis, Germaine M; Bloom, Michael S; Gatto, Nicolle M; Hogue, Carol R; Westreich, Daniel J; Zhang, Cuilin

    2015-04-15

    The 47th annual meeting of the Society for Epidemiologic Research hosted 17 invited speakers charged by the Executive Committee with presenting some of the many ways that epidemiologists have improved the health of the general population. There were 9 "Then and Now" sessions that were structured to focus on how early epidemiologists overcame research hurdles and advanced health through innovative strategies. For most topics, a longstanding expert was paired with an excellent contemporary epidemiologist working in the area, and both were given the freedom to deliver an integrated story about epidemiology's temporal role in protecting and promoting public health. Epidemiologic discoveries in cardiovascular, cancer, and perinatal epidemiology were discussed on day 1, followed by discussions of accomplishments in reducing exposures that adversely impact health (nutrition, environment/occupation, and tobacco use) on day 2. Topics with relevancy for many aspects of epidemiology were presented on day 3, including infectious diseases, social forces, and causal thinking in epidemiologic research. Given the large number of outstanding senior and junior epidemiologists that attended the meeting, choosing speakers was a unique challenge. What became evident from all sessions was the passion that epidemiologists have for population health, tempered with concerns for remaining true to epidemiologic principles, the timely adoption of innovative methods, and the responsible interpretation of research findings. PMID:25810458

  13. Epidemiology's Continuing Contribution to Public Health: The Power of “Then and Now”

    PubMed Central

    Buck Louis, Germaine M.; Bloom, Michael S.; Gatto, Nicolle M.; Hogue, Carol R.; Westreich, Daniel J.; Zhang, Cuilin

    2015-01-01

    The 47th annual meeting of the Society for Epidemiologic Research hosted 17 invited speakers charged by the Executive Committee with presenting some of the many ways that epidemiologists have improved the health of the general population. There were 9 “Then and Now” sessions that were structured to focus on how early epidemiologists overcame research hurdles and advanced health through innovative strategies. For most topics, a longstanding expert was paired with an excellent contemporary epidemiologist working in the area, and both were given the freedom to deliver an integrated story about epidemiology's temporal role in protecting and promoting public health. Epidemiologic discoveries in cardiovascular, cancer, and perinatal epidemiology were discussed on day 1, followed by discussions of accomplishments in reducing exposures that adversely impact health (nutrition, environment/occupation, and tobacco use) on day 2. Topics with relevancy for many aspects of epidemiology were presented on day 3, including infectious diseases, social forces, and causal thinking in epidemiologic research. Given the large number of outstanding senior and junior epidemiologists that attended the meeting, choosing speakers was a unique challenge. What became evident from all sessions was the passion that epidemiologists have for population health, tempered with concerns for remaining true to epidemiologic principles, the timely adoption of innovative methods, and the responsible interpretation of research findings. PMID:25810458

  14. Mining characteristics of epidemiological studies from Medline: a case study in obesity

    PubMed Central

    2014-01-01

    Background The health sciences literature incorporates a relatively large subset of epidemiological studies that focus on population-level findings, including various determinants, outcomes and correlations. Extracting structured information about those characteristics would be useful for more complete understanding of diseases and for meta-analyses and systematic reviews. Results We present an information extraction approach that enables users to identify key characteristics of epidemiological studies from MEDLINE abstracts. It extracts six types of epidemiological characteristic: design of the study, population that has been studied, exposure, outcome, covariates and effect size. We have developed a generic rule-based approach that has been designed according to semantic patterns observed in text, and tested it in the domain of obesity. Identified exposure, outcome and covariate concepts are clustered into health-related groups of interest. On a manually annotated test corpus of 60 epidemiological abstracts, the system achieved precision, recall and F-score between 79-100%, 80-100% and 82-96% respectively. We report the results of applying the method to a large scale epidemiological corpus related to obesity. Conclusions The experiments suggest that the proposed approach could identify key epidemiological characteristics associated with a complex clinical problem from related abstracts. When integrated over the literature, the extracted data can be used to provide a more complete picture of epidemiological efforts, and thus support understanding via meta-analysis and systematic reviews. PMID:24949194

  15. GESDB: a platform of simulation resources for genetic epidemiology studies.

    PubMed

    Yao, Po-Ju; Chung, Ren-Hua

    2016-01-01

    Computer simulations are routinely conducted to evaluate new statistical methods, to compare the properties among different methods, and to mimic the observed data in genetic epidemiology studies. Conducting simulation studies can become a complicated task as several challenges can occur, such as the selection of an appropriate simulation tool and the specification of parameters in the simulation model. Although abundant simulated data have been generated for human genetic research, currently there is no public database designed specifically as a repository for these simulated data. With the lack of such a database, for similar studies, similar simulations may have been repeated, which resulted in redundant work. Thus, we created an online platform, the Genetic Epidemiology Simulation Database (GESDB), for simulation data sharing and discussion of simulation techniques for genetic epidemiology studies. GESDB consists of a database for storing simulation scripts, simulated data and documentation from published articles as well as a discussion forum, which provides a platform for discussion of the simulated data and exchanging simulation ideas. Moreover, summary statistics such as the simulation tools that are most commonly used and datasets that are most frequently downloaded are provided. The statistics will be informative for researchers to choose an appropriate simulation tool or select a common dataset for method comparisons. GESDB can be accessed at http://gesdb.nhri.org.twDatabase URL: http://gesdb.nhri.org.tw. PMID:27242038

  16. GESDB: a platform of simulation resources for genetic epidemiology studies

    PubMed Central

    Yao, Po-Ju; Chung, Ren-Hua

    2016-01-01

    Computer simulations are routinely conducted to evaluate new statistical methods, to compare the properties among different methods, and to mimic the observed data in genetic epidemiology studies. Conducting simulation studies can become a complicated task as several challenges can occur, such as the selection of an appropriate simulation tool and the specification of parameters in the simulation model. Although abundant simulated data have been generated for human genetic research, currently there is no public database designed specifically as a repository for these simulated data. With the lack of such a database, for similar studies, similar simulations may have been repeated, which resulted in redundant work. Thus, we created an online platform, the Genetic Epidemiology Simulation Database (GESDB), for simulation data sharing and discussion of simulation techniques for genetic epidemiology studies. GESDB consists of a database for storing simulation scripts, simulated data and documentation from published articles as well as a discussion forum, which provides a platform for discussion of the simulated data and exchanging simulation ideas. Moreover, summary statistics such as the simulation tools that are most commonly used and datasets that are most frequently downloaded are provided. The statistics will be informative for researchers to choose an appropriate simulation tool or select a common dataset for method comparisons. GESDB can be accessed at http://gesdb.nhri.org.tw. Database URL: http://gesdb.nhri.org.tw PMID:27242038

  17. A review of the epidemiology and treatment of Peyronie’s disease

    PubMed Central

    Ostrowski, Kevin A; Gannon, John R; Walsh, Thomas J

    2016-01-01

    Introduction Peyronie’s disease (PD) has significant effect on patients and their partners. We provide a current review of the epidemiology as well as the nonsurgical and surgical treatment of PD. Materials and methods Review of literature pertaining to PD with focus on epidemiology and treatment options. Conclusion PD is common and likely underreported. The availability of new and highly effective treatment options will catalyze patient awareness and subsequently the prevalence of disease. PMID:27200305

  18. Modelling, Simulation and Social Network Data: What’s New for Public Health and Epidemiology Informatics?

    PubMed Central

    2015-01-01

    Summary Objectives Summarize excellent current research in the field of Public Health and Epidemiology Informatics. Method Synopsis of the articles selected for the IMIA Yearbook 2015. Results Four papers from international peer-reviewed journals have been selected as best papers for the section on Public Health and Epidemiology Informatics. Conclusions The selected articles illustrate current research regarding the impact and assessment of health IT and the latest developments in health information exchange. PMID:26293870

  19. Using an Epidemiological Model for Phylogenetic Inference Reveals Density Dependence in HIV Transmission

    PubMed Central

    Leventhal, Gabriel E.; Günthard, Huldrych F.; Bonhoeffer, Sebastian; Stadler, Tanja

    2014-01-01

    The control, prediction, and understanding of epidemiological processes require insight into how infectious pathogens transmit in a population. The chain of transmission can in principle be reconstructed with phylogenetic methods which analyze the evolutionary history using pathogen sequence data. The quality of the reconstruction, however, crucially depends on the underlying epidemiological model used in phylogenetic inference. Until now, only simple epidemiological models have been used, which make limiting assumptions such as constant rate parameters, infinite total population size, or deterministically changing population size of infected individuals. Here, we present a novel phylogenetic method to infer parameters based on a classical stochastic epidemiological model. Specifically, we use the susceptible-infected-susceptible model, which accounts for density-dependent transmission rates and finite total population size, leading to a stochastically changing infected population size. We first validate our method by estimating epidemic parameters for simulated data and then apply it to transmission clusters from the Swiss HIV epidemic. Our estimates of the basic reproductive number R0 for the considered Swiss HIV transmission clusters are significantly higher than previous estimates, which were derived assuming infinite population size. This difference in key parameter estimates highlights the importance of careful model choice when doing phylogenetic inference. In summary, this article presents the first fully stochastic implementation of a classical epidemiological model for phylogenetic inference and thereby addresses a key aspect in ongoing efforts to merge phylogenetics and epidemiology. PMID:24085839

  20. Epidemiology in Latin America and the Caribbean: current situation and challenges

    PubMed Central

    Barreto, Sandhi M; Miranda, Jaime J; Figueroa, J Peter; Schmidt, Maria Inês; Munoz, Sergio; Kuri-Morales, P Pablo; Silva, Jarbas B

    2012-01-01

    Background This article analyses the epidemiological research developments in Latin America and the Caribbean (LAC). It integrates the series commissioned by the International Epidemiological Association to all WHO Regions to identify global opportunities to promote the development of epidemiology. Methods Health situations of the regions were analysed based on published data on selected mortality, morbidity and risk factors. Epidemiological publication output by country was estimated by Medline bibliometrics. Internet and literature searches and data provided by key informants were used to describe perspectives on epidemiological training, research and funding. Findings Despite important advances in recent decades, LAC remains the world's most unequal region. In 2010, 10% of the LAC's people still lived in conditions of multidimensional poverty, with huge variation among countries. The region has experienced fast and complex epidemiological changes in past decades, combining increasing rates of non-communicable diseases and injuries, and keeping uncontrolled many existing endemic and emerging diseases. Overall, epidemiological publications per year increased from 160 articles between 1961 and 1970 to 2492 between 2001 and 2010. The increase in papers per million inhabitants in the past three decades varied from 57% in Panama to 1339% in Paraguay. Universities are the main epidemiological training providers. There are at least 34 universities and other institutions in the region that offer postgraduate programmes at the master’s and doctoral levels in epidemiology or public health. Most LAC countries rely largely on external funding and donors to initiate and sustain long-term research efforts. Despite the limited resources, the critical mass of LAC researchers has produced significant scientific contributions. Future needs The health research panorama of the region shows enormous regional discrepancies, but great prospects. Improving research and human resources

  1. A growing role for gender analysis in air pollution epidemiology.

    PubMed

    Clougherty, Jane E

    2011-04-01

    Epidemiologic studies of air pollution effects on respiratory health report significant modification by sex, although results are not uniform. Importantly, it remains unclear whether modifications are attributable to socially derived gendered exposures, to sex-linked physiological differences, or to some interplay thereof. Gender analysis, which aims to disaggregate social from biological differences between males and females, may help to elucidate these possible sources of effect modification. Studies of children suggest stronger effects among boys in early life and among girls in later childhood. The qualitative review describes possible sources of difference in air pollution response between women and men, which may vary by life stage, coexposures, hormonal status, or other factors. The sources of observed effect modifications remain unclear, although gender analytic approaches may help to disentangle gender and sex differences in pollution response. A framework for incorporating gender analysis into environmental epidemiology is offered, along with several potentially useful methods from gender analysis. PMID:21584463

  2. Sampling in epidemiological research: issues, hazards and pitfalls

    PubMed Central

    Tyrer, Stephen; Heyman, Bob

    2016-01-01

    Surveys of people's opinions are fraught with difficulties. It is easier to obtain information from those who respond to text messages or to emails than to attempt to obtain a representative sample. Samples of the population that are selected non-randomly in this way are termed convenience samples as they are easy to recruit. This introduces a sampling bias. Such non-probability samples have merit in many situations, but an epidemiological enquiry is of little value unless a random sample is obtained. If a sufficient number of those selected actually complete a survey, the results are likely to be representative of the population. This editorial describes probability and non-probability sampling methods and illustrates the difficulties and suggested solutions in performing accurate epidemiological research. PMID:27087985

  3. Epidemiology of Attention Problems Among Turkish Children and Adolescents

    PubMed Central

    Erol, Nese; Simsek, Zeynep; Öner, Özgür; Munir, Kerim

    2011-01-01

    Objective To evaluate the epidemiology of attention problems using parent, teacher, and youth informants among a nationally representative Turkish sample. Method The children and adolescents, 4 to 18 years old, were selected from a random household survey. Attention problems derived from the Child Behavior Checklist (CBCL) (N = 4,488), Teacher Report Form (TRF) (N = 2,360), and the Youth Self Report (YSR) (N = 2,206) were examined. Results The CBCL and TRF attention problems scores were higher among young male children, whereas the YSR reported scores were higher among older adolescents without a gender effect. The CBCL and YSR scores were also higher by urban residence. Conclusion Compared with other European samples, our national sample had higher mean attention problems scores than the Scandinavian but lower mean scores than the former Soviet Union samples. In addition to elucidating the profile of attention problems in Turkey, our results also contribute to understanding the comparative global epidemiology of attention problems. PMID:18192617

  4. Mental health epidemiological research in South America: recent findings

    PubMed Central

    Silva de Lima, Maurício; Garcia de Oliveira Soares, Bernardo; de Jesus Mari, Jair

    2004-01-01

    This paper aims to review the recent mental health epidemiological research conducted in South America. The Latin American and the Caribbean (LILACS) database was searched from 1999 to 2003 using a specific strategy for identification of cohort, case-control and cross-sectional population-based studies in South America. The authors screened references and identified relevant studies. Further studies were obtained contacting local experts in epidemiology. 140 references were identified, and 12 studies were selected. Most selected studies explored the prevalence and risk factors for common mental disorders, and several of them used sophisticated methods of sample selection and analysis. There is a need for improving the quality of psychiatric journals in Latin America, and for increasing the distribution and access to research data. Regionally relevant problems such as violence and substance abuse should be considered in designing future investigations in this area. PMID:16633474

  5. Systems Epidemiology: What’s in a Name?

    PubMed Central

    Dammann, O.; Gray, P.; Gressens, P.; Wolkenhauer, O.; Leviton, A.

    2014-01-01

    Systems biology is an interdisciplinary effort to integrate molecular, cellular, tissue, organ, and organism levels of function into computational models that facilitate the identification of general principles. Systems medicine adds a disease focus. Systems epidemiology adds yet another level consisting of antecedents that might contribute to the disease process in populations. In etiologic and prevention research, systems-type thinking about multiple levels of causation will allow epidemiologists to identify contributors to disease at multiple levels as well as their interactions. In public health, systems epidemiology will contribute to the improvement of syndromic surveillance methods. We encourage the creation of computational simulation models that integrate information about disease etiology, pathogenetic data, and the expertise of investigators from different disciplines. PMID:25598870

  6. Molecular Epidemiology of Human Intestinal Amoebas in Iran

    PubMed Central

    Hooshyar, H; Rostamkhani, P; Rezaian, M

    2012-01-01

    Many microscopic-based epidemiological surveys on the prevalence of human intestinal pathogenic and non-pathogenic protozoa including intestinal amoeba performed in Iran show a high prevalence of human intestinal amoeba in different parts of Iran. Such epidemiological studies on amoebiasis are confusing, mainly due to recently appreciated distinction between the Entamoeba histolytica, E. dispar and E. moshkovskii. Differential diagnosis can be done by some methods such as PCR-based methods, monoclonal antibodies and the analysis of isoenzyme typing, however the molecular study of these protozoa in Iran is low. Based on molecular studies, it seems that E. dispar is predominant species especially in the central and northern areas of Iran and amoebiasis due to E. histolytica is a rare infection in the country. It is suggested that infection with E. moshkovskii may be common among Iranians. Considering the importance of molecular epidemiology of amoeba in Iran and also the current data, the present study reviews the data currently available on the molecular distribution of intestinal human amoeba in Iran. PMID:23193500

  7. John Snow’s legacy: epidemiology without borders

    PubMed Central

    Fine, Paul; Victora, Cesar G; Rothman, Kenneth J; Moore, Patrick S; Chang, Yuan; Curtis, Val; Heymann, David L; Slutkin, Gary; May, Robert M; Patel, Vikram; Roberts, Ian; Wortley, Richard; Torgerson, Carole; Deaton, Angus

    2013-01-01

    This Review provides abstracts from a meeting held at the London School of Hygiene and Tropical Medicine, on April 11–12, 2013, to celebrate the legacy of John Snow. They describe conventional and unconventional applications of epidemiological methods to problems ranging from diarrhoeal disease, mental health, cancer, and accident care, to education, poverty, financial networks, crime, and violence. Common themes appear throughout, including recognition of the importance of Snow’s example, the philosophical and practical implications of assessment of causality, and an emphasis on the evaluation of preventive, ameliorative, and curative interventions, in a wide variety of medical and societal examples. Almost all self-described epidemiologists nowadays work within the health arena, and this is the focus of most of the societies, journals, and courses that carry the name epidemiology. The range of applications evident in these contributions might encourage some of these institutions to consider broadening their remits. In so doing, they may contribute more directly to, and learn from, non-health-related areas that use the language and methods of epidemiology to address many important problems now facing the world. PMID:23582396

  8. Feasibility of future epidemiological studies on possible health effects of mobile phone base stations.

    PubMed

    Neubauer, Georg; Feychting, Maria; Hamnerius, Yngve; Kheifets, Leeka; Kuster, Niels; Ruiz, Ignacio; Schüz, Joachim; Uberbacher, Richard; Wiart, Joe; Röösli, Martin

    2007-04-01

    The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant radio frequency sources have to be taken into account. The applied exposure assessment method should be piloted and validated. Short to medium term effects on physiology or health related quality of life are best investigated by cohort studies. For long term effects, groups with a potential for high exposure need to first be identified; for immediate effect, human laboratory studies are the preferred approach. PMID:17080459

  9. Presentation: Epidemiology and public health: is a new paradigm needed or a new ethic?

    PubMed

    Gori, G B

    1998-08-01

    Public health militancy has been increasingly frustrated by what many perceive as the marginally fertile studies of risk factors operating at the individual level, whose causal underpinnings are often and inevitably weakened in multifactorial situations. As a remedy, leading advocates propose a refocusing of epidemiology and public health on socioeconomic, cultural, and political studies, and on broad interventions at population level. This new "paradigm" would be aided by a relaxation of evidentiary standards of causality, away from scientific criteria and more toward dialectic (rhetorical) precepts derived in a humanistic and sociologic tradition. It is countered here that such proposals would further reduce the objectivity and thus likely weaken rather than strengthen epidemiology and the justification of public health action. Instead, a realistic appraisal finds that multifactorial epidemiology raises warning signals of varying influence, and that the usefulness of epidemiology and public health could be enhanced by conceiving of methods to score the relative strength and priority of such warnings. PMID:9743311

  10. Global Epidemiology of Campylobacter Infection

    PubMed Central

    Kaakoush, Nadeem O.; Castaño-Rodríguez, Natalia; Mitchell, Hazel M.

