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

Integrating Informative Priors from Experimental Research with Bayesian Methods

PubMed Central

Hamra, Ghassan; Richardson, David; MacLehose, Richard; Wing, Steve

2013-01-01

Informative priors can be a useful tool for epidemiologists to handle problems of sparse data in regression modeling. It is sometimes the case that an investigator is studying a population exposed to two agents, X and Y, where Y is the agent of primary interest. Previous research may suggest that the exposures have different effects on the health outcome of interest, one being more harmful than the other. Such information may be derived from epidemiologic analyses; however, in the case where such evidence is unavailable, knowledge can be drawn from toxicologic studies or other experimental research. Unfortunately, using toxicologic findings to develop informative priors in epidemiologic analyses requires strong assumptions, with no established method for its utilization. We present a method to help bridge the gap between animal and cellular studies and epidemiologic research by specification of an order-constrained prior. We illustrate this approach using an example from radiation epidemiology. PMID:23222512

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

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

PubMed

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; Pacheco, M Andreina; Vallejo, Andres F; Herrera, Socrates; Felger, Ingrid

2015-09-01

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. © The American Society of Tropical Medicine and Hygiene.

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

PHYLOViZ: phylogenetic inference and data visualization for sequence based typing methods

PubMed Central

2012-01-01

Background With the decrease of DNA sequencing costs, sequence-based typing methods are rapidly becoming the gold standard for epidemiological surveillance. These methods provide reproducible and comparable results needed for a global scale bacterial population analysis, while retaining their usefulness for local epidemiological surveys. Online databases that collect the generated allelic profiles and associated epidemiological data are available but this wealth of data remains underused and are frequently poorly annotated since no user-friendly tool exists to analyze and explore it. Results PHYLOViZ is platform independent Java software that allows the integrated analysis of sequence-based typing methods, including SNP data generated from whole genome sequence approaches, and associated epidemiological data. goeBURST and its Minimum Spanning Tree expansion are used for visualizing the possible evolutionary relationships between isolates. The results can be displayed as an annotated graph overlaying the query results of any other epidemiological data available. Conclusions PHYLOViZ is a user-friendly software that allows the combined analysis of multiple data sources for microbial epidemiological and population studies. It is freely available at http://www.phyloviz.net. PMID:22568821

[Bibliometric analysis of scientific articles on epidemiological study of burns in China].

PubMed

Cheng, W F; Shen, Z A; Zhao, D X; Li, D W; Shang, Y R

2017-04-20

Objective: To analyze the current status of epidemiological study of burns in China, and to explore the related strategies. Methods: Retrospective or cross-sectional scientific articles in Chinese or English on epidemiological study of burns in China published from January 2005 to December 2015 were systemically retrieved from 4 databases. The databases include PubMed, Embase, China Biology Medicine disc, and Chinese Journals Full - text Database . From the results retrieved, data with regard to publication year, journal distribution, number of institutions participated in the study, affiliation of the first author and its location, and admission time span and age of patients in all the scientific articles were collected. Furthermore, the definition of age range and the grouping method of age of pediatric patients in English articles on epidemiological study of pediatric burns of China were recorded. Data were processed with descriptive statistical analysis. Results: A total of 256 scientific articles conforming to the study criteria were retrieved, among which 214 (83.59%) articles were in Chinese, and 42 (16.41%) articles were in English; 242 (94.53%) articles were retrospective studies, and 14 (5.47%) articles were cross-sectional studies. During the 11 years, the number of the relevant articles was fluctuant on the whole. The scientific articles were published in 130 journals, with 42 English articles in source journals for SCIENCE CITATION INDEX EXPANDED - JOURNAL LIST, accounting for 16.41%, and 116 Chinese articles in Source Journal for Chinese Scientific and Technical Papers, accounting for 45.31%. Totally 215 (83.98%) articles were single-center studies, and 29 (11.33%) articles were multicenter studies which were conducted by three or more centers. The number of affiliations of the first author of articles was 161 in total. The top 10 institutions regarding the article publishing number published 58 articles, accounting for 22.66%. Scientific articles on epidemiological study of burns were retrieved with location of affiliation of the first author in 31 provinces, autonomous regions, and municipalities directly under the Central Government in Mainland China, and also in Taiwan Province and Hong Kong Special Administrative Region, among which Shanghai ranked first with 24 (9.38%) articles published. The admission time span of patients in the articles ranged from 3 months to 47 years, with 120 (46.87%) articles from 3 months to 5 years, 79 (30.86%) articles from 6 to 10 years, and 57 (22.27%) articles more than 10 years, respectively. Regarding the age of patients in the study, 123 articles were on epidemiological study of pediatric burns, and 16 articles on epidemiological study of elderly burns, accounting for 48.05% and 6.25%, respectively. Further analysis of articles on epidemiological study of pediatric burns in English showed that there was no standard definition of age range or unified grouping method of age for pediatric burn patients. Conclusions: The epidemiological study of burns in China has been carried out nationwide, but the number of institutions conducted relevant study is not that much, and multicenter epidemiological studies remain scanty. The quality of the articles needs to be further improved. The epidemiological study of elderly burns is relatively deficient and calls for more attention. The epidemiological study of burns in China lacks regularity or continuity in time scope. There is an urgent need for the guideline on classification method for items of epidemiological study of burns in China so as to standardize the related research.

The perfect food and the filth disease: milk-borne typhoid and epidemiological practice in late Victorian Britain.

PubMed

Steere-Williams, Jacob

2010-10-01

This article explores the initial set of epidemiological investigations in Victorian Britain that linked typhoid fever to milk from dairy cattle. Because Victorian epidemiologists first recognized the milk-borne route in outbreaks of typhoid fever, these investigations served as a model for later studies of milk-borne scarlet fever, diphtheria, and perhaps tuberculosis. By focusing on epidemiological practices conducted by Medical Inspectors at the Medical Department of the Local Government Board and Medical Officers of Health, I show that Victorian epidemiology was committed to field-based, observational methods that defined the professional nature of the discipline and its theories and practices. Epidemiological investigations of milk-borne typhoid heated up several important public health debates in the second half of the nineteenth century, and demonstrate how Victorian epidemiology was not solely wedded to examining population studies using statistical methods, as historians have typically argued, but also relied on observational case-tracing in individuals, animals, and even environments.

METHODS STUDIES FOR THE NATIONAL CHILDREN'S STUDY: SEMIPERMEABLE MEMBRANE DEVICE (SPMD)

EPA Science Inventory

Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

METHODS STUDIES FOR THE NATIONAL CHILDREN'S STUDY: MOLECULARLY IMPRINTED POLYMERS

EPA Science Inventory

Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

Current Practices in Teaching Introductory Epidemiology: How We Got Here, Where to Go

PubMed Central

Keyes, Katherine M.; Galea, Sandro

2014-01-01

The number of students and disciplines requiring basic instruction in epidemiologic methods is growing. As a field, we now have a lexicon of epidemiologic terminology and particular methods that have developed and become canonical through the historical development of the field. Yet, many of our basic concepts remain elusive to some students, particularly those not pursuing a career in epidemiology. Further, disagreement and redundancy across basic terms limit their utility in teaching epidemiology. Many approaches to teaching epidemiology generally start with labeling key concepts and then move on to explain them. We submit that an approach grounded not in labels but in foundational concepts may offer a useful adjunct to introductory epidemiology education. We propose 7 foundational steps in conducting an epidemiologic study and provide examples of how these steps can be operationalized, using simple graphics that articulate how populations are defined, samples are selected, and individuals are followed to count cases. A reorganization of introductory epidemiology around core first principles may be an effective way forward for educating the next generation of public health scientists. PMID:25190677

Evolution of epidemiologic methods and concepts in selected textbooks of the 20th century.

PubMed

Zhang, Fang F; Michaels, Desireé C; Mathema, Barun; Kauchali, Shuaib; Chatterjee, Anjan; Ferris, David C; James, Tamarra M; Knight, Jennifer; Dounel, Matthew; Tawfik, Hebatullah O; Frohlich, Janet A; Kuang, Li; Hoskin, Elena K; Veldman, Frederick J; Baldi, Giulia; Mlisana, Koleka P; Mametja, Lerole D; Diaz, Angela; Khan, Nealia L; Sternfels, Pamela; Sevigny, Jeffery J; Shamam, Asher; Morabia, Alfredo

2004-01-01

Textbooks are an expression of the state of development of a discipline at a given moment in time. By reviewing eight epidemiology textbooks published over the course of a century, we have attempted to trace the evolution of five epidemiologic concepts and methods: study design (cohort studies and case-control studies), confounding, bias, interaction and causal inference. Overall, these eight textbooks can be grouped into three generations. Greenwood (1935) and Hill (first edition 1937; version reviewed 1961)'s textbooks belong to the first generation, "early epidemiology", which comprise early definitions of bias and confounding. The second generation, "classic epidemiology", represented by the textbooks of Morris (first edition 1957; version reviewed 1964), MacMahon & Pugh (first edition 1960; version reviewed 1970), Susser (1973), and Lilienfeld & Lilienfeld (first edition 1976; version reviewed 1980), clarifies the properties of cohort and case-control study designs and the theory of disease causation. Miettinen (1985) and Rothman (1986)'s textbooks belong to a third generation, "modern epidemiology", presenting an integrated perspective on study designs and their measures of outcome, as well as distinguishing and formalizing the concepts of confounding and interaction. Our review demonstrates that epidemiology, as a scientific discipline, is in constant evolution and transformation. It is likely that new methodological tools, able to assess the complexity of the causes of human health, will be proposed in future generations of textbooks.

An Epidemiology Primer: Bridging the Gap between Epidemiology and Psychology.

DTIC Science & Technology

1981-07-01

to the methods traditionally used in the field of psychology , The intent of this report is to describe some of these methods and explain the. in a...Hypotheses are formulated and tested in much the ame manmer and chi-square, regression, correLation, and analyses of variance are commonly employed in...etudies of morb~idity and mortality. It elsa we fu that epidemiologic studies employ rat"s and measures which, although sldm see in psychology , are

[Biological markers in epidemiology: concepts, applications, perspectives (part I)].

PubMed

Hoffmann, W; Latza, U; Ahrens, W; Greiser, K H; Kroke, A; Nieters, A; Schulze, M B; Steiner, M; Terschüren, C; Wjst, M

2002-02-01

The inclusion of biomarkers in epidemiological research provides new possibilities for exposure assessment and the study of early structural or functional changes and pre-clinical stages of diseases. At the same time issues of validity, reliability, and quality control as well as logistics require special attention. Usually epidemiological studies become more expensive with regard to time and cost. Interdisciplinary collaboration between epidemiology, basic research, and laboratory research is crucial. A prerequisite for this collaboration are agreements on definitions, methods and procedures. The definition of "biomarker" and a description of previous uses of biomarkers in epidemiological studies are presented in the first part of this paper. The second part addresses genetic markers and markers of individual sensitivity and susceptibility. We will end with a discussion about the possible future of biomarkers in epidemiology.

Use of instrumental variables in the analysis of generalized linear models in the presence of unmeasured confounding with applications to epidemiological research.

PubMed

Johnston, K M; Gustafson, P; Levy, A R; Grootendorst, P

2008-04-30

A major, often unstated, concern of researchers carrying out epidemiological studies of medical therapy is the potential impact on validity if estimates of treatment are biased due to unmeasured confounders. One technique for obtaining consistent estimates of treatment effects in the presence of unmeasured confounders is instrumental variables analysis (IVA). This technique has been well developed in the econometrics literature and is being increasingly used in epidemiological studies. However, the approach to IVA that is most commonly used in such studies is based on linear models, while many epidemiological applications make use of non-linear models, specifically generalized linear models (GLMs) such as logistic or Poisson regression. Here we present a simple method for applying IVA within the class of GLMs using the generalized method of moments approach. We explore some of the theoretical properties of the method and illustrate its use within both a simulation example and an epidemiological study where unmeasured confounding is suspected to be present. We estimate the effects of beta-blocker therapy on one-year all-cause mortality after an incident hospitalization for heart failure, in the absence of data describing disease severity, which is believed to be a confounder. 2008 John Wiley & Sons, Ltd

Foodborne outbreak simulation to teach field epidemiology: the Moroccan Field Epidemiology Training Program.

PubMed

Jroundi, Imane; Belarbi, Abdellatif

2016-11-01

Morocco in 2010 launched a new field epidemiology training program to enhance the skills of health professionals in charge of epidemiological surveillance and to investigate outbreaks; including foodborne diseases that represent a very substantial burden of disease. To apply an active learning method to teach outbreak investigation within a controled environment for field epidemiology trainees program at the Moroccan National school of public Health. A scenario describing digestive symptoms evoking a restaurant-associated foodborne outbreak that would affect the school staff was designed for the residents to investigate, to assess their organizational capacity and application of all stages of epidemiological investigation. Nine Residents applied study design, database management and statistical analysis to investigate the foodborne outbreak, to estimate attack rates, classify cases and controls, to identify the contaminated foods and pathogens and to issue preventive recommendations for the control and the prevention of further transmission. The overall resident's satisfaction of the learning method was 67%. A simulation of an outbreak investigation within an academic setting is an active learning method to be used in the curriculum for introducing the residents on field epidemiology program to the principles and practices of outbreak investigation before their implication in a real situation.

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…

A Seven-Year Retrospective View of a Course in Epidemiology and Biostatistics.

ERIC Educational Resources Information Center

Mulvihill, Michael N.; And Others

1980-01-01

Modifications of a course in epidemiology and biostatistics, designed to facilitate the presentation of difficult material in a clinically relevant manner, are described. Key strategies include seminar sessions devoted to methods of epidemiology and the critique of pairs of published studies, and the use of a course-specific syllabus. (JMD)

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...

Oligonucleotide (GTG)5 as an epidemiological tool in the study of nontuberculous mycobacteria.

PubMed Central

Cilliers, F J; Warren, R M; Hauman, J H; Wiid, I J; van Helden, P D

1997-01-01

Analysis of restriction fragment length polymorphisms in the genome of Mycobacterium tuberculosis (DNA fingerprinting) has proved to be a useful epidemiological tool in the study of tuberculosis within populations or communities. However, to date, no similar method has been developed to study the epidemiology of nontuberculous mycobacteria (NTM). In this communication, we report that a simple oligonucleotide repeat, (GTG)5, can be used to accurately genotype all species and strains of NTM tested. We suggest that this technology is an easily applied and accurate tool which can be used for the study of the epidemiology of NTM. PMID:9163479

Genetics and epidemiology, congenital anomalies and cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedman, J.M.

1997-03-01

Many of the basic statistical methods used in epidemiology - regression, analysis of variance, and estimation of relative risk, for example - originally were developed for the genetic analysis of biometric data. The familiarity that many geneticists have with this methodology has helped geneticists to understand and accept genetic epidemiology as a scientific discipline. It worth noting, however, that most of the work in genetic epidemiology during the past decade has been devoted to linkage and other family studies, rather than to population-based investigations of the type that characterize much of mainstream epidemiology. 30 refs., 2 tabs.

[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.

Systematic review of statistical approaches to quantify, or correct for, measurement error in a continuous exposure in nutritional epidemiology.

PubMed

Bennett, Derrick A; Landry, Denise; Little, Julian; Minelli, Cosetta

2017-09-19

Several statistical approaches have been proposed to assess and correct for exposure measurement error. We aimed to provide a critical overview of the most common approaches used in nutritional epidemiology. MEDLINE, EMBASE, BIOSIS and CINAHL were searched for reports published in English up to May 2016 in order to ascertain studies that described methods aimed to quantify and/or correct for measurement error for a continuous exposure in nutritional epidemiology using a calibration study. We identified 126 studies, 43 of which described statistical methods and 83 that applied any of these methods to a real dataset. The statistical approaches in the eligible studies were grouped into: a) approaches to quantify the relationship between different dietary assessment instruments and "true intake", which were mostly based on correlation analysis and the method of triads; b) approaches to adjust point and interval estimates of diet-disease associations for measurement error, mostly based on regression calibration analysis and its extensions. Two approaches (multiple imputation and moment reconstruction) were identified that can deal with differential measurement error. For regression calibration, the most common approach to correct for measurement error used in nutritional epidemiology, it is crucial to ensure that its assumptions and requirements are fully met. Analyses that investigate the impact of departures from the classical measurement error model on regression calibration estimates can be helpful to researchers in interpreting their findings. With regard to the possible use of alternative methods when regression calibration is not appropriate, the choice of method should depend on the measurement error model assumed, the availability of suitable calibration study data and the potential for bias due to violation of the classical measurement error model assumptions. On the basis of this review, we provide some practical advice for the use of methods to assess and adjust for measurement error in nutritional epidemiology.

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

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

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 3(rd) 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.

Empirical evaluation of meta-analytic approaches for nutrient and health outcome dose-response data

USDA-ARS?s Scientific Manuscript database

The objective of this study is to empirically compare alternative meta-analytic methods for combining dose-response data from epidemiological studies. We identified meta-analyses of epidemiological studies that analyzed the association between a single nutrient and a dichotomous outcome. For each to...

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.

The Emergence of Translational Epidemiology: From Scientific Discovery to Population Health Impact

PubMed Central

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

2010-01-01

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

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

Multiple sclerosis epidemiology in Latin America: An updated survey

PubMed Central

Rojas, Juan Ignacio

2017-01-01

Novel epidemiological data have appeared in recent years in Latin America (LATAM). The objective of this study was to perform an updated systematic review of the epidemiology of the disease reported in LATAM. Methods We conducted a systematic review of published epidemiological articles from January 1995 to December 2016. Results Incidence data were found in four studies and ranged from 0.3 to 3 annual cases per 100,000 person-years. Prevalence was reported in 13 studies and ranged from 0.83 to 38.2 cases per 100,000 inhabitants. Two studies showed an increase in prevalence and incidence in the last five years in specific regions. Conclusion The study provides updated information on epidemiological features of MS in the region. The frequency reported is lower compared with some European and North American countries; however, due to recent observations, studies including follow-up assessment of prevalence and incidence should be conducted in the region. PMID:28638628

Challenges and Opportunities for Occupational Epidemiology in the Twenty-first Century.

PubMed

Stayner, L T; Collins, J J; Guo, Y L; Heederik, D; Kogevinas, M; Steenland, K; Wesseling, C; Demers, P A

2017-09-01

There are many opportunities and challenges for conducting occupational epidemiologic studies today. In this paper, we summarize the discussion of a symposium held at the Epidemiology in Occupational Health (EPICOH) conference, Chicago 2014, on challenges for occupational epidemiology in the twenty-first century. The increasing number of publications and attendance at our conferences suggests that worldwide interest in occupational epidemiology has been growing. There are clearly abundant opportunities for new research in occupational epidemiology. Areas ripe for further work include developing improved methods for exposure assessment, statistical analysis, studying migrant workers and other vulnerable populations, the use of biomarkers, and new hazards. Several major challenges are also discussed such as the rapidly changing nature and location of work, lack of funding, and political/legal conflicts. As long as work exists there will be occupational diseases that demand our attention, and a need for epidemiologic studies designed to characterize these risks and to support the development of preventive strategies. Despite the challenges and given the important past contribution in this field, we are optimistic about the importance and continued vitality of the research field of occupational epidemiology.

Identifying public water facilities with low spatial variability of disinfection by-products for epidemiological investigations

PubMed Central

Hinckley, A; Bachand, A; Nuckols, J; Reif, J

2005-01-01

Background and Aims: Epidemiological studies of disinfection by-products (DBPs) and reproductive outcomes have been hampered by misclassification of exposure. In most epidemiological studies conducted to date, all persons living within the boundaries of a water distribution system have been assigned a common exposure value based on facility-wide averages of trihalomethane (THM) concentrations. Since THMs do not develop uniformly throughout a distribution system, assignment of facility-wide averages may be inappropriate. One approach to mitigate this potential for misclassification is to select communities for epidemiological investigations that are served by distribution systems with consistently low spatial variability of THMs. Methods and Results: A feasibility study was conducted to develop methods for community selection using the Information Collection Rule (ICR) database, assembled by the US Environmental Protection Agency. The ICR database contains quarterly DBP concentrations collected between 1997 and 1998 from the distribution systems of 198 public water facilities with minimum service populations of 100 000 persons. Facilities with low spatial variation of THMs were identified using two methods; 33 facilities were found with low spatial variability based on one or both methods. Because brominated THMs may be important predictors of risk for adverse reproductive outcomes, sites were categorised into three exposure profiles according to proportion of brominated THM species and average TTHM concentration. The correlation between THMs and haloacetic acids (HAAs) in these facilities was evaluated to see whether selection by total trihalomethanes (TTHMs) corresponds to low spatial variability for HAAs. TTHMs were only moderately correlated with HAAs (r = 0.623). Conclusions: Results provide a simple method for a priori selection of sites with low spatial variability from state or national public water facility datasets as a means to reduce exposure misclassification in epidemiological studies of DBPs. PMID:15961627

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

Current practices in teaching introductory epidemiology: how we got here, where to go.

PubMed

Keyes, Katherine M; Galea, Sandro

2014-10-01

The number of students and disciplines requiring basic instruction in epidemiologic methods is growing. As a field, we now have a lexicon of epidemiologic terminology and particular methods that have developed and become canonical through the historical development of the field. Yet, many of our basic concepts remain elusive to some students, particularly those not pursuing a career in epidemiology. Further, disagreement and redundancy across basic terms limit their utility in teaching epidemiology. Many approaches to teaching epidemiology generally start with labeling key concepts and then move on to explain them. We submit that an approach grounded not in labels but in foundational concepts may offer a useful adjunct to introductory epidemiology education. We propose 7 foundational steps in conducting an epidemiologic study and provide examples of how these steps can be operationalized, using simple graphics that articulate how populations are defined, samples are selected, and individuals are followed to count cases. A reorganization of introductory epidemiology around core first principles may be an effective way forward for educating the next generation of public health scientists. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Introduction to the use of regression models in epidemiology.

PubMed

Bender, Ralf

2009-01-01

Regression modeling is one of the most important statistical techniques used in analytical epidemiology. By means of regression models the effect of one or several explanatory variables (e.g., exposures, subject characteristics, risk factors) on a response variable such as mortality or cancer can be investigated. From multiple regression models, adjusted effect estimates can be obtained that take the effect of potential confounders into account. Regression methods can be applied in all epidemiologic study designs so that they represent a universal tool for data analysis in epidemiology. Different kinds of regression models have been developed in dependence on the measurement scale of the response variable and the study design. The most important methods are linear regression for continuous outcomes, logistic regression for binary outcomes, Cox regression for time-to-event data, and Poisson regression for frequencies and rates. This chapter provides a nontechnical introduction to these regression models with illustrating examples from cancer research.

Family and Psychosocial Risk Factors in a Longitudinal Epidemiological Study of Adolescents.

ERIC Educational Resources Information Center

Cuffe, Steven P.; McKeown, Robert E.; Addy, Cheryl L.; Garrison, Carol Z.

2005-01-01

Objective: To study the association of family and social risk factors with psychopathology in a longitudinal study of adolescents. Method: From 1986 to 1988, 3,419 seventh through ninth graders were screened with the Center for Epidemiologic Studies Depression Scale. The top decile scorers and a random sample of the remainder were interviewed…

Trends in citations to books on epidemiological and statistical methods in the biomedical literature.

PubMed

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

2013-01-01

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. 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. 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.

Putting Life into Computer-Based Training: The Creation of an Epidemiologic Case Study.

ERIC Educational Resources Information Center

Gathany, Nancy C.; Stehr-Green, Jeanette K.

1994-01-01

Describes the design of "Pharyngitis in Louisiana," a computer-based epidemiologic case study that was created to teach students how to conduct disease outbreak investigations. Topics discussed include realistic content portrayals; graphics; interactive teaching methods; interaction between the instructional designer and the medical…

Current approaches used in epidemiologic studies to examine short-term multipollutant air pollution exposures.

PubMed

Davalos, Angel D; Luben, Thomas J; Herring, Amy H; Sacks, Jason D

2017-02-01

Air pollution epidemiology traditionally focuses on the relationship between individual air pollutants and health outcomes (e.g., mortality). To account for potential copollutant confounding, individual pollutant associations are often estimated by adjusting or controlling for other pollutants in the mixture. Recently, the need to characterize the relationship between health outcomes and the larger multipollutant mixture has been emphasized in an attempt to better protect public health and inform more sustainable air quality management decisions. New and innovative statistical methods to examine multipollutant exposures were identified through a broad literature search, with a specific focus on those statistical approaches currently used in epidemiologic studies of short-term exposures to criteria air pollutants (i.e., particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone). Five broad classes of statistical approaches were identified for examining associations between short-term multipollutant exposures and health outcomes, specifically additive main effects, effect measure modification, unsupervised dimension reduction, supervised dimension reduction, and nonparametric methods. These approaches are characterized including advantages and limitations in different epidemiologic scenarios. By highlighting the characteristics of various studies in which multipollutant statistical methods have been used, this review provides epidemiologists and biostatisticians with a resource to aid in the selection of the most optimal statistical method to use when examining multipollutant exposures. Published by Elsevier Inc.

Comparison of measuring instruments for radiofrequency radiation from mobile telephones in epidemiological studies: implications for exposure assessment.

PubMed

Inyang, Imo; Benke, Geza; McKenzie, Ray; Abramson, Michael

2008-03-01

The debate on mobile telephone safety continues. Most epidemiological studies investigating health effects of radiofrequency (RF) radiation emitted by mobile phone handsets have been criticised for poor exposure assessment. Most of these studies relied on the historical reconstruction of participants' phone use by questionnaires. Such exposure assessment methods are prone to recall bias resulting in misclassification that may lead to conflicting conclusions. Although there have been some studies using software-modified phones (SMP) for exposure assessment in the literature, until now there is no published work on the use of hardware modified phones (HMPs) or RF dosimeters for studies of mobile phones and health outcomes. We reviewed existing literature on mobile phone epidemiology with particular attention to exposure assessment methods used. Owing to the inherent limitations of these assessment methods, we suggest that the use of HMPs may show promise for more accurate exposure assessment of RF radiation from mobile phones.