    2015-01-01

    SUMMARY Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection. PMID:26062576

  11. Epidemiology and control of influenza.

    PubMed

    Rao, B L

    2003-01-01

    Influenza causes frequent epidemics and periodic pandemics, and is a major public health problem. Pandemics occurred in 1918 (swine influenza), 1957 (Asian influenza), 1968 (Hong Kong influenza) and 1977 (Russian influenza) due to major antigenic variation of the type A influenza virus. Frequent epidemics occur after pandemics as a result of minor antigenic variation of the pandemic virus strains. Minor antigenic variant strains of type A (H1N1), A (H3N2) and type B influenza viruses are currently circulating globally, causing frequent epidemics. The World Health Organization (WHO) has established a network of National Influenza Centres all over the world to study the epidemiology and ecology of influenza, and collaborating centres for updating the influenza vaccines and other research activities. As a part of this programme, it has set up the WHO Flunet for disseminating updates on the global influenza situation, current vaccines and antiviral drugs. Some National Influenza Centres in India have investigated and reported pandemics and epidemics caused by global influenza virus strains during the past 50 years. There is a need to expand influenza surveillance in our country, as only a few centres are conducting these studies. PMID:12929857

  12. Epidemiology of Helicobacter pylori infection.

    PubMed

    Leja, Mārcis; Axon, Anthony; Brenner, Hermann

    2016-09-01

    This review of recent publications related to the epidemiology of Helicobacter pylori highlights the origin of the infection, its changing prevalence, transmission, and outcome. A number of studies have addressed the ancestor roots of the bacteria, and the first genomewide analysis of bacterial strains suggests that its coexistence with humans is more ancient than previously thought. As opposed to the generally declining prevalence of H. pylori (including China and Japan), in Sweden, the prevalence of atrophic gastritis in the young population has risen. The prevalence of the infection remains high in the indigenous populations of the Arctic regions, and reinfection rates are high. A high prevalence is permanently found in the Siberian regions of Russia as well. Several studies, some of which used multiplex serology, addressed prevalence of and risks associated with various H. pylori serotypes, thereby enabling more precise risk assessment. Transmission of H. pylori was discussed, specifically fecal-oral transmission and the use of well-water and other unpurified water. Finally, the long-term course of H. pylori infection was considered, with an estimated 89% of noncardia gastric cancer cases being attributable to the infection. PMID:27531531

  13. Epidemiology of cancer in children

    SciTech Connect

    Greenberg, R.S.; Shuster, J.L. Jr.

    1985-01-01

    The epidemiologic features of cancers among children have stimulated abundant descriptive and analytic investigation. The descriptive work has demonstrated consistent differences in the incidence rates of these cancers by anatomic site, age, race, and gender. It is clear that the various forms of cancer during childhood have distinctive patterns of occurrence. To a large extent, the characteristic population distributions of these diseases may represent differences in the underlying etiologic processes. Analytic studies of cancer during childhood have addressed possible genetic and environmental risk factors for these diseases. The demonstration of cancers induced by transplacental exposure to diethylstilbestrol has confirmed the speculation that the prenatal environment may influence subsequent carcinogenesis. Although possible leukemogenic effects of intrauterine diagnostic irradiation remain controversial, the issue may become unimportant clinically as prenatal irradiation is replaced by other diagnostic modalities (194). To date, studies of prenatal ultrasound have provided no evidence of an overall excess of subsequent malignancies. Postnatal exposure to high doses of irradiation is known to produce considerable excesses of leukemias and other cancers. At present, there are insufficient data available to reach a firm conclusion on the possible carcinogenic effects of exposure during childhood to low doses of irradiation, fringe magnetic fields, or chemicals.

  14. Trichloroethylene and cancer: epidemiologic evidence.

    PubMed Central

    Wartenberg, D; Reyner, D; Scott, C S

    2000-01-01

    Trichloroethylene is an organic chemical that has been used in dry cleaning, for metal degreasing, and as a solvent for oils and resins. It has been shown to cause liver and kidney cancer in experimental animals. This article reviews over 80 published papers and letters on the cancer epidemiology of people exposed to trichloroethylene. Evidence of excess cancer incidence among occupational cohorts with the most rigorous exposure assessment is found for kidney cancer (relative risk [RR] = 1.7, 95% confidence interval [CI] 1.1-2.7), liver cancer (RR = 1.9, 95% CI(1.0-3.4), and non-Hodgkin's lymphoma (RR = 1.5, 95% CI 0.9-2.3) as well as for cervical cancer, Hodgkin's disease, and multiple myeloma. However, since few studies isolate trichloroethylene exposure, results are likely confounded by exposure to other solvents and other risk factors. Although we believe that solvent exposure causes cancer in humans and that trichloroethylene likely is one of the active agents, we recommend further study to better specify the specific agents that confer this risk and to estimate the magnitude of that risk. PMID:10807550

  15. Epidemiology of malaria in Malaysia.

    PubMed

    Rahman, K M

    1982-01-01

    Malaria is a major public health problem in Malaysia, particularly in peninsular Malaysia and the state of Sabah. An eradication program started in the states of Sabah and Sarawak in 1961 initially was remarkably successful. A similar but staged program was started in peninsular Malaysia in 1967 and was also quite successful. However, a marked upsurge in incidence in Sabah in 1975-1978 showed that malaria is still a major hazard. The disease leads to great economic losses in terms of the productivity of the labor force and the learning capacity of schoolchildren. The topography, the climate, and the migrations of the people due to increased economic activity are similar in peninsular Malaysia, Sabah, and Sarawak. However, the epidemiologic picture differs strikingly from area to area in terms of species of vectors, distribution of parasitic species, and resistance of Plasmodium falciparum to chloroquine. Likewise, the problems faced by the eradication or control programs in the three regions are dissimilar. Because solutions to only some of these problems are possible, the eradication of malaria in Malaysia is not likely in the near future. However, the situation offers an excellent opportunity for further studies of antimalaria measures. PMID:6755616

  16. Epidemiology in the Chelyabinsk region

    SciTech Connect

    Kossenko, M.M.

    1996-12-31

    Epidemiological studies of radiation exposure in the South Urals (Russia) have been motivated by the operation of the Mayak facility for weapons-grade plutonium production. The Mayak Industrial Association (MIA) is located within 100 km of the city of Chelyabinsk. The first atomic reactor of the Mayak complex came on line in July 1948, and the radiochemical plant for plutonium separation was started in December 1948. At that time the problem of radioactive waste management was not yet solved, and this resulted in two major radiation accidents and a very hazardous radiation situation on the Techa River.Appart from accidental radiation exposures, the population in the vicinity of the Mayak facility was exposed to so-called technological releases. Of the populations exposed due to the operation of the Mayak plant the offsite residents of the areas around Mayak are the subjects of this paper. Sr-90 and Cs-137 were the main dose-forming radionuclides. 28 refs., 2 figs., 3 tabs.

  17. Epidemiology in the Era of Big Data

    PubMed Central

    Mooney, Stephen J; Westreich, Daniel J; El-Sayed, Abdulrahman M

    2015-01-01

    Big Data has increasingly been promoted as a revolutionary development in the future of science, including epidemiology. However, the definition and implications of Big Data for epidemiology remain unclear. We here provide a working definition of Big Data predicated on the so-called ‘3 Vs’: variety, volume, and velocity. From this definition, we argue that Big Data has evolutionary and revolutionary implications for identifying and intervening on the determinants of population health. We suggest that as more sources of diverse data become publicly available, the ability to combine and refine these data to yield valid answers to epidemiologic questions will be invaluable. We conclude that, while epidemiology as practiced today will continue to be practiced in the Big Data future, a component of our field’s future value lies in integrating subject matter knowledge with increased technical savvy. Our training programs and our visions for future public health interventions should reflect this future. PMID:25756221

  18. Epigenetic epidemiology of the developmental origins hypothesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive human epidemiologic and animal model data indicate that during critical periods of prenatal and postnatal mammalian development, nutrition and other environmental stimuli influence developmental pathways and thereby induce permanent changes in metabolism and chronic disease susceptibility....

  19. Comprehensive Epidemiologic Data Resource (CEDR) (Poster)

    SciTech Connect

    Oak Ridge Institute for Science and Education

    2012-12-12

    This poster introduces the Comprehensive Epidemiologic Data Resource (CEDR), an electronic database with demographic, health outcome, and exposure information for over a million DOE nuclear plant and laboratory workers.

  20. DESIGN OF EXPOSURE MEASUREMENTS FOR EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    This presentation will describe the following items: (1) London daily air pollution and deaths that demonstrate how time series epidemiology can indicate that air pollution caused death; (2) Sophisticated statistical models required to establish this relationship for lower pollut...

  1. Gene-Environment Research and Cancer Epidemiology

    Cancer.gov

    The Epidemiology and Genomics Research Program supports extramural research that investigates both genetic and environmental factors that may contribute to the etiology of cancer and/or impact cancer outcomes.

  2. [The epidemiological surveillance of dengue in Mexico].

    PubMed

    Montesano-Castellanos, R; Ruiz-Matus, C

    1995-01-01

    The clinical behavior of dengue fever in Mexico has changed, now with the occurrence of hemorrhagic cases. In response to the emergence of such cases, a specific epidemiologic surveillance system has been designed and implemented. This system includes the means to monitor the factors involved in the evolution of the disease. The identification and analysis of these factors is necessary to implement prevention and control measures. This paper presents the main components and procedures of the epidemiologic surveillance system for common and hemorrhagic dengue fever in Mexico, emphasizing the usefulness of the risk approach to predict the pattern of this disease. The model includes the collaboration of a multidisciplinary group. The Epidemiologic Surveillance State Committee, coordinated by the National Health System, participates in the collection and analysis of epidemiologic data, particularly data related to the population, the individual, the vector, the viruses and the environment. PMID:8599150

  3. Epidemiology of tennis, squash, and racquetball injuries.

    PubMed

    Maylack, F H

    1988-04-01

    This article enumerates and examines the existing epidemiologic data on racquet sports injuries. A framework is provided for the evaluation and interpretation of future studies and research. PMID:3292063

  4. Design and analysis of metabolomics studies in epidemiologic research: a primer on -omic technologies.

    PubMed

    Tzoulaki, Ioanna; Ebbels, Timothy M D; Valdes, Ana; Elliott, Paul; Ioannidis, John P A

    2014-07-15

    Metabolomics is the field of "-omics" research concerned with the comprehensive characterization of the small low-molecular-weight metabolites in biological samples. In epidemiology, it represents an emerging technology and an unprecedented opportunity to measure environmental and other exposures with improved precision and far less measurement error than with standard epidemiologic methods. Advances in the application of metabolomics in large-scale epidemiologic research are now being realized through a combination of improved sample preparation and handling, automated laboratory and processing methods, and reduction in costs. The number of epidemiologic studies that use metabolic profiling is still limited, but it is fast gaining popularity in this area. In the present article, we present a roadmap for metabolomic analyses in epidemiologic studies and discuss the various challenges these data pose to large-scale studies. We discuss the steps of data preprocessing, univariate and multivariate data analysis, correction for multiplicity of comparisons with correlated data, and finally the steps of cross-validation and external validation. As data from metabolomic studies accumulate in epidemiology, there is a need for large-scale replication and synthesis of findings, increased availability of raw data, and a focus on good study design, all of which will highlight the potential clinical impact of metabolomics in this field. PMID:24966222

  5. 16 CFR 1000.26 - Directorate for Epidemiology.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Directorate for Epidemiology. 1000.26 Section 1000.26 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION GENERAL COMMISSION ORGANIZATION AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology,...

  6. 16 CFR 1000.26 - Directorate for Epidemiology.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data...

  7. 16 CFR 1000.26 - Directorate for Epidemiology.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data...

  8. 16 CFR 1000.26 - Directorate for Epidemiology.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data...

  9. 16 CFR 1000.26 - Directorate for Epidemiology.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data...

  10. The evolving epidemiology of stone disease.

    PubMed

    Roudakova, Ksenia; Monga, Manoj

    2014-01-01

    The epidemiology of kidney stones is evolving - not only is the prevalence increasing, but also the gender gap has narrowed. What drives these changes? Diet, obesity or environmental factors? This article will review the possible explanations for a shift in the epidemiology, with the hope of gaining a better understanding of the extent to which modifiable risk factors play a role on stone formation and what measures may be undertaken for disease prevention in view of these changing trends. PMID:24497682

  11. Epidemiology of hepatitis E virus in Iran.

    PubMed

    Taherkhani, Reza; Farshadpour, Fatemeh

    2016-06-14

    Iran is known as an endemic country for hepatitis E virus (HEV) infection, while there are variations in the epidemiology of HEV infection throughout the country. The available epidemiological studies in different regions of Iran show HEV seroprevalence of 1.1%-14.2% among general population, 4.5% -14.3% among blood donors, 6.1%-22.8% among injecting drug users, 6.3%-28.3% among hemodialysis patients, 1.6%-11.3% among patients infected with other hepatitis viruses, 27.5% among patients with chronic liver disease, 30.8% among kidney transplant recipient patients, and 10%-16.4% among human immunodeficiency virus-infected patients. These variations reflect differences in the status of public health and hygiene, risk factors, and routes of transmission in different regions and groups. Therefore, it is necessary to review the epidemiology of HEV infection to determine the most prevalent risk factors and routes of transmission, and to evaluate the effectiveness of preventive strategies employed in the public health services of the country. Moreover, the other epidemiological aspects of HEV, including the genotypic pattern, extra hepatic manifestations, and incidence of chronic infection need to be investigated among Iranian population to expand the current knowledge on the epidemiology of HEV and to clarify the real burden of HEV infection. Therefore, this review was performed to provide a general overview regarding the epidemiology of HEV in Iran. PMID:27298557

  12. The epidemiology of recurrent pregnancy loss.

    PubMed

    Cramer, D W; Wise, L A

    2000-01-01

    In reviewing the epidemiology of recurrent abortion (RAB), we believe it is necessary to consider the epidemiology of spontaneous abortion (SAB) as well, since it is clear that even a single pregnancy loss increases the risk for a subsequent abortion. In addition, any attempt to identify epidemiologic risk factors for SAB or RAB must deal with the fact that at least 50% of SABs are associated with genetic abnormalities. Given that most epidemiologic studies have not distinguished karyotypically abnormal abortuses, risk factors are likely to be underestimated. Nevertheless, there is fair agreement that a variety of factors may increase risk for SAB or RAB, including advanced maternal age, single gene mutations such as PKU or G6PD deficiency, structural abnormalities of the uterus, poorly controlled diabetes, antiphospholipid syndrome, and smoking. More controversial is the role of luteal phase defect or hyperandrogenism, alloimmune factors, genital infections, caffeine or alcohol use, and trace element or chemical exposure from tap water or in the workplace. Besides better designed epidemiologic studies to detect modifiable risk factors for SAB or RAB, there is a clear need for clinical trials of therapy for RAB which meet minimum epidemiologic standards including randomization, double-blinded (when possible), and placebo-controlled (when ethical). PMID:11355791

  13. Epidemiology of hepatitis E virus in Iran

    PubMed Central

    Taherkhani, Reza; Farshadpour, Fatemeh

    2016-01-01

    Iran is known as an endemic country for hepatitis E virus (HEV) infection, while there are variations in the epidemiology of HEV infection throughout the country. The available epidemiological studies in different regions of Iran show HEV seroprevalence of 1.1%-14.2% among general population, 4.5% -14.3% among blood donors, 6.1%-22.8% among injecting drug users, 6.3%-28.3% among hemodialysis patients, 1.6%-11.3% among patients infected with other hepatitis viruses, 27.5% among patients with chronic liver disease, 30.8% among kidney transplant recipient patients, and 10%-16.4% among human immunodeficiency virus-infected patients. These variations reflect differences in the status of public health and hygiene, risk factors, and routes of transmission in different regions and groups. Therefore, it is necessary to review the epidemiology of HEV infection to determine the most prevalent risk factors and routes of transmission, and to evaluate the effectiveness of preventive strategies employed in the public health services of the country. Moreover, the other epidemiological aspects of HEV, including the genotypic pattern, extra hepatic manifestations, and incidence of chronic infection need to be investigated among Iranian population to expand the current knowledge on the epidemiology of HEV and to clarify the real burden of HEV infection. Therefore, this review was performed to provide a general overview regarding the epidemiology of HEV in Iran. PMID:27298557

  14. COPD in Taiwan: a National Epidemiology Survey

    PubMed Central

    Cheng, Shih-Lung; Chan, Ming-Cheng; Wang, Chin-Chou; Lin, Ching-Hsiung; Wang, Hao-Chien; Hsu, Jeng-Yuan; Hang, Liang-Wen; Chang, Chee-Jen; Perng, Diahn-Warng; Yu, Chong-Jen

    2015-01-01

    Objectives To determine the prevalence of COPD in Taiwan and to document the disease characteristics and associated risk factors. Methods We conducted a random cross-sectional national survey of adults older than 40 years in Taiwan. Respiratory health screening questions identified subjects with diagnosed COPD or whose reported symptoms also fulfilled an epidemiological case definition; these were eligible to complete the survey, which also included indices of symptom severity and disability and questions on comorbidities, medical treatments, smoking habits, and occupations potentially harmful to respiratory health. Subjects with diagnosed COPD were subdivided by smoking status. Subjects who fulfilled the case definition of COPD and smoked were designated as “possible COPD”. Participants who did not fit the case definition of COPD were asked only about their personal circumstances and smoking habits. Data from these groups were analyzed and compared. Results Of the 6,600 participants who completed the survey, 404 (6.1%) fulfilled the epidemiological case definition of COPD: 137 with diagnosed COPD and 267 possible COPD. The most common comorbidities of COPD were hypertension or cardiovascular diseases (36.1%). Subjects with definite COPD had significantly higher COPD Assessment Test scores than the possible COPD group (14.6±8.32 vs 12.6±6.49, P=0.01) and significantly more comorbid illnesses (P=0.01). The main risk factors contributing to health care utilization in each COPD cohort were higher COPD Assessment Test scores (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.04–1.26), higher modified Medical Research Council Breathlessness Scale scores (OR 1.97, 95% CI 1.11–3.51), and having more than one comorbidity (OR 5.19, 95% CI 1.05–25.61). Conclusion With estimated prevalence of 6.1% in the general population, COPD in Taiwan has been underdiagnosed. Symptoms and comorbidities were independent risk factors for health care utilization in subjects

  15. Epidemiology of psychosis in Parkinson's disease.

    PubMed

    Fénelon, Gilles; Alves, Guido

    2010-02-15

    Psychotic symptoms are frequent and disabling in patients with Parkinson's disease (PD). Methodological issues in the epidemiology of PD associated psychosis (PDP) include differences in the symptoms assessed, the methods of assessment, and the selection of patients. Most studies are prospective clinic-based cross-sectional studies providing point prevalence rates in samples on dopaminergic treatment. Visual hallucinations are present in about one quarter to one third of the patients, auditory in up to 20%. Tactile/somatic, and olfactory hallucinations are usually not systematically sought. Minor phenomena such as sense of presence and visual illusions affect 17 to 72% of the patients, and delusions about 5%. Lifetime prevalence of visual hallucinations reaches approximately 50%. Prospective longitudinal cohort studies suggest that hallucinations persist and worsen in individual patients, and that their prevalence increases with time. A facilitating role of treatment on PDP is demonstrated at least for dopaminergic agonists, but there is no simple dose-effect relationship between dopaminergic treatment and the presence or severity of hallucinations. The main endogenous non-modifiable risk factor is cognitive impairment. Other associated factors include older age/longer duration of PD, disease severity, altered dream phenomena, daytime somnolence, and possibly depression and dysautonomia. PDP reduces quality of life in patients and increases caregiver distress, and is an independent risk factor for nursing home placement and development of dementia. PMID:19740486

  16. Epidemiology of Gallbladder Disease: Cholelithiasis and Cancer

    PubMed Central

    Stinton, Laura M.

    2012-01-01

    Diseases of the gallbladder are common and costly. The best epidemiological screening method to accurately determine point prevalence of gallstone disease is ultrasonography. Many risk factors for cholesterol gallstone formation are not modifiable such as ethnic background, increasing age, female gender and family history or genetics. Conversely, the modifiable risks for cholesterol gallstones are obesity, rapid weight loss and a sedentary lifestyle. The rising epidemic of obesity and the metabolic syndrome predicts an escalation of cholesterol gallstone frequency. Risk factors for biliary sludge include pregnancy, drugs like ceftiaxone, octreotide and thiazide diuretics, and total parenteral nutrition or fasting. Diseases like cirrhosis, chronic hemolysis and ileal Crohn's disease are risk factors for black pigment stones. Gallstone disease in childhood, once considered rare, has become increasingly recognized with similar risk factors as those in adults, particularly obesity. Gallbladder cancer is uncommon in developed countries. In the U.S., it accounts for only ~ 5,000 cases per year. Elsewhere, high incidence rates occur in North and South American Indians. Other than ethnicity and female gender, additional risk factors for gallbladder cancer include cholelithiasis, advancing age, chronic inflammatory conditions affecting the gallbladder, congenital biliary abnormalities, and diagnostic confusion over gallbladder polyps. PMID:22570746

  17. Time series regression studies in environmental epidemiology

    PubMed Central

    Bhaskaran, Krishnan; Gasparrini, Antonio; Hajat, Shakoor; Smeeth, Liam; Armstrong, Ben

    2013-01-01

    Time series regression studies have been widely used in environmental epidemiology, notably in investigating the short-term associations between exposures such as air pollution, weather variables or pollen, and health outcomes such as mortality, myocardial infarction or disease-specific hospital admissions. Typically, for both exposure and outcome, data are available at regular time intervals (e.g. daily pollution levels and daily mortality counts) and the aim is to explore short-term associations between them. In this article, we describe the general features of time series data, and we outline the analysis process, beginning with descriptive analysis, then focusing on issues in time series regression that differ from other regression methods: modelling short-term fluctuations in the presence of seasonal and long-term patterns, dealing with time varying confounding factors and modelling delayed (‘lagged’) associations between exposure and outcome. We finish with advice on model checking and sensitivity analysis, and some common extensions to the basic model. PMID:23760528

  18. The Environmental Epidemiology of Primary Dystonia

    PubMed Central

    Defazio, Giovanni; Gigante, Angelo F.

    2013-01-01

    Background Dystonia is a movement disorder characterized by involuntary muscle contractions that cause twisting movements and abnormal postures. Primary dystonia is the most common form and is thought to be a multifactorial condition in which one or more genes combine with environmental factors to reach disease. Methods We reviewed controlled studies on possible environmental risk factors for primary early- and late-onset dystonia. Results Environmental factors associated with primary early-onset dystonia are poorly understood. Early childhood illnesses have been reported to be more frequent in patients with DYT1 dystonia than in subjects carrying the DYT1 mutation that did not manifest dystonia, thus raising the possibility that such exposures precipitate dystonia among DYT1 carriers. Conversely, several environmental factors have been associated with primary adult-onset focal dystonias compared to control subjects. Namely, eye diseases, sore throat, idiopathic scoliosis, and repetitive upper limb motor action seem to be associated with blepharospasm (BSP), laryngeal dystonia (LD), cervical dystonia (CD), and upper limb dystonia, respectively. In addition, an inverse association between coffee drinking and BSP has been observed in both case-unrelated control and family-based case-control studies. Additional evidence supporting a causal link with different forms of primary late-onset dystonia is only available for diseases of the anterior segment of the eye, writing activity, and coffee intake. Conclusion There is reasonable epidemiological evidence that some environmental factors are risk-modifying factors for specific forms of primary adult-onset focal dystonia. PMID:23724359

  19. Time series regression studies in environmental epidemiology.

    PubMed

    Bhaskaran, Krishnan; Gasparrini, Antonio; Hajat, Shakoor; Smeeth, Liam; Armstrong, Ben

    2013-08-01

    Time series regression studies have been widely used in environmental epidemiology, notably in investigating the short-term associations between exposures such as air pollution, weather variables or pollen, and health outcomes such as mortality, myocardial infarction or disease-specific hospital admissions. Typically, for both exposure and outcome, data are available at regular time intervals (e.g. daily pollution levels and daily mortality counts) and the aim is to explore short-term associations between them. In this article, we describe the general features of time series data, and we outline the analysis process, beginning with descriptive analysis, then focusing on issues in time series regression that differ from other regression methods: modelling short-term fluctuations in the presence of seasonal and long-term patterns, dealing with time varying confounding factors and modelling delayed ('lagged') associations between exposure and outcome. We finish with advice on model checking and sensitivity analysis, and some common extensions to the basic model. PMID:23760528

  20. Evaluation metrics for biostatistical and epidemiological collaborations.

    PubMed

    Rubio, Doris McGartland; Del Junco, Deborah J; Bhore, Rafia; Lindsell, Christopher J; Oster, Robert A; Wittkowski, Knut M; Welty, Leah J; Li, Yi-Ju; Demets, Dave

    2011-10-15

    Increasing demands for evidence-based medicine and for the translation of biomedical research into individual and public health benefit have been accompanied by the proliferation of special units that offer expertise in biostatistics, epidemiology, and research design (BERD) within academic health centers. Objective metrics that can be used to evaluate, track, and improve the performance of these BERD units are critical to their successful establishment and sustainable future. To develop a set of reliable but versatile metrics that can be adapted easily to different environments and evolving needs, we consulted with members of BERD units from the consortium of academic health centers funded by the Clinical and Translational Science Award Program of the National Institutes of Health. Through a systematic process of consensus building and document drafting, we formulated metrics that covered the three identified domains of BERD practices: the development and maintenance of collaborations with clinical and translational science investigators, the application of BERD-related methods to clinical and translational research, and the discovery of novel BERD-related methodologies. In this article, we describe the set of metrics and advocate their use for evaluating BERD practices. The routine application, comparison of findings across diverse BERD units, and ongoing refinement of the metrics will identify trends, facilitate meaningful changes, and ultimately enhance the contribution of BERD activities to biomedical research. PMID:21284015

  1. Epidemiological review of scorpion stings in Qatar

    PubMed Central

    Alkahlout, Baha H.; Abid, Muhammad M.; Kasim, Mohammad M.; Haneef, Shumaila M.

    2015-01-01

    Objectives: To review the epidemiology of scorpion sting in Qatar, to explore both the clinical significance, and the role of the emergency department (ED) in the management of such cases. Methods: In this retrospective study, we reviewed the records of all scorpion sting cases presented to the ED of Hamad General Hospital, Doha, Qatar between October 2010 and May 2013. Results: A total of 111 cases of scorpion stings were reviewed, 81 (72.9%) were males and 30 (27.1%) were females, with a mean age of 38 years. Localized pain was the most frequent presenting complaint (89 [80.2%]), whereas localized redness (44 [39.6%]) and swelling (38 [34.2%]) were the most common clinical signs. Abroug’s classification was used, and all cases were found to be class I. All patients received symptomatic treatment and were sent home. Conclusion: Scorpion sting problem in Qatar has a low clinical significance. Data from such studies should be utilized to create more specific (local) management guidelines, which should be more efficient with more rational utilization of ED resources. PMID:26108591

  2. Epidemiology of Rheumatoid Arthritis in Southern Albania

    PubMed Central

    Koko, Vjollca; Ndrepepa, Ana; Skenderaj, Skender

    2015-01-01

    Objectives: The aim of this study was to assess the prevalence, incidence and the burden of rheumatoid arthritis (RA) in the Southern Albania. Material and Methods: This is an epidemiologic observational study with cross-sectional analyses of all patients with RA who lived in Southern Albania during the 1995-2011 years. The RA prevalence, incidence and disability-adjusted life years (DALY) were assessed. Results: During the 1995-2011 years, 194 patients (154 females and 40 males) with RA living in Southern Albania were identified. The prevalence of RA in 2011 was 0.25% in general population and 0.34% in adult (>14 years) population. The incidence of RA in 2011 was 0.012% (12 new cases per 100000 inhabitants) and 0.016% (16 new cases per 100000 adults). The prevalence increased (from 0.036% in 1996 to 0.25% in 2011) and the incidence did not change over the study period. The mortality was 3.2% (n=7 deaths). The DALY due to RA was 823 years per 100000 inhabitants during 1995-2011 years. Conclusion: RA in Southern Albania has a prevalence of 0.25 % and an annual incidence of 0.012% in the general population in 2011. RA was responsible for a considerable burden on the health of population during the 1995-2011 years. PMID:26236163

  3. Epidemiology and differential diagnosis of nasal polyps

    PubMed Central

    Chaaban, Mohamad R.; Walsh, Erika M.

    2013-01-01

    Background: Chronic rhinosinusitis (CRS) is one of the most common chronic medical conditions, with a significant impact on patient quality of life. CRS is broadly classified into two groups: CRS with nasal polyposis (CRSwNP) and CRS without NP (CRSsNP). Clinically, the major subtypes of CRSwNP may be divided into eosinophilic chronic rhinosinusitis (e.g., allergic fungal rhinosinusitis and aspirin-exacerbated respiratory disease [AERD]) and nasal polyps associated with neutrophilic inflammation (e.g., cystic fibrosis [CF]). CF is characterized by mutation of the gene encoding the CF transmembrane conductance regulator. Functional endoscopic sinus surgery is usually required for most NP patients with increased frequency in patients with AERD. This study provides a review of the epidemiology and major classification of CRSwNP. Methods: A review was performed of the literature regarding different subtypes of CRSwNP. Results: Many definitions of CRSwNP exist and estimates of prevalence vary. Conclusion: CRSwNP is a clinical syndrome with a heterogeneous inflammatory profile. Of the subtypes associated with eosinophilic inflammation, AERD remains the most recalcitrant to medical and surgical therapeutic interventions. PMID:24274222

  4. Epidemiology of Nursemaid’s Elbow

    PubMed Central

    Vitello, Sarah; Dvorkin, Ronald; Sattler, Steven; Levy, David; Ung, Lyncean

    2014-01-01

    Introduction To provide an epidemiological description of radial head subluxation, also known as nursemaid’s elbow, from a database of emergency department visits. Methods We conducted a retrospective medical record review of patients 6 years of age and younger, who presented to the ED between January 1, 2005, and December 31, 2012, and were diagnosed with nursemaid’s elbow. Inclusion criteria consisted of chart information, including date, unique account number, medical record number, weight, age, sex, and arm affected. Exclusion criteria included any charts with missing or incomplete data. Results There were 1,228 charts that met inclusion criteria. The majority of patients were female (60%). The mean age was 28.6 months (±12.6). The left arm was affected 60% of the time. Most of the included patients were over the 75th percentile for weight and more than one quarter were over the 95th percentile in each gender. Conclusion The average age of children presenting with nursemaid’s elbow was 28.6 months. Females were affected more than males, and the left arm was predominately affected. Most patients were above the 75th percentile for weight and more than one quarter were over the 95th percentile for weight. PMID:25035767

  5. Epidemiology, Mechanisms and Management of Diabetic Gastroparesis

    PubMed Central

    Camilleri, Michael; Bharucha, Adil E.; Farrugia, Gianrico

    2010-01-01

    Background Recent evidence of the significant impact of gastroparesis on morbidity and mortality mandates optimized management of this condition. Gastroparesis affects nutritional state and, in diabetics, it also has deleterious effects on glycemic control and secondary effects on organs that lead to increased mortality. First-line treatment includes restoration of nutrition and medications (prokinetic and antiemetic). Aim To review the epidemiology, pathophysiology, impact, natural history, time trends and treatment of gastroparesis with particular focus on diabetic gastroparesis. Methods The pros and cons of current treatment options including metoclopramide are discussed. Second-line approaches include surgery, venting gastrostomy or jejunostomy, and gastric electrical stimulation; most of these treatments are based on open-label treatment trials. Results/Conclusions In the future, drugs that target the underlying defects and new prokinetics such as newer 5-HT4 agonists (which appear to be devoid of cardiac or vascular effects), ghrelin agonists, new approaches to pacing the stomach, and stem cell therapies may bring more effective treatments to ameliorate the management of patients with gastroparesis. PMID:20951838

  6. Epidemiological study of cauda equina syndrome

    PubMed Central

    Fuso, Fernando Augusto Freitas; Dias, André Luiz Natálio; Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; Marcon, Raphael Martus; de Barros, Tarcísio Eloy Pessoa

    2013-01-01

    OBJECTIVE : The primary purpose of this study was to determine the characteristics and outcomes of the patients admitted at our clinics diagnosed with cauda equina syndrome (CES). Secondarily, this study will serve as a basis for other comparative studies aiming at a better understanding of this condition and its epidemiology. METHODS : We conducted a retrospective study by reviewing the medical records of patients diagnosed with CES and neurogenic bladder between 2005 and 2011. The following variables were analyzed: gender, age, etiology, topographic level of the lesion, time between disease onset and diagnosis, presence of neurogenic bladder, time between diagnosis and surgery, neurological damage and neurogenic bladder persistence. RESULTS : Considering that CES is a rare condition, we were not able to establish statistic correlation between the analyzed variables and the outcomes of the disease. However, this study brought to light the inadequacy of our public health system in treating that kind of patient. CONCLUSION : The study shows that despite the well-defined basis for managing CES, we noted a greater number of patients with sequels caused by this condition, than is seen in the literature. The delayed diagnosis and, consequently, delayed treatment, were the main causes for the results observed. Level of Evidence IV, Case Series. PMID:24453661

  7. Critical issues in air pollution epidemiology.

    PubMed Central

    Lippmann, M; Lioy, P J

    1985-01-01

    The epidemiological studies which have had significant impact on the setting of National Ambient Air Quality Standards (NAAQSs) were performed more than twenty years ago. Most of the more recent studies have been seriously flawed in their design and/or execution because they neglected to account for important variables such as: pollutant exposures other than those from ambient air; the influence of personal activity on pollutant uptake; host responsiveness; and the separate contributions of recent transient peak exposures and long-term chronic exposures on the effects endpoints. For particulate pollutants, the influence of composition and size distribution has also received too little consideration. In order to address these deficiencies, research and methods development are needed on: indices for particulate exposures; identification of exposures relevant to the effects; improved indices of effects; acquisition of response data; identification of exposed populations; and identification of susceptible subgroups. Approaches to these needs are discussed, along with brief reviews of several recent studies that have focused on critical issues of concern, made the necessary efforts to characterize the relevant exposures of the populations being studied, and demonstrated human responses to ambient pollutants at current exposure levels. PMID:4085428

  8. Ribotyping of Pseudomonas aeruginosa: discriminatory power and usefulness as a tool for epidemiological studies.

    PubMed Central

    Blanc, D S; Siegrist, H H; Sahli, R; Francioli, P

    1993-01-01

    Restriction fragment length polymorphism of ribosomal DNA regions (ribotyping) of Pseudomonas aeruginosa was evaluated as a tool for epidemiological purposes. Fifty-five epidemiologically unrelated isolates from three geographic areas of Switzerland and 11 isolates obtained during an outbreak of P. aeruginosa infections in a burn unit were typed by this method. Typeability and reproducibility of the method reached 100%. With four selected restriction enzymes (BamHI, ClaI, EcoRI, and PstI), the 55 unrelated isolates could be classified into 33 ribotypes. To assess the value of this method for the interpretation of epidemiological data, we calculated an index of discrimination (ID) which takes into consideration both the number of types defined by the typing method and their relative frequencies. Our ribotyping system obtained a high ID of 0.958 with only four restriction enzymes, comparing well with other different typing schemes for which ID values could be calculated from published data. All clinical isolates of the outbreak belonged to the same ribotype, whereas environmental isolates, initially thought to be the source of the epidemic, belonged to a different ribotype. Thus, the typeability, reproducibility, and discriminatory power of our method as well as its value established in an epidemiological investigation were found to be appropriate for further epidemiological studies of P. aeruginosa. Images PMID:8093252

  9. spa typing for epidemiological surveillance of Staphylococcus aureus.

    PubMed

    Hallin, Marie; Friedrich, Alexander W; Struelens, Marc J

    2009-01-01

    The spa typing method is based on sequencing of the polymorphic X region of the protein A gene (spa), present in all strains of Staphylococcus aureus. The X region is constituted of a variable number of 24-bp repeats flanked by well-conserved regions. This single-locus sequence-based typing method combines a number of technical advantages, such as rapidity, reproducibility, and portability. Moreover, due to its repeat structure, the spa locus simultaneously indexes micro- and macrovariations, enabling the use of spa typing in both local and global epidemiological studies. These studies are facilitated by the establishment of standardized spa type nomenclature and Internet shared databases. PMID:19521876

  10. Atrazine and Pregnancy Outcomes: A Systematic Review of Epidemiologic Evidence

    PubMed Central

    Goodman, Michael; Mandel, Jack S; DeSesso, John M; Scialli, Anthony R

    2014-01-01

    Atrazine (ATR) is a commonly used agricultural herbicide that has been the subject of epidemiologic studies assessing its relation to reproductive health problems. This review evaluates both the consistency and the quality of epidemiologic evidence testing the hypothesis that ATR exposure, at usually encountered levels, is a risk factor for birth defects, small for gestational age birth weight, prematurity, miscarriages, and problems of fetal growth and development. We followed the current methodological guidelines for systematic reviews by using two independent researchers to identify, retrieve, and evaluate the relevant epidemiologic literature on the relation of ATR to various adverse outcomes of birth and pregnancy. Each eligible paper was summarized with respect to its methods and results with particular attention to study design and exposure assessment, which have been cited as the main areas of weakness in ATR research. As a quantitative meta-analysis was not feasible, the study results were categorized qualitatively as positive, null, or mixed. The literature on ATR and pregnancy-related health outcomes is growing rapidly, but the quality of the data is poor with most papers using aggregate rather than individual-level information. Without good quality data, the results are difficult to assess; however, it is worth noting that none of the outcome categories demonstrated consistent positive associations across studies. Considering the poor quality of the data and the lack of robust findings across studies, conclusions about a causal link between ATR and adverse pregnancy outcomes are not warranted. PMID:24797711

  11. The Singapore Field Epidemiology Service: Insights Into Outbreak Management

    PubMed Central

    Seetoh, Theresa; Cutter, Jeffery

    2012-01-01

    Field epidemiology involves the implementation of quick and targeted public health interventions with the aid of epidemiological methods. In this article, we share our practical experiences in outbreak management and in safeguarding the population against novel diseases. Given that cities represent the financial nexuses of the global economy, global health security necessitates the safeguard of cities against epidemic diseases. Singapore's public health landscape has undergone a systemic and irreversible shift with global connectivity, rapid urbanization, ecological change, increased affluence, as well as shifting demographic patterns over the past two decades. Concomitantly, the threat of epidemics, ranging from severe acute respiratory syndrome and influenza A (H1N1) to the resurgence of vector-borne diseases as well as the rise of modern lifestyle-related outbreaks, have worsened difficulties in safeguarding public health amidst much elusiveness and unpredictability. One critical factor that has helped the country overcome these innate and man-made public health vulnerabilities is the development of a resilient field epidemiology service, which includes our enhancement of surveillance and response capacities for outbreak management, and investment in public health leadership. We offer herein the Singapore story as a case study in meeting the challenges of disease control in our modern built environment. PMID:23091652

  12. Colorectal Cancer Epidemiology in the Nurses’ Health Study

    PubMed Central

    Lee, Dong Hoon; Giovannucci, Edward L.