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. (c) 2006 Wiley-Liss, Inc.

Current methods for molecular epidemiology studies of implant infections.

PubMed

Campoccia, Davide; Montanaro, Lucio; Arciola, Carla Renata

2009-09-01

Over the last few decades, the number of surgical procedures involving prosthetic materials has greatly multiplied, along with the rising medical and economic impact of implant-associated infections. The need to appropriately counteract and deal with this phenomenon has led to growing efforts to elucidate the etiology, pathogenesis and epidemiology of these types of infections, characterized by opportunistic pathogens. Molecular epidemiology studies have progressively emerged as a leading multitask tool to identify and fingerprint bacterial strains, unveil the complex clonal nature of important pathogens, detect outbreak events, track the origin of the infections, assess the clinical significance of individual strain types, survey their distribution, recognize associations of strain types with specific virulence determinants and/or pathological conditions, assess the role played by the specific components of the virulon, and reveal the phylogeny and the mechanisms through which new strain types have emerged. Despite the many advances that have been made thanks to these flourishing new approaches to molecular epidemiology, a number of critical aspects remain challenging. In this paper, we briefly discuss the current limitations and possible developments of molecular epidemiology methods in the investigation and surveillance of implant infections.

Empirical Evaluation of Meta-Analytic Approaches for Nutrient and Health Outcome Dose-Response Data

ERIC Educational Resources Information Center

Yu, Winifred W.; Schmid, Christopher H.; Lichtenstein, Alice H.; Lau, Joseph; Trikalinos, Thomas A.

2013-01-01

The objective of this study is to empirically compare alternative meta-analytic methods for combining dose-response data from epidemiological studies. We identified meta-analyses of epidemiological studies that analyzed the association between a single nutrient and a dichotomous outcome. For each topic, we performed meta-analyses of odds ratios…

Late Language Emergence at 24 Months: An Epidemiological Study of Prevalence, Predictors, and Covariates

ERIC Educational Resources Information Center

Zubrick, Stephen R.; Taylor, Catherine L.; Rice, Mabel L.; Slegers, David W.

2007-01-01

Purpose: The primary objectives of this study were to determine the prevalence of late language emergence (LLE) and to investigate the predictive status of maternal, family, and child variables. Method: This is a prospective cohort study of 1,766 epidemiologically ascertained 24-month-old singleton children. The framework was an ecological model…

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

Measuring taste impairment in epidemiologic studies: the Beaver Dam Offspring Study.

PubMed

Cruickshanks, K J; Schubert, C R; Snyder, D J; Bartoshuk, L M; Huang, G H; Klein, B E K; Klein, R; Nieto, F J; Pankow, J S; Tweed, T S; Krantz, E M; Moy, G S

2009-07-01

Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 frommore » 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.« less

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

PubMed Central

Fabrikant, J. I.

1981-01-01

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. PMID:7043913

Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

PubMed

Laurent, Olivier; Gomolka, Maria; Haylock, Richard; Blanchardon, Eric; Giussani, Augusto; Atkinson, Will; Baatout, Sarah; Bingham, Derek; Cardis, Elisabeth; Hall, Janet; Tomasek, Ladislav; Ancelet, Sophie; Badie, Christophe; Bethel, Gary; Bertho, Jean-Marc; Bouet, Ségolène; Bull, Richard; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Davesne, Estelle; Ebrahimian, Teni; Engels, Hilde; Gillies, Michael; Grellier, James; Grison, Stephane; Gueguen, Yann; Hornhardt, Sabine; Ibanez, Chrystelle; Kabacik, Sylwia; Kotik, Lukas; Kreuzer, Michaela; Lebacq, Anne Laure; Marsh, James; Nosske, Dietmar; O'Hagan, Jackie; Pernot, Eileen; Puncher, Matthew; Rage, Estelle; Riddell, Tony; Roy, Laurence; Samson, Eric; Souidi, Maamar; Turner, Michelle C; Zhivin, Sergey; Laurier, Dominique

2016-06-01

The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation.

Telomere Length in Epidemiology: A Biomarker of Aging, Age-Related Disease, Both, or Neither?

PubMed Central

Sanders, Jason L.; Newman, Anne B.

2013-01-01

Telomeres are nucleoprotein caps flanking DNA. They are shortened by cell division and oxidative stress and are lengthened by the enzyme telomerase and DNA exchange during mitosis. Short telomeres induce cellular senescence. As an indicator of oxidative stress and senescence (2 processes thought to be fundamental to aging), telomere length is hypothesized to be a biomarker of aging. This hypothesis has been tested for more than a decade with epidemiologic study methods. In cross-sectional studies, researchers have investigated whether leukocyte telomere length (LTL) is associated with demographic, behavioral, and health variables. In prospective studies, baseline LTL has been used to predict mortality and occasionally other adverse health outcomes. Conflicting data have generated heated debate about the value of LTL as a biomarker of overall aging. In this review, we address the epidemiologic data on LTL and demonstrate that shorter LTL is associated with older age, male gender, Caucasian race, and possibly atherosclerosis; associations with other markers of health are equivocal. We discuss the reasons for discrepancy across studies, including a detailed review of methods for measuring telomere length as they apply to epidemiology. Finally, we conclude with questions about LTL as a biomarker of aging and how epidemiology can be used to answer these questions. PMID:23302541

Silicosis in Sandblasters: A Case Study Adapted for Use in U.S. High Schools. NIOSH Case Study in Occupational Epidemiology.

ERIC Educational Resources Information Center

Malit, Bonita D.

This document presents a case study of silicosis in sandblasters that has been adapted for instructional use in U.S. high schools. The primary objective of the case study is to teach students about epidemiology by studying an occupational hazard, disease associated with the hazard, and methods for preventing the disease. The introduction offers…

Cryptic relatedness in epidemiologic collections accessed for genetic association studies: experiences from the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study and the National Health and Nutrition Examination Surveys (NHANES).

PubMed

Malinowski, Jennifer; Goodloe, Robert; Brown-Gentry, Kristin; Crawford, Dana C

2015-01-01

Epidemiologic collections have been a major resource for genotype-phenotype studies of complex disease given their large sample size, racial/ethnic diversity, and breadth and depth of phenotypes, traits, and exposures. A major disadvantage of these collections is they often survey households and communities without collecting extensive pedigree data. Failure to account for substantial relatedness can lead to inflated estimates and spurious associations. To examine the extent of cryptic relatedness in an epidemiologic collection, we as the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study accessed the National Health and Nutrition Examination Surveys (NHANES) linked to DNA samples ("Genetic NHANES") from NHANES III and NHANES 1999-2002. NHANES are population-based cross-sectional surveys conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention. Genome-wide genetic data is not yet available in NHANES, and current data use agreements prohibit the generation of GWAS-level data in NHANES samples due issues in maintaining confidentiality among other ethical concerns. To date, only hundreds of single nucleotide polymorphisms (SNPs) genotyped in a variety of candidate genes are available for analysis in NHANES. We performed identity-by-descent (IBD) estimates in three self-identified subpopulations of Genetic NHANES (non-Hispanic white, non- Hispanic black, and Mexican American) using PLINK software to identify potential familial relationships from presumed unrelated subjects. We then compared the PLINKidentified relationships to those identified by an alternative method implemented in Kinship-based INference for Genome-wide association studies (KING). Overall, both methods identified familial relationships in NHANES III and NHANES 1999-2002 for all three subpopulations, but little concordance was observed between the two methods due in major part to the limited SNP data available in Genetic NHANES. Despite the lack of genome-wide data, our results suggest the presence of cryptic relatedness in this epidemiologic collection and highlight the limitations of restricted datasets such as NHANES in the context of modern day genetic epidemiology studies.

UNRECOGNIZED OR POTENTIAL RISK FACTORS FOR CHILDHOOD CANCER

EPA Science Inventory

Traditional epidemiological studies suggest that the contribution of environmental agents to childhood cancer may be minor. However, epidemiological methods can only seldom identify causal factors associated with a relative risk of less than a factor of one and a half to two. App...

Clostridium difficile infection: Early history, diagnosis and molecular strain typing methods.

PubMed

Rodriguez, C; Van Broeck, J; Taminiau, B; Delmée, M; Daube, G

2016-08-01

Recognised as the leading cause of nosocomial antibiotic-associated diarrhoea, the incidence of Clostridium difficile infection (CDI) remains high despite efforts to improve prevention and reduce the spread of the bacterium in healthcare settings. In the last decade, many studies have focused on the epidemiology and rapid diagnosis of CDI. In addition, different typing methods have been developed for epidemiological studies. This review explores the history of C. difficile and the current scope of the infection. The variety of available laboratory tests for CDI diagnosis and strain typing methods are also examined. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

The science of epidemiology and the methods needed for public health assessments: a review of epidemiology textbooks.

PubMed

Gouda, Hebe N; Powles, John W

2014-02-10

Epidemiology is often described as 'the science of public health'. Here we aim to assess the extent that epidemiological methods, as covered in contemporary standard textbooks, provide tools that can assess the relative magnitude of public health problems and can be used to help rank and assess public health priorities. Narrative literature review. Thirty textbooks were grouped into three categories; pure, extended or applied epidemiology, were reviewed with attention to the ways the discipline is characterised and the nature of the analytical methods described. Pure texts tend to present a strict hierarchy of methods with those metrics deemed to best serve aetiological inquiry at the top. Extended and applied texts employ broader definitions of epidemiology but in most cases, the metrics described are also those used in aetiological inquiry and may not be optimal for capturing the consequences and social importance of injuries and disease onsets. The primary scientific purpose of epidemiology, even amongst 'applied' textbooks, is aetiological inquiry. Authors do not readily extend to methods suitable for assessing public health problems and priorities.

Accounting for response misclassification and covariate measurement error improves power and reduces bias in epidemiologic studies.

PubMed

Cheng, Dunlei; Branscum, Adam J; Stamey, James D

2010-07-01

To quantify the impact of ignoring misclassification of a response variable and measurement error in a covariate on statistical power, and to develop software for sample size and power analysis that accounts for these flaws in epidemiologic data. A Monte Carlo simulation-based procedure is developed to illustrate the differences in design requirements and inferences between analytic methods that properly account for misclassification and measurement error to those that do not in regression models for cross-sectional and cohort data. We found that failure to account for these flaws in epidemiologic data can lead to a substantial reduction in statistical power, over 25% in some cases. The proposed method substantially reduced bias by up to a ten-fold margin compared to naive estimates obtained by ignoring misclassification and mismeasurement. We recommend as routine practice that researchers account for errors in measurement of both response and covariate data when determining sample size, performing power calculations, or analyzing data from epidemiological studies. 2010 Elsevier Inc. All rights reserved.

A survey of variable selection methods in two Chinese epidemiology journals

PubMed Central

2010-01-01

Background Although much has been written on developing better procedures for variable selection, there is little research on how it is practiced in actual studies. This review surveys the variable selection methods reported in two high-ranking Chinese epidemiology journals. Methods Articles published in 2004, 2006, and 2008 in the Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine were reviewed. Five categories of methods were identified whereby variables were selected using: A - bivariate analyses; B - multivariable analysis; e.g. stepwise or individual significance testing of model coefficients; C - first bivariate analyses, followed by multivariable analysis; D - bivariate analyses or multivariable analysis; and E - other criteria like prior knowledge or personal judgment. Results Among the 287 articles that reported using variable selection methods, 6%, 26%, 30%, 21%, and 17% were in categories A through E, respectively. One hundred sixty-three studies selected variables using bivariate analyses, 80% (130/163) via multiple significance testing at the 5% alpha-level. Of the 219 multivariable analyses, 97 (44%) used stepwise procedures, 89 (41%) tested individual regression coefficients, but 33 (15%) did not mention how variables were selected. Sixty percent (58/97) of the stepwise routines also did not specify the algorithm and/or significance levels. Conclusions The variable selection methods reported in the two journals were limited in variety, and details were often missing. Many studies still relied on problematic techniques like stepwise procedures and/or multiple testing of bivariate associations at the 0.05 alpha-level. These deficiencies should be rectified to safeguard the scientific validity of articles published in Chinese epidemiology journals. PMID:20920252

[Commentary on "group and organization: a dimension of collaboration of anthropology and epidemiology" by Song LM and Wang N].

PubMed

Liao, Su-Su; Zhang, Qing-Ning; Hou, Lei

2012-10-01

Epidemiology, as the study of occurrence and distribution of diseases or health events in specified populations and the application of the study to control health problems, is not just a method to study determinants of diseases at individual level through analysis of mass data based on individuals. To achieve the aims on the control of health problems in specified populations, Epidemiology should be public health-oriented to reduce incidence, prevalence and mortality, and should include study on determinants at the population level. Interdisplinarity and systems science will facilitate the breakthrough in improving health of the populations.

Epidemiological studies of cognitive impairment and dementia across Eastern and Middle European countries (epidemiology of dementia in Eastern and Middle European Countries).

PubMed

Kiejna, A; Frydecka, D; Adamowski, T; Bickel, H; Reynish, E; Prince, M; Caracciolo, B; Fratiglioni, L; Georges, J

2011-02-01

To determine the availability and the consistency of prevalence findings of epidemiological studies on cognitive impairment and dementia conducted in Eastern and Middle Europe. We adopted a stepwise multimethod study approach consisting of iterative literature searches for epidemiological articles published between 1990 and 2006 and subsequent data analyses of published material, reanalyses of existing accessible epidemiological data sets and expert inquiries in Eastern and Middle European countries. Systematic computer-assisted searches used the keywords: "dementia", "Alzheimer", "cognitive impairment", "incidence", "prevalence", "epidemiology" in combination with the name of the relevant countries or "Europe" in English and Polish language. We supplemented the literature search with a review of the references in the articles that were identified during the initial search. We were able to find few regional and country-specific epidemiological studies of various kinds (population-based, cohort, cross-sectional studies) and conducted on different restricted population groups of patients (from neurological units, out-patients units, residential homes). No studies were identified from most of the countries taken under consideration and the ones we found were characterized by an immense diversity with a considerable degree of clinical and methodological variations. The few studies that there are suggest prevalence rates of dementia in Eastern Europe similar to those in Western Europe. There is strong need for epidemiological studies in Eastern and Middle Europe, as well as for greater coordination and standardization of methods to improve the quality and comparability of epidemiological data to determine the prevalences' rates of dementia in all the EU countries. Copyright © 2010 John Wiley & Sons, Ltd.

Understanding outbreaks of waterborne infectious disease: quantitative microbial risk assessment vs. epidemiology

USDA-ARS?s Scientific Manuscript database

Drinking water contaminated with microbial pathogens can cause outbreaks of infectious disease, and these outbreaks are traditionally studied using epidemiologic methods. Quantitative microbial risk assessment (QMRA) can predict – and therefore help prevent – such outbreaks, but it has never been r...

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Quasi-Experimental Designs.

PubMed

Schweizer, Marin L; Braun, Barbara I; Milstone, Aaron M

2016-10-01

Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt, nonrandomized interventions. Quasi-experimental studies can be categorized into 3 major types: interrupted time-series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship, including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. Infect Control Hosp Epidemiol 2016;1-6.

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship – Quasi-Experimental Designs

PubMed Central

Schweizer, Marin L.; Braun, Barbara I.; Milstone, Aaron M.

2016-01-01

Quasi-experimental studies evaluate the association between an intervention and an outcome using experiments in which the intervention is not randomly assigned. Quasi-experimental studies are often used to evaluate rapid responses to outbreaks or other patient safety problems requiring prompt non-randomized interventions. Quasi-experimental studies can be categorized into three major types: interrupted time series designs, designs with control groups, and designs without control groups. This methods paper highlights key considerations for quasi-experimental studies in healthcare epidemiology and antimicrobial stewardship including study design and analytic approaches to avoid selection bias and other common pitfalls of quasi-experimental studies. PMID:27267457

Invited commentary: do-it-yourself modern epidemiology--at last!

PubMed

Morabia, Alfredo

2014-10-01

In this issue of the Journal, Keyes and Galea (Am J Epidemiol. 2014;180(7):661-668) propose "7 foundational steps" for introducing epidemiologic methods and concepts to beginners. Keyes and Galea's credo is that the methododological and conceptual components that comprise epidemiology, today scattered in textbook chapters, come together as an integrated and coherent methodological corpus in the process of designing studies. Thus, they expound, the process of designing studies should be the core of teaching epidemiology. Two aspects of their 7-steps-to-epidemiology, do-it-yourself user manual stand out as novel: 1) the approach, because of its emphasis on modern epidemiology's causal framework of a dynamic population in a steady state evolving across time, and 2) the ambition to teach modern epidemiology in introductory courses, instead of the popular mix of classical and modern epidemiology that is often used today to keep introductory courses simple. Both aspects are of potentially great significance for our discipline. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An argument for renewed focus on epidemiology for public health

PubMed Central

Rogawski, Elizabeth T.; Gray, Christine L.; Poole, Charles

2016-01-01

Purpose While epidemiology has an indispensable role in serving public health, the relative emphasis of applications of epidemiology often tend toward individual-level medicine over public health in terms of resources and impact. Methods We make distinctions between public health and medical applications of epidemiology to raise awareness among epidemiologists, many of whom came to the field with public health in mind. We discuss reasons for the overemphasis on medical epidemiology and suggest ways to counteract these incentives. Results Public health epidemiology informs interventions that are applied to populations or that confer benefits beyond the individual, while medical epidemiology informs interventions that improve the health of treated individuals. Available resources, new biomedical technologies, and existing epidemiologic methods favor medical applications of epidemiology. Focus on public health impact and methods suited to answer public health questions can create better balance and promote population-level improvements in public health. Conclusions By deliberately reflecting on research motivations and long-term goals, we hope the distinctions presented here will facilitate critical discussion and a greater consciousness of our potential impact on both individual and population-level health. Renewed intentions towards public health can help epidemiologists navigate potential projects and ultimately contribute to an epidemiology of consequence. PMID:27659585

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…

Nested PCR detection of malaria directly using blood filter paper samples from epidemiological surveys.

PubMed

Li, Peipei; Zhao, Zhenjun; Wang, Ying; Xing, Hua; Parker, Daniel M; Yang, Zhaoqing; Baum, Elizabeth; Li, Wenli; Sattabongkot, Jetsumon; Sirichaisinthop, Jeeraphat; Li, Shuying; Yan, Guiyun; Cui, Liwang; Fan, Qi

2014-05-08

Nested PCR is considered a sensitive and specific method for detecting malaria parasites and is especially useful in epidemiological surveys. However, the preparation of DNA templates for PCR is often time-consuming and costly. A simplified PCR method was developed to directly use a small blood filter paper square (2 × 2 mm) as the DNA template after treatment with saponin. This filter paper-based nested PCR method (FP-PCR) was compared to microscopy and standard nested PCR with DNA extracted by using a Qiagen DNA mini kit from filter paper blood spots of 204 febrile cases. The FP-PCR technique was further applied to evaluate malaria infections in 1,708 participants from cross-sectional epidemiological surveys conducted in Myanmar and Thailand. The FP-PCR method had a detection limit of ~0.2 parasites/μL blood, estimated using cultured Plasmodium falciparum parasites. With 204 field samples, the sensitivity of the FP-PCR method was comparable to that of the standard nested PCR method, which was significantly higher than that of microscopy. Application of the FP-PCR method in large cross-sectional studies conducted in Myanmar and Thailand detected 1.9% (12/638) and 6.2% (66/1,070) asymptomatic Plasmodium infections, respectively, as compared to the detection rates of 1.3% (8/638) and 0.04% (4/1,070) by microscopy. This FP-PCR method was much more sensitive than microscopy in detecting Plasmodium infections. It drastically increased the detection sensitivity of asymptomatic infections in cross-sectional surveys conducted in Thailand and Myanmar, suggesting that this FP-PCR method has a potential for future applications in malaria epidemiology studies.

[Health risk assessment of traffic-related air pollution near busy roads].

PubMed

Host, S; Chatignoux, E; Leal, C; Grémy, I

2012-08-01

Although ambient urban air pollution has well-established health effects, epidemiology faces many difficulties in estimating the risks due to exposure to traffic pollutants near busy roads. This review aims to summarize how exposure to traffic-related air pollution near busy roads is assessed in epidemiological studies and main findings regarding health effects. After presenting the specificity of emissions due to traffic road, this review identifies the key methods and main results found in epidemiologic studies seeking to measure the influence of exposure to nearby traffic on health published over the past decade. The characterization and measurement of population exposure to traffic pollution faces many difficulties. Thus, epidemiological studies have used two broad categories of surrogates to assess exposure: direct measures of traffic itself such as distance of the residence to the nearest road and traffic volume and modeled concentrations of pollutant surrogates. Studies that implemented these methods showed that people living near heavy traffic road or exposed to near-road air pollution tend to report more health outcomes. Traffic-related air pollution near busy roads is the subject of increasing attention, and tends to be better characterized. However, its health impacts remain difficult to grasp, especially because of the vast diversity of approaches used in epidemiological studies. Greater consistency in the protocols would be desirable to provide better understanding of the health issue of traffic in urban areas and thus to better implement policies to protect those most at risk. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Defining Chronic Cough: A Systematic Review of the Epidemiological Literature

PubMed Central

Song, Woo-Jung; Chang, Yoon-Seok; Faruqi, Shoaib; Kang, Min-Koo; Kim, Ju-Young; Kang, Min-Gyu; Kim, Sujeong; Jo, Eun-Jung; Lee, Seung-Eun; Kim, Min-Hye; Plevkova, Jana; Park, Heung-Woo

2016-01-01

Purpose Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. Methods A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. Results A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I2=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity. Conclusions This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required. PMID:26739408

[Hierarchical regionalization for spatial epidemiology: a case study of thyroid cancer incidence in Yiwu, Zhejiang].

PubMed

Teng, Shizhu; Jia, Qiaojuan; Huang, Yijian; Chen, Liangcao; Fei, Xufeng; Wu, Jiaping

2015-10-01

Sporadic cases occurring in mall geographic unit could lead to extreme value of incidence due to the small population bases, which would influence the analysis of actual incidence. This study introduced a method of hierarchy clustering and partitioning regionalization, which integrates areas with small population into larger areas with enough population by using Geographic Information System (GIS) based on the principles of spatial continuity and geographical similarity (homogeneity test). This method was applied in spatial epidemiology by using a data set of thyroid cancer incidence in Yiwu, Zhejiang province, between 2010 and 2013. Thyroid cancer incidence data were more reliable and stable in the new regionalized areas. Hotspot analysis (Getis-Ord) on the incidence in new areas indicated that there was obvious case clustering in the central area of Yiwu. This method can effectively solve the problem of small population base in small geographic units in spatial epidemiological analysis of thyroid cancer incidence and can be used for other diseases and in other areas.

[Which definition and taxonomy of incident to use for a French reporting system in primary care settings?].

PubMed

Keriel-Gascou, M; Brami, J; Chanelière, M; Haeringer-Cholet, A; Larrieu, C; Villebrun, F; Robert, T; Michel, P

2014-02-01

There is no widely accepted definition of incident for primary care doctors in France and no taxonomic classification system for epidemiological use. In preparation for a future epidemiological study on primary care incidents in France (the ESPRIT study), this work was designed to identify the definitions and taxonomic classifications used internationally along with the usual methods and results in terms of frequency in the literature. The goal was to determine a French definition and taxonomy. Systematic review of the literature and consensus methods. An exhaustive search of epidemiological surveys was performed. A structured grid was used. After having identified the definitions used in the literature, a definition was chosen using the focus groups method. Taxonomies identified in the literature were classified by relationship, architecture, code number, and number of studies published. Subsequently, a consensus among experts, who independently tested these taxonomies on six incidents, was reached for choosing the most appropriate for epidemiological data collection (little information on a large number of cases). Twenty-four papers reporting 17 studies were selected among 139 articles. Five definitions and eight taxonomies were found. The chosen definition of incident was based on the WHO definition "A patient safety incident is an event or circumstance that could have resulted, or did result, in harm to a patient, and whose wish it is not repeated again". The test of incidents resulted in the choice of the TAPS version of the International Taxonomy of Medical Error in Primary Care for a reproducible and internationally recognized codification and the tempos method for its current use in French general practice. The definitions, taxonomies, data collection characteristics and frequency of incidents results in the international literature on incidents in primary care are key components for the preparation of an epidemiological survey on incidents in primary care. Copyright © 2014. Published by Elsevier Masson SAS.

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 Construction. The study will contribute to defining the role that realism and mixed methods can play in explaining the social determinants and developmental origins of health and disease.

Epidemiological reflections of the contribution of anthropology to public health policy and practice.

PubMed

Porter, John D H

2006-01-01

Academic disciplines like anthropology and epidemiology provide a niche for researchers to speak the same language, and to interrogate the assumptions that they use to investigate problems. How anthropological and epidemiological methods communicate and relate to each other affects the way public health policy is created but the philosophical underpinnings of each discipline makes this difficult. Anthropology is reflective, subjective and investigates complexity and the individual; epidemiology, in contrast, is objective and studies populations. Within epidemiological methods there is the utilitarian concept of potentially sacrificing the interests of the individual for the benefits of maximizing population welfare, whereas in anthropology the individual is always included. Other strengths of anthropology in the creation of public health policy include: its attention to complexity, questioning the familiar; helping with language and translation; reconfiguring boundaries to create novel frameworks; and being reflective. Public health requires research that is multi-, inter- and trans-disciplinary. To do this, there is a need for each discipline to respect the 'dignity of difference' between disciplines in order to help create appropriate and effective public health policy.