    2016-01-01

    Objectives. To review the contribution of the Nurses’ Health Study (NHS) to identifying risk and protective factors for colorectal adenomas and colorectal cancer (CRC). Methods. We performed a narrative review of the publications using the NHS between 1976 and 2016. Results. Existing epidemiological studies using the NHS have reported that red and processed meat, alcohol, smoking, and obesity were associated with an increased risk of CRC, whereas folate, calcium, vitamin D, aspirin, and physical activity were associated with decreased risk of CRC. Moreover, modifiable factors, such as physical activity, vitamin D, folate, insulin and insulin-like growth factor binding protein-1, and diet quality, were identified to be associated with survival among CRC patients. In recent years, molecular pathological epidemiological studies have been actively conducted and have shown refined results by molecular subtypes of CRC. Conclusions. The NHS has provided new insights into colorectal adenomas, CRC etiology, and pathogenic mechanisms. With its unique strengths, the NHS should continue to contribute to the field of CRC epidemiology and play a major role in public health. PMID:27459444

  13. The health impacts of semiconductor production: an epidemiologic review

    PubMed Central

    Kim, Myoung-Hee; Kim, Hyunjoo; Paek, Domyung

    2014-01-01

    Background: Despite concerns over the harmful health effects of semiconductor production, epidemiological studies have shown mixed results. Objectives: We aim to critically appraise epidemiologic studies to date, and to suggest future research and actions to protect workers in semiconductor industry. Methods: Epidemiologic studies were identified through electronic database searches, review of reference lists of relevant published works, and expert consultations, and were narratively reviewed. Results: Most evidence suggests reproductive risks from fabrication jobs, including spontaneous abortion (SAB), congenital malformation, and reduced fertility. Although chemicals have been suspected as causal agents, knowledge of the likely contribution(s) from specific exposures is still limited. Evidence of cancer risk seems to be equivocal. However, the available studies had serious limitations including healthy worker effects (HWEs), information bias, and insufficient power, all of which are associated with underestimation. Nevertheless, excess risks for non-Hodgkin's lymphoma (NHL), leukemia, brain tumor, and breast cancer were observed. Conclusions: Monitoring and innovative research based on international collaboration with a focus on sentinel events are required. PMID:24999845

  14. The epidemiology of Varicella Zoster Virus infection in Italy

    PubMed Central

    Gabutti, Giovanni; Rota, Maria C; Guido, Marcello; De Donno, Antonella; Bella, Antonino; Ciofi degli Atti, Marta L; Crovari, Pietro

    2008-01-01

    Background The epidemiological importance of varicella and zoster and the availability of an efficacious and safe vaccine have led to an important international debate regarding the suitability of mass vaccination. The objective of the study was to describe the epidemiology of varicella and zoster in Italy and to determine whether there have been changes with respect to observations provided by an analogous study conducted 8 years ago, in order to define the most appropriate vaccination strategy. Methods A number of data sources were evaluated, a cross-sectional population-based seroprevalence study was conducted on samples collected in 2004, and the results were compared with data obtained in 1996. Results The data from active and passive surveillance systems confirm that varicella is a widespread infectious disease which mainly affects children. VZV seroprevalence did not substantially differ from that found in the previous study. The sero-epidemiological profile in Italy is different from that in other European countries. In particular, the percentage of susceptible adolescents is at least nearly twice as high as in other European countries and in the age group 20–39 yrs, approximately 9% of individuals are susceptible to VZV. Conclusion The results of this study can contribute to evaluating the options for varicella vaccination. It is possible that in a few years, in all Italian Regions, there will exist the conditions necessary for implementing a mass vaccination campaign and that the large-scale availability of MMRV tetravalent vaccines will facilitate mass vaccination. PMID:18954432

  15. The Role of Epidemiology in Disaster Response Policy Development

    PubMed Central

    Thorpe, Lorna E; Assari, Shervin; Deppen, Stephen; Glied, Sherry; Lurie, Nicole; Mauer, Matthew P; Mays, Vickie M.; Trapido, Edward

    2015-01-01

    Purpose Disasters expose the general population and responders to a range of potential contaminants and stressors which may harm physical and mental health. This article addresses the role of epidemiology in informing policies after a disaster to mitigate ongoing exposures, provide care and compensation, and improve preparedness for future disasters. Methods The World Trade Center (WTC) disaster response is used as a case study. We examine how epidemiologic evidence was used to shape post-disaster policy and identify important gaps in early research. Results In the wake of WTC attacks, epidemiologic research played a key role in identifying and characterizing affected populations, assessing environmental exposures, quantifying physical and mental health impacts, and producing evidence to ascribe causation. However, most studies suffered from methodological challenges, including delays, selection biases, poor exposure measurement, and nonstandardized outcomes. Gaps included measuring unmet health needs and financing coverage, as well as coordination across longitudinal cohorts of studies for rare conditions with long latency, such as cancer. Conclusions Epidemiologists can increase their impact on evidence-based policymaking by ensuring core mechanisms are in place prior to a disaster to mount monitoring of responders and other affected populations, improve early exposure assessment efforts, identify critical gaps in scientific knowledge, and coordinate communication of scientific findings to policymakers and the public. PMID:25150446

  16. Epidemiology, Policy, and Racial/Ethnic Minority Health Disparities

    PubMed Central

    Carter-Pokras, Olivia; Offutt-Powell, Tabatha; Kaufman, Jay S.; Giles, Wayne; Mays, Vickie

    2013-01-01

    Purpose Epidemiologists have long contributed to policy efforts to address health disparities. Three examples illustrate how epidemiologists have addressed health disparities in the U.S. and abroad through a “social determinants of health” lens. Methods To identify examples of how epidemiologic research has been applied to reduce health disparities, we queried epidemiologists engaged in disparities research in the U.S., Canada, and New Zealand, and drew upon the scientific literature. Results Resulting examples covered a wide range of topic areas. Three areas selected for their contributions to policy were: 1) epidemiology's role in definition and measurement, 2) the study of housing and asthma, and 3) the study of food policy strategies to reduce health disparities. While epidemiologic research has done much to define and quantify health inequalities, it has generally been less successful at producing evidence that would identify targets for health equity intervention. Epidemiologists have a role to play in measurement and basic surveillance, etiologic research, intervention research, and evaluation research. However, our training and funding sources generally place greatest emphasis on surveillance and etiologic research. Conclusions: The complexity of health disparities requires better training for epidemiologists to effectively work in multidisciplinary teams. Together we can evaluate contextual and multilevel contributions to disease and study intervention programs in order to gain better insights into evidenced-based health equity strategies. PMID:22626003

  17. Epidemiology of pyridoxine dependent seizures in the Netherlands

    PubMed Central

    Been, J; Bok, L; Andriessen, P; Renier, W

    2005-01-01

    Background: Pyridoxine dependent epilepsy is a rare cause of seizures in childhood. The diagnosis is made on clinical criteria, that in many cases are never met. Therefore, epidemiological data on pyridoxine dependency are scarce. Aims: To study the epidemiology of pyridoxine dependent epilepsy in the Netherlands, and to determine whether the diagnosis is based on the appropriate criteria. Methods: Nationwide all departments of paediatrics (n = 113) and of paediatric or neonatal neurology (n = 17) were asked to report cases of pyridoxine dependent seizures. Birth incidences were calculated using national data on live births from 1991 to 2003. Results: Response was received from 67% of paediatric departments, including all university hospitals and 94% of child neurology departments. Thirteen patients were reported. Four definite (31%), three probable (23%), and four possible cases (31%) were identified. Two cases (15%) did not meet criteria for either of these groups. The birth incidence was 1:396 000 for definite and probable cases and 1:252 000 when possible cases are included. Conclusions: Thus far, epidemiological data on pyridoxine dependent seizures were only available from the UK and Ireland. A higher incidence was found in the Netherlands, in accordance with earlier suggestions of a regional difference. The study shows that the diagnosis is often made without performance of a formal trial of withdrawal. The importance of confirming the diagnosis, concerning the consequences as for individual prognosis, the potential side effects of prolonged pyridoxine substitution, and the possibility of treating the mother in case of future pregnancies are emphasised. PMID:16159904

  18. Major depression epidemiology from a diathesis-stress conceptualization

    PubMed Central

    2013-01-01

    Background Major depression is a widely used diagnostic category but there is increasing dissatisfaction with its performance. The diathesis-stress model is an alternative approach that does not require the (sometimes arbitrary) imposition of categories onto the spectrum of depressive morbidity. However, application of this model has not been well explored and its consistency with available epidemiologic data is uncertain. Methods Simulation provides an opportunity to explore these issues. In this study, a simulation model based on an intuitive representation of diathesis-stress interaction was developed. Both diathesis and stress were represented using continuous distributions, without categorization. A diagnostic threshold was then applied to the simulation output to create nominal categories and to explore their consistency with available information. Results An apparently complex epidemiologic pattern emerged from the diathesis-stress interaction when thresholds were applied: incidence was time dependent, recurrence depended on the number of past episodes, baseline symptoms were associated with an increased risk of subsequent episodes and the remission rate declined with increasing episode duration. Conclusions A diathesis-stress conceptualization coupled with application of a threshold-based diagnostic definition may explain several of the apparent complexities of major depression epidemiology. Some of these complexities may be artifacts of the nominal diagnostic approach. These observations should encourage an empirical exploration of whether diathesis-stress interactions provide a more parsimonious framework for understanding depression than current approaches. PMID:23305517

  19. Visions for the 20th International Epidemiological Association's World Congress of Epidemiology (WCE 2014).

    PubMed

    Monsour, B B; Johnston, J M; Hennessy, T W; Schmidt, M I; Krieger, N

    2012-03-01

    During August 17th-21st, 2014, the University of Alaska Anchorage, along with other local, state, and federal agencies throughout Alaska, will host the 20(th) International Epidemiological Association's (IEA) World Congress of Epidemiology (WCE 2014). The theme for this Congress is "Global Epidemiology in a Changing Environment: The Circumpolar Perspective." The changing environment includes the full range of environments that shape population health and health inequities from the physical to the social and economic. Our circumpolar perspective on these environments includes views on how political systems, work, immigration, Indigenous status, and gender relations and sexuality affect the global world and the health of its people. Suggestions and insights from the 3(rd) North American Congress of Epidemiology (2011) and the first-ever joint regional workshop co-organized by the IEA North American Region and the IEA Latin American and Caribbean Region held at the 19(th) IEA World Congress of Epidemiology (2011) have helped direct the focus for WCE 2014. Since the Arctic regions are feeling the effects of climate change first, we believe focusing on the emerging data on the health impacts of climate change throughout the world will be an important topic for this Congress. This will include a broad range of more traditional epidemiology areas such as infectious disease epidemiology, environmental epidemiology, health disparities, and surveillance and emergency preparedness. Addressing health inequities and promoting health equity is likewise a key concern of the Congress. This Congress will also host presentations on injury epidemiology, occupational health, infectious diseases, chronic diseases, maternal and child health, surveillance and field epidemiology, mental health, violence (from self-directed, e.g., suicide, to interpersonal to structural), psychoactive substance use (including tobacco), and measures of subjective health. Attention will be given to

  20. The epidemiology of drowning worldwide.

    PubMed

    Peden, M M; McGee, K

    2003-12-01

    The purpose of this analysis was to quantify the magnitude of death and disability from drowning and near-drowning worldwide and to provide epidemiological data on which to base prevention efforts. All data are from the Global Burden of Disease 2000 (Version 1) estimates in which deaths and disabilities are based on the WHO International Classification of Diseases. Extrapolations were made by age, sex, and WHO region. The six WHO regions of the world were further divided into high-income, and low- and middle-income based on the 1998 World Development indicators. According to the GBD 2000 data, an estimated 449,000 people drowned worldwide (7.4 per 100,000 population) and a further 1.3 million Disability Adjusted Life Years (DALYs) were lost as a result of premature death or disability from drowning. 97% of drownings occurred in low- and middle-income countries. Although 38% of drownings occurred in the Western Pacific Region, Africa had the highest drowning mortality rate (13.1 per 100,000 population). Males had higher drowning mortality rates than females for all ages and in all regions. Children under the age of 5 years had the highest drowning mortality rate for both sexes in all of the WHO regions except for Africa, where children aged 5 to 14 years had the highest mortality rate. Worldwide, for children under the age of 15 years, drowning accounted for a higher mortality rate than any other cause of injury. Drowning is a significant problem worldwide particularly for children under the age of 15 years. Low- and middle-income countries have the highest rates of drowning and account for more than 90% of such fatalities. Primary prevention efforts should thus be focused on these countries where many children who cannot swim drown in large bodies of water. PMID:14664361

  1. Epidemiology of paramphistomosis in cattle.

    PubMed

    Rolfe, P F; Boray, J C; Nichols, P; Collins, G H

    1991-11-01

    The epidemiology of paramphistomosis in cattle was studied using tracer calves in a subtropical location in eastern Australia. Two species of paramphistomes were present; Calicophoron calicophorum and Paramphistomum ichikawai. The former species was the most abundant. Gyraulus scottianus and Helicorbis australiensis acted as intermediate hosts, respectively. Paramphistome burdens varied seasonally and were dependent upon the number of infected host snails. Peak fluke burdens and clinical paramphistomosis occurred in late summer in year 1 and early winter in year 2. The peak fluke burdens coincided with prolonged inundation of the grazing areas resulting in rapid multiplication and infection of host snails, and the period after the inundated areas dried out. The prevalence of infection in snails was high in both years, peaking at 98% in year 1 and 58% in year 2. The main host snail, G. scottianus, aestivated and retained infection for at least 24 weeks in soil, and in vegetable debris on the surface of the soil, resulting in rapid reappearance of host snails and infective metacercariae after the onset of seasonal rain. Metacercariae survived on herbage for up to 12 weeks, depending on the environmental conditions. Paramphistome burdens in calves could be predicted from the prevalence of infection in the host snail, the water levels and an index of surface water on the grazing site. Control of paramphistomosis during and after flooding may be achieved by removal of susceptible cattle from pasture or regular treatment during these periods. Strategic treatment during the dry season may reduce contamination of snail habitats and infectivity of the pasture in the following wet season. PMID:1774118

  2. Epidemiology of asthma in India.

    PubMed

    Paramesh, H

    2002-04-01

    Allergic respiratory disorders, in particular asthma are increasing in prevalence, which is a global phenomenon. Even though genetic predisposition is one of the factors in children for the increased prevalence - urbanisation, air pollution and environmental tobacco smoke contribute more significantly. Our hospital based study on 20,000 children under the age of 18 years from 1979,1984,1989,1994 and 1999 in the city of Bangalore showed a prevalence of 9%,10.5%,18.5%, 24.5% and 29.5% respectively. The increased prevalence correlated well with demographic changes of the city. Further to the hospital study, a school survey in 12 schools on 6550 children in the age group of 6 to 15 years was undertaken for prevalence of asthma and children were categorized into three groups depending upon the geographical situation of the school in relation to vehicular traffic and the socioeconomic group of children. Group I-Children from schools of heavy traffic area showed prevalence of 19.34%, Group II-Children from heavy traffic region and low socioeconomic population had 31.14% and Group III-Children from low traffic area school had 11.15% respectively. (P: I & II; II & III <0.001). A continuation of study in rural areas showed 5.7% in children of 6-15 years. The persistent asthma also showed an increase from 20% to 27.5% and persistent severe asthma 4% to 6.5% between 1994-99. Various epidemiological spectra of asthma in children are discussed here. PMID:12019551

  3. Norovirus Surveillance: An Epidemiological Perspective.

    PubMed

    Harris, John P

    2016-02-01

    Surveillance for norovirus is challenging because the nature of illness due to norovirus is such that the majority of people who are infected will not have any contact with medical services and are highly unlikely to have a sample collected for diagnosis. Public health advice urges people to not visit hospitals or their family physicians, to prevent the risk further spread. The recognition of the importance of this pathogen was quickly established following the introduction of surveillance of outbreaks of gastrointestinal infection in England and Wales in 1992. This period saw >1800 outbreaks of norovirus infection reported in hospitals in England, affecting >45 000 patients and staff. A new system for reporting outbreaks of norovirus infection in hospitals, the Hospital Norovirus outbreak Reporting Scheme (HNORS), began in January 2009. Summary information on outbreaks is provided by infection control staff at hospitals and includes questions on the date the first and last person in the outbreak became symptomatic and whether closure of a bay or ward was needed. In the first 3 years (2009-2011) of the HNORS surveillance scheme, 4000 outbreaks were reported, affecting 40 000 patients and 10 000 staff. Over the last 3 years, these outbreaks have been associated with an average of 13 000 patients and 3400 staff becoming ill, with 15 000 lost bed-days annually. With the possible introduction of a vaccine on the horizon, targeted research with a more integrated approach to laboratory testing and outbreak reporting is essential to a greater understanding of the epidemiology of norovirus. PMID:26744431

  4. Evaluating Uncertainty to Strengthen Epidemiologic Data for Use in Human Health Risk Assessments

    PubMed Central

    Burns, Carol J.; Wright, J. Michael; Bateson, Thomas F.; Burstyn, Igor; Goldstein, Daniel A.; Klaunig, James E.; Luben, Thomas J.; Mihlan, Gary; Ritter, Leonard; Schnatter, A. Robert; Symons, J. Morel; Don Yi, Kun

    2014-01-01

    Background: There is a recognized need to improve the application of epidemiologic data in human health risk assessment especially for understanding and characterizing risks from environmental and occupational exposures. Although there is uncertainty associated with the results of most epidemiologic studies, techniques exist to characterize uncertainty that can be applied to improve weight-of-evidence evaluations and risk characterization efforts. Methods: This report derives from a Health and Environmental Sciences Institute (HESI) workshop held in Research Triangle Park, North Carolina, to discuss the utility of using epidemiologic data in risk assessments, including the use of advanced analytic methods to address sources of uncertainty. Epidemiologists, toxicologists, and risk assessors from academia, government, and industry convened to discuss uncertainty, exposure assessment, and application of analytic methods to address these challenges. Synthesis: Several recommendations emerged to help improve the utility of epidemiologic data in risk assessment. For example, improved characterization of uncertainty is needed to allow risk assessors to quantitatively assess potential sources of bias. Data are needed to facilitate this quantitative analysis, and interdisciplinary approaches will help ensure that sufficient information is collected for a thorough uncertainty evaluation. Advanced analytic methods and tools such as directed acyclic graphs (DAGs) and Bayesian statistical techniques can provide important insights and support interpretation of epidemiologic data. Conclusions: The discussions and recommendations from this workshop demonstrate that there are practical steps that the scientific community can adopt to strengthen epidemiologic data for decision making. Citation: Burns CJ, Wright JM, Pierson JB, Bateson TF, Burstyn I, Goldstein DA, Klaunig JE, Luben TJ, Mihlan G, Ritter L, Schnatter AR, Symons JM, Yi KD. 2014. Evaluating uncertainty to strengthen

  5. Utilization of health insurance data in an environmental epidemiology

    PubMed Central

    Ha, Jongsik; Cho, Seongkyung

    2015-01-01

    Objectives In South Korea, health insurance data are used as material for the health insurance of national whole subject. In general, health insurance data could be useful for estimating prevalence or incidence rate that is representative of the actual value in a population. The purpose of this study was to apply the concept of episode of care (EoC) in the utilization of health insurance data in the field of environmental epidemiology and to propose an improved methodology through an uncertainty assessment of disease course and outcome. Methods In this study, we introduced the concept of EoC as a methodology to utilize health insurance data in the field of environmental epidemiology. The characterization analysis of the course and outcome of applying the EoC concept to health insurance data was performed through an uncertainty assessment. Results The EoC concept in this study was applied to heat stroke (International Classification of Disease, 10th revision, code T67). In the comparison of results between before and after applying the EoC concept, we observed a reduction in the deviation of daily claims after applying the EoC concept. After that, we categorized context, model, and input uncertainty and characterized these uncertainties in three dimensions by using uncertainty typology. Conclusions This study is the first to show the process of constructing episode data for environmental epidemiological studies by using health insurance data. Our results will help in obtaining representative results for the processing of health insurance data in environmental epidemiological research. Furthermore, these results could be used in the processing of health insurance data in the future. PMID:26796891

  6. History, Epidemiology, and Clinical Manifestations of Zika: A Systematic Review

    PubMed Central

    Barreto, Florisneide; da Glória Teixeira, Maria; da Conceição N. Costa, Maria; Rodrigues, Laura C.

    2016-01-01

    Objectives. To describe salient epidemiological characteristics of Zika virus outbreaks across the world and to examine the clinical presentations, complications, and atypical manifestations related to their occurrence in recent history. Methods. We conducted a systematic review of the literature by searching through MEDLINE, Embase, and Global Health Library, as well as the epidemiological bulletins and alerts from the World Health Organization, the Pan American Health Organization, and the European Centre for Disease Prevention and Control over the period 1954 to 2016. Results. The search yielded 547 records. We retained 333 for further analysis, to which we added 11 epidemiological bulletins from various sources. Of these, we systematically reviewed 52 articles and reports, revealing some epidemiological features and patterns of spread of the Zika virus worldwide, as well as pathological outcomes suspected to be linked to Zika outbreaks. Neurologic disorders among zika patients were similar in Brazil and French Polynesia but a causal link is not established. Incidence of zika infection in pregnant women is not known. In Brazil, during the zika outbreak the incidence of microcephaly increased more than 20 times. Among 35 infants with microcephaly, born from women suspected to have Zika infection during pregnancy in northeast Brazil, 74% of the mothers reported rash during the first and second trimester. Conclusions. On February 1, 2016, The World Health Organization declared the ongoing Zika crisis an emergency and that, although not yet scientifically proven, the link between the virus and growing numbers of microcephaly cases was “strongly suspected.” However, the causal relationship between zika and microcephaly is not universally accepted. Public Health Implications. The current situation with regard to Zika is not encouraging, because there is no vaccine, no treatment, and no good serological test, and vector control remains a challenge. PMID:26959260

  7. Integrating remote sensing and spatially explicit epidemiological modeling

    NASA Astrophysics Data System (ADS)

    Finger, Flavio; Knox, Allyn; Bertuzzo, Enrico; Mari, Lorenzo; Bompangue, Didier; Gatto, Marino; Rinaldo, Andrea

    2015-04-01

    Spatially explicit epidemiological models are a crucial tool for the prediction of epidemiological patterns in time and space as well as for the allocation of health care resources. In addition they can provide valuable information about epidemiological processes and allow for the identification of environmental drivers of the disease spread. Most epidemiological models rely on environmental data as inputs. They can either be measured in the field by the means of conventional instruments or using remote sensing techniques to measure suitable proxies of the variables of interest. The later benefit from several advantages over conventional methods, including data availability, which can be an issue especially in developing, and spatial as well as temporal resolution of the data, which is particularly crucial for spatially explicit models. Here we present the case study of a spatially explicit, semi-mechanistic model applied to recurring cholera outbreaks in the Lake Kivu area (Democratic Republic of the Congo). The model describes the cholera incidence in eight health zones on the shore of the lake. Remotely sensed datasets of chlorophyll a concentration in the lake, precipitation and indices of global climate anomalies are used as environmental drivers. Human mobility and its effect on the disease spread is also taken into account. Several model configurations are tested on a data set of reported cases. The best models, accounting for different environmental drivers, and selected using the Akaike information criterion, are formally compared via cross validation. The best performing model accounts for seasonality, El Niño Southern Oscillation, precipitation and human mobility.

  8. [Yellow fever epidemiology in Brazil].

    PubMed

    Mondet, B

    2001-08-01

    We have carried out a meticulous time-space-analysis of the incidence of yellow fever in humans in Brazil from 1954 to 1972 and especially from 1973 to 1999. This study has added to our knowledge of the epidemiology of yellow fever and enabled us to redefine epidemiological zones and determine their geographical limits. The endemic area is located within the Amazon basin; here cases are scattered and generally limited in number. However, there are also "foci of endemic emergence" within this area, where cases are less rare, although occurrence remains irregular. The epidemic area is for the most part situated outside the Amazon basin, to the north east and particularly to the south. It has been divided into two parts according to whether the occurrence of yellow fever is cyclic or sporadic. The epidemics, which are all sylvatic, follow either a circular path (in the forest area) or a linear path (in forest-galleries of the savannah area). The study of the development of the 3 main epidemics (1972-74; 1979-82; 1986-92) in the cyclic emergence area showed that, on each occasion, the yellow fever virus appeared at a particularly active outbreak site located in the "serra dos Carajás", and from there, it followed the courses of the Tocantins and Araguaia rivers upstream, moving southwards during the "pre-epidemic phase" which may be visible due to the occurrence of a few cases, or may remain invisible. Subsequently the virus reached the emergence area, where it appeared in the form of epidemics. In this zone, it also followed privileged south-western pathways, moving from one hydraulic basin to another along the upstream courses of the rivers. Almost exactly the same pathways have been identified for each of the 3 epidemics studied. The distances travelled by the virus over a period of one year--when it goes rapidly--can reach several hundred kilometers. On the other hand, it may be stationary for a period of one or two consecutive years, occasionally three, remaining

  9. The Schisto Track: A System for Gathering and Monitoring Epidemiological Surveys by Connecting Geographical Information Systems in Real Time

    PubMed Central

    2014-01-01

    Background Using the Android platform as a notification instrument for diseases and disorders forms a new alternative for computerization of epidemiological studies. Objective The objective of our study was to construct a tool for gathering epidemiological data on schistosomiasis using the Android platform. Methods The developed application (app), named the Schisto Track, is a tool for data capture and analysis that was designed to meet the needs of a traditional epidemiological survey. An initial version of the app was finished and tested in both real situations and simulations for epidemiological surveys. Results The app proved to be a tool capable of automation of activities, with data organization and standardization, easy data recovery (to enable interfacing with other systems), and totally modular architecture. Conclusions The proposed Schisto Track is in line with worldwide trends toward use of smartphones with the Android platform for modeling epidemiological scenarios. PMID:25099881

  10. Genomic Signatures of Emerging Viruses: A New Era of Systems Epidemiology.

    PubMed

    Rasmussen, Angela L; Katze, Michael G

    2016-05-11

    Compared to classical epidemiologic methods, genomics can be used to precisely monitor virus evolution and transmission in real time across large, diverse populations. Integration of pathogen genomics with data about host genetics and global transcriptional responses to infection allows for comprehensive studies of population-level responses to infection and provides novel methods for predicting clinical outcomes. As genomic technologies become more accessible, these methods will redefine how emerging viruses are studied and outbreaks are contained. Here we review the existing and emerging genomic technologies that are enabling systems epidemiology and systems virology and making it possible to respond rapidly to emerging viruses such as Zika. PMID:27173929

  11. Epidemiologic research topics in Germany: a keyword network analysis of 2014 DGEpi conference presentations.

    PubMed

    Peter, Raphael Simon; Brehme, Torben; Völzke, Henry; Muche, Rainer; Rothenbacher, Dietrich; Büchele, Gisela

    2016-06-01

    Knowledge of epidemiologic research topics as well as trends is useful for scientific societies, researchers and funding agencies. In recent years researchers recognized the usefulness of keyword network analysis for visualizing and analyzing scientific research topics. Therefore, we applied keyword network analysis to present an overview of current epidemiologic research topics in Germany. Accepted submissions to the 9th annual congress of the German Society for Epidemiology (DGEpi) in 2014 were used as data source. Submitters had to choose one of 19 subject areas, and were ask to provide a title, structured abstract, names of authors along with their affiliations, and a list of freely selectable keywords. Keywords had been provided for 262 (82 %) submissions, 1030 keywords in total. Overall the most common keywords were: "migration" (18 times), "prevention" (15 times), followed by "children", "cohort study", "physical activity", and "secondary data analysis" (11 times each). Some keywords showed a certain concentration under one specific subject area, e.g. "migration" with 8 of 18 in social epidemiology or "breast cancer" with 4 of 7 in cancer epidemiology. While others like "physical activity" were equally distributed over multiple subject areas (cardiovascular & metabolic diseases, ageing, methods, paediatrics, prevention & health service research). This keyword network analysis demonstrated the high diversity of epidemiologic research topics with a large number of distinct keywords as presented at the annual conference of the DGEpi. PMID:26994764

  12. Review of epidemiological studies on the occupational risk of tuberculosis in low-incidence areas.

    PubMed

    Seidler, Andreas; Nienhaus, Albert; Diel, Roland

    2005-01-01

    This review summarizes the epidemiological evidence for occupationally acquired tuberculosis and considers the implications for the prevention of tuberculosis. The relevant epidemiological studies were identified on the basis of the Medline data bank, starting with the year 1966. The evaluation of occupational groups with an elevated tuberculosis risk is exclusively based on epidemiologic studies of good or acceptable quality, applying clearly defined criteria of methodological quality. In summary, the available epidemiological evidence suggests that the risk of tuberculosis is elevated in the following occupational groups: hospital employees in wards with tuberculosis patients; nurses in hospitals; nurses attending HIV-positive or drug-addicted patients; pathology and laboratory workers; respiratory therapists and physiotherapists; physicians in internal medicine, anaesthesia, surgery and psychiatry; non-medical hospital personnel in housekeeping and transport work; funeral home employees, and prison employees. However, the epidemiological evidence is limited for all these occupations, with the exception of the nurses, because of the lack of methodologically adequate studies that have got the statistical power to differentiate between specific work tasks. There is a need for large population-based studies with precise definition of exposure, which should include molecular epidemiologic methods in the investigation of occupational risk factors of tuberculosis. PMID:16088290

  13. The contribution of molecular epidemiology to the understanding and control of viral diseases of salmonid aquaculture

    PubMed Central

    2011-01-01

    analyse knowledge from a range of more traditional information sources. The development of methods to systematically record and share such epidemiologically important information thus represents a major challenge for fish health professionals in making the best future use of molecular data in supporting fish health policy and disease control. PMID:21466673

  14. Epidemiology and statistics at the Nordic School of Public Health: Teaching and research 1979-2014.

    PubMed

    Eriksson, Bo

    2015-08-01

    The Nordic School of Public Health (NHV) was jointly founded in 1953 by the Nordic countries. Until 1979, the school provided ad hoc courses on public health topics, using external teachers drawn mainly from the Nordic countries. At the time, the permanent staff of the school was small. In 1979, it began a Master's degree programme and a few academic positions were established and filled, to support these courses. The programme included four main areas: Epidemiology, Social Medicine, Environmental Health and Health Services Administration. Epidemiology was compulsory in all Master of Public Health (MPH) exams, but there were a handful of optional courses that could be substituted for the other subjects.This paper tells the story of Epidemiology at NHV from about 1980, up until closure of the school in 2014. The original MPH model ran until 1995. Nursing Science entered NHV from about 1985 and worked mainly with qualitative research that often focused on individual patients. The new methods attracted nurses, midwives, psychologists and other groups that previously had been less represented in NHV. Being quantitative and population oriented, Epidemiology lost its unique position as a mandatory subject for the MPH examination. In addition the 'New Public Health' proposed by the World Health Organisation (WHO) that advocated health promotion and the philosophy of salutogenesis became a challenge for the programme in epidemiology: pathogenesis no longer was of primary interest. From 1995, the MPH format changed repeatedly and a DrPH programme was begun. For the last 8 years of its existence, NHV offered a reasonably comprehensive, basic course in Epidemiology.Throughout the years, epidemiology training and research at NHV were very traditional. In being a relatively free institution in terms of academic choices, NHV should have contributed to the development and innovation of epidemiology in public health. For several reasons, this did not happen. PMID:26311794

  15. Adjustment Disorder: epidemiology, diagnosis and treatment

    PubMed Central

    2009-01-01

    Background Adjustment Disorder is a condition strongly tied to acute and chronic stress. Despite clinical suggestion of a large prevalence in the general population and the high frequency of its diagnosis in the clinical settings, there has been relatively little research reported and, consequently, very few hints about its treatments. Methods the authors gathered old and current information on the epidemiology, clinical features, comorbidity, treatment and outcome of adjustment disorder by a systematic review of essays published on PUBMED. Results After a first glance at its historical definition and its definition in the DSM and ICD systems, the problem of distinguishing AD from other mood and anxiety disorders, the difficulty in the definition of stress and the implied concept of 'vulnerability' are considered. Comorbidity of AD with other conditions, and outcome of AD are then analyzed. This review also highlights recent data about trends in the use of antidepressant drugs, evidence on their efficacy and the use of psychotherapies. Conclusion AD is a very common diagnosis in clinical practice, but we still lack data about its rightful clinical entity. This may be caused by a difficulty in facing, with a purely descriptive methods, a "pathogenic label", based on a stressful event, for which a subjective impact has to be considered. We lack efficacy surveys concerning treatment. The use of psychotropic drugs such as antidepressants, in AD with anxious or depressed mood is not properly supported and should be avoided, while the usefulness of psychotherapies is more solidly supported by clinical evidence. To better determine the correct course of therapy, randomized-controlled trials, even for the combined use of drugs and psychotherapies, are needed vitally, especially for the resistant forms of AD. PMID:19558652

  16. Epidemiological and molecular characteristics of meticillin-resistant Staphylococcus aureus in Turkey: A multicentre study.

    PubMed

    Dündar, Devrim; Willke, Ayse; Sayan, Murat; Koc, Meliha Meric; Akan, Ozay Arıkan; Sumerkan, Bulent; Saltoglu, Nese; Yaman, Akgun; Ayaz, Celal; Koksal, Iftihar

    2016-09-01

    The aim of this study was to investigate the epidemiological and molecular features of clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates in Turkey. MRSA isolates were collected from six regions of Turkey. The mecA and nuc genes were detected by PCR. Antimicrobial susceptibilities were determined by the disk diffusion method. Staphylococcal cassette chromosome mec (SCCmec) and staphylococcal protein A (spa) typing were performed by the sequencing method for 270 randomly selected MRSA isolates. The US Centers for Disease Control and Prevention (CDC) definition was used for epidemiological diagnosis of community-associated MRSA (CA-MRSA). Resistance rates of MRSA to ciprofloxacin, gentamicin, clindamycin, erythromycin, rifampicin, trimethoprim/sulfamethoxazole and tetracycline were 93.4%, 81.2%, 38.5%, 57.8%, 93.9%, 1.1% and 93.1%, respectively. The most frequent SCCmec type was SCCmec III (91.1%). SCCmec type IV was found in 5.2% of the isolates. The most frequent spa type was t030 (81.1%). Five isolates were CA-MRSA if only the epidemiological definition was used (5/725; 0.7%). Two isolates were defined as CA-MRSA both by epidemiological features and SCCmec typing (2/270; 0.7%). Of 14 SCCmec type IV isolates, 12 were not defined as CA-MRSA by epidemiological features. In conclusion, this is the most comprehensive multicentre study in Turkey investigating MRSA using both epidemiological and genotypic features. The CA-MRSA rate is low in Turkey. Combined use of epidemiological and genotypic methods is the most accurate approach for the diagnosis of CA-MRSA. PMID:27530838

  17. Epidemiology of human African trypanosomiasis

    PubMed Central

    Franco, Jose R; Simarro, Pere P; Diarra, Abdoulaye; Jannin, Jean G

    2014-01-01

    Human African trypanosomiasis (HAT), or sleeping sickness, is caused by Trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central Africa, and by Trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern Africa. The rhodesiense form is a zoonosis, with the occasional infection of humans, but in the gambiense form, the human being is regarded as the main reservoir that plays a key role in the transmission cycle of the disease. The gambiense form currently assumes that 98% of the cases are declared; the Democratic Republic of the Congo is the most affected country, with more than 75% of the gambiense cases declared. The epidemiology of the disease is mediated by the interaction of the parasite (trypanosome) with the vectors (tsetse flies), as well as with the human and animal hosts within a particular environment. Related to these interactions, the disease is confined in spatially limited areas called “foci”, which are located in Sub-Saharan Africa, mainly in remote rural areas. The risk of contracting HAT is, therefore, determined by the possibility of contact of a human being with an infected tsetse fly. Epidemics of HAT were described at the beginning of the 20th century; intensive activities have been set up to confront the disease, and it was under control in the 1960s, with fewer than 5,000 cases reported in the whole continent. The disease resurged at the end of the 1990s, but renewed efforts from endemic countries, cooperation agencies, and nongovernmental organizations led by the World Health Organization succeeded to raise awareness and resources, while reinforcing national programs, reversing the trend of the cases reported, and bringing the disease under control again. In this context, sustainable elimination of the gambiense HAT, defined as the interruption of the transmission of the disease, was considered as a feasible target for 2030. Since rhodesiense HAT is a zoonosis

  18. Epidemiological approaches to safety investigations.

    PubMed

    Wood, J L N; Adams, V J

    2006-10-01

    This paper considers the different approaches to post-authorisation safety monitoring of veterinary medicinal products that is essential to ensure confidence in their safety. Most safety testing is undertaken prior to granting of a marketing authorisation and is generally on a small scale. Field trials are usually much larger, but still involve relatively low numbers of animals compared to the number to which authorised products are administered. Safety testing is generally aimed at detecting common events; the numbers of animals used in the tests are too small for detection of all but the most common reactions. The efficiency of the tests depends on the frequency and severity of the adverse reaction and the ability to associate the adverse event with the product. The latter is affected by the period of time between administration and the event, as well as by its underlying frequency. Adverse reaction surveillance is critical in monitoring the safety of a marketed product. Most is entirely passive and so reporting rates are likely to underestimate true incidence. It is relatively efficient for rare, serious adverse effects and for those with a low underlying frequency in the population, but it is less useful when there is long period between administration and the event, or where the event has a relatively high underlying frequency. Greater emphasis should be placed on active surveillance after production registration. Detailed epidemiological investigations, including cohort, case control and cross-sectional designs, offer the only approaches that provide more information on the association between a product and events that have a high underlying frequency in the population or where there is a long period between administration and the adverse event. The relative merits of different approaches are discussed, with particular reference to our recently published study of the temporal association between canine vaccination and non-specific signs of ill health and

  19. Gallbladder cancer: epidemiology and outcome

    PubMed Central

    Hundal, Rajveer; Shaffer, Eldon A

    2014-01-01

    Gallbladder cancer, though generally considered rare, is the most common malignancy of the biliary tract, accounting for 80%–95% of biliary tract cancers. An early diagnosis is essential as this malignancy progresses silently with a late diagnosis, often proving fatal. Its carcinogenesis follows a progression through a metaplasia–dysplasia–carcinoma sequence. This comprehensive review focuses on and explores the risks, management, and outcomes for primary gallbladder carcinoma. Epidemiological studies have identified striking geographic and ethnic disparities – inordinately high occurrence in American Indians, elevated in Southeast Asia, yet quite low elsewhere in the Americas and the world. Age, female sex, congenital biliary tract anomalies, and a genetic predisposition represent important risk factors that are immutable. Environmental triggers play a critical role in eliciting cancer developing in the gallbladder, best exemplified by cholelithiasis and chronic inflammation from biliary tract and parasitic infections. Mortality rates closely follow incidence; those countries with the highest prevalence of gallstones experience the greatest mortality from gallbladder cancer. Vague symptoms often delay the diagnosis of gallbladder cancer, contributing to its overall progression and poor outcome. Surgery represents the only potential for cure. Some individuals are fortunate to be incidentally found to have gallbladder cancer at the time of cholecystectomy being performed for cholelithiasis. Such an early diagnosis is imperative as a late presentation connotes advanced staging, nodal involvement, and possible recurrence following attempted resection. Overall mean survival is a mere 6 months, while 5-year survival rate is only 5%. The dismal prognosis, in part, relates to the gallbladder lacking a serosal layer adjacent to the liver, enabling hepatic invasion and metastatic progression. Improved imaging modalities are helping to diagnose patients at an earlier

  20. Epidemiology of human African trypanosomiasis.

    PubMed

    Franco, Jose R; Simarro, Pere P; Diarra, Abdoulaye; Jannin, Jean G

    2014-01-01

    Human African trypanosomiasis (HAT), or sleeping sickness, is caused by Trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central Africa, and by Trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern Africa. The rhodesiense form is a zoonosis, with the occasional infection of humans, but in the gambiense form, the human being is regarded as the main reservoir that plays a key role in the transmission cycle of the disease. The gambiense form currently assumes that 98% of the cases are declared; the Democratic Republic of the Congo is the most affected country, with more than 75% of the gambiense cases declared. The epidemiology of the disease is mediated by the interaction of the parasite (trypanosome) with the vectors (tsetse flies), as well as with the human and animal hosts within a particular environment. Related to these interactions, the disease is confined in spatially limited areas called "foci", which are located in Sub-Saharan Africa, mainly in remote rural areas. The risk of contracting HAT is, therefore, determined by the possibility of contact of a human being with an infected tsetse fly. Epidemics of HAT were described at the beginning of the 20th century; intensive activities have been set up to confront the disease, and it was under control in the 1960s, with fewer than 5,000 cases reported in the whole continent. The disease resurged at the end of the 1990s, but renewed efforts from endemic countries, cooperation agencies, and nongovernmental organizations led by the World Health Organization succeeded to raise awareness and resources, while reinforcing national programs, reversing the trend of the cases reported, and bringing the disease under control again. In this context, sustainable elimination of the gambiense HAT, defined as the interruption of the transmission of the disease, was considered as a feasible target for 2030. Since rhodesiense HAT is a zoonosis, where

  1. Invited commentary: Agent-based models for causal inference—reweighting data and theory in epidemiology.

    PubMed

    Hernán, Miguel A

    2015-01-15

    The relative weights of empirical facts (data) and assumptions (theory) in causal inference vary across disciplines. Typically, disciplines that ask more complex questions tend to better tolerate a greater role of theory and modeling in causal inference. As epidemiologists move toward increasingly complex questions, Marshall and Galea (Am J Epidemiol. 2015;181(2):92-99) support a reweighting of data and theory in epidemiologic research via the use of agent-based modeling. The parametric g-formula can be viewed as an intermediate step between traditional epidemiologic methods and agent-based modeling and therefore is a method that can ease the transition toward epidemiologic methods that rely heavily on modeling. PMID:25480820

  2. The origins of American psychiatric epidemiology.

    PubMed Central

    Grob, G N

    1985-01-01

    Psychiatric epidemiology developed relatively late (as compared with epidemiology generally). Nineteenth century psychiatrists, although avid collectors of statistics, did not use such data in any systematic manner. The impetus for the creation of an epidemiology of mental illness came from the work of late nineteenth century social scientists concerned with understanding individual and social behavior and applying their findings to social problems. Initially they helped to create the modern census, which represented a radical faith that quantitative research, when merged with administrative rationality, could replace politics. During and after the 1920s, the demographic analysis of the institutionalized mentally ill population expanded sharply; by the late 1930s and 1940s psychiatric epidemiologists had begun to study the role of socioenvironmental variables and the incidence of mental illness in the community. Twentieth century psychiatric epidemiologists, however, faced a severe intellectual problem; their work rested on a descriptive rather than an etiological nosology. Consequently, the results of epidemiological studies in psychiatry often differed precisely because of variations in the design of studies and classification systems as well as the subjective observations of the investigators themselves. The ensuing disagreements among those involved in the epidemiologic study of mental illness were a natural consequence. Images p230-a p231-a p231-b p232-a p233-a p233-b p234-a PMID:3883818

  3. Evolution of environmental epidemiologic risk assessment

    SciTech Connect

    Anderson, H.A.