Molecular testing for clinical diagnosis and epidemiological investigations of intestinal parasitic infections.

PubMed

Verweij, Jaco J; Stensvold, C Rune

2014-04-01

Over the past few decades, nucleic acid-based methods have been developed for the diagnosis of intestinal parasitic infections. Advantages of nucleic acid-based methods are numerous; typically, these include increased sensitivity and specificity and simpler standardization of diagnostic procedures. DNA samples can also be stored and used for genetic characterization and molecular typing, providing a valuable tool for surveys and surveillance studies. A variety of technologies have been applied, and some specific and general pitfalls and limitations have been identified. This review provides an overview of the multitude of methods that have been reported for the detection of intestinal parasites and offers some guidance in applying these methods in the clinical laboratory and in epidemiological studies.

Molecular Testing for Clinical Diagnosis and Epidemiological Investigations of Intestinal Parasitic Infections

PubMed Central

Stensvold, C. Rune

2014-01-01

SUMMARY Over the past few decades, nucleic acid-based methods have been developed for the diagnosis of intestinal parasitic infections. Advantages of nucleic acid-based methods are numerous; typically, these include increased sensitivity and specificity and simpler standardization of diagnostic procedures. DNA samples can also be stored and used for genetic characterization and molecular typing, providing a valuable tool for surveys and surveillance studies. A variety of technologies have been applied, and some specific and general pitfalls and limitations have been identified. This review provides an overview of the multitude of methods that have been reported for the detection of intestinal parasites and offers some guidance in applying these methods in the clinical laboratory and in epidemiological studies. PMID:24696439

Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria

PubMed Central

Minias, Alina; van Ingen, Jakko; Rastogi, Nalin; Brzostek, Anna; Żaczek, Anna; Dziadek, Jarosław

2016-01-01

SUMMARY Molecular typing has revolutionized epidemiological studies of infectious diseases, including those of a mycobacterial etiology. With the advent of fingerprinting techniques, many traditional concepts regarding transmission, infectivity, or pathogenicity of mycobacterial bacilli have been revisited, and their conventional interpretations have been challenged. Since the mid-1990s, when the first typing methods were introduced, a plethora of other modalities have been proposed. So-called molecular epidemiology has become an essential subdiscipline of modern mycobacteriology. It serves as a resource for understanding the key issues in the epidemiology of tuberculosis and other mycobacterial diseases. Among these issues are disclosing sources of infection, quantifying recent transmission, identifying transmission links, discerning reinfection from relapse, tracking the geographic distribution and clonal expansion of specific strains, and exploring the genetic mechanisms underlying specific phenotypic traits, including virulence, organ tropism, transmissibility, or drug resistance. Since genotyping continues to unravel the biology of mycobacteria, it offers enormous promise in the fight against and prevention of the diseases caused by these pathogens. In this review, molecular typing methods for Mycobacterium tuberculosis and nontuberculous mycobacteria elaborated over the last 2 decades are summarized. The relevance of these methods to the epidemiological investigation, diagnosis, evolution, and control of mycobacterial diseases is discussed. PMID:26912567

Health effects and water quality at marine sites: Results from the National Epidemiologic and Environmental Assessment of Recreational Water

EPA Science Inventory

Since 2003, we have conducted a series of epidemiological studies at beach sites impacted by treated sewage discharge. The goal was to evaluate the association between swimming-associated illness and novel and faster methods of measuring water quality. In 2005 and 2007, we expand...

Epidemiology of Attention Problems among Turkish Children and Adolescents: A National Study

ERIC Educational Resources Information Center

Erol, Nese; Simsek, Zeynep; Oner, Ozgur; Munir, Kerim

2008-01-01

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…

Has epidemiology become infatuated with methods? A historical perspective on the place of methods during the classical (1945-1965) phase of epidemiology.

PubMed

Morabia, Alfredo

2015-03-18

Before World War II, epidemiology was a small discipline, practiced by a handful of people working mostly in the United Kingdom and in the United States. Today it is practiced by tens of thousands of people on all continents. Between 1945 and 1965, during what is known as its "classical" phase, epidemiology became recognized as a major academic discipline in medicine and public health. On the basis of a review of the historical evidence, this article examines to which extent classical epidemiology has been a golden age of an action-driven, problem-solving science, in which epidemiologists were less concerned with the sophistication of their methods than with the societal consequences of their work. It also discusses whether the paucity of methods stymied or boosted classical epidemiology's ability to convince political and financial agencies about the need to intervene in order to improve the health of the people.

Reducing random measurement error in assessing postural load on the back in epidemiologic surveys.

PubMed

Burdorf, A

1995-02-01

The goal of this study was to design strategies to assess postural load on the back in occupational epidemiology by taking into account the reliability of measurement methods and the variability of exposure among the workers under study. Intermethod reliability studies were evaluated to estimate the systematic bias (accuracy) and random measurement error (precision) of various methods to assess postural load on the back. Intramethod reliability studies were reviewed to estimate random variability of back load over time. Intermethod surveys have shown that questionnaires have a moderate reliability for gross activities such as sitting, whereas duration of trunk flexion and rotation should be assessed by observation methods or inclinometers. Intramethod surveys indicate that exposure variability can markedly affect the reliability of estimates of back load if the estimates are based upon a single measurement over a certain time period. Equations have been presented to evaluate various study designs according to the reliability of the measurement method, the optimum allocation of the number of repeated measurements per subject, and the number of subjects in the study. Prior to a large epidemiologic study, an exposure-oriented survey should be conducted to evaluate the performance of measurement instruments and to estimate sources of variability for back load. The strategy for assessing back load can be optimized by balancing the number of workers under study and the number of repeated measurements per worker.

Strengthening the Reporting of Molecular Epidemiology for Infectious Diseases (STROME-ID): an extension of the STROBE statement.

PubMed

Field, Nigel; Cohen, Ted; Struelens, Marc J; Palm, Daniel; Cookson, Barry; Glynn, Judith R; Gallo, Valentina; Ramsay, Mary; Sonnenberg, Pam; Maccannell, Duncan; Charlett, Andre; Egger, Matthias; Green, Jonathan; Vineis, Paolo; Abubakar, Ibrahim

2014-04-01

Molecular data are now widely used in epidemiological studies to investigate the transmission, distribution, biology, and diversity of pathogens. Our objective was to establish recommendations to support good scientific reporting of molecular epidemiological studies to encourage authors to consider specific threats to valid inference. The statement Strengthening the Reporting of Molecular Epidemiology for Infectious Diseases (STROME-ID) builds upon the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative. The STROME-ID statement was developed by a working group of epidemiologists, statisticians, bioinformaticians, virologists, and microbiologists with expertise in control of infection and communicable diseases. The statement focuses on issues relating to the reporting of epidemiological studies of infectious diseases using molecular data that were not addressed by STROBE. STROME-ID addresses terminology, measures of genetic diversity within pathogen populations, laboratory methods, sample collection, use of molecular markers, molecular clocks, timeframe, multiple-strain infections, non-independence of infectious-disease data, missing data, ascertainment bias, consistency between molecular and epidemiological data, and ethical considerations with respect to infectious-disease research. In total, 20 items were added to the 22 item STROBE checklist. When used, the STROME-ID recommendations should advance the quality and transparency of scientific reporting, with clear benefits for evidence reviews and health-policy decision making. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genomic Characterization Helps Dissecting an Outbreak of Listeriosis in Northern Italy

PubMed Central

Comandatore, Francesco; Corbella, Marta; Andreoli, Giuseppina; Scaltriti, Erika; Aguzzi, Massimo; Gaiarsa, Stefano; Mariani, Bianca; Morganti, Marina; Bandi, Claudio; Fabbi, Massimo; Marone, Piero; Pongolini, Stefano; Sassera, Davide

2017-01-01

Introduction Listeria monocytogenes (Lm) is a bacterium widely distributed in nature and able to contaminate food processing environments, including those of dairy products. Lm is a primary public health issue, due to the very low infectious dose and the ability to produce severe outcomes, in particular in elderly, newborns, pregnant women and immunocompromised patients. Methods In the period between April and July 2015, an increased number of cases of listeriosis was observed in the area of Pavia, Northern Italy. An epidemiological investigation identified a cheesemaking small organic farm as the possible origin of the outbreak. In this work we present the results of the retrospective epidemiological study that we performed using molecular biology and genomic epidemiology methods. The strains sampled from patients and those from the target farm's cheese were analyzed using PFGE and whole genome sequencing (WGS) based methods. The performed WGS based analyses included: a) in-silico MLST typing; b) SNPs calling and genetic distance evaluation; c) determination of the resistance and virulence genes profiles; d) SNPs based phylogenetic reconstruction. Results Three of the patient strains and all the cheese strains resulted to belong to the same phylogenetic cluster, in Sequence Type 29. A further accurate SNPs analysis revealed that two of the three patient strains and all the cheese strains were highly similar (0.8 SNPs of average distance) and exhibited a higer distance from the third patient isolate (9.4 SNPs of average distance). Discussion Despite the global agreement among the results of the PFGE and WGS epidemiological studies, the latter approach agree with epidemiological data in indicating that one the patient strains could have originated from a different source. This result highlights that WGS methods can allow to better PMID:28856063

Epidemiology of Enterocytozoon bieneusi Infection in Humans.

PubMed

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.

[Training programs for staff at local Infectious Disease Surveillance Centers: the needs and usefulness].

PubMed

Suzuki, Tomoyuki; Kamiya, Nobuyuki; Yahata, Yuichiro; Ozeki, Yukie; Kishimoto, Tsuyoshi; Nadaoka, Yoko; Nakanishi, Yoshiko; Yoshimura, Takesumi; Shimada, Tomoe; Tada, Yuki; Shirabe, Komei; Kozawa, Kunihisa

2013-03-01

The objective of this study was to assess the need for and usefulness of training programs for Local Infectious Disease Surveillance Center (LIDSC) staff. A structured questionnaire survey was conducted to assess the needs and usefulness of training programs. The subjects of the survey were participants of a workshop held after an annual conference for the LIDSC staff. Data on demographic information, the necessity of training programs for LIDSC staff, the themes and contents of the training program, self-assessment of knowledge on epidemiology and statistics were covered by the questionnaire. A total of 55 local government officials responded to the questionnaire (response rate: 100%). Among these, 95% of participants believed that the training program for the LIDSC staff was necessary. Basic statistical analysis (85%), descriptive epidemiology (65%), outline of epidemiology (60%), interpretation of surveillance data (65%), background and objectives of national infectious disease surveillance in Japan (60%), methods of field epidemiology (60%), and methods of analysis data (51%) were selected by over half of the respondents as suitable themes for training programs. A total of 34 LIDSC staff answered the self-assessment question on knowledge of epidemiology. A majority of respondents selected "a little" or "none" for all questions about knowledge. Only a few respondents had received education in epidemiology. The results of this study indicate that LIDSC staff have basic demands for fundamental and specialized education to improve their work. Considering the current situation regarding the capacity of LIDSC staff, these training programs should be started immediately.

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

Association Between Cannabis and Psychosis: Epidemiologic Evidence.

PubMed

Gage, Suzanne H; Hickman, Matthew; Zammit, Stanley

2016-04-01

Associations between cannabis use and psychotic outcomes are consistently reported, but establishing causality from observational designs can be problematic. We review the evidence from longitudinal studies that have examined this relationship and discuss the epidemiologic evidence for and against interpreting the findings as causal. We also review the evidence identifying groups at particularly high risk of developing psychosis from using cannabis. Overall, evidence from epidemiologic studies provides strong enough evidence to warrant a public health message that cannabis use can increase the risk of psychotic disorders. However, further studies are required to determine the magnitude of this effect, to determine the effect of different strains of cannabis on risk, and to identify high-risk groups particularly susceptible to the effects of cannabis on psychosis. We also discuss complementary epidemiologic methods that can help address these questions. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

[Prevalence of the Diabetic Retinopathy and Genetic Factors Significance in the Development of Diabetic Retinopathy in Patients with Diabetes Mellitus type I and II in Slovakia (DIARET SK study). Overview of Actual Findings and Design of the Epidemiological DIARET SK Study].

PubMed

Krásnik, V; Štefaničková, J; Fabková, J; Bucková, D; Helbich, M

2015-09-01

Diabetic retinopathy (DR) is the second most common microvascular complication and the most common cause of blindness in patients with diabetes mellitus (DM). Despite the ongoing research, the findings of diabetic retinopathy epidemiological and risk factors are, until now, not consistent. More finding may be revealed by epidemiological studies, consistently mapping DR epidemiology under the current possibilities of investigations and treatment of the DM. DIARET SK Study, with 5 000 enrolled patients with diabetes mellitus in the Slovak Republic, is, until now, the largest epidemiological study to set the prevalence of diabetic retinopathy. The primary aim is to establish the prevalence of diabetic retinopathy in patients with diabetes mellitus type I and II, according to the duration of the disease. The secondary aim is to establish prevalence of the different stages of the DR and diabetic macular edema (DME) and analysis of the risk factors influence. Included are patients with DM type I and II regardless to the ocular complications history and the period of DM duration. Each enrolled patient has both complex diabetic and ophthalmic examinations.Projects to establish DR prevalence: Tens of projects concerned with diabetic retinopathy epidemiology with different approaches to establish the prevalence and with different patients population. Results from different studies vary significantly (from 12.3 % to 66.9 %). The results depend on the design of the study and the patients recruitment, used examination methods, specific patients population with regard to the geography, prevalence of risk factors, period of diabetes duration, glycated hemoglobin (HbA1C) level, blood pressure, and is higher in type I diabetic patients. The most accurate results are from population epidemiological studies with well-controlled patient recruitment and uniform complex examination that are similar to the DIARET SK study. The DIARET SK study represents the largest epidemiological study to establish the prevalence of the diabetic retinopathy in patients with DM type I and II. Thanks to the quality design, similar to the already published studies, but with larger number of patients and newest examinations methods, the DIARET SK study has the aspiration to obtain the most accurate up to date data of diabetic retinopathy prevalence and risk factors influence to its outbreak. The patients recruitment started in February 2015. The expected date of patients recruitment termination is in the end of the year 2015, and the data analysis in 2016.

Using Accelerometers to Measure Physical Activity in Large-Scale Epidemiologic Studies: Issues and Challenges

PubMed Central

Lee, I-Min; Shiroma, Eric J

2013-01-01

Background Current guidelines for aerobic activity require that adults carry out ≥150 minutes/week of moderate-intensity physical activity, with a large body of epidemiologic evidence showing this level of activity to decrease the incidence of many chronic diseases. Less is known about whether light-intensity activities also have such benefits, and whether sedentary behavior is an independent predictor of increased risks of these chronic diseases, as imprecise assessments of these behaviours and cross-sectional study designs have limited knowledge to date. Methods Recent technological advances in assessment methods have made the use of movement sensors, such as the accelerometer, feasible for use in longitudinal, large-scale epidemiologic studies. Several such studies are collecting sensor-assessed, objective measures of physical activity with the aim of relating these to the development of clinical endpoints. This is a relatively new area of research; thus, in this paper, we use the Women’s Health Study (WHS) as a case study to illustrate challenges related to data collection, data processing, and analyses of the vast amount of data collected. Results The WHS plans to collect 7 days of accelerometer-assessed physical activity and sedentary behavior in ~18,000 women aged ≥62 years. Several logistical challenges exist in collecting data; nonetheless as of 31 August 2013, 11,590 women have already provided some data. Additionally, the WHS experience on data reduction and data analyses can help inform other similar large-scale epidemiologic studies. Conclusions Important data on the health effects of light-intensity activity and sedentary behaviour will emerge from large-scale epidemiologic studies collecting objective assessments of these behaviours. PMID:24297837

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Mathematical Modeling.

PubMed

Barnes, Sean L; Kasaie, Parastu; Anderson, Deverick J; Rubin, Michael

2016-11-01

Mathematical modeling is a valuable methodology used to study healthcare epidemiology and antimicrobial stewardship, particularly when more traditional study approaches are infeasible, unethical, costly, or time consuming. We focus on 2 of the most common types of mathematical modeling, namely compartmental modeling and agent-based modeling, which provide important advantages-such as shorter developmental timelines and opportunities for extensive experimentation-over observational and experimental approaches. We summarize these advantages and disadvantages via specific examples and highlight recent advances in the methodology. A checklist is provided to serve as a guideline in the development of mathematical models in healthcare epidemiology and antimicrobial stewardship. Infect Control Hosp Epidemiol 2016;1-7.

Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method.

PubMed

Lázzari, J O; Pereira, M; Antunes, C M; Guimarães, A; Moncayo, A; Chávez Domínguez, R; Hernández Pieretti, O; Macedo, V; Rassi, A; Maguire, J; Romero, A

1998-11-01

An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (kappa) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (kappa = 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

A method for meta-analysis of epidemiological studies.

PubMed

Einarson, T R; Leeder, J S; Koren, G

1988-10-01

This article presents a stepwise approach for conducting a meta-analysis of epidemiological studies based on proposed guidelines. This systematic method is recommended for practitioners evaluating epidemiological studies in the literature to arrive at an overall quantitative estimate of the impact of a treatment. Bendectin is used as an illustrative example. Meta-analysts should establish a priori the purpose of the analysis and a complete protocol. This protocol should be adhered to, and all steps performed should be recorded in detail. To aid in developing such a protocol, we present methods the researcher can use to perform each of 22 steps in six major areas. The illustrative meta-analysis confirmed previous traditional narrative literature reviews that Bendectin is not related to teratogenic outcomes in humans. The overall summary odds ratio was 1.01 (chi 2 = 0.05, p = 0.815) with a 95 percent confidence interval of 0.66-1.55. When the studies were separated according to study type, the summary odds ratio for cohort studies was 0.95 with a 95 percent confidence interval of 0.62-1.45. For case-control studies, the summary odds ratio was 1.27 with a 95 percent confidence interval of 0.83-1.94. The corresponding chi-square values were not statistically significant at the p = 0.05 level.

THE EXPOSURE PARADOX IN PARTICULATE MATTER COMMUNITY TIME-SERIES EPIDEMIOLOGY: CAN AMBIENT CONCENTRATIONS OF PM BE USED AS A SURROGATE FOR PERSONAL EXPOSURE TO PM ?

EPA Science Inventory

Objective: Explain why epidemiologic studies find a statistically significant relationship between ambient concentrations of PM and health effects even though only a near-zero correlation is found between ambient concentrations of PM and personal exposures to PM. Method: Consider...

Incorporating microbiota data into epidemiologic models: examples from vaginal microbiota research.

PubMed

van de Wijgert, Janneke H; Jespers, Vicky

2016-05-01

Next generation sequencing and quantitative polymerase chain reaction technologies are now widely available, and research incorporating these methods is growing exponentially. In the vaginal microbiota (VMB) field, most research to date has been descriptive. The purpose of this article is to provide an overview of different ways in which next generation sequencing and quantitative polymerase chain reaction data can be used to answer clinical epidemiologic research questions using examples from VMB research. We reviewed relevant methodological literature and VMB articles (published between 2008 and 2015) that incorporated these methodologies. VMB data have been analyzed using ecologic methods, methods that compare the presence or relative abundance of individual taxa or community compositions between different groups of women or sampling time points, and methods that first reduce the complexity of the data into a few variables followed by the incorporation of these variables into traditional biostatistical models. To make future VMB research more clinically relevant (such as studying associations between VMB compositions and clinical outcomes and the effects of interventions on the VMB), it is important that these methods are integrated with rigorous epidemiologic methods (such as appropriate study designs, sampling strategies, and adjustment for confounding). Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Epidemiological links between tuberculosis cases identified twice as efficiently by whole genome sequencing than conventional molecular typing: A population-based study.

PubMed

Jajou, Rana; de Neeling, Albert; van Hunen, Rianne; de Vries, Gerard; Schimmel, Henrieke; Mulder, Arnout; Anthony, Richard; van der Hoek, Wim; van Soolingen, Dick

2018-01-01

Patients with Mycobacterium tuberculosis isolates sharing identical DNA fingerprint patterns can be epidemiologically linked. However, municipal health services in the Netherlands are able to confirm an epidemiological link in only around 23% of the patients with isolates clustered by the conventional variable number of tandem repeat (VNTR) genotyping. This research aims to investigate whether whole genome sequencing (WGS) is a more reliable predictor of epidemiological links between tuberculosis patients than VNTR genotyping. VNTR genotyping and WGS were performed in parallel on all Mycobacterium tuberculosis complex isolates received at the Netherlands National Institute for Public Health and the Environment in 2016. Isolates were clustered by VNTR when they shared identical 24-loci VNTR patterns; isolates were assigned to a WGS cluster when the pair-wise genetic distance was ≤ 12 single nucleotide polymorphisms (SNPs). Cluster investigation was performed by municipal health services on all isolates clustered by VNTR in 2016. The proportion of epidemiological links identified among patients clustered by either method was calculated. In total, 535 isolates were genotyped, of which 25% (134/535) were clustered by VNTR and 14% (76/535) by WGS; the concordance between both typing methods was 86%. The proportion of epidemiological links among WGS clustered cases (57%) was twice as common than among VNTR clustered cases (31%). When WGS was applied, the number of clustered isolates was halved, while all epidemiologically linked cases remained clustered. WGS is therefore a more reliable tool to predict epidemiological links between tuberculosis cases than VNTR genotyping and will allow more efficient transmission tracing, as epidemiological investigations based on false clustering can be avoided.

Inference of Epidemiological Dynamics Based on Simulated Phylogenies Using Birth-Death and Coalescent Models

PubMed Central

Boskova, Veronika; Bonhoeffer, Sebastian; Stadler, Tanja

2014-01-01

Quantifying epidemiological dynamics is crucial for understanding and forecasting the spread of an epidemic. The coalescent and the birth-death model are used interchangeably to infer epidemiological parameters from the genealogical relationships of the pathogen population under study, which in turn are inferred from the pathogen genetic sequencing data. To compare the performance of these widely applied models, we performed a simulation study. We simulated phylogenetic trees under the constant rate birth-death model and the coalescent model with a deterministic exponentially growing infected population. For each tree, we re-estimated the epidemiological parameters using both a birth-death and a coalescent based method, implemented as an MCMC procedure in BEAST v2.0. In our analyses that estimate the growth rate of an epidemic based on simulated birth-death trees, the point estimates such as the maximum a posteriori/maximum likelihood estimates are not very different. However, the estimates of uncertainty are very different. The birth-death model had a higher coverage than the coalescent model, i.e. contained the true value in the highest posterior density (HPD) interval more often (2–13% vs. 31–75% error). The coverage of the coalescent decreases with decreasing basic reproductive ratio and increasing sampling probability of infecteds. We hypothesize that the biases in the coalescent are due to the assumption of deterministic rather than stochastic population size changes. Both methods performed reasonably well when analyzing trees simulated under the coalescent. The methods can also identify other key epidemiological parameters as long as one of the parameters is fixed to its true value. In summary, when using genetic data to estimate epidemic dynamics, our results suggest that the birth-death method will be less sensitive to population fluctuations of early outbreaks than the coalescent method that assumes a deterministic exponentially growing infected population. PMID:25375100

Analyses of infectious disease patterns and drivers largely lack insights from social epidemiology: contemporary patterns and future opportunities

PubMed Central

Noppert, Grace A; Kubale, John T; Wilson, Mark L

2017-01-01

Background Infectious disease epidemiologists have long recognised the importance of social variables as drivers of epidemics and disease risk, yet few apply analytic approaches from social epidemiology. We quantified and evaluated the extent to which recent infectious disease research is employing the perspectives and methods of social epidemiology by replicating the methodology used by Cohen et al in a 2007 study. Methods 2 search strategies were used to identify and review articles published from 1 January 2005 to 31 December 2013. First, we performed a keyword search of ‘social epidemiology’ in the title/abstract/text of published studies identified in PubMed, PsychInfo and ISI Web of Science, and classified each study as pertaining to infectious, non-infectious or other outcomes. A second PubMed search identified articles that were cross-referenced under non-infectious or infectious, and search terms relating to social variables. The abstracts of all articles were read, classified and examined to identify patterns over time. Results Findings suggest that infectious disease research publications that explicitly or implicitly incorporate social epidemiological approaches have stagnated in recent years. While the number of publications that were explicitly self-classified as ‘social epidemiology’ has risen, the proportion that investigated infectious disease outcomes has declined. Furthermore, infectious diseases accounted for the smallest proportion of articles that were cross-referenced with Medical Subject Headings (MeSH) terms related to social factors, and most of these involved sexually transmitted diseases. Conclusions The current landscape of infectious disease epidemiology could benefit from new approaches to understanding how the social and biophysical environment sustains transmission and exacerbates disparities. The framework of social epidemiology provides infectious disease researchers with such a perspective and research opportunity. PMID:27799618

Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary Extension.

PubMed

O'Connor, A M; Sargeant, J M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-11-01

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers, and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples, and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet statement. Thus, this is a companion document to the STROBE-Vet statement methods and process document (JVIM_14575 "Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology-Veterinary (STROBE-Vet) Statement" undergoing proofing), which describes the checklist and how it was developed. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Integration of DNA sample collection into a multi-site birth defects case-control study.

PubMed

Rasmussen, Sonja A; Lammer, Edward J; Shaw, Gary M; Finnell, Richard H; McGehee, Robert E; Gallagher, Margaret; Romitti, Paul A; Murray, Jeffrey C

2002-10-01

Advances in quantitative analysis and molecular genotyping have provided unprecedented opportunities to add biological sampling and genetic information to epidemiologic studies. The purpose of this article is to describe the incorporation of DNA sample collection into the National Birth Defects Prevention Study (NBDPS), an ongoing case-control study in an eight-state consortium with a primary goal to identify risk factors for birth defects. Babies with birth defects are identified through birth defects surveillance systems in the eight participating centers. Cases are infants with one or more of over 30 major birth defects. Controls are infants without defects from the same geographic area. Epidemiologic information is collected through an hour-long interview with mothers of both cases and controls. We added the collection of buccal cytobrush DNA samples for case-infants, control-infants, and their parents to this study. We describe here the methods by which the samples have been collected and processed, establishment of a centralized resource for DNA banking, and quality control, database management, access, informed consent, and confidentiality issues. Biological sampling and genetic analyses are important components to epidemiologic studies of birth defects aimed at identifying risk factors. The DNA specimens collected in this study can be used for detection of mutations, study of polymorphic variants that confer differential susceptibility to teratogens, and examination of interactions among genetic risk factors. Information on the methods used and issues faced by the NBDPS may be of value to others considering the addition of DNA sampling to epidemiologic studies.

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

Utility of inverse probability weighting in molecular pathological epidemiology.

PubMed

Liu, Li; Nevo, Daniel; Nishihara, Reiko; Cao, Yin; Song, Mingyang; Twombly, Tyler S; Chan, Andrew T; Giovannucci, Edward L; VanderWeele, Tyler J; Wang, Molin; Ogino, Shuji

2018-04-01

As one of causal inference methodologies, the inverse probability weighting (IPW) method has been utilized to address confounding and account for missing data when subjects with missing data cannot be included in a primary analysis. The transdisciplinary field of molecular pathological epidemiology (MPE) integrates molecular pathological and epidemiological methods, and takes advantages of improved understanding of pathogenesis to generate stronger biological evidence of causality and optimize strategies for precision medicine and prevention. Disease subtyping based on biomarker analysis of biospecimens is essential in MPE research. However, there are nearly always cases that lack subtype information due to the unavailability or insufficiency of biospecimens. To address this missing subtype data issue, we incorporated inverse probability weights into Cox proportional cause-specific hazards regression. The weight was inverse of the probability of biomarker data availability estimated based on a model for biomarker data availability status. The strategy was illustrated in two example studies; each assessed alcohol intake or family history of colorectal cancer in relation to the risk of developing colorectal carcinoma subtypes classified by tumor microsatellite instability (MSI) status, using a prospective cohort study, the Nurses' Health Study. Logistic regression was used to estimate the probability of MSI data availability for each cancer case with covariates of clinical features and family history of colorectal cancer. This application of IPW can reduce selection bias caused by nonrandom variation in biospecimen data availability. The integration of causal inference methods into the MPE approach will likely have substantial potentials to advance the field of epidemiology.

[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 urgent to us. In conclusion, we would suggest that some technical-scientific and institutional initiatives should overcome the intrinsic limits of the current aetiological researches. The rigorous adhesion of epidemiology to its scientific method appears to be absolutely necessary in order to enforce the Italian constitutional principle which states that health defence is a fundamental right of each individual and a concern for the whole community.

Brain Tumor Epidemiology: Consensus from the Brain Tumor Epidemiology Consortium (BTEC)

PubMed Central

Bondy, Melissa L.; Scheurer, Michael E.; Malmer, Beatrice; Barnholtz-Sloan, Jill S.; Davis, Faith G.; Il’yasova, Dora; Kruchko, Carol; McCarthy, Bridget J.; Rajaraman, Preetha; Schwartzbaum, Judith A.; Sadetzki, Siegal; Schlehofer, Brigitte; Tihan, Tarik; Wiemels, Joseph L.; Wrensch, Margaret; Buffler, Patricia A.

2010-01-01

Epidemiologists in the Brain Tumor Epidemiology Consortium (BTEC) have prioritized areas for further research. Although many risk factors have been examined over the past several decades, there are few consistent findings possibly due to small sample sizes in individual studies and differences between studies in subjects, tumor types, and methods of classification. Individual studies have generally lacked sufficient sample size to examine interactions. A major priority based on available evidence and technologies includes expanding research in genetics and molecular epidemiology of brain tumors. BTEC has taken an active role in promoting understudied groups such as pediatric brain tumors, the etiology of rare glioma subtypes, such as oligodendroglioma, and meningioma, which not uncommon, has only recently been systematically registered in the US. There is also a pressing need to bring more researchers, especially junior investigators, to study brain tumor epidemiology. However, relatively poor funding for brain tumor research has made it difficult to encourage careers in this area. We review the group’s consensus on the current state of scientific findings and present a consensus on research priorities to identify the important areas the science should move to address. PMID:18798534

A clinical research analytics toolkit for cohort study.

PubMed

Yu, Yiqin; Zhu, Yu; Sun, Xingzhi; Tao, Ying; Zhang, Shuo; Xu, Linhao; Pan, Yue

2012-01-01

This paper presents a clinical informatics toolkit that can assist physicians to conduct cohort studies effectively and efficiently. The toolkit has three key features: 1) support of procedures defined in epidemiology, 2) recommendation of statistical methods in data analysis, and 3) automatic generation of research reports. On one hand, our system can help physicians control research quality by leveraging the integrated knowledge of epidemiology and medical statistics; on the other hand, it can improve productivity by reducing the complexities for physicians during their cohort studies.

Study designs appropriate for the workplace.

PubMed

Hogue, C J

1986-01-01

Carlo and Hearn have called for "refinement of old [epidemiologic] methods and an ongoing evaluation of where methods fit in the overall scheme as we address the multiple complexities of reproductive hazard assessment." This review is an attempt to bring together the current state-of-the-art methods for problem definition and hypothesis testing available to the occupational epidemiologist. For problem definition, meta analysis can be utilized to narrow the field of potential causal hypotheses. Passive active surveillance may further refine issues for analytic research. Within analytic epidemiology, several methods may be appropriate for the workplace setting. Those discussed here may be used to estimate the risk ratio in either a fixed or dynamic population.

Experimental design and quantitative analysis of microbial community multiomics.

PubMed

Mallick, Himel; Ma, Siyuan; Franzosa, Eric A; Vatanen, Tommi; Morgan, Xochitl C; Huttenhower, Curtis

2017-11-30

Studies of the microbiome have become increasingly sophisticated, and multiple sequence-based, molecular methods as well as culture-based methods exist for population-scale microbiome profiles. To link the resulting host and microbial data types to human health, several experimental design considerations, data analysis challenges, and statistical epidemiological approaches must be addressed. Here, we survey current best practices for experimental design in microbiome molecular epidemiology, including technologies for generating, analyzing, and integrating microbiome multiomics data. We highlight studies that have identified molecular bioactives that influence human health, and we suggest steps for scaling translational microbiome research to high-throughput target discovery across large populations.

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.

Molecular epidemiology of mastitis pathogens of dairy cattle and comparative relevance to humans.

PubMed

Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H

2011-12-01

Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine.

An epidemiological examination of the subluxation construct using Hill's criteria of causation

PubMed Central

2009-01-01

Background Chiropractors claim to locate, analyze and diagnose a putative spinal lesion known as subluxation and apply the mode of spinal manipulation (adjustment) for the correction of this lesion. Aim The purpose of this examination is to review the current evidence on the epidemiology of the subluxation construct and to evaluate the subluxation by applying epidemiologic criteria for it's significance as a causal factor. Methods The databases of PubMed, Cinahl, and Mantis were searched for studies using the keywords subluxation, epidemiology, manipulation, dose-response, temporality, odds ratio, relative risk, biological plausibility, coherence, and analogy. Results The criteria for causation in epidemiology are strength (strength of association), consistency, specificity, temporality (temporal sequence), dose response, experimental evidence, biological plausibility, coherence, and analogy. Applied to the subluxation all of these criteria remain for the most part unfulfilled. Conclusion There is a significant lack of evidence to fulfill the basic criteria of causation. This lack of crucial supportive epidemiologic evidence prohibits the accurate promulgation of the chiropractic subluxation. PMID:19954544

Phage typing or CRISPR typing for epidemiological surveillance of Salmonella Typhimurium?

PubMed

Mohammed, Manal

2017-11-07

Salmonella Typhimurium is the most dominant Salmonella serovar around the world. It is associated with foodborne gastroenteritis outbreaks but has recently been associated with invasive illness and deaths. Characterization of S. Typhimurium is therefore very crucial for epidemiological surveillance. Phage typing has been used for decades for subtyping of S. Typhimurium to determine the epidemiological relation among isolates. Recent studies however have suggested that high throughput clustered regular interspaced short palindromic repeats (CRISPR) typing has the potential to replace phage typing. This study aimed to determine the efficacy of high-throughput CRISPR typing over conventional phage typing in epidemiological surveillance and outbreak investigation of S. Typhimurium. In silico analysis of whole genome sequences (WGS) of well-documented phage types of S. Typhimurium reveals the presence of different CRISPR type among strains belong to the same phage type. Furthermore, different phage types of S. Typhimurium share identical CRISPR type. Interestingly, identical spacers were detected among outbreak and non-outbreak associated DT8 strains of S. Typhimurium. Therefore, CRISPR typing is not useful for the epidemiological surveillance and outbreak investigation of S. Typhimurium and phage typing, until it is replaced by WGS, is still the gold standard method for epidemiological surveillance of S. Typhimurium.

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.

An open source software for fast grid-based data-mining in spatial epidemiology (FGBASE).

PubMed

Baker, David M; Valleron, Alain-Jacques

2014-10-30

Examining whether disease cases are clustered in space is an important part of epidemiological research. Another important part of spatial epidemiology is testing whether patients suffering from a disease are more, or less, exposed to environmental factors of interest than adequately defined controls. Both approaches involve determining the number of cases and controls (or population at risk) in specific zones. For cluster searches, this often must be done for millions of different zones. Doing this by calculating distances can lead to very lengthy computations. In this work we discuss the computational advantages of geographical grid-based methods, and introduce an open source software (FGBASE) which we have created for this purpose. Geographical grids based on the Lambert Azimuthal Equal Area projection are well suited for spatial epidemiology because they preserve area: each cell of the grid has the same area. We describe how data is projected onto such a grid, as well as grid-based algorithms for spatial epidemiological data-mining. The software program (FGBASE), that we have developed, implements these grid-based methods. The grid based algorithms perform extremely fast. This is particularly the case for cluster searches. When applied to a cohort of French Type 1 Diabetes (T1D) patients, as an example, the grid based algorithms detected potential clusters in a few seconds on a modern laptop. This compares very favorably to an equivalent cluster search using distance calculations instead of a grid, which took over 4 hours on the same computer. In the case study we discovered 4 potential clusters of T1D cases near the cities of Le Havre, Dunkerque, Toulouse and Nantes. One example of environmental analysis with our software was to study whether a significant association could be found between distance to vineyards with heavy pesticide. None was found. In both examples, the software facilitates the rapid testing of hypotheses. Grid-based algorithms for mining spatial epidemiological data provide advantages in terms of computational complexity thus improving the speed of computations. We believe that these methods and this software tool (FGBASE) will lower the computational barriers to entry for those performing epidemiological research.

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

Assessment of phylogenetic sensitivity for reconstructing HIV-1 epidemiological relationships.

PubMed

Beloukas, Apostolos; Magiorkinis, Emmanouil; Magiorkinis, Gkikas; Zavitsanou, Asimina; Karamitros, Timokratis; Hatzakis, Angelos; Paraskevis, Dimitrios

2012-06-01

Phylogenetic analysis has been extensively used as a tool for the reconstruction of epidemiological relations for research or for forensic purposes. It was our objective to assess the sensitivity of different phylogenetic methods and various phylogenetic programs to reconstruct epidemiological links among HIV-1 infected patients that is the probability to reveal a true transmission relationship. Multiple datasets (90) were prepared consisting of HIV-1 sequences in protease (PR) and partial reverse transcriptase (RT) sampled from patients with documented epidemiological relationship (target population), and from unrelated individuals (control population) belonging to the same HIV-1 subtype as the target population. Each dataset varied regarding the number, the geographic origin and the transmission risk groups of the sequences among the control population. Phylogenetic trees were inferred by neighbor-joining (NJ), maximum likelihood heuristics (hML) and Bayesian methods. All clusters of sequences belonging to the target population were correctly reconstructed by NJ and Bayesian methods receiving high bootstrap and posterior probability (PP) support, respectively. On the other hand, TreePuzzle failed to reconstruct or provide significant support for several clusters; high puzzling step support was associated with the inclusion of control sequences from the same geographic area as the target population. In contrary, all clusters were correctly reconstructed by hML as implemented in PhyML 3.0 receiving high bootstrap support. We report that under the conditions of our study, hML using PhyML, NJ and Bayesian methods were the most sensitive for the reconstruction of epidemiological links mostly from sexually infected individuals. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of methods of extracting information for meta-analysis of observational studies in nutritional epidemiology.

PubMed

Bae, Jong-Myon

2016-01-01

A common method for conducting a quantitative systematic review (QSR) for observational studies related to nutritional epidemiology is the "highest versus lowest intake" method (HLM), in which only the information concerning the effect size (ES) of the highest category of a food item is collected on the basis of its lowest category. However, in the interval collapsing method (ICM), a method suggested to enable a maximum utilization of all available information, the ES information is collected by collapsing all categories into a single category. This study aimed to compare the ES and summary effect size (SES) between the HLM and ICM. A QSR for evaluating the citrus fruit intake and risk of pancreatic cancer and calculating the SES by using the HLM was selected. The ES and SES were estimated by performing a meta-analysis using the fixed-effect model. The directionality and statistical significance of the ES and SES were used as criteria for determining the concordance between the HLM and ICM outcomes. No significant differences were observed in the directionality of SES extracted by using the HLM or ICM. The application of the ICM, which uses a broader information base, yielded more-consistent ES and SES, and narrower confidence intervals than the HLM. The ICM is advantageous over the HLM owing to its higher statistical accuracy in extracting information for QSR on nutritional epidemiology. The application of the ICM should hence be recommended for future studies.

75 FR 14170 - Medical Device Epidemiology Network: Developing Partnership Between the Center for Devices and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... methods for medical device comparative analyses, best practices and best design and analysis methods. II... the performance of medical devices (including comparative effectiveness studies). The centers...

LONGITUDINAL COHORT METHODS STUDIES

EPA Science Inventory

Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Exposure classification for occupational studies is relatively easy compared to predicting residential childhood exposures. Recent NHEXAS (Maryland) study articl...

Selection of key ambient particulate variables for epidemiological studies - applying cluster and heatmap analyses as tools for data reduction.

PubMed

Gu, Jianwei; Pitz, Mike; Breitner, Susanne; Birmili, Wolfram; von Klot, Stephanie; Schneider, Alexandra; Soentgen, Jens; Reller, Armin; Peters, Annette; Cyrys, Josef

2012-10-01

The success of epidemiological studies depends on the use of appropriate exposure variables. The purpose of this study is to extract a relatively small selection of variables characterizing ambient particulate matter from a large measurement data set. The original data set comprised a total of 96 particulate matter variables that have been continuously measured since 2004 at an urban background aerosol monitoring site in the city of Augsburg, Germany. Many of the original variables were derived from measured particle size distribution (PSD) across the particle diameter range 3 nm to 10 μm, including size-segregated particle number concentration, particle length concentration, particle surface concentration and particle mass concentration. The data set was complemented by integral aerosol variables. These variables were measured by independent instruments, including black carbon, sulfate, particle active surface concentration and particle length concentration. It is obvious that such a large number of measured variables cannot be used in health effect analyses simultaneously. The aim of this study is a pre-screening and a selection of the key variables that will be used as input in forthcoming epidemiological studies. In this study, we present two methods of parameter selection and apply them to data from a two-year period from 2007 to 2008. We used the agglomerative hierarchical cluster method to find groups of similar variables. In total, we selected 15 key variables from 9 clusters which are recommended for epidemiological analyses. We also applied a two-dimensional visualization technique called "heatmap" analysis to the Spearman correlation matrix. 12 key variables were selected using this method. Moreover, the positive matrix factorization (PMF) method was applied to the PSD data to characterize the possible particle sources. Correlations between the variables and PMF factors were used to interpret the meaning of the cluster and the heatmap analyses. Copyright © 2012 Elsevier B.V. All rights reserved.

Genomic epidemiology of Lineage 4 Mycobacterium tuberculosis subpopulations in New York City and New Jersey, 1999-2009.

PubMed

Brown, Tyler S; Narechania, Apurva; Walker, John R; Planet, Paul J; Bifani, Pablo J; Kolokotronis, Sergios-Orestis; Kreiswirth, Barry N; Mathema, Barun

2016-11-21

Whole genome sequencing (WGS) has rapidly become an important research tool in tuberculosis epidemiology and is likely to replace many existing methods in public health microbiology in the near future. WGS-based methods may be particularly useful in areas with less diverse Mycobacterium tuberculosis populations, such as New York City, where conventional genotyping is often uninformative and field epidemiology often difficult. This study applies four candidate strategies for WGS-based identification of emerging M. tuberculosis subpopulations, employing both phylogenomic and population genetics methods. M. tuberculosis subpopulations in New York City and New Jersey can be distinguished via phylogenomic reconstruction, evidence of demographic expansion and subpopulation-specific signatures of selection, and by determination of subgroup-defining nucleotide substitutions. These methods identified known historical outbreak clusters and previously unidentified subpopulations within relatively monomorphic M. tuberculosis endemic clone groups. Neutrality statistics based on the site frequency spectrum were less useful for identifying M. tuberculosis subpopulations, likely due to the low levels of informative genetic variation in recently diverged isolate groups. In addition, we observed that isolates from New York City endemic clone groups have acquired multiple non-synonymous SNPs in virulence- and growth-associated pathways, and relatively few mutations in drug resistance-associated genes, suggesting that overall pathoadaptive fitness, rather than the acquisition of drug resistance mutations, has played a central role in the evolutionary history and epidemiology of M. tuberculosis subpopulations in New York City. Our results demonstrate that some but not all WGS-based methods are useful for detection of emerging M. tuberculosis clone groups, and support the use of phylogenomic reconstruction in routine tuberculosis laboratory surveillance, particularly in areas with relatively less diverse M. tuberculosis populations. Our study also supports the use of wider-reaching phylogenomic and population genomic methods in tuberculosis public health practice, which can support tuberculosis control activities by identifying genetic polymorphisms contributing to epidemiological success in local M. tuberculosis populations and possibly explain why certain isolate groups are apparently more successful in specific host populations.

Statistical methods for studying disease subtype heterogeneity.

PubMed

Wang, Molin; Spiegelman, Donna; Kuchiba, Aya; Lochhead, Paul; Kim, Sehee; Chan, Andrew T; Poole, Elizabeth M; Tamimi, Rulla; Tworoger, Shelley S; Giovannucci, Edward; Rosner, Bernard; Ogino, Shuji

2016-02-28

A fundamental goal of epidemiologic research is to investigate the relationship between exposures and disease risk. Cases of the disease are often considered a single outcome and assumed to share a common etiology. However, evidence indicates that many human diseases arise and evolve through a range of heterogeneous molecular pathologic processes, influenced by diverse exposures. Pathogenic heterogeneity has been considered in various neoplasms such as colorectal, lung, prostate, and breast cancers, leukemia and lymphoma, and non-neoplastic diseases, including obesity, type II diabetes, glaucoma, stroke, cardiovascular disease, autism, and autoimmune disease. In this article, we discuss analytic options for studying disease subtype heterogeneity, emphasizing methods for evaluating whether the association of a potential risk factor with disease varies by disease subtype. Methods are described for scenarios where disease subtypes are categorical and ordinal and for cohort studies, matched and unmatched case-control studies, and case-case study designs. For illustration, we apply the methods to a molecular pathological epidemiology study of alcohol intake and colon cancer risk by tumor LINE-1 methylation subtypes. User-friendly software to implement the methods is publicly available. Copyright © 2015 John Wiley & Sons, Ltd.

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

Genomic Characterization Helps Dissecting an Outbreak of Listeriosis in Northern Italy.

PubMed

Comandatore, Francesco; Corbella, Marta; Andreoli, Giuseppina; Scaltriti, Erika; Aguzzi, Massimo; Gaiarsa, Stefano; Mariani, Bianca; Morganti, Marina; Bandi, Claudio; Fabbi, Massimo; Marone, Piero; Pongolini, Stefano; Sassera, Davide

2017-07-06

Listeria monocytogenes (Lm) is a bacterium widely distributed in nature and able to contaminate food processing environments, including those of dairy products. Lm is a primary public health issue, due to the very low infectious dose and the ability to produce severe outcomes, in particular in elderly, newborns, pregnant women and immunocompromised patients. In the period between April and July 2015, an increased number of cases of listeriosis was observed in the area of Pavia, Northern Italy. An epidemiological investigation identified a cheesemaking small organic farm as the possible origin of the outbreak. In this work we present the results of the retrospective epidemiological study that we performed using molecular biology and genomic epidemiology methods. The strains sampled from patients and those from the target farm's cheese were analyzed using PFGE and whole genome sequencing (WGS) based methods. The performed WGS based analyses included: a) in-silico MLST typing; b) SNPs calling and genetic distance evaluation; c) determination of the resistance and virulence genes profiles; d) SNPs based phylogenetic reconstruction. Three of the patient strains and all the cheese strains resulted to belong to the same phylogenetic cluster, in Sequence Type 29. A further accurate SNPs analysis revealed that two of the three patient strains and all the cheese strains were highly similar (0.8 SNPs of average distance) and exhibited a higer distance from the third patient isolate (9.4 SNPs of average distance). Despite the global agreement among the results of the PFGE and WGS epidemiological studies, the latter approach agree with epidemiological data in indicating that one the patient strains could have originated from a different source. This result highlights that WGS methods can allow to better.

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

Diagnosis of Hepatitis A Virus Infection: a Molecular Approach

PubMed Central

Nainan, Omana V.; Xia, Guoliang; Vaughan, Gilberto; Margolis, Harold S.

2006-01-01

Current serologic tests provide the foundation for diagnosis of hepatitis A and hepatitis A virus (HAV) infection. Recent advances in methods to identify and characterize nucleic acid markers of viral infections have provided the foundation for the field of molecular epidemiology and increased our knowledge of the molecular biology and epidemiology of HAV. Although HAV is primarily shed in feces, there is a strong viremic phase during infection which has allowed easy access to virus isolates and the use of molecular markers to determine their genetic relatedness. Molecular epidemiologic studies have provided new information on the types and extent of HAV infection and transmission in the United States. In addition, these new diagnostic methods have provided tools for the rapid detection of food-borne HAV transmission and identification of the potential source of the food contamination. PMID:16418523

Transforming Epidemiology for 21st Century Medicine and Public Health

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khoury, Muin J; Lam, Tram Kim; Ioannidis, John

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 acceleratemore » 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.« less

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

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. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

mec-associated dru typing in the epidemiological analysis of ST239 MRSA in Malaysia.

PubMed

Ghaznavi-Rad, E; Goering, R V; Nor Shamsudin, M; Weng, P L; Sekawi, Z; Tavakol, M; van Belkum, A; Neela, V

2011-11-01

The usefulness of mec-associated dru typing in the epidemiological analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolated in Malaysia was investigated and compared with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and spa and SCCmec typing. The isolates studied included all MRSA types in Malaysia. Multilocus sequence type ST188 and ST1 isolates were highly clonal by all typing methods. However, the dru typing of ST239 isolates produced the clearest discrimination between SCCmec IIIa and III isolates, yielding more subtypes than any other method. Evaluation of the discriminatory power for each method identified dru typing and PFGE as the most discriminatory, with Simpson's index of diversity (SID) values over 89%, including an isolate which was non-typeable by spa, but dru-typed as dt13j. The discriminatory ability of dru typing, especially with closely related MRSA ST239 strains (e.g., Brazilian and Hungarian), underscores its utility as a tool for the epidemiological investigation of MRSA.

[Causal analysis approaches in epidemiology].

PubMed

Dumas, O; Siroux, V; Le Moual, N; Varraso, R

2014-02-01

Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the formulation of causal hypotheses, which will be a basis for all methodological choices. Beyond this step, statistical analysis tools recently developed offer new possibilities to delineate complex relationships, in particular in life course epidemiology. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Mapping child maltreatment risk: a 12-year spatio-temporal analysis of neighborhood influences.

PubMed

Gracia, Enrique; López-Quílez, Antonio; Marco, Miriam; Lila, Marisol

2017-10-18

'Place' matters in understanding prevalence variations and inequalities in child maltreatment risk. However, most studies examining ecological variations in child maltreatment risk fail to take into account the implications of the spatial and temporal dimensions of neighborhoods. In this study, we conduct a high-resolution small-area study to analyze the influence of neighborhood characteristics on the spatio-temporal epidemiology of child maltreatment risk. We conducted a 12-year (2004-2015) small-area Bayesian spatio-temporal epidemiological study with all families with child maltreatment protection measures in the city of Valencia, Spain. As neighborhood units, we used 552 census block groups. Cases were geocoded using the family address. Neighborhood-level characteristics analyzed included three indicators of neighborhood disadvantage-neighborhood economic status, neighborhood education level, and levels of policing activity-, immigrant concentration, and residential instability. Bayesian spatio-temporal modelling and disease mapping methods were used to provide area-specific risk estimations. Results from a spatio-temporal autoregressive model showed that neighborhoods with low levels of economic and educational status, with high levels of policing activity, and high immigrant concentration had higher levels of substantiated child maltreatment risk. Disease mapping methods were used to analyze areas of excess risk. Results showed chronic spatial patterns of high child maltreatment risk during the years analyzed, as well as stability over time in areas of low risk. Areas with increased or decreased child maltreatment risk over the years were also observed. A spatio-temporal epidemiological approach to study the geographical patterns, trends over time, and the contextual determinants of child maltreatment risk can provide a useful method to inform policy and action. This method can offer a more accurate description of the problem, and help to inform more localized prevention and intervention strategies. This new approach can also contribute to an improved epidemiological surveillance system to detect ecological variations in risk, and to assess the effectiveness of the initiatives to reduce this risk.

[Epidemiology and laboratories: the missing link on the plans to study and prevent infectious diseases in Chile].