    1985-10-01

    Epidemiology has historically played an important role in the recognition of causes for diseases affecting the health of the public. Initially, epidemiology was concerned with infectious diseases. Later it became involved in metabolic and dietary deficiency diseases. Most recently, epidemiology has addressed the question of the public health effects of chemicals from production facilities, accidental spills, and chemical waste disposal sites. Concurrent improvements in the sensitivity of chemical analyses have enabled the identification of chemicals arising from waste disposal sites in the soil, air, drinking water, and food supplies of neighboring residential areas, albeit usually at very low concentrations. This knowledge has created great concerns among the affected populations and their public health agencies. The responsibility for interpreting the potential severity of the health effects of these environmental contaminants has fallen to those scientists experienced in epidemiology. This has led to a subdiscipline, reactive epidemiology, which describes investigations focused on specific events, usually under emotion-laden circumstances, rather than scientific merit. The reactive epidemiologist is rigidly constrained as to the size, timing, and location of the study. There is a strong requirement for public communication skills. New data bases are needed including ''sentinel'' diseases that are linked to exposure to chemicals, records of land use, and residency data for the population at risk.

  4. Candida and candidaemia. Susceptibility and epidemiology.

    PubMed

    Arendrup, Maiken Cavling

    2013-11-01

    In our part of the world invasive fungal infections include invasive yeast infections with Candida as the absolutely dominating pathogen and invasive mould infections with Aspergillus as the main organism. Yeasts are part of our normal micro-flora and invasive infections arise only when barrier leakage or impaired immune function occurs. On the contrary, moulds are ubiquitous in the nature and environment and their conidia inhaled at a daily basis. Hence invasive mould infections typically arise from the airways whereas invasive yeast infections typically enter the bloodstream causing fungaemia. Candida is by far the most common fungal blood stream pathogen; hence this genus has been the main focus of this thesis. As neither the Danish epidemiology nor the susceptibility of fungal pathogens was well described when we initiated our studies we initially wanted to be able to include animal models in our work. Therefore, a comprehensive animal study was undertaken comparing the virulence in a haematogenous mouse model of eight different Candida species including the five most common ones in human infections (C. albicans, C. glabrata, C. krusei, C. parapsilosis and C. tropicalis and in addition three rarer species C. guilliermondii, C. lusitaniae and C. kefyr). We found remarkable differences in the virulence among these species and were able to group the species according to decreasing virulence in three groups I: C. albicans and C. tropicalis, II: C. glabrata, C. lusitaniae and C. kefyr, and III: C. krusei, C. parapsilosis and C. guilliermondii. Apart from being necessary for our subsequent animal experiments exploring in vivo antifungal susceptibility, these findings also helped us understand at least part of the reason for the differences in the epidemiology and the pitfalls associated with the establishment of genus rather than species specific breakpoints. In example, it was less surprising that C. albicans has been the dominant pathogen and associated with a

  5. [Congenital ChagaśDisease: epidemiology, laboratorial diagnosis, prognosis and treatment].

    PubMed

    Reiche, E M; Inouye, M M; Bonametti, A M; Jankevicius, J V

    1996-01-01

    The authors review studies about epidemiology, clinical aspects and methods used in laboratorial diagnosis of congenital Chagas'disease, emphasizing the limitations in their specificity and sensibility, and suggest alternative methods to improve the accuracy and the quality of the laboratorial diagnosis of congenital Chagaśdisease, essential to an efficient treatment. PMID:14688943

  6. Hierarchical regression for epidemiologic analyses of multiple exposures.

    PubMed Central

    Greenland, S

    1994-01-01

    Many epidemiologic investigations are designed to study the effects of multiple exposures. Most of these studies are analyzed either by fitting a risk-regression model with all exposures forced in the model, or by using a preliminary-testing algorithm, such as stepwise regression, to produce a smaller model. Research indicates that hierarchical modeling methods can outperform these conventional approaches. These methods are reviewed and compared to two hierarchical methods, empirical-Bayes regression and a variant here called "semi-Bayes" regression, to full-model maximum likelihood and to model reduction by preliminary testing. The performance of the methods in a problem of predicting neonatal-mortality rates are compared. Based on the literature to date, it is suggested that hierarchical methods should become part of the standard approaches to multiple-exposure studies. PMID:7851328

  7. Molecular Epidemiology of Cases of Mycoplasma californicum Infection in Japan

    PubMed Central

    Suzuki, Kan-ichiro; Hanyu, Hideki; Itoh, Megumi; Higuchi, Hidetoshi; Kobayashi, Hideki

    2014-01-01

    Bovine mastitis due to Mycoplasma californicum is often accompanied by huge economic losses, and the disease spreads very quickly. An appropriate molecular epidemiological analysis is needed to prevent and control infectious disease, but molecular epidemiological analysis methods for M. californicum have not yet been reported. Here we developed a combination of multiple-locus variable-number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) methods, which are common genotyping methods for various bacteria, for M. californicum. The MLVA is based on four interspersed repeat units that were found in the M. californicum genome data. The MLVA using these repeat units showed sufficient discriminatory power for a molecular epidemiological analysis; i.e., a Hunter-Gaston diversity index (HGDI) of 0.949, against M. californicum strains in Japan and M. californicum strain ATCC 33461. The PFGE for M. californicum also showed sufficient discriminatory power, with an HGDI of 0.985. Strain ATCC 33461 showed MLVA profiles and pulsotypes that differed greatly from those of strains from Japan. These results indicate that MLVA and PFGE are good tools for identifying M. californicum transmission events more accurately. Our combined MLVA and PFGE analysis suggests the persistence of M. californicum infection among herds in a specific area for a long period of time, as well as the movement of cows and heifers accompanying the expansion of M. californicum infection. Failure to identify asymptomatic infected cows is suspected as one of the central causes of the present M. californicum infection scenario in Japan. PMID:25281385

  8. Genesis of Preeclampsia: An Epidemiological Approach

    PubMed Central

    Salvador-Moysén, Jaime; Martínez-López, Yolanda; Ramírez-Aranda, José M.; Aguilar-Durán, Marisela; Terrones-González, Alberto

    2012-01-01

    There are analyzed some of the main aspects related to the causality of preeclampsia, privileging two types of models: the clinic model and the epidemiologic model, first one represented by the hypothesis of the reduced placental perfusion and the second one considering the epidemiologic findings related to the high levels of psychosocial stress and its association with preeclampsia. It is reasoned out the relevance of raising the causality of the disease from an interdisciplinary perspective, integrating the valuable information generated from both types, clinical and epidemiologic, and finally a tentative explanatory model of preeclampsia is proposed, the subclinical and sociocultural aspects that predispose and trigger the disease are emphasized making aspects to stand out: the importance of reduced placental perfusion as an indicator of individual risk, and the high levels of physiological stress, as a result of the unfavorable conditions of the psychosocial surroundings (indicator of population risk) of the pregnant women. PMID:22462008

  9. Prevention, communication and equity in environmental epidemiology: ethical issues.

    PubMed

    Pagliarani, Giovanna; Botti, Caterina

    2011-01-01

    In environmental epidemiology research, decisions about when and how to intervene requires adequate ethical reflection. In fact, different kinds of issues may arise about: research methods and knowledge production; management of the results in terms of their overall assessments or for the implementation of preventive actions; reclamation intervention. In this contribution we propose to consider three topics we regard as crucial to this ethical debate: the reporting of conclusive research data; the correct application of the precautionary principle; and the environmental equity issues. PMID:21952151

  10. [Lead poisoning: towards a paleo-epidemiologic re-interpretation?].

    PubMed

    Bourdieu, Anne

    2014-01-01

    Lead is a major public health issue. Its use has been increasing since Neolithic times, climaxing in the Ancient Rome and the nineteenth century. Defining the frequency of plumbism before modern times proves to be a difficult matter because of its various and delayed symptoms, and of diagenetic processes affecting bones. After reviewing various methods of lead measurement in bone and tooth, we will expose ways to ascertain lead measurement interpretation in order to estimate the epidemiology of plumbism in ancient times. PMID:25230524

  11. Epidemiology of Uterine Fibroids: From Menarche to Menopause.

    PubMed

    Wise, Lauren A; Laughlin-Tommaso, Shannon K

    2016-03-01

    Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses. PMID:26744813

  12. Radiation dose reconstruction for epidemiologic uses. Final report

    SciTech Connect

    1995-05-12

    The report presents specific and practical recommendations for whether, when, and how dose-reconstruction studies should be conducted, with an emphasis on public participation. The book provides an overview of the basic requirements and technical aspects of dose reconstruction; presents lessons to be learned from dose reconstructions after Chernobyl, Three Mile Island, and elsewhere; explores the potential benefits and limitations of using current available biological markers; discusses how to establish the source term determining what was released; explores methods for identifying the environmental pathways by which radiation reaches the body; offers details on three major categories of dose assessment; and examines priority-setting and strengths and limitations of epidemiological studies.

  13. [Epidemiological imaginary in Campania Region].

    PubMed

    Greco, Pietro

    2012-01-01

    The interviews on the epidemiological imaginary, collected within the framework of the project Sebiorec,(1) clearly demonstrate that also in Campania, on the border between the provinces of Naples and Caserta - where the issue of waste and land devastation take forms that are unprecedented compared to any other part of Europe - there is a widespread, strong, sacrosanct demand of participation in environment and health management. The request of deliberative ecological democracy is pressing.(2) There is an urgent need to meet that plethora of rights emerging in the "knowledge society" and in the "risk society" that someone has called "rights for scientific citizenship."(3) This request of the population of Campania, net of local cultural specificity, it is quite similar to that of the people of any other region of Europe. The context in which this request of participation is expressed, however, is quite different. Not only and not just for that real or perceived social pre-modern and familist web that would replace a modern civil society in Campania and all across the Southern Italian regions, but also and especially for some structural causes that we here try to list. Campania is a unique region in Europe - in many ways different even from other regions of southern Italy - due to the conjunction of at least five factors, not independent from each other. 1) The presence of a widespread organized crime which, in many areas, metropolitan and non-metropolitan alike, and especially in the provinces of Naples and Caserta, is a sort of state against the State and has one of its main levers of power and a major source of its wealth in the illegal control of the territory, in its different dimensions (military, but also economic, social and even cultural). 2) A huge social and economic disintegration, exacerbated in the last twenty years by a process of deindustrialization (until the early nineties Naples was the fifth industrial city of Italy, today it is a desert where

  14. Extrahuman Epidemiology of Acinetobacter baumannii in Lebanon

    PubMed Central

    Rafei, Rayane; Hamze, Monzer; Pailhoriès, Hélène; Eveillard, Matthieu; Marsollier, Laurent; Joly-Guillou, Marie-Laure; Dabboussi, Fouad

    2015-01-01

    The presence of Acinetobacter baumannii outside hospitals is still a controversial issue. The objective of our study was to explore the extrahospital epidemiology of A. baumannii in Lebanon. From February 2012 to October 2013, a total of 73 water samples, 51 soil samples, 37 raw cow milk samples, 50 cow meat samples, 7 raw cheese samples, and 379 animal samples were analyzed by cultural methods for the presence of A. baumannii. Species identification was performed by rpoB gene sequencing. Antibiotic susceptibility was investigated, and the A. baumannii population was studied by two genotyping approaches: multilocus sequence typing (MLST) and blaOXA-51 sequence-based typing (SBT). A. baumannii was detected in 6.9% of water samples, 2.7% of milk samples, 8.0% of meat samples, 14.3% of cheese samples, and 7.7% of animal samples. All isolates showed a susceptible phenotype against most of the antibiotics tested and lacked carbapenemase-encoding genes, except one that harbored a blaOXA-143 gene. MLST analysis revealed the presence of 36 sequence types (STs), among which 24 were novel STs reported for the first time in this study. blaOXA-51 SBT showed the presence of 34 variants, among which 21 were novel and all were isolated from animal origins. Finally, 30 isolates had new partial rpoB sequences and were considered putative new Acinetobacter species. In conclusion, animals can be a potential reservoir for A. baumannii and the dissemination of new emerging carbapenemases. The roles of the novel animal clones identified in community-acquired infections should be investigated. PMID:25616788

  15. Epidemiology of Cholera in the Philippines

    PubMed Central

    Lopez, Anna Lena; Macasaet, Lino Y.; Ylade, Michelle; Tayag, Enrique A.; Ali, Mohammad

    2015-01-01

    Background Despite being a cholera-endemic country, data on cholera in the Philippines remain sparse. Knowing the areas where cholera is known to occur and the factors that lead to its occurrence will assist in planning preventive measures and disaster mitigation. Methods Using sentinel surveillance data, PubMed and ProMED searches covering information from 2008–2013 and event-based surveillance reports from 2010–2013, we assessed the epidemiology of cholera in the Philippines. Using spatial log regression, we assessed the role of water, sanitation and population density on the incidence of cholera. Results and Discussion We identified 12 articles from ProMED and none from PubMed that reported on cholera in the Philippines from 2008 to 2013. Data from ProMed and surveillance revealed 42,071 suspected and confirmed cholera cases reported from 2008 to 2013, among which only 5,006 were confirmed. 38 (47%) of 81 provinces and metropolitan regions reported at least one confirmed case of cholera and 32 (40%) reported at least one suspected case. The overall case fatality ratio in sentinel sites was 0.62%, but was 2% in outbreaks. All age groups were affected. Using both confirmed and suspected cholera cases, the average annual incidence in 2010–2013 was 9.1 per 100,000 population. Poor access to improved sanitation was consistently associated with higher cholera incidence. Paradoxically, access to improved water sources was associated with higher cholera incidence using both suspected and confirmed cholera data sources. This finding may have been due to the breakdown in the infrastructure and non-chlorination of water supplies, emphasizing the need to maintain public water systems. Conclusion Our findings confirm that cholera affects a large proportion of the provinces in the country. Identifying areas most at risk for cholera will support the development and implementation of policies to minimize the morbidity and mortality due to this disease. PMID:25569505

  16. Trends in the Epidemiology of Osteomyelitis

    PubMed Central

    Kremers, Hilal Maradit; Nwojo, Macaulay E.; Ransom, Jeanine E.; Wood-Wentz, Christina M.; Melton, L. Joseph; Huddleston, Paul M.

    2015-01-01

    Background: The epidemiology of osteomyelitis in the United States is largely unknown. The purpose of this study was to determine long-term secular trends in the incidence of osteomyelitis in a population-based setting. Methods: The study population comprised 760 incident cases of osteomyelitis first diagnosed between January 1, 1969, and December 31, 2009, among residents of Olmsted County, Minnesota. The complete medical records for each potential subject were reviewed to confirm the osteomyelitis diagnosis and to extract details on anatomical sites, infecting organisms, etiological risk factors, and outcomes. Results: The overall age and sex-adjusted annual incidence of osteomyelitis was 21.8 cases per 100,000 person-years. The annual incidence was higher for men than for women and increased with age (p < 0.001). Rates increased with the calendar year (p < 0.001) from 11.4 cases per 100,000 person-years in the period from 1969 to 1979 to 24.4 per 100,000 person-years in the period from 2000 to 2009. The incidence remained relatively stable among children and young adults but almost tripled among individuals older than sixty years; this was partly driven by a significant increase in diabetes-related osteomyelitis from 2.3 cases per 100,000 person-years in the period from 1969 to 1979 to 7.6 cases per 100,000 person-years in the period from 2000 to 2009 (p < 0.001). Forty-four percent of cases involved Staphylococcus aureus infections. Conclusions: The reasons for the increase in osteomyelitis between 1969 and 2009 are unclear but could comprise a variety of factors, including changes in diagnosing patterns or increases in the prevalence of risk factors (e.g., diabetes) in this population. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. PMID:25995495

  17. Synthetic Cannabinoids: Epidemiology, Pharmacodynamics, and Clinical Implications*

    PubMed Central

    Castaneto, Marisol S.; Gorelick, David A.; Desrosiers, Nathalie A.; Hartman, Rebecca L.; Pirard, Sandrine; Huestis, Marilyn A.

    2014-01-01

    Background Synthetic cannabinoids (SC) are a heterogeneous group of compounds developed to probe the endogenous cannabinoid system or as potential therapeutics. Clandestine laboratories subsequently utilized published data to develop SC variations marketed as abuseable “designer drugs.” In the early 2000’s, SC became popular as “legal highs” under brand names such as “Spice” and “K2,” in part due to their ability to escape detection by standard cannabinoid screening tests. The majority of SC detected in herbal products have greater binding affinity to the cannabinoid CB1 receptor than does Δ9-tetrahydrocannabinol (THC), the primary psychoactive compound in the cannabis plant, and greater affinity at the CB1 than the CB2 receptor. In-vitro and animal in-vivo studies show SC pharmacological effects 2-100 times more potent than THC, including analgesic, anti-seizure, weight-loss, anti-inflammatory, and anti-cancer growth effects. SC produce physiological and psychoactive effects similar to THC, but with greater intensity, resulting in medical and psychiatric emergencies. Human adverse effects include nausea and vomiting, shortness of breath or depressed breathing, hypertension, tachycardia, chest pain, muscle twitches, acute renal failure, anxiety, agitation, psychosis, suicidal ideation, and cognitive impairment. Long-term or residual effects are unknown. Due to these public health consequences, many SC are classified as controlled substances. However, frequent structural modification by clandestine laboratories results in a stream of novel SC that may not be legally controlled or detectable by routine laboratory tests. Methods We present here a comprehensive review, based on a systematic electronic literature search, of SC epidemiology and pharmacology and their clinical implications. PMID:25220897

  18. Spatial Epidemiology: Current Approaches and Future Challenges

    PubMed Central

    Elliott, Paul; Wartenberg, Daniel

    2004-01-01

    Spatial epidemiology is the description and analysis of geographic variations in disease with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors. We focus on small-area analyses, encompassing disease mapping, geographic correlation studies, disease clusters, and clustering. Advances in geographic information systems, statistical methodology, and availability of high-resolution, geographically referenced health and environmental quality data have created unprecedented new opportunities to investigate environmental and other factors in explaining local geographic variations in disease. They also present new challenges. Problems include the large random component that may predominate disease rates across small areas. Though this can be dealt with appropriately using Bayesian statistics to provide smooth estimates of disease risks, sensitivity to detect areas at high risk is limited when expected numbers of cases are small. Potential biases and confounding, particularly due to socioeconomic factors, and a detailed understanding of data quality are important. Data errors can result in large apparent disease excess in a locality. Disease cluster reports often arise nonsystematically because of media, physician, or public concern. One ready means of investigating such concerns is the replication of analyses in different areas based on routine data, as is done in the United Kingdom through the Small Area Health Statistics Unit (and increasingly in other European countries, e.g., through the European Health and Environment Information System collaboration). In the future, developments in exposure modeling and mapping, enhanced study designs, and new methods of surveillance of large health databases promise to improve our ability to understand the complex relationships of environment to health. PMID:15198920

  19. Epidemiology of asbestos-related diseases.

    PubMed Central

    Lemen, R A; Dement, J M; Wagoner, J K

    1980-01-01

    This paper is intended to give the reader an overview of the epidemiology of asbestos-related diseases and is restricted to primarily occupational exposure studies. However, some mention of nonoccupational exposures are made because of their direct relationship to a worker or to a secondary occupational source. Over 100 epidemiological studies are reviewed, dating back to the first case of asbestos-associated disease reported by Montague Murray in 1906. The studies are divided by specific fiber type and by specific disease outcomes and the interaction of asbestos and cigarette smoking is discussed in great detail. PMID:6993197

  20. Landmarks in the history of cancer epidemiology.

    PubMed

    Greenwald, Peter; Dunn, Barbara K

    2009-03-15

    The application of epidemiology to cancer prevention is relatively new, although observations of the potential causes of cancer have been reported for more than 2,000 years. Cancer was generally considered incurable until the late 19th century. Only with a refined understanding of the nature of cancer and strategies for cancer treatment could a systematic approach to cancer prevention emerge. The 20th century saw the elucidation of clues to cancer causation from observed associations with population exposures to tobacco, diet, environmental chemicals, and other exogenous factors. With repeated confirmation of such associations, researchers entertained for the first time the possibility that cancer, like many of the infectious diseases of the time, might be prevented. By the mid-20th century, with antibiotics successfully addressing the majority of infectious diseases and high blood pressure treatment beginning to affect the prevalence of heart disease in a favorable direction, the focus of much of epidemiology shifted to cancer. The early emphasis was on exploring, in greater depth, the environmental, dietary, hormonal, and other exogenous exposures for their potential associations with increased cancer risk. The first major breakthrough in identifying a modifiable cancer risk factor was the documentation of an association between tobacco smoking and lung cancer. During the past four decades, epidemiologic studies have generated population data identifying risk factors for cancers at almost every body site, with many cancers having multiple risk factors. The development of technologies to identify biological molecules has facilitated the incorporation of these molecular manifestations of biological variation into epidemiologic studies, as markers of exposure as well as putative surrogate markers of cancer outcome. This technological trend has, during the past two decades, culminated in emphasis on the identification of genetic variants and their products as

  1. The epidemiology of osteoarthritis: Manchester and beyond.

    PubMed

    Croft, P

    2005-12-01

    The paper describes the contribution made to the understanding of the epidemiology of osteoarthritis by the Arthritis Research Campaign Epidemiology Unit. Kellgren and Lawrence defined the condition radiographically and produced the widely used Atlas of Standard Radiographs of Arthritis. They documented the age- and sex-specific prevalence of osteoarthritis. Based on studies in occupational groups, they proposed that local biomechanical stress was linked to causation. Philip Wood focused on osteoarthritis as a syndrome of pain and disability. During the directorship of Alan Silman the emphasis has been on osteoarthritis as a public health problem. PMID:16306479

  2. Against anti-health epidemiology: corporate obstruction of public health via manipulation of epidemiology.

    PubMed

    Egilman, David; Howe, Samantha

    2007-01-01

    In response to several articles on corporate corruption of science that appeared earlier in this journal, a critic outlined an epistemological model based on an unsupported assertion that epidemiologic evidence is always required to support cause-effect relationships. This model, if adopted, would eliminate compensation to victims of toxic exposures and impede regulation of accepted hazards. Epidemiology is only one element in support of cause-effect determinations. The critic's proposal of an anti-health epidemiology was initially developed by corporations with the goal of providing defense in litigation, and is based not on science but on a corporate need to enhance profits at the expense of public health. PMID:17427356

  3. Impact of environmental inequity on health outcome: where is the epidemiological evidence?

    PubMed Central

    René, A. A.; Daniels, D. E.; Martin, S. A.