PubMed

Cabello C, Felipe

2008-02-01

Viral meningitis, hantavirus and Vibrio parahaemolyticus infections are used as examples to demonstrate that important shortcomings and limitations exist in Chile to study the epidemiology of infectious diseases with modern methods. The lack of a national network of well-connected local and national microbiology laboratories is one of these important shortcomings. The author summarizes the evolution of the systems and institutions that deal with the infectious diseases in the world and in Chile.

Mechanistic and Technical Challenges in Studying the Human Microbiome and Cancer Epidemiology.

PubMed

Verma, Mukesh

2017-04-01

This article reviews the significance of the microbiome in cancer epidemiology, mechanistic and technical challenges in the field, and characterization of the microbiome in different tumor types to identify biomarkers of risk, progression, and prognosis. Publications on the microbiome and cancer epidemiology were reviewed to analyze sample collection and processing, microbiome taxa characterization by 16S ribosomal RNA sequencing, and microbiome metabolite characterization (metabotyping) by nuclear magnetic resonance and mass spectrometry. The analysis identified methodology types, research design, sample types, and issues in integrating data from different platforms. Aerodigestive cancer epidemiology studies conducted by different groups demonstrated the significance of microbiome information in developing approaches to improve health. Challenges exist in sample preparation and processing (eg, standardization of methods for collection and analysis). These challenges relate to technology, data integration from "omics" studies, inherent bias in primer selection during 16S ribosomal RNA sequencing, the need for large consortia with well-characterized biospecimens, cause and effect issues, resilience of microbiota to exposure events (requires longitudinal studies), and expanding studies for fungal and viral diversity (most studies used bacterial 16S ribosomal RNA sequencing for microbiota characterization). Despite these challenges, microbiome and cancer epidemiology studies are significant and may facilitate cancer risk assessment, diagnosis, and prognosis. In the future, clinical trials likely will use microbiota modifications to improve the efficacy of existing treatments.

Mechanistic and Technical Challenges in Studying the Human Microbiome and Cancer Epidemiology

PubMed Central

2016-01-01

This article reviews the significance of the microbiome in cancer epidemiology, mechanistic and technical challenges in the field, and characterization of the microbiome in different tumor types to identify biomarkers of risk, progression, and prognosis. Publications on the microbiome and cancer epidemiology were reviewed to analyze sample collection and processing, microbiome taxa characterization by 16S ribosomal RNA sequencing, and microbiome metabolite characterization (metabotyping) by nuclear magnetic resonance and mass spectrometry. The analysis identified methodology types, research design, sample types, and issues in integrating data from different platforms. Aerodigestive cancer epidemiology studies conducted by different groups demonstrated the significance of microbiome information in developing approaches to improve health. Challenges exist in sample preparation and processing (eg, standardization of methods for collection and analysis). These challenges relate to technology, data integration from “omics” studies, inherent bias in primer selection during 16S ribosomal RNA sequencing, the need for large consortia with well-characterized biospecimens, cause and effect issues, resilience of microbiota to exposure events (requires longitudinal studies), and expanding studies for fungal and viral diversity (most studies used bacterial 16S ribosomal RNA sequencing for microbiota characterization). Despite these challenges, microbiome and cancer epidemiology studies are significant and may facilitate cancer risk assessment, diagnosis, and prognosis. In the future, clinical trials likely will use microbiota modifications to improve the efficacy of existing treatments. PMID:27121074

The evaluation and application of multilocus variable number tandem repeat analysis (MLVA) for the molecular epidemiological study of Salmonella enterica subsp. enterica serovar Enteritidis infection.

PubMed

Liu, Yao; Shi, Xiaolu; Li, Yinghui; Chen, Qiongcheng; Jiang, Min; Li, Wanli; Qiu, Yaqun; Lin, Yiman; Jiang, Yixiang; Kan, Biao; Sun, Qun; Hu, Qinghua

2016-01-29

Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent Salmonella serotypes that cause gastroenteritis worldwide and the most prevalent serotype causing Salmonella infections in China. A rapid molecular typing method with high throughput and good epidemiological discrimination is urgently needed for detecting the outbreaks and finding the source for effective control of S. Enteritidis infections. In this study, 194 strains which included 47 from six outbreaks that were well-characterized epidemiologically were analyzed with pulse field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA). Seven VNTR loci published by the US Center for Disease Control and Prevention (CDC) were used to evaluate and develop MLVA scheme for S. Enteritidis molecular subtyping by comparing with PFGE, and then MLVA was applied to the suspected outbreaks detection. All S. Enteritidis isolates were analyzed with MLVA to establish a MLVA database in Shenzhen, Guangdong province, China to facilitate the detection of S. Enteritidis infection clusters. There were 33 MLVA types and 29 PFGE patterns among 147 sporadic isolates. These two measures had Simpson indices of 0.7701 and 0.8043, respectively, which did not differ significantly. Epidemiological concordance was evaluated by typing 47 isolates from six epidemiologically well-characterized outbreaks and it did not differ for PFGE and MLVA. We applied the well established MLVA method to detect two S. Enteritidis foodborne outbreaks and find their sources successfully in 2014. A MLVA database of 491 S. Enteritidis strains isolated from 2004 to 2014 was established for the surveillance of clusters in the future. MLVA typing of S. Enteritidis would be an effective tool for early warning and epidemiological surveillance of S. Enteritidis infections.

An argument for renewed focus on epidemiology for public health.

PubMed

Rogawski, Elizabeth T; Gray, Christine L; Poole, Charles

2016-10-01

Although epidemiology has an indispensable role in serving public health, the relative emphasis of applications of epidemiology often tend toward individual-level medicine over public health in terms of resources and impact. We make distinctions between public health and medical applications of epidemiology to raise awareness among epidemiologists, many of whom came to the field with public health in mind. We discuss reasons for the overemphasis on medical epidemiology and suggest ways to counteract these incentives. Public health epidemiology informs interventions that are applied to populations or that confer benefits beyond the individual, whereas medical epidemiology informs interventions that improve the health of treated individuals. Available resources, new biomedical technologies, and existing epidemiologic methods favor medical applications of epidemiology. Focus on public health impact and methods suited to answer public health questions can create better balance and promote population-level improvements in public health. By deliberately reflecting on research motivations and long-term goals, we hope the distinctions presented here will facilitate critical discussion and a greater consciousness of our potential impact on both individual and population-level health. Renewed intentions towards public health can help epidemiologists navigate potential projects and ultimately contribute to an epidemiology of consequence. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

Epidemiological study of suicide by physical methods between 1993 and 2013 in Ilam province, Iran.

PubMed

Azizpour, Yosra; Sayehmiri, Kourosh; Asadollahi, Khairollah; Kaikhavani, Satar; Bagheri, Maryam

2017-08-23

Suicide by aggressive physical methods such as firearms, hanging, and jumping is well known; however, different factors may influence a person while selecting a particular method. The aim of this study was to investigate the epidemiological factors involved in the selection and use of different physical methods for suicide over a long-term period in Ilam province, Iran. The present study was conducted retrospectively between 1993 and 2013 using recorded data from a comprehensive system for registration of suicide attempts in Ilam University of Medical Sciences. The epidemiological characteristics included person, time and place variables, and the outcomes of the suicide attempts. The chi square, univariate and multivariate logistic regression models were used for data analysis. Totally, 1516 suicide attempts were evaluated (the annual incidence rate: 19/100,000 individuals). The most commonly used suicide method in females (88.4%) and males (38.9%) was self-immolation. Furthermore, the annual incidence rate among males and females was within the age group of 15-24 years (24.6 and 47.8/100,000 individuals). The risk of death by suicide in the age group of 55-64 years was 2.93 compared with the age group of 10-14 years (OR = 2.93; 95% CI = 0.64-13.54, P = 0.168). This study revealed that self-immolation was the most selected physical method of suicide and had the highest incidence rate, and inflicted the survivors with severe physical and mental complications. In order to reduce the use of physical methods, especially self-immolation, life skills training becomes more important than ever.

Principled Approaches to Missing Data in Epidemiologic Studies

PubMed Central

Perkins, Neil J; Cole, Stephen R; Harel, Ofer; Tchetgen Tchetgen, Eric J; Sun, BaoLuo; Mitchell, Emily M; Schisterman, Enrique F

2018-01-01

Abstract Principled methods with which to appropriately analyze missing data have long existed; however, broad implementation of these methods remains challenging. In this and 2 companion papers (Am J Epidemiol. 2018;187(3):576–584 and Am J Epidemiol. 2018;187(3):585–591), we discuss issues pertaining to missing data in the epidemiologic literature. We provide details regarding missing-data mechanisms and nomenclature and encourage the conduct of principled analyses through a detailed comparison of multiple imputation and inverse probability weighting. Data from the Collaborative Perinatal Project, a multisite US study conducted from 1959 to 1974, are used to create a masked data-analytical challenge with missing data induced by known mechanisms. We illustrate the deleterious effects of missing data with naive methods and show how principled methods can sometimes mitigate such effects. For example, when data were missing at random, naive methods showed a spurious protective effect of smoking on the risk of spontaneous abortion (odds ratio (OR) = 0.43, 95% confidence interval (CI): 0.19, 0.93), while implementation of principled methods multiple imputation (OR = 1.30, 95% CI: 0.95, 1.77) or augmented inverse probability weighting (OR = 1.40, 95% CI: 1.00, 1.97) provided estimates closer to the “true” full-data effect (OR = 1.31, 95% CI: 1.05, 1.64). We call for greater acknowledgement of and attention to missing data and for the broad use of principled missing-data methods in epidemiologic research. PMID:29165572

Principled Approaches to Missing Data in Epidemiologic Studies.

PubMed

Perkins, Neil J; Cole, Stephen R; Harel, Ofer; Tchetgen Tchetgen, Eric J; Sun, BaoLuo; Mitchell, Emily M; Schisterman, Enrique F

2018-03-01

Principled methods with which to appropriately analyze missing data have long existed; however, broad implementation of these methods remains challenging. In this and 2 companion papers (Am J Epidemiol. 2018;187(3):576-584 and Am J Epidemiol. 2018;187(3):585-591), we discuss issues pertaining to missing data in the epidemiologic literature. We provide details regarding missing-data mechanisms and nomenclature and encourage the conduct of principled analyses through a detailed comparison of multiple imputation and inverse probability weighting. Data from the Collaborative Perinatal Project, a multisite US study conducted from 1959 to 1974, are used to create a masked data-analytical challenge with missing data induced by known mechanisms. We illustrate the deleterious effects of missing data with naive methods and show how principled methods can sometimes mitigate such effects. For example, when data were missing at random, naive methods showed a spurious protective effect of smoking on the risk of spontaneous abortion (odds ratio (OR) = 0.43, 95% confidence interval (CI): 0.19, 0.93), while implementation of principled methods multiple imputation (OR = 1.30, 95% CI: 0.95, 1.77) or augmented inverse probability weighting (OR = 1.40, 95% CI: 1.00, 1.97) provided estimates closer to the "true" full-data effect (OR = 1.31, 95% CI: 1.05, 1.64). We call for greater acknowledgement of and attention to missing data and for the broad use of principled missing-data methods in epidemiologic research.

[Applying temporally-adjusted land use regression models to estimate ambient air pollution exposure during pregnancy].

PubMed

Zhang, Y J; Xue, F X; Bai, Z P

2017-03-06

The impact of maternal air pollution exposure on offspring health has received much attention. Precise and feasible exposure estimation is particularly important for clarifying exposure-response relationships and reducing heterogeneity among studies. Temporally-adjusted land use regression (LUR) models are exposure assessment methods developed in recent years that have the advantage of having high spatial-temporal resolution. Studies on the health effects of outdoor air pollution exposure during pregnancy have been increasingly carried out using this model. In China, research applying LUR models was done mostly at the model construction stage, and findings from related epidemiological studies were rarely reported. In this paper, the sources of heterogeneity and research progress of meta-analysis research on the associations between air pollution and adverse pregnancy outcomes were analyzed. The methods of the characteristics of temporally-adjusted LUR models were introduced. The current epidemiological studies on adverse pregnancy outcomes that applied this model were systematically summarized. Recommendations for the development and application of LUR models in China are presented. This will encourage the implementation of more valid exposure predictions during pregnancy in large-scale epidemiological studies on the health effects of air pollution in China.

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

The National Heart, Lung, and Blood Institute retrovirus epidemiology donor studies (Retrovirus Epidemiology Donor Study and Retrovirus Epidemiology Donor Study-II): twenty years of research to advance blood product safety and availability.

PubMed

Kleinman, Steven; King, Melissa R; Busch, Michael P; Murphy, Edward L; Glynn, Simone A

2012-10-01

The Retrovirus Epidemiology Donor Study (REDS), conducted from 1989 to 2001, and the REDS-II, conducted from 2004 to 2012, were National Heart, Lung, and Blood Institute-funded, multicenter programs focused on improving blood safety and availability in the United States. The REDS-II also included international study sites in Brazil and China. The 3 major research domains of REDS/REDS-II have been infectious disease risk evaluation, blood donation availability, and blood donor characterization. Both programs have made significant contributions to transfusion medicine research methodology by the use of mathematical modeling, large-scale donor surveys, innovative methods of repository sample storage, and establishing an infrastructure that responded to potential emerging blood safety threats such as xenotropic murine leukemia virus-related virus. Blood safety studies have included protocols evaluating epidemiologic and/or laboratory aspects of human immunodeficiency virus, human T-lymphotropic virus 1/2, hepatitis C virus, hepatitis B virus, West Nile virus, cytomegalovirus, human herpesvirus 8, parvovirus B19, malaria, Creutzfeldt-Jakob disease, influenza, and Trypanosoma cruzi infections. Other analyses have characterized blood donor demographics, motivations to donate, factors influencing donor return, behavioral risk factors, donors' perception of the blood donation screening process, and aspects of donor deferral. In REDS-II, 2 large-scale blood donor protocols examined iron deficiency in donors and the prevalence of leukocyte antibodies. This review describes the major study results from over 150 peer-reviewed articles published by these 2 REDS programs. In 2011, a new 7-year program, the Recipient Epidemiology and Donor Evaluation Study-III, was launched. The Recipient Epidemiology and Donor Evaluation Study-III expands beyond donor-based research to include studies of blood transfusion recipients in the hospital setting and adds a third country, South Africa, to the international program. Copyright © 2012 Elsevier Inc. All rights reserved.

Ensemble modelling and structured decision-making to support Emergency Disease Management.

PubMed

Webb, Colleen T; Ferrari, Matthew; Lindström, Tom; Carpenter, Tim; Dürr, Salome; Garner, Graeme; Jewell, Chris; Stevenson, Mark; Ward, Michael P; Werkman, Marleen; Backer, Jantien; Tildesley, Michael

2017-03-01

Epidemiological models in animal health are commonly used as decision-support tools to understand the impact of various control actions on infection spread in susceptible populations. Different models contain different assumptions and parameterizations, and policy decisions might be improved by considering outputs from multiple models. However, a transparent decision-support framework to integrate outputs from multiple models is nascent in epidemiology. Ensemble modelling and structured decision-making integrate the outputs of multiple models, compare policy actions and support policy decision-making. We briefly review the epidemiological application of ensemble modelling and structured decision-making and illustrate the potential of these methods using foot and mouth disease (FMD) models. In case study one, we apply structured decision-making to compare five possible control actions across three FMD models and show which control actions and outbreak costs are robustly supported and which are impacted by model uncertainty. In case study two, we develop a methodology for weighting the outputs of different models and show how different weighting schemes may impact the choice of control action. Using these case studies, we broadly illustrate the potential of ensemble modelling and structured decision-making in epidemiology to provide better information for decision-making and outline necessary development of these methods for their further application. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

The failure of academic epidemiology: witness for the prosecution.

PubMed

Shy, C M

1997-03-15

Academic epidemiology has failed to develop the scientific methods and the knowledge base to support the fundamental public health mission of preventing disease and promoting health through organized community efforts. As a basic science of public health, epidemiology should attempt to understand health and disease from a community and ecologic perspective as a consequence of how society is organized and behaves, what impact social and economic forces have on disease incidence rates, and what community actions will be effective in altering incidence rates. However, as taught in most textbooks and as widely practiced by academicians, epidemiology has become a biomedical discipline focused on the distribution and determinants of disease in groups of individuals who happen to have some common characteristics, exposures, or diseases. The ecology of human health has not been addressed, and the societal context in which disease occurs has been either disregarded or deliberately abstracted from consideration. By essentially assuming that risk factors for disease in individuals can be summed to understand the causes of disease in populations, academic epidemiology has limited itself to a narrow biomedical perspective, thereby committing the bio-medical fallacy of inferring that disease in populations can be understood by studying risk factors for disease in individuals. Epidemiology should be redefined as a study of the distribution and societal determinants of the health status of populations. This definition provides a stronger link to be the primary mission of public health and places an appropriate emphasis on the social, economic, environmental, and cultural determinants of population health. Epidemiology must cross the boundaries of other population sciences and add to its scope a macro-epidemiology, a study of causes from a truly population perspective, considering health and disease within the context of the total human environment.

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...

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship-Observational Studies.

PubMed

Snyder, Graham M; Young, Heather; Varman, Meera; Milstone, Aaron M; Harris, Anthony D; Munoz-Price, Silvia

2016-10-01

Observational studies compare outcomes among subjects with and without an exposure of interest, without intervention from study investigators. Observational studies can be designed as a prospective or retrospective cohort study or as a case-control study. In healthcare epidemiology, these observational studies often take advantage of existing healthcare databases, making them more cost-effective than clinical trials and allowing analyses of rare outcomes. This paper addresses the importance of selecting a well-defined study population, highlights key considerations for study design, and offers potential solutions including biostatistical tools that are applicable to observational study designs. Infect Control Hosp Epidemiol 2016;1-6.

Epidemiologic methods in mastitis treatment and control.

PubMed

Thurmond, M C

1993-11-01

Methods and concepts of epidemiology offer means whereby udder health can be monitored and evaluated. Prerequisite to a sound epidemiologic approach is development of measures of mastitis that minimize biases and that account for sensitivity and specificity of diagnostic tests. Mastitis surveillance offers an ongoing and passive system for evaluation of udder health, whereas clinical and observational trials offer a more proactive and developmental approach to improving udder health.

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

Market analyses of livestock trade networks to inform the prevention of joint economic and epidemiological risks.

PubMed

Moslonka-Lefebvre, Mathieu; Gilligan, Christopher A; Monod, Hervé; Belloc, Catherine; Ezanno, Pauline; Filipe, João A N; Vergu, Elisabeta

2016-03-01

Conventional epidemiological studies of infections spreading through trade networks, e.g., via livestock movements, generally show that central large-size holdings (hubs) should be preferentially surveyed and controlled in order to reduce epidemic spread. However, epidemiological strategies alone may not be economically optimal when costs of control are factored in together with risks of market disruption from targeting core holdings in a supply chain. Using extensive data on animal movements in supply chains for cattle and swine in France, we introduce a method to identify effective strategies for preventing outbreaks with limited budgets while minimizing the risk of market disruptions. Our method involves the categorization of holdings based on position along the supply chain and degree of market share. Our analyses suggest that trade has a higher risk of propagating epidemics through cattle networks, which are dominated by exchanges involving wholesalers, than for swine. We assess the effectiveness of contrasting interventions from the perspectives of regulators and the market, using percolation analysis. We show that preferentially targeting minor, non-central agents can outperform targeting of hubs when the costs to stakeholders and the risks of market disturbance are considered. Our study highlights the importance of assessing joint economic-epidemiological risks in networks underlying pathogen propagation and trade. © 2016 The Authors.

Market analyses of livestock trade networks to inform the prevention of joint economic and epidemiological risks

PubMed Central

Gilligan, Christopher A.; Belloc, Catherine; Filipe, João A. N.; Vergu, Elisabeta

2016-01-01

Conventional epidemiological studies of infections spreading through trade networks, e.g. via livestock movements, generally show that central large-size holdings (hubs) should be preferentially surveyed and controlled in order to reduce epidemic spread. However, epidemiological strategies alone may not be economically optimal when costs of control are factored in together with risks of market disruption from targeting core holdings in a supply chain. Using extensive data on animal movements in supply chains for cattle and swine in France, we introduce a method to identify effective strategies for preventing outbreaks with limited budgets while minimizing the risk of market disruptions. Our method involves the categorization of holdings based on position along the supply chain and degree of market share. Our analyses suggest that trade has a higher risk of propagating epidemics through cattle networks, which are dominated by exchanges involving wholesalers, than for swine. We assess the effectiveness of contrasting interventions from the perspectives of regulators and the market, using percolation analysis. We show that preferentially targeting minor, non-central agents can outperform targeting of hubs when the costs to stakeholders and the risks of market disturbance are considered. Our study highlights the importance of assessing joint economic–epidemiological risks in networks underlying pathogen propagation and trade. PMID:26984191

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.

Accuracy of the Omron HEM-705 CP for blood pressure measurement in large epidemiologic studies.

PubMed

Vera-Cala, Lina M; Orostegui, Myriam; Valencia-Angel, Laura I; López, Nahyr; Bautista, Leonelo E

2011-05-01

Accurate measurement of blood pressure is of utmost importance in hypertension research. In the context of epidemiologic and clinical studies, oscillometric devices offer important advantages to overcome some of the limitations of the auscultatory method. Even though their accuracy has been evaluated in multiple studies in the clinical setting, there is little evidence of their performance in large epidemiologic studies. We evaluated the accuracy of the Omron HEM-705-CP, an automatic device for blood pressure (BP) measurement, as compared to the standard auscultatory method with a mercury sphygmomanometer in a large cohort study. We made three auscultatory measurements, followed by two measurements with the Omron device in 1,084 subjects. Bias was estimated as the average of the two Omron minus the average of the last two auscultatory measurements, with its corresponding 95% limits of agreement (LA). The Omron overestimated systolic blood pressure (SBP) by 1.8 mmHg (LA:-10.1, 13.7) and underestimated diastolic blood pressure (DBP) by 1.6 mmHg (LA:-12.3, 9.2). Bias was significantly larger in men. Bias in SBP increased with age and decreased with BP level, while bias in DBP decreased with age and increased with BP level. The sensitivity and specificity of the Omron to detect hypertension were 88.2% and 98.6%, respectively. Minimum bias in the estimates of the effects of several factors resulted from the use of Omron measurements. Our results showed that the Omron HEM-705-CP could be used for measuring BP in large epidemiology studies without compromising study validity or precision.

Quantitative Serum Nuclear Magnetic Resonance Metabolomics in Large-Scale Epidemiology: A Primer on -Omic Technologies

PubMed Central

Kangas, Antti J; Soininen, Pasi; Lawlor, Debbie A; Davey Smith, George; Ala-Korpela, Mika

2017-01-01

Abstract Detailed metabolic profiling in large-scale epidemiologic studies has uncovered novel biomarkers for cardiometabolic diseases and clarified the molecular associations of established risk factors. A quantitative metabolomics platform based on nuclear magnetic resonance spectroscopy has found widespread use, already profiling over 400,000 blood samples. Over 200 metabolic measures are quantified per sample; in addition to many biomarkers routinely used in epidemiology, the method simultaneously provides fine-grained lipoprotein subclass profiling and quantification of circulating fatty acids, amino acids, gluconeogenesis-related metabolites, and many other molecules from multiple metabolic pathways. Here we focus on applications of magnetic resonance metabolomics for quantifying circulating biomarkers in large-scale epidemiology. We highlight the molecular characterization of risk factors, use of Mendelian randomization, and the key issues of study design and analyses of metabolic profiling for epidemiology. We also detail how integration of metabolic profiling data with genetics can enhance drug development. We discuss why quantitative metabolic profiling is becoming widespread in epidemiology and biobanking. Although large-scale applications of metabolic profiling are still novel, it seems likely that comprehensive biomarker data will contribute to etiologic understanding of various diseases and abilities to predict disease risks, with the potential to translate into multiple clinical settings. PMID:29106475

Exploring multiple trajectories of causality: collaboration between Anthropology and Epidemiology in the 1982 birth cohort, Pelotas, Southern Brazil

PubMed Central

Béhague, Dominique P; Gonçalves, Helen

2009-01-01

OBJECTIVE: Although the relationship between epidemiology and anthropology has a long history, it has generally been comprised of the integration of quantitative and qualitative methods. Only recently have the two fields begun to converge along theoretical lines, leading to a growing mutual interest in explaining rather than simply describing phenomena. This paper aimed to illustrate how ethnographic analyses can be used to assist with the in-depth and theoretically-imbued interpretation of epidemiological results. METHODS: The anthropological analysis presented in this paper used ethnographic data collected as part of the ongoing 1982 birth cohort study, between 1997 and 2007 in Pelotas, Southern Brazil. Analyses were framed according to the results presented in two of the epidemiological articles published in this series on the determinants of mental morbidity and age of sexual initiation. RESULTS AND CONCLUSIONS: The ethnographic results show that statistical associations consist of multiple pathways of influence and causality that generally correspond to the unique experiences of specific subgroups. In exploring these pathways, the paper highlights the importance of an additional set of mediating factors that account for epidemiological results; these include the awareness and experience of inequities, the role of violence in everyday life, traumatic life events, increasing social isolation and emotional introversion as a response to life's difficulties, and differing approaches towards socio-psychological maturation. Theoretical and methodological collaboration between anthropology and epidemiology is important for public health, as it has positively modified both fields. PMID:19142353

A unifying theory for genetic epidemiological analysis of binary disease data

PubMed Central

2014-01-01

Background Genetic selection for host resistance offers a desirable complement to chemical treatment to control infectious disease in livestock. Quantitative genetics disease data frequently originate from field studies and are often binary. However, current methods to analyse binary disease data fail to take infection dynamics into account. Moreover, genetic analyses tend to focus on host susceptibility, ignoring potential variation in infectiousness, i.e. the ability of a host to transmit the infection. This stands in contrast to epidemiological studies, which reveal that variation in infectiousness plays an important role in the progression and severity of epidemics. In this study, we aim at filling this gap by deriving an expression for the probability of becoming infected that incorporates infection dynamics and is an explicit function of both host susceptibility and infectiousness. We then validate this expression according to epidemiological theory and by simulating epidemiological scenarios, and explore implications of integrating this expression into genetic analyses. Results Our simulations show that the derived expression is valid for a range of stochastic genetic-epidemiological scenarios. In the particular case of variation in susceptibility only, the expression can be incorporated into conventional quantitative genetic analyses using a complementary log-log link function (rather than probit or logit). Similarly, if there is moderate variation in both susceptibility and infectiousness, it is possible to use a logarithmic link function, combined with an indirect genetic effects model. However, in the presence of highly infectious individuals, i.e. super-spreaders, the use of any model that is linear in susceptibility and infectiousness causes biased estimates. Thus, in order to identify super-spreaders, novel analytical methods using our derived expression are required. Conclusions We have derived a genetic-epidemiological function for quantitative genetic analyses of binary infectious disease data, which, unlike current approaches, takes infection dynamics into account and allows for variation in host susceptibility and infectiousness. PMID:24552188

A unifying theory for genetic epidemiological analysis of binary disease data.

PubMed

Lipschutz-Powell, Debby; Woolliams, John A; Doeschl-Wilson, Andrea B

2014-02-19

Genetic selection for host resistance offers a desirable complement to chemical treatment to control infectious disease in livestock. Quantitative genetics disease data frequently originate from field studies and are often binary. However, current methods to analyse binary disease data fail to take infection dynamics into account. Moreover, genetic analyses tend to focus on host susceptibility, ignoring potential variation in infectiousness, i.e. the ability of a host to transmit the infection. This stands in contrast to epidemiological studies, which reveal that variation in infectiousness plays an important role in the progression and severity of epidemics. In this study, we aim at filling this gap by deriving an expression for the probability of becoming infected that incorporates infection dynamics and is an explicit function of both host susceptibility and infectiousness. We then validate this expression according to epidemiological theory and by simulating epidemiological scenarios, and explore implications of integrating this expression into genetic analyses. Our simulations show that the derived expression is valid for a range of stochastic genetic-epidemiological scenarios. In the particular case of variation in susceptibility only, the expression can be incorporated into conventional quantitative genetic analyses using a complementary log-log link function (rather than probit or logit). Similarly, if there is moderate variation in both susceptibility and infectiousness, it is possible to use a logarithmic link function, combined with an indirect genetic effects model. However, in the presence of highly infectious individuals, i.e. super-spreaders, the use of any model that is linear in susceptibility and infectiousness causes biased estimates. Thus, in order to identify super-spreaders, novel analytical methods using our derived expression are required. We have derived a genetic-epidemiological function for quantitative genetic analyses of binary infectious disease data, which, unlike current approaches, takes infection dynamics into account and allows for variation in host susceptibility and infectiousness.

Epidemiology of Uterine Fibroids – From Menarche to Menopause

PubMed Central

Wise, Lauren A.; Laughlin-Tommaso, Shannon K.

2015-01-01

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

Investigating Sociodemographic Disparities in Cancer Risk Using Web-Based Informatics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Hong-Jun; Tourassi, Georgia

Cancer health disparities due to demographic and socioeconomic factors are an area of great interest in the epidemiological community. Adjusting for such factors is important when developing cancer risk models. However, for digital epidemiology studies relying on online sources such information is not readily available. This paper presents a novel method for extracting demographic and socioeconomic information from openly available online obituaries. The method relies on tailored language processing rules and a probabilistic scheme to map subjects’ occupation history to the occupation classification codes and related earnings provided by the U.S. Census Bureau. Using this information, a case-control study ismore » executed fully in silico to investigate how age, gender, parity, and income level impact breast and lung cancer risk. Based on 48,368 online obituaries (4,643 for breast cancer, 6,274 for lung cancer, and 37,451 cancer-free) collected automatically and a generalized cancer risk model, our study shows strong association between age, parity, and socioeconomic status and cancer risk. Although for breast cancer the observed trends are very consistent with traditional epidemiological studies, some inconsistency is observed for lung cancer with respect to socioeconomic status.« less

Investigating Sociodemographic Disparities in Cancer Risk Using Web-Based Informatics

DOE PAGES

Yoon, Hong-Jun; Tourassi, Georgia

2018-01-24

Cancer health disparities due to demographic and socioeconomic factors are an area of great interest in the epidemiological community. Adjusting for such factors is important when developing cancer risk models. However, for digital epidemiology studies relying on online sources such information is not readily available. This paper presents a novel method for extracting demographic and socioeconomic information from openly available online obituaries. The method relies on tailored language processing rules and a probabilistic scheme to map subjects’ occupation history to the occupation classification codes and related earnings provided by the U.S. Census Bureau. Using this information, a case-control study ismore » executed fully in silico to investigate how age, gender, parity, and income level impact breast and lung cancer risk. Based on 48,368 online obituaries (4,643 for breast cancer, 6,274 for lung cancer, and 37,451 cancer-free) collected automatically and a generalized cancer risk model, our study shows strong association between age, parity, and socioeconomic status and cancer risk. Although for breast cancer the observed trends are very consistent with traditional epidemiological studies, some inconsistency is observed for lung cancer with respect to socioeconomic status.« less

Epidemiologic research using probabilistic outcome definitions.

PubMed

Cai, Bing; Hennessy, Sean; Lo Re, Vincent; Small, Dylan S

2015-01-01

Epidemiologic studies using electronic healthcare data often define the presence or absence of binary clinical outcomes by using algorithms with imperfect specificity, sensitivity, and positive predictive value. This results in misclassification and bias in study results. We describe and evaluate a new method called probabilistic outcome definition (POD) that uses logistic regression to estimate the probability of a clinical outcome using multiple potential algorithms and then uses multiple imputation to make valid inferences about the risk ratio or other epidemiologic parameters of interest. We conducted a simulation to evaluate the performance of the POD method with two variables that can predict the true outcome and compared the POD method with the conventional method. The simulation results showed that when the true risk ratio is equal to 1.0 (null), the conventional method based on a binary outcome provides unbiased estimates. However, when the risk ratio is not equal to 1.0, the traditional method, either using one predictive variable or both predictive variables to define the outcome, is biased when the positive predictive value is <100%, and the bias is very severe when the sensitivity or positive predictive value is poor (less than 0.75 in our simulation). In contrast, the POD method provides unbiased estimates of the risk ratio both when this measure of effect is equal to 1.0 and not equal to 1.0. Even when the sensitivity and positive predictive value are low, the POD method continues to provide unbiased estimates of the risk ratio. The POD method provides an improved way to define outcomes in database research. This method has a major advantage over the conventional method in that it provided unbiased estimates of risk ratios and it is easy to use. Copyright © 2014 John Wiley & Sons, Ltd.

Evaluating Evidence for Association of Human Bladder Cancer with Drinking-Water Chlorination Disinfection By-Products.

PubMed

Hrudey, Steve E; Backer, Lorraine C; Humpage, Andrew R; Krasner, Stuart W; Michaud, Dominique S; Moore, Lee E; Singer, Philip C; Stanford, Benjamin D

2015-01-01

Exposure to chlorination disinfection by-products (CxDBPs) is prevalent in populations using chlorination-based methods to disinfect public water supplies. Multifaceted research has been directed for decades to identify, characterize, and understand the toxicology of these compounds, control and minimize their formation, and conduct epidemiologic studies related to exposure. Urinary bladder cancer has been the health risk most consistently associated with CxDBPs in epidemiologic studies. An international workshop was held to (1) discuss the qualitative strengths and limitations that inform the association between bladder cancer and CxDBPs in the context of possible causation, (2) identify knowledge gaps for this topic in relation to chlorine/chloramine-based disinfection practice(s) in the United States, and (3) assess the evidence for informing risk management. Epidemiological evidence linking exposures to CxDBPs in drinking water to human bladder cancer risk provides insight into causality. However, because of imprecise, inaccurate, or incomplete estimation of CxDBPs levels in epidemiologic studies, translation from hazard identification directly to risk management and regulatory policy for CxDBPs can be challenging. Quantitative risk estimates derived from toxicological risk assessment for CxDBPs currently cannot be reconciled with those from epidemiologic studies, notwithstanding the complexities involved, making regulatory interpretation difficult. Evidence presented here has both strengths and limitations that require additional studies to resolve and improve the understanding of exposure response relationships. Replication of epidemiologic findings in independent populations with further elaboration of exposure assessment is needed to strengthen the knowledge base needed to better inform effective regulatory approaches.

Evaluating Evidence for Association of Human Bladder Cancer with Drinking-Water Chlorination Disinfection By-Products

PubMed Central

Hrudey, Steve E.; Backer, Lorraine C.; Humpage, Andrew R.; Krasner, Stuart W.; Michaud, Dominique S.; Moore, Lee E.; Singer, Philip C.; Stanford, Benjamin D.

2015-01-01

Exposure to chlorination disinfection by-products (CxDBPs) is prevalent in populations using chlorination-based methods to disinfect public water supplies. Multifaceted research has been directed for decades to identify, characterize, and understand the toxicology of these compounds, control and minimize their formation, and conduct epidemiologic studies related to exposure. Urinary bladder cancer has been the health risk most consistently associated with CxDBPs in epidemiologic studies. An international workshop was held to (1) discuss the qualitative strengths and limitations that inform the association between bladder cancer and CxDBPs in the context of possible causation, (2) identify knowledge gaps for this topic in relation to chlorine/chloramine-based disinfection practice(s) in the United States, and (3) assess the evidence for informing risk management. Epidemiological evidence linking exposures to CxDBPs in drinking water to human bladder cancer risk provides insight into causality. However, because of imprecise, inaccurate, or incomplete estimation of CxDBPs levels in epidemiologic studies, translation from hazard identification directly to risk management and regulatory policy for CxDBPs can be challenging. Quantitative risk estimates derived from toxicological risk assessment for CxDBPs currently cannot be reconciled with those from epidemiologic studies, notwithstanding the complexities involved, making regulatory interpretation difficult. Evidence presented here has both strengths and limitations that require additional studies to resolve and improve the understanding of exposure response relationships. Replication of epidemiologic findings in independent populations with further elaboration of exposure assessment is needed to strengthen the knowledge base needed to better inform effective regulatory approaches. PMID:26309063

Proteomics in the study of the molecular taxonomy and epidemiology of bacterial pathogens.

PubMed

Cash, Phillip

2009-06-01

The ability to discriminate bacterial isolates is important for a number of areas of research in Medical Microbiology, particularly in defining bacterial taxonomy and monitoring transmission in epidemiological investigations. Molecular techniques capable of typing bacteria at the level of the genome and proteome are now widely used for these investigations. This review considers two electrophoretic methods for typing bacteria on the basis of their proteomes, namely 1-D SDS-PAGE and 2-DE. The application of these two techniques for bacterial typing is described with reference to two publications that appeared in Electrophoresis [Costa, Electrophoresis 1990, 11, 382-391 and Cash et al., Electrophoresis 1997, 18, 1472-1482]. Even though these methods have been used for nearly 20 years to differentiate bacterial isolates they remain key technologies in proteome-based typing methods. The developments that have arisen from the two key papers are described in order to highlight the advantages and disadvantages in typing bacteria at the level of their proteomes. Some of the difficulties associated with electrophoretic typing methods can be overcome by using non-gel proteomic methods based on MS to provide improved sensitivity and specificity. The application of proteomic methods to investigate bacterial taxonomy, epidemiology and pathogenesis in general has significant potential in furthering our understanding of infectious diseases.

The second molecular epidemiological study of HIV infection in Mongolia between 2010 and 2016.

PubMed

Jagdagsuren, Davaalkham; Hayashida, Tsunefusa; Takano, Misao; Gombo, Erdenetuya; Zayasaikhan, Setsen; Kanayama, Naomi; Tsuchiya, Kiyoto; Oka, Shinichi

2017-01-01

Our previous 2005-2009 molecular epidemiological study in Mongolia identified a hot spot of HIV-1 transmission in men who have sex with men (MSM). To control the infection, we collaborated with NGOs to promote safer sex and HIV testing since mid-2010. In this study, we carried out the second molecular epidemiological survey between 2010 and 2016 to determine the status of HIV-1 infection in Mongolia. The study included 143 new cases of HIV-1 infection. Viral RNA was extracted from stocked plasma samples and sequenced for the pol and the env regions using the Sanger method. Near-full length sequencing using MiSeq was performed in 3 patients who were suspected to be infected with recombinant HIV-1. Phylogenetic analysis was performed using the neighbor-joining method and Bayesian Markov chain Monte Carlo method. MSM was the main transmission route in the previous and current studies. However, heterosexual route showed a significant increase in recent years. Phylogenetic analysis documented three taxa; Mongolian B, Korean B, and CRF51_01B, though the former two were also observed in the previous study. CRF51_01B, which originated from Singapore and Malaysia, was confirmed by near-full length sequencing. Although these strains were mainly detected in MSM, they were also found in increasing numbers of heterosexual males and females. Bayesian phylogenetic analysis estimated transmission of CRF51_01B into Mongolia around early 2000s. An extended Bayesian skyline plot showed a rapid increase in the effective population size of Mongolian B cluster around 2004 and that of CRF51_01B cluster around 2011. HIV-1 infection might expand to the general population in Mongolia. Our study documented a new cluster of HIV-1 transmission, enhancing our understanding of the epidemiological status of HIV-1 in Mongolia.

Helicobacter pylori and Cancer

MedlinePlus

... alpha-tocopherol, beta-carotene lung cancer prevention study: Design, methods, participant characteristics, and compliance. The ATBC Cancer Prevention Study Group. Annals of Epidemiology 1994; 4(1):1–10. [PubMed Abstract] Kamangar F, Dawsey ...

A systematic review of data mining and machine learning for air pollution epidemiology.

PubMed

Bellinger, Colin; Mohomed Jabbar, Mohomed Shazan; Zaïane, Osmar; Osornio-Vargas, Alvaro

2017-11-28

Data measuring airborne pollutants, public health and environmental factors are increasingly being stored and merged. These big datasets offer great potential, but also challenge traditional epidemiological methods. This has motivated the exploration of alternative methods to make predictions, find patterns and extract information. To this end, data mining and machine learning algorithms are increasingly being applied to air pollution epidemiology. We conducted a systematic literature review on the application of data mining and machine learning methods in air pollution epidemiology. We carried out our search process in PubMed, the MEDLINE database and Google Scholar. Research articles applying data mining and machine learning methods to air pollution epidemiology were queried and reviewed. Our search queries resulted in 400 research articles. Our fine-grained analysis employed our inclusion/exclusion criteria to reduce the results to 47 articles, which we separate into three primary areas of interest: 1) source apportionment; 2) forecasting/prediction of air pollution/quality or exposure; and 3) generating hypotheses. Early applications had a preference for artificial neural networks. In more recent work, decision trees, support vector machines, k-means clustering and the APRIORI algorithm have been widely applied. Our survey shows that the majority of the research has been conducted in Europe, China and the USA, and that data mining is becoming an increasingly common tool in environmental health. For potential new directions, we have identified that deep learning and geo-spacial pattern mining are two burgeoning areas of data mining that have good potential for future applications in air pollution epidemiology. We carried out a systematic review identifying the current trends, challenges and new directions to explore in the application of data mining methods to air pollution epidemiology. This work shows that data mining is increasingly being applied in air pollution epidemiology. The potential to support air pollution epidemiology continues to grow with advancements in data mining related to temporal and geo-spacial mining, and deep learning. This is further supported by new sensors and storage mediums that enable larger, better quality data. This suggests that many more fruitful applications can be expected in the future.

Diagnosis of Dementia by Machine learning methods in Epidemiological studies: a pilot exploratory study from south India.

PubMed

Bhagyashree, Sheshadri Iyengar Raghavan; Nagaraj, Kiran; Prince, Martin; Fall, Caroline H D; Krishna, Murali

2018-01-01

There are limited data on the use of artificial intelligence methods for the diagnosis of dementia in epidemiological studies in low- and middle-income country (LMIC) settings. A culture and education fair battery of cognitive tests was developed and validated for population based studies in low- and middle-income countries including India by the 10/66 Dementia Research Group. We explored the machine learning methods based on the 10/66 battery of cognitive tests for the diagnosis of dementia based in a birth cohort study in South India. The data sets for 466 men and women for this study were obtained from the on-going Mysore Studies of Natal effect of Health and Ageing (MYNAH), in south India. The data sets included: demographics, performance on the 10/66 cognitive function tests, the 10/66 diagnosis of mental disorders and population based normative data for the 10/66 battery of cognitive function tests. Diagnosis of dementia from the rule based approach was compared against the 10/66 diagnosis of dementia. We have applied machine learning techniques to identify minimal number of the 10/66 cognitive function tests required for diagnosing dementia and derived an algorithm to improve the accuracy of dementia diagnosis. Of 466 subjects, 27 had 10/66 diagnosis of dementia, 19 of whom were correctly identified as having dementia by Jrip classification with 100% accuracy. This pilot exploratory study indicates that machine learning methods can help identify community dwelling older adults with 10/66 criterion diagnosis of dementia with good accuracy in a LMIC setting such as India. This should reduce the duration of the diagnostic assessment and make the process easier and quicker for clinicians, patients and will be useful for 'case' ascertainment in population based epidemiological studies.

Comparison of a newly developed binary typing with ribotyping and multilocus sequence typing methods for Clostridium difficile.

PubMed

Li, Zhirong; Liu, Xiaolei; Zhao, Jianhong; Xu, Kaiyue; Tian, Tiantian; Yang, Jing; Qiang, Cuixin; Shi, Dongyan; Wei, Honglian; Sun, Suju; Cui, Qingqing; Li, Ruxin; Niu, Yanan; Huang, Bixing

2018-04-01

Clostridium difficile is the causative pathogen for antibiotic-related nosocomial diarrhea. For epidemiological study and identification of virulent clones, a new binary typing method was developed for C. difficile in this study. The usefulness of this newly developed optimized 10-loci binary typing method was compared with two widely used methods ribotyping and multilocus sequence typing (MLST) in 189 C. difficile samples. The binary typing, ribotyping and MLST typed the samples into 53 binary types (BTs), 26 ribotypes (RTs), and 33 MLST sequence types (STs), respectively. The typing ability of the binary method was better than that of either ribotyping or MLST expressed in Simpson Index (SI) at 0.937, 0.892 and 0.859, respectively. The ease of testing, portability and cost-effectiveness of the new binary typing would make it a useful typing alternative for outbreak investigations within healthcare facilities and epidemiological research. Copyright © 2018 Elsevier B.V. All rights reserved.

Reproductive Outcomes Associated with Noise Exposure — A Systematic Review of the Literature

PubMed Central

Ristovska, Gordana; Laszlo, Helga Elvira; Hansell, Anna L.

2014-01-01

Introduction: High noise exposure during critical periods in gestation is a potential stressor that may result in increased risk of implantation failure, dysregulation of placentation or decrease of uterine blood flow. This paper systematically reviews published evidence on associations between reproductive outcomes and occupational and environmental noise exposure. Methods: The Web of Science, PubMed and Embase electronic databases were searched for papers published between 1970 to June 2014 and via colleagues. We included 14 epidemiological studies related to occupational noise exposure and nine epidemiological studies related to environmental noise exposure. There was some evidence for associations between occupational noise exposure and low birthweight, preterm birth and small for gestational age, either independently or together with other occupational risk factors. Five of six epidemiologic studies, including the two largest studies, found significant associations between lower birthweight and higher noise exposure. There were few studies on other outcomes and study design issues may have led to bias in assessments in some studies. Conclusions: There is evidence for associations between noise exposure and adverse reproductive outcomes from animal studies. Few studies in have been conducted in humans but there is some suggestive evidence of adverse associations with environmental noise from both occupational and epidemiological studies, especially for low birthweight. PMID:25101773

Estimation of low back moments from video analysis: a validation study.

PubMed

Coenen, Pieter; Kingma, Idsart; Boot, Cécile R L; Faber, Gert S; Xu, Xu; Bongers, Paulien M; van Dieën, Jaap H

2011-09-02

This study aimed to develop, compare and validate two versions of a video analysis method for assessment of low back moments during occupational lifting tasks since for epidemiological studies and ergonomic practice relatively cheap and easily applicable methods to assess low back loads are needed. Ten healthy subjects participated in a protocol comprising 12 lifting conditions. Low back moments were assessed using two variants of a video analysis method and a lab-based reference method. Repeated measures ANOVAs showed no overall differences in peak moments between the two versions of the video analysis method and the reference method. However, two conditions showed a minor overestimation of one of the video analysis method moments. Standard deviations were considerable suggesting that errors in the video analysis were random. Furthermore, there was a small underestimation of dynamic components and overestimation of the static components of the moments. Intraclass correlations coefficients for peak moments showed high correspondence (>0.85) of the video analyses with the reference method. It is concluded that, when a sufficient number of measurements can be taken, the video analysis method for assessment of low back loads during lifting tasks provides valid estimates of low back moments in ergonomic practice and epidemiological studies for lifts up to a moderate level of asymmetry. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Ancient Disease, Modern Epidemiology: A Century of Progress in Understanding and Fighting Tuberculosis.

PubMed

Zwerling, Alice; Hanrahan, Colleen; Dowdy, David W

2016-03-01

A century's worth of efforts to better understand the epidemiology of tuberculosis (TB) and to develop new vaccines, drugs, preventive interventions, and case-finding approaches have provided important insights and helped to advance the field of epidemiology as a whole. Wade Hampton Frost developed methods for cohort analysis that formed the early basis for adjustment of confounding variables. The streptomycin trial in the United Kingdom in the 1940s introduced random allocation for participants to either the treatment or control group, ensuring blinded treatment assignment and comparable treatment groups, which is now a key element in randomized clinical trials. Research into the bacille Calmette-Guérin vaccine demonstrated the importance of comparative analyses, potential difficulties in generalizability to populations not under study, and the role of meta-analysis for discrepant data-approaches now strongly recommended prior to implementing any novel public health intervention. George Comstock's work on preventive therapy for TB demonstrated the use of epidemiologic methods to evaluate interventions on a population level. Finally, studies from the Consortium to Respond Effectively to the AIDS/TB Epidemic focused on the evaluation of real-world effectiveness and of targeting of high-risk subpopulations. In this article, we discuss how TB research in each of these domains has helped to advance epidemiologic thinking and methodology over the past 100 years. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Four years into the Indian ocean field epidemiology training programme

PubMed Central

Halm, Ariane; Seyler, Thomas; Mohamed, Sainda; Ali Mbaé, Saindou Ben; Randrianarivo-Solofoniaina, Armand Eugène; Ratsitorahina, Maherisoa; Nundlall, Ram; Aboobakar, Shahina; Bibi, Jastin; Filleul, Laurent; Piola, Patrice; Razafimandimby, Harimahefa; Rasamoelina, Harena; Valenciano, Marta; Moren, Alain; Cardinale, Eric; Lepec, Richard; Flachet, Loïc

2017-01-01

Introduction Following the 2005-6 chikungunya outbreak, a project to strengthen regional Public Health preparedness in the Indian Ocean was implemented. It includes the Comoros, Madagascar, Mauritius, Reunion (France) and Seychelles. A Field Epidemiology Training Programme (FETP-OI) was started in 2011 to develop a pool of well-trained intervention epidemiologists. Methods The FETP-OI consists of two years of supervised, learning-by-doing, on-the-job training at national sites involved in disease surveillance and response. It includes work placements at the Madagascar Pasteur Institute and the French regional epidemiology unit in Reunion and up to three training courses per year. Training objectives include epidemiological surveillance, outbreak investigations, research studies, scientific communication and transfer of competencies. Results In four years, two cohorts of in total 15 fellows originating from four countries followed the FETP-OI. They led 42 surveillance projects (71% routine management, 14% evaluations, 12% setup, 3% other) and investigated 36 outbreak alerts, 58% of them in Madagascar; most investigations (72%) concerned foodborne pathogens, plague or malaria. Fellows performed 18 studies (44% descriptive analyses, 22% disease risk factors, and 34% on other subjects), and presented results during regional and international conferences through 26 oral and 15 poster presentations. Four articles were published in regional Public Health bulletins and several scientific manuscripts are in process. Conclusion The FETP-OI has created a regional force of intervention consisting of field epidemiologists and trained supervisors using the same technical language and epidemiological methods. The third cohort is now ongoing. Technically and financially sustainable FETP-OI projects help addressing public health priorities of the Indian Ocean. PMID:28674588

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

PubMed Central

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

Reproductive and developmental effects of disinfection by-products in drinking water.

PubMed Central

Reif, J S; Hatch, M C; Bracken, M; Holmes, L B; Schwetz, B A; Singer, P C

1996-01-01

Recent epidemiologic studies have reported associations between the consumption of chlorinated drinking water and reproductive and developmental effects. Here we review the available epidemiologic data, assess the hazard potential posed by exposure to disinfection by-products, identify critical data gaps, and offer recommendations for further research. The epidemiologic evidence supporting associations between exposure to water disinfection by-products (DBPs) and adverse pregnancy outcomes is sparse, and positive findings should be interpreted cautiously. The methods used during the early stages of research in this area have been diverse. Variability in exposure assessment and endpoints makes it difficult to synthesize or combine the available data. Exposure misclassification and unmeasured confounding may have lead to bias in risk estimation. Future studies of reproductive outcome and exposure to chlorinated water should use improved methods for exposure assessment to 1) assure selection of appropriate exposure markers, 2) assess seasonal and annual fluctuations in DBPs, 3) assess variability within the distribution system, and 4) assess exposure through multiple routes such as bathing and showering, as well as consumption. Population-based studies should be conducted to evaluate male and female fertility, conception delay, growth retardation, and specific birth defects. The reproductive and developmental effects of exposure to DBPs could be efficiently explored in ongoing investigations by incorporating valid exposure markers and relevant questionnaire information. Future studies should make use of naturally occurring variability in the concentrations of DBPs and may incorporate biomarkers of exposure and effect in their design. Epidemiologic investigations should be conducted in parallel with laboratory-based and animal studies in a coordinated, multidisciplinary approach. PMID:8930546

The application of epidemiology in aquatic animal health -opportunities and challenges.