    2000-01-01

    A significant amount of evidence reveals a presence of environmental inequity. Although there is a disproportionate distribution of waste treatment, storage and disposal facilities, and chemical and manufacturing plants in minority and low-income communities in the United States, little research has been devoted to show any associations based on analytic epidemiological methods. To date, attempts to quantify health disparities have included demographic data, race, sex, income, other socioeconomic factors, and broad symptomatic survey instruments. To study this, we examined the latest epidemiological evidence documenting the existence of adverse health impacts resulting from environmental inequity. We observed that the overwhelming majority of studies were descriptive in nature and lacked comparison populations. As a result, we believe that further research based on analytic epidemiological methods would further contribute to the determination of the cause-effect relationship between environmental exposure and health outcome. PMID:10918762

  4. Discovering environmental cancer: Wilhelm Hueper, post-World War II epidemiology, and the vanishing clinician's eye.

    PubMed Central

    Sellers, C

    1997-01-01

    Today, our understanding of and approach to the exogenous causes of cancer are dominated by epidemiological practices that came into widespread use after World War II. This paper examines the forces, considerations, and controversies that shaped postwar risk factor epidemiology in the United States. It is argued that, for all of the new capabilities it brought, this risk factor epidemiology has left us with less of a clinical eye for unrecognized cancer hazards, especially from limited and localized exposures in the work-place. The focus here is on Wilhelm Hueper, author of the first textbook on occupational cancer (1942). Hueper became the foremost spokesman for earlier identification practices centering on occupational exposures. The new epidemiological methods and associated institutions that arose in the 1940s and 1950s bore an unsettled relation to earlier claims and methods that some, Hueper among them, interpreted as a challenge. Hueper's critique of the new epidemiology identified some of its limitations and potentially debilitating consequences that remain with us today. Images p1825-a p1827-a p1829-a PMID:9366640

  5. Parameter and uncertainty estimation for mechanistic, spatially explicit epidemiological models

    NASA Astrophysics Data System (ADS)

    Finger, Flavio; Schaefli, Bettina; Bertuzzo, Enrico; Mari, Lorenzo; Rinaldo, Andrea

    2014-05-01

    Epidemiological models can be a crucially important tool for decision-making during disease outbreaks. The range of possible applications spans from real-time forecasting and allocation of health-care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. Our spatially explicit, mechanistic models for cholera epidemics have been successfully applied to several epidemics including, the one that struck Haiti in late 2010 and is still ongoing. Calibration and parameter estimation of such models represents a major challenge because of properties unusual in traditional geoscientific domains such as hydrology. Firstly, the epidemiological data available might be subject to high uncertainties due to error-prone diagnosis as well as manual (and possibly incomplete) data collection. Secondly, long-term time-series of epidemiological data are often unavailable. Finally, the spatially explicit character of the models requires the comparison of several time-series of model outputs with their real-world counterparts, which calls for an appropriate weighting scheme. It follows that the usual assumption of a homoscedastic Gaussian error distribution, used in combination with classical calibration techniques based on Markov chain Monte Carlo algorithms, is likely to be violated, whereas the construction of an appropriate formal likelihood function seems close to impossible. Alternative calibration methods, which allow for accurate estimation of total model uncertainty, particularly regarding the envisaged use of the models for decision-making, are thus needed. Here we present the most recent developments regarding methods for parameter and uncertainty estimation to be used with our mechanistic, spatially explicit models for cholera epidemics, based on informal measures of goodness of fit.

  6. Examination of Different Exposure Metrics in an Epidemiological Study

    EPA Science Inventory

    Epidemiological studies of air pollution have traditionally relied upon measurements of ambient concentration from central-site monitoring stations as surrogates of population exposures. However, depending on the epidemiological study design, this approach may introduce exposure...

  7. An Epidemiologic Perspective. Does Running Cause Osteoarthritis?

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1989-01-01

    A review of literature on exercise and arthritis considers relevant epidemiologic and experimental studies of animals and humans, focusing on the relationship between running and osteoarthritis. No conclusive evidence exists that running causes osteoarthritis; research trends suggest that running may slow the functional aspects of musculoskeletal…

  8. Epidemiology of hepatitis C virus in Iran

    PubMed Central

    Taherkhani, Reza; Farshadpour, Fatemeh

    2015-01-01

    In Iran, the prevalence of hepatitis C virus (HCV) infection is relatively low according to the population-based epidemiological studies. However, the epidemiology of HCV is changing and the rate of HCV infection is increasing due to the growth in the number of injecting drug users in the society. In addition, a shift has occurred in the distribution pattern of HCV genotypes among HCV-infected patients in Iran. Genotype 1a is the most prevalent genotype in Iran, but in recent years, an increase in the frequency of 3a and a decrease in 1a and 1b have been reported. These variations in the epidemiology of HCV reflect differences in the routes of transmission, status of public health, lifestyles, and risk factors in different groups and geographic regions of Iran. Health policy makers should consider these differences to establish better strategies for control and prevention of HCV infection. Therefore, this review was conducted to present a clear view regarding the current epidemiology of HCV infection in Iran. PMID:26478671

  9. The Epidemiology of Human Immunodeficiency Virus Infection.

    ERIC Educational Resources Information Center

    Glasner, Peter D.; Kaslow, Richard A.

    1990-01-01

    Reviews epidemiology and natural history of human immunodeficiency virus-Type 1 (HIV-1) infection. Discusses early and late clinical manifestations, diagnosis of infection, incubation and latency periods, and survival time. Reviews data from published literature on distribution of HIV infection in adult United States population and factors that…

  10. EPIDEMIOLOGY IN RISK ASSESSMENT FOR REGULATORY POLICY

    EPA Science Inventory

    Epidemiology and risk assessment have several of the features needed to make the difficult decisions required in setting standards for levels of toxic agents in the workplace and environment. hey differ in their aims, orientation, and time scale. While the distribution of disease...

  11. On putative periodontal pathogens: an epidemiological perspective

    PubMed Central

    Lopez, Rodrigo; Hujoel, Philippe; Belibasakis, Georgios N

    2015-01-01

    The current understanding on the role of microbiology on periodontitis causation is reviewed. An appraisal of the literature reveals several issues that have limited the attempts to investigate candidate periodontal pathogens as causes of periodontitis and confirms that only limited epidemiological evidence is available. Several aspects of the contemporary understanding on causal inference are discussed with examples for periodontitis. PMID:25874553

  12. Epidemiology of Falls in Older Age

    ERIC Educational Resources Information Center

    Peel, Nancye May

    2011-01-01

    Worldwide, falls among older people are a public health concern because of their frequency and adverse consequences in terms of morbidity, mortality, and quality of life, as well as their impact on health system services and costs. This epidemiological review outlines the public health burden of falls and fall-related injuries and the impact of…

  13. Epidemiology of cancer of the penis.

    PubMed

    Persky, L

    1977-01-01

    World-wide incidences of penile cancer are reviewed and epidemiologic factors including ciecumcision, hygiene, phimosis, smegma, irritation, infection, veneral disease, viruses, environment, race, immune response, trauma, and age are discussed. The lowest rates appear in groups practicing infant circumcision and in areas where standards of sexual hygiene are high. PMID:325611

  14. Ethnicity/race, ethics, and epidemiology.

    PubMed Central

    Whaley, Arthur L.

    2003-01-01

    Ethnicity/race is a much-studied variable in epidemiology. There has been little consensus about what self-reported ethnicity/race represents, but it is a measure of some combination of genetic, socioeconomic, and cultural factors. The present article will attempt to: 1.) Elucidate the limitations of contemporary discourse on ethnicity/race that emphasizes the genetic and socioeconomic dimensions as competing explanatory frameworks; 2.) Demonstrate how considerable attention to the cultural dimension facilitates understanding of race differences in health-related outcomes; and 3.) Discuss interpretations of disparities in health status of African Americans versus European Americans from an ethical perspective. A major challenge to the discourse on ethnicity/race and health being limited to socioeconomic and genetic considerations is the lack of attention to the third alternative of a cultural perspective. The combined cultural ideologies of individualism and racism undermine the utility of epidemiologic research in health promotion and disease prevention campaigns aimed at reducing the racial gaps in health status. An ethical analysis supplements the cultural perspective. Ethics converge with culture on the notion of values influencing the study of ethnicity/race in epidemiology. A cultural approach to the use of ethnicity/race in epidemiologic research addresses methodological limitations, public health traditions, and ethical imperatives. PMID:12934873

  15. Epidemiological Modeling of Bovine Brucellosis in India

    PubMed Central

    Kang, Gloria J.; Gunaseelan, L.; Abbas, Kaja M.

    2015-01-01

    The study objective is to develop an epidemiological model of brucellosis transmission dynamics among cattle in India and to estimate the impact of different prevention and control strategies. The prevention and control strategies are test-and-slaughter, transmission rate reduction, and mass vaccination. We developed a mathematical model based on the susceptible-infectious-recovered epidemic model to simulate brucellosis transmission dynamics, calibrated to the endemically stable levels of bovine brucellosis prevalence of cattle in India. We analyzed the epidemiological benefit of different rates of reduced transmission and vaccination. Test-and-slaughter is an effective strategy for elimination and eradication of brucellosis, but socio-cultural constraints forbid culling of cattle in India. Reducing transmission rates lowered the endemically stable levels of brucellosis prevalence correspondingly. One-time vaccination lowered prevalence initially but increased with influx of new susceptible births. While this epidemiological model is a basic representation of brucellosis transmission dynamics in India and constrained by limitations in surveillance data, this study illustrates the comparative epidemiological impact of different bovine brucellosis prevention and control strategies. PMID:26280026

  16. IMPROVING EXPOSURE ASSESSMENT IN DBP EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    In 1997, an EPA expert panel was convened to evaluate epidemiologic studies of adverse reproductive or developmental outcomes that may be associated with drinking water DBPs. The panel recommended that further efforts be made in an existing cohort study, headed by Dr. Waller and ...

  17. Epidemiology and Pulmonary Physiology of Severe Asthma.

    PubMed

    O'Toole, Jacqueline; Mikulic, Lucas; Kaminsky, David A

    2016-08-01

    The epidemiology and physiology of severe asthma are inherently linked because of varying phenotypes and expressions of asthma throughout the population. To understand how to better treat severe asthma, we must use both population data and physiologic principles to individualize therapies among groups with similar expressions of this disease. PMID:27401616

  18. The birth of Emerging Themes in Epidemiology: a tale of Valerie, causality and epidemiology

    PubMed Central

    Tam, Clarence C

    2004-01-01

    Emerging Themes in Epidemiology (ETE) is a new, online, Open Access peer-reviewed journal. The Journal is unique in that it was conceived and is managed by research degree students in epidemiology and related public health fields. The Journal's management is overseen by its Editor-in-Chief and Associate Faculty Editors, all of whom are senior members of faculty. ETE aims to encourage debate and discussion on the theoretical, methodological and practical aspects of epidemiologic research and practice. In addition, ETE is dedicated to the promotion of Open Access publication and the training of research students in the scientific publishing process. This editorial, to coincide with the launch of ETE, sets out the Journal's philosophy and aims. Epidemiology is a rich and innovative science that has much to gain from broader discussion of the causal frameworks that underpin it. ETE aims to be a major forum for such discussion. PMID:15679908

  19. MOLECULAR EPIDEMIOLOGY: POTENTIAL IMPACTS ON THE ASSESSMENT OF PUBLIC HEALTH

    EPA Science Inventory

    Introduction

    The term "molecular epidemiology" has been used to cover a broad range of scientific activities, often without specific reference to epidemiology. In fact, as noted by Foxman and Riley [1],molecular epidemiology has often been described almost exclusively in...

  20. An epidemiologic approach to studying heterocyclic amines.

    PubMed

    Sinha, Rashmi

    2002-09-30

    Diets containing substantial amounts of red meat may increase the risk of colorectal, pancreatic, breast, prostate, and renal cancer. The association with red meat intake may be due to a combination of factors, such as content of fat, protein, and iron, and/or meat preparation (e.g. cooking or preserving methods). Laboratory results have shown that meats cooked at high temperatures contain heterocyclic amines (HCAs) known to be mutagenic and carcinogenic in animals. Many older epidemiologic studies of colon cancer using surrogates for HCA exposure from meat (for example, doneness level, surface browning, frying, intake of gravy) have produced suggestive but inconsistent results. These discrepancies may have resulted in part from having used dietary questionnaires that combined meat-cooking practices in ways that made the intake of HCAs difficult to estimate. Thus, over the last decade we have taken a multidisciplinary approach to investigating whether the association with red meat intake can be explained by meat-cooking practices that produce mutagens/carcinogens. To estimate intake, a database for HCAs have been developed and used in conjunction with a validated meat-cooking food frequency questionnaire (FFQ). To develop biological markers of internal exposure, a metabolic study was conducted where subjects consumed controlled amounts of meat cooked at low and high temperatures. The role of meat type, cooking methods, doneness levels, and meat-cooking mutagens were examined in case-control studies of colorectal adenomas, lung, and breast cancers using both questionnaire information and biomarkers. In a case-control study of colorectal adenomas, an increased risk was associated with a high intake of red meat. Most of this risk was due to intake of red meat cooked until well/very well done and/or by high-temperature cooking techniques such as grilling. Linking the FFQ information to HCA database, the impact several HCAs on risk was evaluated. An increased risk was

  1. The epidemiology of vertebral fractures. European Vertebral Osteoporosis Study Group.

    PubMed

    Cooper, C; O'Neill, T; Silman, A

    1993-01-01

    Vertebral fractures are recognised as a hallmark of osteoporosis, yet little is known of their epidemiology. This deficiency limits accurate characterisation of the public health importance of osteoporosis. Assessment of the impact of vertebral fractures has been hampered by the absence of formal criteria for identifying fractures on a thoracolumbar radiograph. Initial methods relying upon subjective radiological assessments have given way to morphometric measurements of vertebral heights, with deformities defined according to various algorithms. These methods have been used in a series of studies performed in Rochester, MN, to determine the incidence, outcome, and time trends of vertebral deformities. The results suggest a prevalence rate of vertebral deformity of 25.3 per 100 Rochester women aged 50 years and over (95% CI, 22.3-28.2), with an estimated incidence of 17.8 per 1,000 person-years. The incidence of clinically diagnosed vertebral fractures among women in the same population was 5.3 per 1,000 person-years, suggesting that around 30% of such deformities in women receive clinical attention. Morphometric measurement on the radiographs of women with clinically diagnosed fractures revealed that 80% had grade 2 ( > 4 SD) deformities. Comparable data on the occurrence and health impact of vertebral deformities throughout Europe are urgently required. The European Vertebral Osteoporosis Study (EVOS) is a multicentre epidemiological study that aims to address this issue. It is designed as a radiographic prevalence study in 34 European centres.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8110529

  2. [Scan statistic theory and its application in spatial epidemiology].

    PubMed

    Li, Xiu-yang; Chen, Kun

    2008-08-01

    To introduce the basic concept of scan statistic, its computation method and application in the area of spatial epidemiology. Retrospective space-time permutation statistics for evaluating the clustering of disease monitoring program is illustrated, using data on recent acute onset of cardiovascular disease in Hangzhou, China. Calculations were performed with SaTScan Version 7.0.3. With 999 Monte Carlo replications, the program took 5 seconds to run on a 100-MHz Pentium PC. The geographical surveillance program on acute onset clusters of cardiovascular disease, data which showed statistical significance, would include: a) from January 1, 1997 to February 28, 2007 in Qiantan township, Jiande county (P = 0.001); b) highly significant between January 1, 1997 and February 28, 1999 for Lushan street, Lingqiao township in Fuyang county (P = 0.003); c) between March 1, 2001 and February 29, 2004 for Dayuan town, Xinyi town, Shouxiang town in Fuyang (P = 0.004); d) between March 1, 2004 and Feb 28, 2006 for Chengzhan street, Ziyang street, Hubin street, Qinbo street, Xiaoying street, Wangjiang street, Chaoming street, Changqing street, Wulin street, Tianshui street, Wenhui street and Shiqiao street in Hangzhou (P = 0.005), respectively. The retrospective space-time permutation statistics seems useful as a screening tool for identifying the cluster of disease. Scan statistics are practical and effective method for deciding which cluster alarms would merit further investigation and which clusters are probably chance occurrences in the study of spatial epidemiology. PMID:19103124

  3. Using epidemiology and neurotoxicology to reduce risks to young workers.

    PubMed

    Rohlman, Diane S; Nuwayhid, Iman; Ismail, Ahmed; Saddik, Basema

    2012-08-01

    Children around the world are working in hazardous or unsafe conditions and they are at risk to injury through manual labor and susceptible to poisoning due to chemical exposures in the work place. Because of their behavior and the developmental changes occurring throughout childhood and adolescence children are more vulnerable to injury. Often children work because of economic necessity, coming from families living in extreme poverty, with poor housing conditions, unsafe water supplies, poor sanitation, and inadequate food supplies making them even more vulnerable to poor developmental outcomes. This presents a multifaceted problem that can be challenging to address. Although many studies have examined occupational risks among adults very few studies have examined the impact of these risks on children. This paper reflects a summary of the talks from the symposium "Using Epidemiology and Neurotoxicology to Reduce Risks to Young Workers" presented at the 13th International Neurotoxicology Association Meeting and the 11th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health in Xi'an China in June 2011. Epidemiological studies have demonstrated that children are exposed to various neurotoxicants, show increased symptoms and health problems and are working in hazardous conditions with minimal safety restrictions. Other studies have identified neurotoxicology effects in children from occupational exposures. Prevention methods have potential for reducing risks to young workers short of eliminating child labor and should be addressed to multiple stakeholders, parents, employers and children. PMID:22394482

  4. The Brazilian Football Association (CBF) model for epidemiological studies on professional soccer player injuries

    PubMed Central

    Arliani, Gustavo Gonçalves; Belangero, Paulo Santoro; Runco, Jose Luiz; Cohen, Moisés

    2011-01-01

    OBJECTIVE: This study aims to establish a national methodological model for epidemiological studies on professional soccer player injuries and to describe the numerous relevant studies previously published on this topic. INTRODUCTION: The risk of injury in professional soccer is high. However, previous studies of injury risk in Brazil and other countries have been characterized by large variations in study design and data collection methods as well as definitions of injury, standardized diagnostic criteria, and recovery times. METHODS: A system developed by the Union of European Football for epidemiological studies on professional soccer players is being used as a starting point to create a methodological model for the Brazilian Football Association. To describe the existing studies on professional soccer player injuries, we developed a search strategy to identify relevant epidemiological studies. We included the Latin American and Caribbean Center on Health Sciences and Medline databases in our study. RESULTS: We considered 60 studies from Medline and 16 studies from the Latin American and Caribbean Center on Health Sciences in the final analysis. Twelve studies were selected for final inclusion in this review: seven from the Latin American and Caribbean Center on Health Sciences and five from Medline. We identified a lack of uniformity in the study design, data collection methods, injury definitions, standardized diagnostic criteria, and the definition of recovery time. Based on the information contained within these articles, we developed a model for epidemiological studies for the Brazilian Football Association. CONCLUSIONS: There is no uniform model for epidemiological studies of professional soccer injuries. Here, we propose a novel model to be applied for epidemiological studies of professional soccer player injuries in Brazil and throughout the world. PMID:22012041

  5. Shared dosimetry error in epidemiological dose-response analyses

    DOE PAGESBeta

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore » up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.« less

  6. Shared dosimetry error in epidemiological dose-response analyses

    SciTech Connect

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.

  7. Epidemiological Surveillance of Lymphocryptovirus Infection in Wild Bonobos

    PubMed Central

    Yoshida, Tomoyuki; Takemoto, Hiroyuki; Sakamaki, Tetsuya; Tokuyama, Nahoko; Hart, John; Hart, Terese; Dupain, Jef; Cobden, Amy; Mulavwa, Mbangi; Kawamoto, Yoshi; Kaneko, Akihisa; Enomoto, Yuki; Sato, Eiji; Kooriyama, Takanori; Miyabe-Nishiwaki, Takako; Suzuki, Juri; Saito, Akatsuki; Okamoto, Munehiro; Tomonaga, Masaki; Matsuzawa, Tetsuro; Furuichi, Takeshi; Akari, Hirofumi

    2016-01-01

    Lymphocryptovirus (LCV) is one of the major gena in the herpesvirus family and is widely disseminated among primates. LCVs of human and rhesus macaques are shown to be causative agents of a number of malignant diseases including lymphoma and carcinoma. Bonobos (Pan paniscus) are highly endangered and the least studied species of the great apes. Considering the potential pathogenicity of the LCV that might threaten the fate of wild bonobos, population-based epidemiological information in terms of LCV prevalence in different location of Bonobo’s habitats will help propose improved conservation strategies for the bonobos. However, such data are not available yet because it is very difficult to collect blood samples in the wild and thus virtually impossible to conduct sero-epidemiological study on the wild ape. In order to overcome this issue, we focused on evaluating anti-LCV IgA in the feces of bonobos, which are available in a non-invasive manner. Preliminary study showed that anti-LCV IgA but not IgG was efficiently and reproducibly detected in the feces of captive chimpanzees. It is noteworthy that the fecal IgA-positive individuals were seropositive for both anti-LCV IgG and IgA and that the IgA antibodies in both sera and feces were also detectable by Western blotting assay. These results indicate that the detection of fecal anti-LCV IgA is likely a reliable and feasible for epidemiological surveillance of LCV prevalence in the great apes. We then applied this method and found that 31% of wild bonobos tested were positive for anti-LCV IgA antibody in the feces. Notably, the positivity rates varied extensively among their sampled populations. In conclusion, our results in this study demonstrate that LCV is highly disseminated among wild bonobos while the prevalence is remarkably diverse in their population-dependent manner. PMID:27570523

  8. Shared dosimetry error in epidemiological dose-response analyses.

    PubMed

    Stram, Daniel O; Preston, Dale L; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed. PMID:25799311

  9. Proceedings of The Second International Molecular Pathological Epidemiology (MPE) Meeting

    PubMed Central

    Ogino, Shuji; Campbell, Peter T.; Nishihara, Reiko; Phipps, Amanda I.; Beck, Andrew H.; Sherman, Mark E.; Chan, Andrew T.; Troester, Melissa A.; Bass, Adam J.; Fitzgerald, Kathryn C.; Irizarry, Rafael A.; Kelsey, Karl T.; Nan, Hongmei; Peters, Ulrike; Poole, Elizabeth M.; Qian, Zhi Rong; Tamimi, Rulla M.; Tchetgen Tchetgen, Eric J.; Tworoger, Shelley S.; Zhang, Xuehong; Giovannucci, Edward L.; van den Brandt, Piet A.; Rosner, Bernard A.; Wang, Molin; Chatterjee, Nilanjan; Begg, Colin B.

    2015-01-01

    Disease classification system increasingly incorporates information on pathogenic mechanisms to predict clinical outcomes and response to therapy and intervention. Technological advancements to interrogate omics (genomics, epigenomics, transcriptomics, proteomics, metabolomics, metagenomics, interactomics, etc.) provide widely-open opportunities in population-based research. Molecular pathological epidemiology (MPE) represents integrative science of molecular pathology and epidemiology. This unified paradigm requires multidisciplinary collaboration between pathology, epidemiology, biostatistics, bioinformatics, and computational biology. Integration of these fields enables better understanding of etiologic heterogeneity, disease continuum, causal inference, and the impact of environment, diet, lifestyle, host factors (including genetics and immunity), and their interactions on disease evolution. Hence, the Second International MPE Meeting was held in Boston in December 2014, with aims to: (1) develop conceptual and practical frameworks; (2) cultivate and expand opportunities; (3) address challenges; and (4) initiate the effort of specifying guidelines for MPE. The meeting mainly consisted of presentations of method developments and recent data in various malignant neoplasms and tumors (breast, prostate, ovarian and colorectal cancers, renal cell carcinoma, lymphoma, and leukemia), followed by open discussion sessions on challenges and future plans. In particular, we recognized need for efforts to further develop statistical methodologies. This meeting provided an unprecedented opportunity for interdisciplinary collaboration, consistent with the purposes of the BD2K (Big Data to Knowledge), GAME-ON (Genetic Associations and Mechanisms in Oncology), and Precision Medicine Initiatives of the U.S.A. National Institute of Health. The MPE Meeting Series can help advance transdisciplinary population science, and optimize training and education systems for 21st century

  10. Epidemiology of periodontal diseases in Indian population since last decade

    PubMed Central

    Chandra, Anuja; Yadav, Om Prakash; Narula, Sugandha; Dutta, Angel

    2016-01-01

    Objective: India suffers lot of disparities in terms of oral health care and 95% of the Indian population suffers from periodontal disease. The aim of this review is to estimate the risk factors responsible for periodontal diseases as well as prevalence for the same in the last decade to make an attempt to develop a strategy to improve formulation of an effective oral health care policy in India. Materials and Methods: Keywords such as “prevalence of periodontal diseases,” “epidemiology,” “periodontitis in India,” and “oral hygiene status in India” were searched for appropriate studies to obtain a bibliographic database. The references of selected articles and relevant reviews were searched for any missed publications that included studies conducted in India estimating periodontal diseases with adequate sample size. Clinical parameters, sample size, and findings for each study were tabulated from 2006 to 2015 (till September 15, 2015) in chronological order to observe the prevalence as well as epidemiology of periodontal disease in India. Results: The projection of periodontal disease is disturbing. In addition, the majority of studies done have used the Community Periodontal Index of Treatment Needs (CPITN) as its epidemiological tool that can grossly underestimate the presence of deep pockets. Conclusion: Current knowledge has shown that periodontitis does not present a linear progression and is not age-dependent. Moreover, its distribution and severity are strongly influenced by host susceptibility and risk factors. A structured all-inclusive survey of all districts of the states is a prerequisite for the constitution of an apt and cogent health care policy in our country. PMID:27114945

  11. Epidemiological Surveillance of Lymphocryptovirus Infection in Wild Bonobos.

    PubMed

    Yoshida, Tomoyuki; Takemoto, Hiroyuki; Sakamaki, Tetsuya; Tokuyama, Nahoko; Hart, John; Hart, Terese; Dupain, Jef; Cobden, Amy; Mulavwa, Mbangi; Kawamoto, Yoshi; Kaneko, Akihisa; Enomoto, Yuki; Sato, Eiji; Kooriyama, Takanori; Miyabe-Nishiwaki, Takako; Suzuki, Juri; Saito, Akatsuki; Okamoto, Munehiro; Tomonaga, Masaki; Matsuzawa, Tetsuro; Furuichi, Takeshi; Akari, Hirofumi

    2016-01-01

    Lymphocryptovirus (LCV) is one of the major gena in the herpesvirus family and is widely disseminated among primates. LCVs of human and rhesus macaques are shown to be causative agents of a number of malignant diseases including lymphoma and carcinoma. Bonobos (Pan paniscus) are highly endangered and the least studied species of the great apes. Considering the potential pathogenicity of the LCV that might threaten the fate of wild bonobos, population-based epidemiological information in terms of LCV prevalence in different location of Bonobo's habitats will help propose improved conservation strategies for the bonobos. However, such data are not available yet because it is very difficult to collect blood samples in the wild and thus virtually impossible to conduct sero-epidemiological study on the wild ape. In order to overcome this issue, we focused on evaluating anti-LCV IgA in the feces of bonobos, which are available in a non-invasive manner. Preliminary study showed that anti-LCV IgA but not IgG was efficiently and reproducibly detected in the feces of captive chimpanzees. It is noteworthy that the fecal IgA-positive individuals were seropositive for both anti-LCV IgG and IgA and that the IgA antibodies in both sera and feces were also detectable by Western blotting assay. These results indicate that the detection of fecal anti-LCV IgA is likely a reliable and feasible for epidemiological surveillance of LCV prevalence in the great apes. We then applied this method and found that 31% of wild bonobos tested were positive for anti-LCV IgA antibody in the feces. Notably, the positivity rates varied extensively among their sampled populations. In conclusion, our results in this study demonstrate that LCV is highly disseminated among wild bonobos while the prevalence is remarkably diverse in their population-dependent manner. PMID:27570523

  12. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    SciTech Connect

    Stram, Daniel; Preston, D. L.; Sokolnkov, Mikhail; Napier, Bruce A.; Kopecky, Kenneth; Boice, John; Beck, Harold L.; Till, John E.; Bouville, A.

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. Use of these methods for several studies, including the Mayak Worker Cohort and the U.S. Atomic Veterans Study, is discussed.

  13. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    PubMed Central

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed. PMID:25799311

  14. Leveraging epidemiologic and clinical collections for genomic studies of complex traits

    PubMed Central

    Crawford, Dana C.; Goodloe, Robert; Farber-Eger, Eric; Boston, Jonathan; Pendergrass, Sarah A.; Haines, Jonathan L.; Ritchie, Marylyn D.; Bush, William S.

    2015-01-01

    Background/Aims Present day limited resources demand DNA and phenotyping alternatives to the traditional prospective population-based epidemiologic collections. Methods To accelerate genomic discovery with an emphasis on diverse populations, we as part of the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study accessed all non-European American samples (n=15,863) available in BioVU, the Vanderbilt University biorepository linked to de-identified electronic medical records, for genomic studies as part of the larger Population Architecture using Genomics and Epidemiology (PAGE) I Study. Given previous studies have cautioned against the secondary use of clinically collected data compared with epidemiologically-collected data, we present here a characterization of EAGLE BioVU, including the billing and diagnostic (ICD-9) code distributions for adult and pediatric patients as well as comparisons made for select health metrics (body mass index, glucose, HbA1c, HDL-C, LDL-C, and triglycerides) with the population-based National Health and Nutrition Examination Surveys (NHANES) linked to DNA samples (NHANES III; n=7,159 and NHANES 1999–2002; n=7,839). Results Overall, the distributions of billing and diagnostic codes suggest this clinical sample is mixture of healthy and sick patients like that expected for a contemporary American population. Conclusion Little bias is observed among health metrics suggesting this clinical collection is suitable for genomic studies along with traditional epidemiologic cohorts. PMID:26201699

  15. Evaluation and use of epidemiological evidence for environmental health risk assessment: WHO guideline document.

    PubMed Central

    2000-01-01

    Environmental health risk assessment is increasingly being used in the development of environmental health policies, public health decision making, the establishment of environmental regulations, and research planning. The credibility of risk assessment depends, to a large extent, on the strength of the scientific evidence on which it is based. It is, therefore, imperative that the processes and methods used to evaluate the evidence and estimate health risks are clear, explicit, and based on valid epidemiological theory and practice. Epidemiological Evidence for Environmental Health Risk Assessment is a World Health Organization (WHO) guideline document. The primary target audiences of the guidelines are expert review groups that WHO (or other organizations) might convene in the future to evaluate epidemiological evidence on the health effects of environmental factors. These guidelines identify a set of processes and general approaches to assess available epidemiological information in a clear, consistent, and explicit manner. The guidelines should also help in the evaluation of epidemiological studies with respect to their ability to support risk assessment and, consequently, risk management. Conducting expert reviews according to such explicit guidelines would make health risk assessment and subsequent risk management and risk communication processes more readily understood and likely to be accepted by policymakers and the public. It would also make the conclusions reached by reviews more readily acceptable as a basis for future WHO guidelines and other recommendations, and would provide a more rational basis for setting priorities for future research. PMID:11049823

  16. Social network analysis and agent-based modeling in social epidemiology

    PubMed Central

    2012-01-01

    The past five years have seen a growth in the interest in systems approaches in epidemiologic research. These approaches may be particularly appropriate for social epidemiology. Social network analysis and agent-based models (ABMs) are two approaches that have been used in the epidemiologic literature. Social network analysis involves the characterization of social networks to yield inference about how network structures may influence risk exposures among those in the network. ABMs can promote population-level inference from explicitly programmed, micro-level rules in simulated populations over time and space. In this paper, we discuss the implementation of these models in social epidemiologic research, highlighting the strengths and weaknesses of each approach. Network analysis may be ideal for understanding social contagion, as well as the influences of social interaction on population health. However, network analysis requires network data, which may sacrifice generalizability, and causal inference from current network analytic methods is limited. ABMs are uniquely suited for the assessment of health determinants at multiple levels of influence that may couple with social interaction to produce population health. ABMs allow for the exploration of feedback and reciprocity between exposures and outcomes in the etiology of complex diseases. They may also provide the opportunity for counterfactual simulation. However, appropriate implementation of ABMs requires a balance between mechanistic rigor and model parsimony, and the precision of output from complex models is limited. Social network and agent-based approaches are promising in social epidemiology, but continued development of each approach is needed. PMID:22296660

  17. Children’s Exposure to Diagnostic Medical Radiation and Cancer Risk: Epidemiologic and Dosimetric Considerations

    PubMed Central

    Linet, Martha S.; Kim, Kwang pyo; Rajaraman, Preetha

    2009-01-01

    While the etiology of most childhood cancers is largely unknown, epidemiologic studies have consistently found an association between exposure to medical radiation during pregnancy and risk of childhood cancer in offspring. The relation between early life diagnostic radiation exposure and occurrence of pediatric cancer risks is less clear. This review summarizes current and historical estimated doses for common diagnostic radiologic procedures as well as the epidemiologic literature on the role of maternal prenatal, children’s postnatal and parental preconception diagnostic radiologic procedures on subsequent risk of childhood malignancies Risk estimates are presented according to factors such as the year of birth of the child, trimester and medical indication for the procedure, and the number of films taken. The paper also discusses limitations of the methods employed in epidemiologic studies to assess pediatric cancer risks, the effects on clinical practice of the results reported from the epidemiologic studies, and clinical and public health policy implications of the findings. Gaps in understanding and additional research needs are identified. Important research priorities include nationwide surveys to estimate fetal and childhood radiation doses from common diagnostic procedures, and epidemiologic studies to quantify pediatric and lifetime cancer risks from prenatal and early childhood exposures to diagnostic radiography, computed tomography, and fluoroscopically-guided procedures. PMID:19083224

  18. Evaluation and use of epidemiological evidence for environmental health risk assessment: WHO guideline document.

    PubMed

    2000-10-01

    Environmental health risk assessment is increasingly being used in the development of environmental health policies, public health decision making, the establishment of environmental regulations, and research planning. The credibility of risk assessment depends, to a large extent, on the strength of the scientific evidence on which it is based. It is, therefore, imperative that the processes and methods used to evaluate the evidence and estimate health risks are clear, explicit, and based on valid epidemiological theory and practice. Epidemiological Evidence for Environmental Health Risk Assessment is a World Health Organization (WHO) guideline document. The primary target audiences of the guidelines are expert review groups that WHO (or other organizations) might convene in the future to evaluate epidemiological evidence on the health effects of environmental factors. These guidelines identify a set of processes and general approaches to assess available epidemiological information in a clear, consistent, and explicit manner. The guidelines should also help in the evaluation of epidemiological studies with respect to their ability to support risk assessment and, consequently, risk management. Conducting expert reviews according to such explicit guidelines would make health risk assessment and subsequent risk management and risk communication processes more readily understood and likely to be accepted by policymakers and the public. It would also make the conclusions reached by reviews more readily acceptable as a basis for future WHO guidelines and other recommendations, and would provide a more rational basis for setting priorities for future research. PMID:11049823

  19. [Role of social epidemiology in the evaluation of psychosocial health determinants].

    PubMed

    Zagozdzon, Paweł; Zaborski, Leszek

    2002-01-01

    The relationship between social factors and health status is well known in medical sciences. However, the importance of methods implemented in the assessment of psychosocial health determinants has been addressed only recently. The combined perspective of epidemiology and sociology showed the need for the new science called social epidemiology. The aim of this work was to review the results of studies on effects of psychosocial factors on increased risk of disease and death. The association between socioeconomic position and health is well established. There is a direct relationship--the better the socioeconomic position the better health. The socioeconomic relative inequalities not only the absolute differences between socioeconomic groups influence health. The relationship between unemployment and increased mortality has been reported in western industrialized countries. Classical longitudinal studies of unemployed cohorts showed that unemployed men had higher mortality. Social epidemiology has also revealed the influence of social relationships on mortality. The theory of social support and social network buffer links social ties to less morbidity, mortality and better functioning. Randomized clinical trials positively tested the role of social support in preventive medicine, especially for secondary prevention of cardiovascular diseases. It is critical to adopt findings of social epidemiology by health care policy. The epidemiological investigations and experimental research have shown how psychosocial interventions and economic policies are central to improving population health. PMID:15002306

  20. Epidemiology's contribution to health service management and planning in developing countries: a missing link.

    PubMed Central

    Unger, J. P.; Dujardin, B.

    1992-01-01

    Two hypotheses are examined in the light of experience and the literature: (1) health service planning requires little epidemiological information, and (2) health services rarely get useful answers to relevant epidemiological questions. In the first hypothesis, the theoretical robustness of the concept of a minimum package of activities common to all facilities belonging to the same level of the system and the extent to which it is unaffected by variations in the frequencies of most diseases are examined. Semi-quantitative analyses and analysis of routine entries and participation suffice to adapt this package to the local context. Some of the methods which give a fundamental role to epidemiological information are criticized. With regard to the second hypothesis, the pertinent contributions epidemiology may make to health service organization are reviewed. These include identification of diseases that justify special activities (health maps and interepidemic surveillance), determination of the activities that should be added to the health centres, the political usefulness of rare impact assessments, and the relevant demographic elements. Finally an epidemiological agenda is proposed for specialized centres, districts, universities, and the central decision-making level of health ministries in developing countries. PMID:1394783