PubMed

Peeler, Edmund J; Taylor, Nicholas G H

2011-08-11

Over recent years the growth in aquaculture, accompanied by the emergence of new and transboundary diseases, has stimulated epidemiological studies of aquatic animal diseases. Great potential exists for both observational and theoretical approaches to investigate the processes driving emergence but, to date, compared to terrestrial systems, relatively few studies exist in aquatic animals. Research using risk methods has assessed routes of introduction of aquatic animal pathogens to facilitate safe trade (e.g. import risk analyses) and support biosecurity. Epidemiological studies of risk factors for disease in aquaculture (most notably Atlantic salmon farming) have effectively supported control measures. Methods developed for terrestrial livestock diseases (e.g. risk-based surveillance) could improve the capacity of aquatic animal surveillance systems to detect disease incursions and emergence. The study of disease in wild populations presents many challenges and the judicious use of theoretical models offers some solutions. Models, parameterised from observational studies of host pathogen interactions, have been used to extrapolate estimates of impacts on the individual to the population level. These have proved effective in estimating the likely impact of parasite infections on wild salmonid populations in Switzerland and Canada (where the importance of farmed salmon as a reservoir of infection was investigated). A lack of data is often the key constraint in the application of new approaches to surveillance and modelling. The need for epidemiological approaches to protect aquatic animal health will inevitably increase in the face of the combined challenges of climate change, increasing anthropogenic pressures, limited water sources and the growth in aquaculture.

Some applications of categorical data analysis to epidemiological studies.

PubMed Central

Grizzle, J E; Koch, G G

1979-01-01

Several examples of categorized data from epidemiological studies are analyzed to illustrate that more informative analysis than tests of independence can be performed by fitting models. All of the analyses fit into a unified conceptual framework that can be performed by weighted least squares. The methods presented show how to calculate point estimate of parameters, asymptotic variances, and asymptotically valid chi 2 tests. The examples presented are analysis of relative risks estimated from several 2 x 2 tables, analysis of selected features of life tables, construction of synthetic life tables from cross-sectional studies, and analysis of dose-response curves. PMID:540590

The application of HIV molecular epidemiology to public health.

PubMed

Paraskevis, D; Nikolopoulos, G K; Magiorkinis, G; Hodges-Mameletzis, I; Hatzakis, A

2016-12-01

HIV is responsible for one of the largest viral pandemics in human history. Despite a concerted global response for prevention and treatment, the virus persists. Thus, urgent public health action, utilizing novel interventions, is needed to prevent future transmission events, critical to eliminating HIV. For public health planning to prove effective and successful, we need to understand the dynamics of regional epidemics and to intervene appropriately. HIV molecular epidemiology tools as implemented in phylogenetic, phylodynamic and phylogeographic analyses have proven to be powerful tools in public health planning across many studies. Numerous applications with HIV suggest that molecular methods alone or in combination with mathematical modelling can provide inferences about the transmission dynamics, critical epidemiological parameters (prevalence, incidence, effective number of infections, Re, generation times, time between infection and diagnosis), or the spatiotemporal characteristics of epidemics. Molecular tools have been used to assess the impact of an intervention and outbreak investigation which are of great public health relevance. In some settings, molecular sequence data may be more readily available than HIV surveillance data, and can therefore allow for molecular analyses to be conducted more easily. Nonetheless, classic methods have an integral role in monitoring and evaluation of public health programmes, and should supplement emerging techniques from the field of molecular epidemiology. Importantly, molecular epidemiology remains a promising approach in responding to viral diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Doses for post-Chernobyl epidemiological studies: are they reliable?

PubMed

Drozdovitch, Vladimir; Chumak, Vadim; Kesminiene, Ausrele; Ostroumova, Evgenia; Bouville, André

2016-09-01

On 26 April 2016, thirty years will have elapsed since the occurrence of the Chernobyl accident, which has so far been the most severe in the history of the nuclear reactor industry. Numerous epidemiological studies were conducted to evaluate the possible health consequences of the accident. Since the credibility of the association between the radiation exposure and health outcome is highly dependent on the adequacy of the dosimetric quantities used in these studies, this paper makes an effort to overview the methods used to estimate individual doses and the associated uncertainties in the main analytical epidemiological studies (i.e. cohort or case-control) related to the Chernobyl accident. Based on the thorough analysis and comparison with other radiation studies, the authors conclude that individual doses for the Chernobyl analytical epidemiological studies have been calculated with a relatively high degree of reliability and well-characterized uncertainties, and that they compare favorably with many other non-Chernobyl studies. The major strengths of the Chernobyl studies are: (1) they are grounded on a large number of measurements, either performed on humans or made in the environment; and (2) extensive effort has been invested to evaluate the uncertainties associated with the dose estimates. Nevertheless, gaps in the methodology are identified and suggestions for the possible improvement of the current dose estimates are made.

Diesel Exhaust Exposure and the Risk of Lung Cancer—A Review of the Epidemiological Evidence

PubMed Central

Sun, Yi; Bochmann, Frank; Nold, Annette; Mattenklott, Markus

2014-01-01

To critically evaluate the association between diesel exhaust (DE) exposure and the risk of lung cancer, we conducted a systematic review of published epidemiological evidences. To comprehensively identify original studies on the association between DE exposure and the risk of lung cancer, literature searches were performed in literature databases for the period between 1970 and 2013, including bibliographies and cross-referencing. In total, 42 cohort studies and 32 case-control studies were identified in which the association between DE exposures and lung cancer was examined. In general, previous studies suffer from a series of methodological limitations, including design, exposure assessment methods and statistical analysis used. A lack of objective exposure information appears to be the main problem in interpreting epidemiological evidence. To facilitate the interpretation and comparison of previous studies, a job-exposure matrix (JEM) of DE exposures was created based on around 4,000 historical industrial measurements. The values from the JEM were considered during interpretation and comparison of previous studies. Overall, neither cohort nor case-control studies indicate a clear exposure-response relationship between DE exposure and lung cancer. Epidemiological studies published to date do not allow a valid quantification of the association between DE and lung cancer. PMID:24473109

Linking pesticides and human health: a geographic information system (GIS) and Landsat remote sensing method to estimate agricultural pesticide exposure.

PubMed

VoPham, Trang; Wilson, John P; Ruddell, Darren; Rashed, Tarek; Brooks, Maria M; Yuan, Jian-Min; Talbott, Evelyn O; Chang, Chung-Chou H; Weissfeld, Joel L

2015-08-01

Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located.

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. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

A toolkit for measurement error correction, with a focus on nutritional epidemiology

PubMed Central

Keogh, Ruth H; White, Ian R

2014-01-01

Exposure measurement error is a problem in many epidemiological studies, including those using biomarkers and measures of dietary intake. Measurement error typically results in biased estimates of exposure-disease associations, the severity and nature of the bias depending on the form of the error. To correct for the effects of measurement error, information additional to the main study data is required. Ideally, this is a validation sample in which the true exposure is observed. However, in many situations, it is not feasible to observe the true exposure, but there may be available one or more repeated exposure measurements, for example, blood pressure or dietary intake recorded at two time points. The aim of this paper is to provide a toolkit for measurement error correction using repeated measurements. We bring together methods covering classical measurement error and several departures from classical error: systematic, heteroscedastic and differential error. The correction methods considered are regression calibration, which is already widely used in the classical error setting, and moment reconstruction and multiple imputation, which are newer approaches with the ability to handle differential error. We emphasize practical application of the methods in nutritional epidemiology and other fields. We primarily consider continuous exposures in the exposure-outcome model, but we also outline methods for use when continuous exposures are categorized. The methods are illustrated using the data from a study of the association between fibre intake and colorectal cancer, where fibre intake is measured using a diet diary and repeated measures are available for a subset. © 2014 The Authors. PMID:24497385

Infectious disease control in a long-term refugee camp: the role of epidemiologic surveillance and investigation.

PubMed Central

Elias, C J; Alexander, B H; Sokly, T

1990-01-01

This report demonstrates the role of epidemiologic surveillance and investigation in the control of infectious diseases in a long-term refugee camp. The applications of simple epidemiologic methods in a refugee camp on the Thai-Cambodian border are described for a one-year period. The development of a Health Information Office facilitated the collection of demographic and vital statistics data, administration of a disease surveillance system, regular monitoring of hospital and outpatient discharge diagnoses, and investigation of disease outbreaks. This office also organized community health education campaigns and disease control efforts. Examples of specific disease investigations are provided to demonstrate the utility of epidemiologic surveillance in the control of infectious disease. We conclude that simple epidemiologic methods play an important role in health planning in long-term refugee camps. PMID:2356906

The contribution of molecular epidemiology to the understanding and control of viral diseases of salmonid aquaculture

PubMed Central

2011-01-01

Molecular epidemiology is a science which utilizes molecular biology to define the distribution of disease in a population (descriptive epidemiology) and relies heavily on integration of traditional (or analytical) epidemiological approaches to identify the etiological determinants of this distribution. The study of viral pathogens of aquaculture has provided many exciting opportunities to apply such tools. This review considers the extent to which molecular epidemiological studies have contributed to better understanding and control of disease in aquaculture, drawing on examples of viral diseases of salmonid fish of commercial significance including viral haemorrhagic septicaemia virus (VHSV), salmonid alphavirus (SAV) and infectious salmon anaemia virus (ISAV). Significant outcomes of molecular epidemiological studies include: Improved taxonomic classification of viruses A better understanding of the natural distribution of viruses An improved understanding of the origins of viral pathogens in aquaculture An improved understanding of the risks of translocation of pathogens outwith their natural host range An increased ability to trace the source of new disease outbreaks Development of a basis for ensuring development of appropriate diagnostic tools An ability to classify isolates and thus target future research aimed at better understanding biological function While molecular epidemiological studies have no doubt already made a significant contribution in these areas, the advent of new technologies such as pyrosequencing heralds a quantum leap in the ability to generate descriptive molecular sequence data. The ability of molecular epidemiology to fulfil its potential to translate complex disease pathways into relevant fish health policy is thus unlikely to be limited by the generation of descriptive molecular markers. More likely, full realisation of the potential to better explain viral transmission pathways will be dependent on the ability to assimilate and 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

A simplified method of performance indicators development for epidemiological surveillance networks--application to the RESAPATH surveillance network.

PubMed

Sorbe, A; Chazel, M; Gay, E; Haenni, M; Madec, J-Y; Hendrikx, P

2011-06-01

Develop and calculate performance indicators allows to continuously follow the operation of an epidemiological surveillance network. This is an internal evaluation method, implemented by the coordinators in collaboration with all the actors of the network. Its purpose is to detect weak points in order to optimize management. A method for the development of performance indicators of epidemiological surveillance networks was developed in 2004 and was applied to several networks. Its implementation requires a thorough description of the network environment and all its activities to define priority indicators. Since this method is considered to be complex, our objective consisted in developing a simplified approach and applying it to an epidemiological surveillance network. We applied the initial method to a theoretical network model to obtain a list of generic indicators that can be adapted to any surveillance network. We obtained a list of 25 generic performance indicators, intended to be reformulated and described according to the specificities of each network. It was used to develop performance indicators for RESAPATH, an epidemiological surveillance network of antimicrobial resistance in pathogenic bacteria of animal origin in France. This application allowed us to validate the simplified method, its value in terms of practical implementation, and its level of user acceptance. Its ease of use and speed of application compared to the initial method argue in favor of its use on broader scale. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Directed acyclic graphs (DAGs): an aid to assess confounding in dental research.

PubMed

Merchant, Anwar T; Pitiphat, Waranuch

2002-12-01

Confounding, a special type of bias, occurs when an extraneous factor is associated with the exposure and independently affects the outcome. In order to get an unbiased estimate of the exposure-outcome relationship, we need to identify potential confounders, collect information on them, design appropriate studies, and adjust for confounding in data analysis. However, it is not always clear which variables to collect information on and adjust for in the analyses. Inappropriate adjustment for confounding can even introduce bias where none existed. Directed acyclic graphs (DAGs) provide a method to select potential confounders and minimize bias in the design and analysis of epidemiological studies. DAGs have been used extensively in expert systems and robotics. Robins (1987) introduced the application of DAGs in epidemiology to overcome shortcomings of traditional methods to control for confounding, especially as they related to unmeasured confounding. DAGs provide a quick and visual way to assess confounding without making parametric assumptions. We introduce DAGs, starting with definitions and rules for basic manipulation, stressing more on applications than theory. We then demonstrate their application in the control of confounding through examples of observational and cross-sectional epidemiological studies.

Multiple Imputation for Incomplete Data in Epidemiologic Studies

PubMed Central

Harel, Ofer; Mitchell, Emily M; Perkins, Neil J; Cole, Stephen R; Tchetgen Tchetgen, Eric J; Sun, BaoLuo; Schisterman, Enrique F

2018-01-01

Abstract Epidemiologic studies are frequently susceptible to missing information. Omitting observations with missing variables remains a common strategy in epidemiologic studies, yet this simple approach can often severely bias parameter estimates of interest if the values are not missing completely at random. Even when missingness is completely random, complete-case analysis can reduce the efficiency of estimated parameters, because large amounts of available data are simply tossed out with the incomplete observations. Alternative methods for mitigating the influence of missing information, such as multiple imputation, are becoming an increasing popular strategy in order to retain all available information, reduce potential bias, and improve efficiency in parameter estimation. In this paper, we describe the theoretical underpinnings of multiple imputation, and we illustrate application of this method as part of a collaborative challenge to assess the performance of various techniques for dealing with missing data (Am J Epidemiol. 2018;187(3):568–575). We detail the steps necessary to perform multiple imputation on a subset of data from the Collaborative Perinatal Project (1959–1974), where the goal is to estimate the odds of spontaneous abortion associated with smoking during pregnancy. PMID:29165547

Recent transmission of Mycobacterium tuberculosis in China: the implication of molecular epidemiology for tuberculosis control.

PubMed

Yang, Chongguang; Gao, Qian

2018-02-01

Tuberculosis (TB) has remained an ongoing concern in China. The national scale-up of the Directly Observed Treatment, Short Course (DOTS) program has accelerated the fight against TB in China. Nevertheless, many challenges still remain, including the spread of drug-resistant strains, high disease burden in rural areas, and enormous rural-to-urban migrations. Whether incident active TB represents recent transmission or endogenous reactivation has helped to prioritize the strategies for TB control. Evidence from molecular epidemiology studies has delineated the recent transmission of Mycobacterium tuberculosis (M. tuberculosis) strains in many settings. However, the transmission patterns of TB in most areas of China are still not clear. Studies carried out to date could not capture the real burden of recent transmission of the disease in China because of the retrospective study design, incomplete sampling, and use of low-resolution genotyping methods. We reviewed the implementations of molecular epidemiology of TB in China, the estimated disease burden due to recent transmission of M. tuberculosis strains, the primary transmission of drug-resistant TB, and the evaluation of a feasible genotyping method of M. tuberculosis strains in circulation.

Causality and causal inference in epidemiology: the need for a pluralistic approach.

PubMed

Vandenbroucke, Jan P; Broadbent, Alex; Pearce, Neil

2016-12-01

Causal inference based on a restricted version of the potential outcomes approach reasoning is assuming an increasingly prominent place in the teaching and practice of epidemiology. The proposed concepts and methods are useful for particular problems, but it would be of concern if the theory and practice of the complete field of epidemiology were to become restricted to this single approach to causal inference. Our concerns are that this theory restricts the questions that epidemiologists may ask and the study designs that they may consider. It also restricts the evidence that may be considered acceptable to assess causality, and thereby the evidence that may be considered acceptable for scientific and public health decision making. These restrictions are based on a particular conceptual framework for thinking about causality. In Section 1, we describe the characteristics of the restricted potential outcomes approach (RPOA) and show that there is a methodological movement which advocates these principles, not just for solving particular problems, but as ideals for which epidemiology as a whole should strive. In Section 2, we seek to show that the limitation of epidemiology to one particular view of the nature of causality is problematic. In Section 3, we argue that the RPOA is also problematic with regard to the assessment of causality. We argue that it threatens to restrict study design choice, to wrongly discredit the results of types of observational studies that have been very useful in the past and to damage the teaching of epidemiological reasoning. Finally, in Section 4 we set out what we regard as a more reasonable 'working hypothesis' as to the nature of causality and its assessment: pragmatic pluralism. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association.

Epidemiologic Consequences of Microvariation in Mycobacterium tuberculosis

PubMed Central

Mathema, Barun; Kurepina, Natalia; Yang, Guibin; Shashkina, Elena; Manca, Claudia; Mehaffy, Carolina; Bielefeldt-Ohmann, Helle; Ahuja, Shama; Fallows, Dorothy A.; Izzo, Angelo; Bifani, Pablo; Dobos, Karen; Kaplan, Gilla

2012-01-01

Background. Evidence from genotype-phenotype studies suggests that genetic diversity in pathogens have clinically relevant manifestations that can impact outcome of infection and epidemiologic success. We studied 5 closely related Mycobacterium tuberculosis strains that collectively caused extensive disease (n = 862), particularly among US-born tuberculosis patients. Methods. Representative isolates were selected using population-based genotyping data from New York City and New Jersey. Growth and cytokine/chemokine response were measured in infected human monocytes. Survival was determined in aerosol-infected guinea pigs. Results. Multiple genotyping methods and phylogenetically informative synonymous single nucleotide polymorphisms showed that all strains were related by descent. In axenic culture, all strains grew similarly. However, infection of monocytes revealed 2 growth phenotypes, slower (doubling ∼55 hours) and faster (∼25 hours). The faster growing strains elicited more tumor necrosis factor α and interleukin 1β than the slower growing strains, even after heat killing, and caused accelerated death of infected guinea pigs (∼9 weeks vs 24 weeks) associated with increased lung inflammation/pathology. Epidemiologically, the faster growing strains were associated with human immunodeficiency virus and more limited in spread, possibly related to their inherent ability to induce a strong protective innate immune response in immune competent hosts. Conclusions. Natural variation, with detectable phenotypic changes, among closely related clinical isolates of M. tuberculosis may alter epidemiologic patterns in human populations. PMID:22315279

Realist identification of group-level latent variables for perinatal social epidemiology theory building.

PubMed

Eastwood, John Graeme; Jalaludin, Bin Badrudin; Kemp, Lynn Ann; Phung, Hai Ngoc

2014-01-01

We have previously reported in this journal on an ecological study of perinatal depressive symptoms in South Western Sydney. In that article, we briefly reported on a factor analysis that was utilized to identify empirical indicators for analysis. In this article, we report on the mixed method approach that was used to identify those latent variables. Social epidemiology has been slow to embrace a latent variable approach to the study of social, political, economic, and cultural structures and mechanisms, partly for philosophical reasons. Critical realist ontology and epistemology have been advocated as an appropriate methodological approach to both theory building and theory testing in the health sciences. We describe here an emergent mixed method approach that uses qualitative methods to identify latent constructs followed by factor analysis using empirical indicators chosen to measure identified qualitative codes. Comparative analysis of the findings is reported together with a limited description of realist approaches to abstract reasoning.

Population Neuroscience: Dementia Epidemiology Serving Precision Medicine and Population Health.

PubMed

Ganguli, Mary; Albanese, Emiliano; Seshadri, Sudha; Bennett, David A; Lyketsos, Constantine; Kukull, Walter A; Skoog, Ingmar; Hendrie, Hugh C

2018-01-01

Over recent decades, epidemiology has made significant contributions to our understanding of dementia, translating scientific discoveries into population health. Here, we propose reframing dementia epidemiology as "population neuroscience," blending techniques and models from contemporary neuroscience with those of epidemiology and biostatistics. On the basis of emerging evidence and newer paradigms and methods, population neuroscience will minimize the bias typical of traditional clinical research, identify the relatively homogenous subgroups that comprise the general population, and investigate broader and denser phenotypes of dementia and cognitive impairment. Long-term follow-up of sufficiently large study cohorts will allow the identification of cohort effects and critical windows of exposure. Molecular epidemiology and omics will allow us to unravel the key distinctions within and among subgroups and better understand individuals' risk profiles. Interventional epidemiology will allow us to identify the different subgroups that respond to different treatment/prevention strategies. These strategies will inform precision medicine. In addition, insights into interactions between disease biology, personal and environmental factors, and social determinants of health will allow us to measure and track disease in communities and improve population health. By placing neuroscience within a real-world context, population neuroscience can fulfill its potential to serve both precision medicine and population health.

Utility of Whole-Genome Sequencing of Escherichia coli O157 for Outbreak Detection and Epidemiological Surveillance.

PubMed

Holmes, Anne; Allison, Lesley; Ward, Melissa; Dallman, Timothy J; Clark, Richard; Fawkes, Angie; Murphy, Lee; Hanson, Mary

2015-11-01

Detailed laboratory characterization of Escherichia coli O157 is essential to inform epidemiological investigations. This study assessed the utility of whole-genome sequencing (WGS) for outbreak detection and epidemiological surveillance of E. coli O157, and the data were used to identify discernible associations between genotypes and clinical outcomes. One hundred five E. coli O157 strains isolated over a 5-year period from human fecal samples in Lothian, Scotland, were sequenced with the Ion Torrent Personal Genome Machine. A total of 8,721 variable sites in the core genome were identified among the 105 isolates; 47% of the single nucleotide polymorphisms (SNPs) were attributable to six "atypical" E. coli O157 strains and included recombinant regions. Phylogenetic analyses showed that WGS correlated well with the epidemiological data. Epidemiological links existed between cases whose isolates differed by three or fewer SNPs. WGS also correlated well with multilocus variable-number tandem repeat analysis (MLVA) typing data, with only three discordant results observed, all among isolates from cases not known to be epidemiologically related. WGS produced a better-supported, higher-resolution phylogeny than MLVA, confirming that the method is more suitable for epidemiological surveillance of E. coli O157. A combination of in silico analyses (VirulenceFinder, ResFinder, and local BLAST searches) were used to determine stx subtypes, multilocus sequence types (15 loci), and the presence of virulence and acquired antimicrobial resistance genes. There was a high level of correlation between the WGS data and our routine typing methods, although some discordant results were observed, mostly related to the limitation of short sequence read assembly. The data were used to identify sublineages and clades of E. coli O157, and when they were correlated with the clinical outcome data, they showed that one clade, Ic3, was significantly associated with severe disease. Together, the results show that WGS data can provide higher resolution of the relationships between E. coli O157 isolates than that provided by MLVA. The method has the potential to streamline the laboratory workflow and provide detailed information for the clinical management of patients and public health interventions. Copyright © 2015, Holmes et al.

Utility of Whole-Genome Sequencing of Escherichia coli O157 for Outbreak Detection and Epidemiological Surveillance

PubMed Central

Allison, Lesley; Ward, Melissa; Dallman, Timothy J.; Clark, Richard; Fawkes, Angie; Murphy, Lee; Hanson, Mary

2015-01-01

Detailed laboratory characterization of Escherichia coli O157 is essential to inform epidemiological investigations. This study assessed the utility of whole-genome sequencing (WGS) for outbreak detection and epidemiological surveillance of E. coli O157, and the data were used to identify discernible associations between genotypes and clinical outcomes. One hundred five E. coli O157 strains isolated over a 5-year period from human fecal samples in Lothian, Scotland, were sequenced with the Ion Torrent Personal Genome Machine. A total of 8,721 variable sites in the core genome were identified among the 105 isolates; 47% of the single nucleotide polymorphisms (SNPs) were attributable to six “atypical” E. coli O157 strains and included recombinant regions. Phylogenetic analyses showed that WGS correlated well with the epidemiological data. Epidemiological links existed between cases whose isolates differed by three or fewer SNPs. WGS also correlated well with multilocus variable-number tandem repeat analysis (MLVA) typing data, with only three discordant results observed, all among isolates from cases not known to be epidemiologically related. WGS produced a better-supported, higher-resolution phylogeny than MLVA, confirming that the method is more suitable for epidemiological surveillance of E. coli O157. A combination of in silico analyses (VirulenceFinder, ResFinder, and local BLAST searches) were used to determine stx subtypes, multilocus sequence types (15 loci), and the presence of virulence and acquired antimicrobial resistance genes. There was a high level of correlation between the WGS data and our routine typing methods, although some discordant results were observed, mostly related to the limitation of short sequence read assembly. The data were used to identify sublineages and clades of E. coli O157, and when they were correlated with the clinical outcome data, they showed that one clade, Ic3, was significantly associated with severe disease. Together, the results show that WGS data can provide higher resolution of the relationships between E. coli O157 isolates than that provided by MLVA. The method has the potential to streamline the laboratory workflow and provide detailed information for the clinical management of patients and public health interventions. PMID:26354815

Methodological Challenges in the Application of the Glycemic Index in Epidemiological Studies Using Data from the European Prospective Investigation into Cancer and Nutrition1–3

PubMed Central

van Bakel, Marit M. E.; Slimani, Nadia; Feskens, Edith J. M.; Du, Huaidong; Beulens, Joline W. J.; van der Schouw, Yvonne T.; Brighenti, Furio; Halkjaer, Jytte; Cust, Anne E.; Ferrari, Pietro; Brand-Miller, Jennie; Bueno-de-Mesquita, H. Bas; Peeters, Petra; Ardanaz, Eva; Dorronsoro, Miren; Crowe, Francesca L.; Bingham, Sheila; Rohrmann, Sabine; Boeing, Heiner; Johansson, Ingegerd; Manjer, Jonas; Tjonneland, Anne; Overvad, Kim; Lund, Eiliv; Skeie, Guri; Mattiello, Amalia; Salvini, Simonetta; Clavel-Chapelon, Françoise; Kaaks, Rudolf

2009-01-01

Associations between the glycemic index (GI) or glycemic load (GL) and diseases are heterogeneous in epidemiological studies. Differences in assigning GI values to food items may contribute to this inconsistency. Our objective was to address methodological issues related to the use of current GI and GL values in epidemiological studies. We performed ecological comparison and correlation studies by calculating dietary GI and GL from country-specific dietary questionnaires (DQ) from 422,837 participants from 9 countries participating in the European Prospective Investigation into Cancer and Nutrition study and single standardized 24-h dietary recalls (24-HDR) obtained from a representative sample (n = 33,404) using mainly Foster Powell's international table as a reference source. Further, 2 inter-rater and 1 inter-method comparison were conducted, comparing DQ GI values assigned by independent groups with values linked by us. The ecological correlation between DQ and 24-HDR was good for GL (overall r = 0.76; P < 0.005) and moderate for GI (r = 0.57; P < 0.05). Mean GI/GL differences between DQ and 24-HDR were significant for most centers. GL but not GI from DQ was highly correlated with total carbohydrate (r = 0.98 and 0.15, respectively; P < 0.0001) and this was higher for starch (r = 0.72; P < 0.0001) than for sugars (r = 0.36; P < 0.0001). The inter-rater and inter-method variations were considerable for GI (weighted κ coefficients of 0.49 and 0.65 for inter-rater and 0.25 for inter-method variation, respectively) but only mild for GL (weighted κ coefficients > 0.80). A more consistent methodology to attribute GI values to foods and validated DQ is needed to derive meaningful GI/GL estimates for nutritional epidemiology. PMID:19158224

Environmental Viral Metagenomics Analyses in Aquaculture: Applications in Epidemiology and Disease Control

PubMed Central

Munang’andu, Hetron M.

2016-01-01

Studies on the epidemiology of viral diseases in aquaculture have for a long time depended on isolation of viruses from infected aquatic organisms. The role of aquatic environments in the epidemiology of viral diseases in aquaculture has not been extensively expounded mainly because of the lack of appropriate tools for environmental studies on aquatic viruses. However, the upcoming of metagenomics analyses opens great avenues in which environmental samples can be used to study the epidemiology of viral diseases outside their host species. Hence, in this review I have shown that epidemiological factors that influence the composition of viruses in different aquatic environments include ecological factors, anthropogenic activities and stocking densities of cultured organisms based on environmental metagenomics studies carried out this far. Ballast water transportation and global trade of aquatic organisms are the most common virus dispersal process identified this far. In terms of disease control for outdoor aquaculture systems, baseline data on viruses found in different environments intended for aquaculture use can be obtained to enable the design of effective disease control strategies. And as such, high-risk areas having a high specter of pathogenic viruses can be identified as an early warning system. As for the control of viral diseases for indoor recirculation aquaculture systems (RAS), the most effective disinfection methods able to eliminate pathogenic viruses from water used in RAS can be identified. Overall, the synopsis I have put forth in this review shows that environmental samples can be used to study the epidemiology of viral diseases in aquaculture using viral metagenomics analysis as an overture for the design of rational disease control strategies. PMID:28018317

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

Detection of high-risk mucosal human papillomavirus DNA in human specimens by a novel and sensitive multiplex PCR method combined with DNA microarray.

PubMed

Gheit, Tarik; Tommasino, Massimo

2011-01-01

Epidemiological and functional studies have clearly demonstrated that certain types of human papillomavirus (HPV) from the genus alpha of the HPV phylogenetic tree, referred to as high-risk (HR) types, are the etiological cause of cervical cancer. Several methods for HPV detection and typing have been developed, and their importance in clinical and epidemiological studies has been well demonstrated. However, comparative studies have shown that several assays have different sensitivities for the detection of specific HPV types, particularly in the case of multiple infections. In this chapter, we describe a novel one-shot method for the detection and typing of 19 mucosal HR HPV types (types 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73, and 82). The assay combines the advantages of the multiplex PCR methods, i.e., high sensitivity and the possibility to perform multiple amplifications in a single reaction, with an array primer extension (APEX) assay. The latter method offers the benefits of Sanger dideoxy sequencing with the high-throughput potential of the microarray. Initial studies have revealed that the assay is very sensitive in detecting multiple HPV infections.

Jumping on the Train of Personalized Medicine: A Primer for Non-Geneticist Clinicians: Part 2. Fundamental Concepts in Genetic Epidemiology.

PubMed

Li, Aihua; Meyre, David

2014-05-01

With the decrease in sequencing costs, personalized genome sequencing will eventually become common in medical practice. We therefore write this series of three reviews to help non-geneticist clinicians to jump into the fast-moving field of personalized medicine. In the first article of this series, we reviewed the fundamental concepts in molecular genetics. In this second article, we cover the key concepts and methods in genetic epidemiology including the classification of genetic disorders, study designs and their implementation, genetic marker selection, genotyping and sequencing technologies, gene identification strategies, data analyses and data interpretation. This review will help the reader critically appraise a genetic association study. In the next article, we will discuss the clinical applications of genetic epidemiology in the personalized medicine area.

Applications and Comparisons of Four Time Series Models in Epidemiological Surveillance Data

PubMed Central

Young, Alistair A.; Li, Xiaosong

2014-01-01

Public health surveillance systems provide valuable data for reliable predication of future epidemic events. This paper describes a study that used nine types of infectious disease data collected through a national public health surveillance system in mainland China to evaluate and compare the performances of four time series methods, namely, two decomposition methods (regression and exponential smoothing), autoregressive integrated moving average (ARIMA) and support vector machine (SVM). The data obtained from 2005 to 2011 and in 2012 were used as modeling and forecasting samples, respectively. The performances were evaluated based on three metrics: mean absolute error (MAE), mean absolute percentage error (MAPE), and mean square error (MSE). The accuracy of the statistical models in forecasting future epidemic disease proved their effectiveness in epidemiological surveillance. Although the comparisons found that no single method is completely superior to the others, the present study indeed highlighted that the SVMs outperforms the ARIMA model and decomposition methods in most cases. PMID:24505382

Costs and Epidemiological Changes of Chronic Diseases: Implications and Challenges for Health Systems

PubMed Central

Arredondo, Armando; Aviles, Raul

2015-01-01

Background The need to integrate economic and epidemiological aspects in the clinical perspective leads to a proposal for the analysis of health disparities and to an evaluation of the health services and of the new challenges which are now being faced by health system reforms in middle income countries. Objective To identify the epidemiological changes, the demand for health services and economic burden from chronic diseases (diabetes and hypertension) in a middle income county. Methods We conducted longitudinal analyses of costs and epidemiological changes for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations. The cost-evaluation method was used, based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2014–2016, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95%, and the Box-Pierce test. Results Regarding epidemiological changes expected in both diseases for 2014 vs. 2016, an increase is expected, although results predict a greater increase for diabetes, 8–12% in all three studied institutions, (p < .05). Indeed, in the case of diabetes, the increase was 41469 cases for uninsured population (SSA) and 65737 for the insured population (IMSS and ISSSTE). On hypertension cases the increase was 38109 for uninsured vs 62895 for insured. Costs in US$ ranged from $699 to $748 for annual case management per patient in the case of diabetes, and from $485 to $622 in patients with hypertension. Comparing financial consequences of health services required by insured and uninsured populations, the greater increase (23%) will be for the insured population (p < .05). The financial requirements of both diseases will amount to 19.5% of the total budget for the uninsured and 12.5% for the insured population. Conclusions If the risk factors and the different health care models remain as they currently are, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant challenge is the appearance of internal competition in the use and allocation of financial resources with programs for other chronic and infectious diseases. PMID:25781625

Structural and Practical Identifiability Issues of Immuno-Epidemiological Vector-Host Models with Application to Rift Valley Fever.

PubMed

Tuncer, Necibe; Gulbudak, Hayriye; Cannataro, Vincent L; Martcheva, Maia

2016-09-01

In this article, we discuss the structural and practical identifiability of a nested immuno-epidemiological model of arbovirus diseases, where host-vector transmission rate, host recovery, and disease-induced death rates are governed by the within-host immune system. We incorporate the newest ideas and the most up-to-date features of numerical methods to fit multi-scale models to multi-scale data. For an immunological model, we use Rift Valley Fever Virus (RVFV) time-series data obtained from livestock under laboratory experiments, and for an epidemiological model we incorporate a human compartment to the nested model and use the number of human RVFV cases reported by the CDC during the 2006-2007 Kenya outbreak. We show that the immunological model is not structurally identifiable for the measurements of time-series viremia concentrations in the host. Thus, we study the non-dimensionalized and scaled versions of the immunological model and prove that both are structurally globally identifiable. After fixing estimated parameter values for the immunological model derived from the scaled model, we develop a numerical method to fit observable RVFV epidemiological data to the nested model for the remaining parameter values of the multi-scale system. For the given (CDC) data set, Monte Carlo simulations indicate that only three parameters of the epidemiological model are practically identifiable when the immune model parameters are fixed. Alternatively, we fit the multi-scale data to the multi-scale model simultaneously. Monte Carlo simulations for the simultaneous fitting suggest that the parameters of the immunological model and the parameters of the immuno-epidemiological model are practically identifiable. We suggest that analytic approaches for studying the structural identifiability of nested models are a necessity, so that identifiable parameter combinations can be derived to reparameterize the nested model to obtain an identifiable one. This is a crucial step in developing multi-scale models which explain multi-scale data.

Analyses of infectious disease patterns and drivers largely lack insights from social epidemiology: contemporary patterns and future opportunities.

PubMed

Noppert, Grace A; Kubale, John T; Wilson, Mark L

2017-04-01

Infectious disease epidemiologists have long recognised the importance of social variables as drivers of epidemics and disease risk, yet few apply analytic approaches from social epidemiology. We quantified and evaluated the extent to which recent infectious disease research is employing the perspectives and methods of social epidemiology by replicating the methodology used by Cohen et al in a 2007 study. 2 search strategies were used to identify and review articles published from 1 January 2005 to 31 December 2013. First, we performed a keyword search of 'social epidemiology' in the title/abstract/text of published studies identified in PubMed, PsychInfo and ISI Web of Science, and classified each study as pertaining to infectious, non-infectious or other outcomes. A second PubMed search identified articles that were cross-referenced under non-infectious or infectious, and search terms relating to social variables. The abstracts of all articles were read, classified and examined to identify patterns over time. Findings suggest that infectious disease research publications that explicitly or implicitly incorporate social epidemiological approaches have stagnated in recent years. While the number of publications that were explicitly self-classified as 'social epidemiology' has risen, the proportion that investigated infectious disease outcomes has declined. Furthermore, infectious diseases accounted for the smallest proportion of articles that were cross-referenced with Medical Subject Headings (MeSH) terms related to social factors, and most of these involved sexually transmitted diseases. The current landscape of infectious disease epidemiology could benefit from new approaches to understanding how the social and biophysical environment sustains transmission and exacerbates disparities. The framework of social epidemiology provides infectious disease researchers with such a perspective and research opportunity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

DOE PAGES

Cologne, John; Grant, Eric J.; Nakashima, Eiji; ...

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 relativemore » 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

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

Inferring epidemiological parameters from phylogenies using regression-ABC: A comparative study

PubMed Central

Gascuel, Olivier

2017-01-01

Inferring epidemiological parameters such as the R0 from time-scaled phylogenies is a timely challenge. Most current approaches rely on likelihood functions, which raise specific issues that range from computing these functions to finding their maxima numerically. Here, we present a new regression-based Approximate Bayesian Computation (ABC) approach, which we base on a large variety of summary statistics intended to capture the information contained in the phylogeny and its corresponding lineage-through-time plot. The regression step involves the Least Absolute Shrinkage and Selection Operator (LASSO) method, which is a robust machine learning technique. It allows us to readily deal with the large number of summary statistics, while avoiding resorting to Markov Chain Monte Carlo (MCMC) techniques. To compare our approach to existing ones, we simulated target trees under a variety of epidemiological models and settings, and inferred parameters of interest using the same priors. We found that, for large phylogenies, the accuracy of our regression-ABC is comparable to that of likelihood-based approaches involving birth-death processes implemented in BEAST2. Our approach even outperformed these when inferring the host population size with a Susceptible-Infected-Removed epidemiological model. It also clearly outperformed a recent kernel-ABC approach when assuming a Susceptible-Infected epidemiological model with two host types. Lastly, by re-analyzing data from the early stages of the recent Ebola epidemic in Sierra Leone, we showed that regression-ABC provides more realistic estimates for the duration parameters (latency and infectiousness) than the likelihood-based method. Overall, ABC based on a large variety of summary statistics and a regression method able to perform variable selection and avoid overfitting is a promising approach to analyze large phylogenies. PMID:28263987

Improved performance of epidemiologic and genetic risk models for rheumatoid arthritis serologic phenotypes using family history

PubMed Central

Sparks, Jeffrey A.; Chen, Chia-Yen; Jiang, Xia; Askling, Johan; Hiraki, Linda T.; Malspeis, Susan; Klareskog, Lars; Alfredsson, Lars; Costenbader, Karen H.; Karlson, Elizabeth W.

2014-01-01

Objective To develop and validate rheumatoid arthritis (RA) risk models based on family history, epidemiologic factors, and known genetic risk factors. Methods We developed and validated models for RA based on known RA risk factors, among women in two cohorts: the Nurses’ Health Study (NHS, 381 RA cases and 410 controls) and the Epidemiological Investigation of RA (EIRA, 1244 RA cases and 971 controls). Model discrimination was evaluated using the area under the receiver operating characteristic curve (AUC) in logistic regression models for the study population and for those with positive family history. The joint effect of family history with genetics, smoking, and body mass index (BMI) was evaluated using logistic regression models to estimate odds ratios (OR) for RA. Results The complete model including family history, epidemiologic risk factors, and genetics demonstrated AUCs of 0.74 for seropositive RA in NHS and 0.77 for anti-citrullinated protein antibody (ACPA)-positive RA in EIRA. Among women with positive family history, discrimination was excellent for complete models for seropositive RA in NHS (AUC 0.82) and ACPA-positive RA in EIRA (AUC 0.83). Positive family history, high genetic susceptibility, smoking, and increased BMI had an OR of 21.73 for ACPA-positive RA. Conclusions We developed models for seropositive and seronegative RA phenotypes based on family history, epidemiologic and genetic factors. Among those with positive family history, models utilizing epidemiologic and genetic factors were highly discriminatory for seropositive and seronegative RA. Assessing epidemiological and genetic factors among those with positive family history may identify individuals suitable for RA prevention strategies. PMID:24685909

Advancing Research on Racial–Ethnic Health Disparities: Improving Measurement Equivalence in Studies with Diverse Samples

PubMed Central

Landrine, Hope; Corral, Irma

2014-01-01

To conduct meaningful, epidemiologic research on racial–ethnic health disparities, racial–ethnic samples must be rendered equivalent on other social status and contextual variables via statistical controls of those extraneous factors. The racial–ethnic groups must also be equally familiar with and have similar responses to the methods and measures used to collect health data, must have equal opportunity to participate in the research, and must be equally representative of their respective populations. In the absence of such measurement equivalence, studies of racial–ethnic health disparities are confounded by a plethora of unmeasured, uncontrolled correlates of race–ethnicity. Those correlates render the samples, methods, and measures incomparable across racial–ethnic groups, and diminish the ability to attribute health differences discovered to race–ethnicity vs. to its correlates. This paper reviews the non-equivalent yet normative samples, methodologies and measures used in epidemiologic studies of racial–ethnic health disparities, and provides concrete suggestions for improving sample, method, and scalar measurement equivalence. PMID:25566524

How medicine has become a science?

PubMed

Zieliński, Andrzej

2014-01-01

The historical review of medical activities draws attention how late in its very long history therapies of proven effectiveness were introduced. Author attributes it to the late development of methods which would be capable to determine the causal relations which would scientifically justified identification the causes and risk factors of diseases as well as checking the effectiveness of preventive and therapeutic procedures. Among the fundamental tools for scientific knowledge of the causes and mechanisms of diseases, the author indicates: achievements of basic science and the development of epidemiological methods used to study causal relationships. In the author's opinion the results of basic research are an essential source of variables among which, with an increased likelihood could be found the causes and risk factors of studied conditions, including diseases. The author also stresses the role of medical technology, which is the primary source of potential medicines, other therapeutic procedures and diagnostic methods whose effectiveness is tested in experimental epidemiological studies. Medical technologies create also tools for the development of basic sciences.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis

PubMed Central

Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole

2018-01-01

Background With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. Objective The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. Methods The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. Results A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). Conclusions The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. PMID:29792293

Reconstruction of organ dose for external radiotherapy patients in retrospective epidemiologic studies

NASA Astrophysics Data System (ADS)

Lee, Choonik; Jung, Jae Won; Pelletier, Christopher; Pyakuryal, Anil; Lamart, Stephanie; Kim, Jong Oh; Lee, Choonsik

2015-03-01

Organ dose estimation for retrospective epidemiological studies of late effects in radiotherapy patients involves two challenges: radiological images to represent patient anatomy are not usually available for patient cohorts who were treated years ago, and efficient dose reconstruction methods for large-scale patient cohorts are not well established. In the current study, we developed methods to reconstruct organ doses for radiotherapy patients by using a series of computational human phantoms coupled with a commercial treatment planning system (TPS) and a radiotherapy-dedicated Monte Carlo transport code, and performed illustrative dose calculations. First, we developed methods to convert the anatomy and organ contours of the pediatric and adult hybrid computational phantom series to Digital Imaging and Communications in Medicine (DICOM)-image and DICOM-structure files, respectively. The resulting DICOM files were imported to a commercial TPS for simulating radiotherapy and dose calculation for in-field organs. The conversion process was validated by comparing electron densities relative to water and organ volumes between the hybrid phantoms and the DICOM files imported in TPS, which showed agreements within 0.1 and 2%, respectively. Second, we developed a procedure to transfer DICOM-RT files generated from the TPS directly to a Monte Carlo transport code, x-ray Voxel Monte Carlo (XVMC) for more accurate dose calculations. Third, to illustrate the performance of the established methods, we simulated a whole brain treatment for the 10 year-old male phantom and a prostate treatment for the adult male phantom. Radiation doses to selected organs were calculated using the TPS and XVMC, and compared to each other. Organ average doses from the two methods matched within 7%, whereas maximum and minimum point doses differed up to 45%. The dosimetry methods and procedures established in this study will be useful for the reconstruction of organ dose to support retrospective epidemiological studies of late effects in radiotherapy patients.

Evaluation of a rule-based method for epidemiological document classification towards the automation of systematic reviews.

PubMed

Karystianis, George; Thayer, Kristina; Wolfe, Mary; Tsafnat, Guy

2017-06-01

Most data extraction efforts in epidemiology are focused on obtaining targeted information from clinical trials. In contrast, limited research has been conducted on the identification of information from observational studies, a major source for human evidence in many fields, including environmental health. The recognition of key epidemiological information (e.g., exposures) through text mining techniques can assist in the automation of systematic reviews and other evidence summaries. We designed and applied a knowledge-driven, rule-based approach to identify targeted information (study design, participant population, exposure, outcome, confounding factors, and the country where the study was conducted) from abstracts of epidemiological studies included in several systematic reviews of environmental health exposures. The rules were based on common syntactical patterns observed in text and are thus not specific to any systematic review. To validate the general applicability of our approach, we compared the data extracted using our approach versus hand curation for 35 epidemiological study abstracts manually selected for inclusion in two systematic reviews. The returned F-score, precision, and recall ranged from 70% to 98%, 81% to 100%, and 54% to 97%, respectively. The highest precision was observed for exposure, outcome and population (100%) while recall was best for exposure and study design with 97% and 89%, respectively. The lowest recall was observed for the population (54%), which also had the lowest F-score (70%). The generated performance of our text-mining approach demonstrated encouraging results for the identification of targeted information from observational epidemiological study abstracts related to environmental exposures. We have demonstrated that rules based on generic syntactic patterns in one corpus can be applied to other observational study design by simple interchanging the dictionaries aiming to identify certain characteristics (i.e., outcomes, exposures). At the document level, the recognised information can assist in the selection and categorization of studies included in a systematic review. Copyright © 2017 Elsevier Inc. All rights reserved.

Review of analytical methods for the quantification of iodine in complex matrices.

PubMed

Shelor, C Phillip; Dasgupta, Purnendu K

2011-09-19

Iodine is an essential element of human nutrition. Nearly a third of the global population has insufficient iodine intake and is at risk of developing Iodine Deficiency Disorders (IDD). Most countries have iodine supplementation and monitoring programs. Urinary iodide (UI) is the biomarker used for epidemiological studies; only a few methods are currently used routinely for analysis. These methods either require expensive instrumentation with qualified personnel (inductively coupled plasma-mass spectrometry, instrumental nuclear activation analysis) or oxidative sample digestion to remove potential interferences prior to analysis by a kinetic colorimetric method originally introduced by Sandell and Kolthoff ~75 years ago. The Sandell-Kolthoff (S-K) method is based on the catalytic effect of iodide on the reaction between Ce(4+) and As(3+). No available technique fully fits the needs of developing countries; research into inexpensive reliable methods and instrumentation are needed. There have been multiple reviews of methods used for epidemiological studies and specific techniques. However, a general review of iodine determination on a wide-ranging set of complex matrices is not available. While this review is not comprehensive, we cover the principal developments since the original development of the S-K method. Copyright © 2011 Elsevier B.V. All rights reserved.

Hospital prescribing errors: epidemiological assessment of predictors

PubMed Central

Fijn, R; Van den Bemt, P M L A; Chow, M; De Blaey, C J; De Jong-Van den Berg, L T W; Brouwers, J R B J

2002-01-01

Aims To demonstrate an epidemiological method to assess predictors of prescribing errors. Methods A retrospective case-control study, comparing prescriptions with and without errors. Results Only prescriber and drug characteristics were associated with errors. Prescriber characteristics were medical specialty (e.g. orthopaedics: OR: 3.4, 95% CI 2.1, 5.4) and prescriber status (e.g. verbal orders transcribed by nursing staff: OR: 2.5, 95% CI 1.8, 3.6). Drug characteristics were dosage form (e.g. inhalation devices: OR: 4.1, 95% CI 2.6, 6.6), therapeutic area (e.g. gastrointestinal tract: OR: 1.7, 95% CI 1.2, 2.4) and continuation of preadmission treatment (Yes: OR: 1.7, 95% CI 1.3, 2.3). Conclusions Other hospitals could use our epidemiological framework to identify their own error predictors. Our findings suggest a focus on specific prescribers, dosage forms and therapeutic areas. We also found that prescriptions originating from general practitioners involved errors and therefore, these should be checked when patients are hospitalized. PMID:11874397

Lessons Learned From Methodological Validation Research in E-Epidemiology

PubMed Central

Assmann, Karen; Andreeva, Valentina; Castetbon, Katia; Méjean, Caroline; Touvier, Mathilde; Salanave, Benoît; Deschamps, Valérie; Péneau, Sandrine; Fezeu, Léopold; Julia, Chantal; Allès, Benjamin; Galan, Pilar; Hercberg, Serge

2016-01-01

Background Traditional epidemiological research methods exhibit limitations leading to high logistics, human, and financial burden. The continued development of innovative digital tools has the potential to overcome many of the existing methodological issues. Nonetheless, Web-based studies remain relatively uncommon, partly due to persistent concerns about validity and generalizability. Objective The objective of this viewpoint is to summarize findings from methodological studies carried out in the NutriNet-Santé study, a French Web-based cohort study. Methods On the basis of the previous findings from the NutriNet-Santé e-cohort (>150,000 participants are currently included), we synthesized e-epidemiological knowledge on sample representativeness, advantageous recruitment strategies, and data quality. Results Overall, the reported findings support the usefulness of Web-based studies in overcoming common methodological deficiencies in epidemiological research, in particular with regard to data quality (eg, the concordance for body mass index [BMI] classification was 93%), reduced social desirability bias, and access to a wide range of participant profiles, including the hard-to-reach subgroups such as young (12.30% [15,118/122,912], <25 years) and old people (6.60% [8112/122,912], ≥65 years), unemployed or homemaker (12.60% [15,487/122,912]), and low educated (38.50% [47,312/122,912]) people. However, some selection bias remained (78.00% (95,871/122,912) of the participants were women, and 61.50% (75,590/122,912) had postsecondary education), which is an inherent aspect of cohort study inclusion; other specific types of bias may also have occurred. Conclusions Given the rapidly growing access to the Internet across social strata, the recruitment of participants with diverse socioeconomic profiles and health risk exposures was highly feasible. Continued efforts concerning the identification of specific biases in e-cohorts and the collection of comprehensive and valid data are still needed. This summary of methodological findings from the NutriNet-Santé cohort may help researchers in the development of the next generation of high-quality Web-based epidemiological studies. PMID:27756715

Health effects of electric and magnetic fields: Overview of research recommendations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savitz, D.A.

We developed a series of articles concerning epidemiologic research on potential health effects of electric and magnetic fields. Our goal was to identify methodological issues that have arisen through past studies of cancer, reproduction, and neurobehavioral outcomes in order to suggest strategies to extend knowledge. Following an overview of relevant physics and engineering principles, cancer epidemiology of electric and magnetic fields is discussed separately with a focus on epidemiologic methods and cancer biology, respectively. Reproductive health studies, many of which focus on exposure from video display terminals are then summarized, followed by an evaluation of the limited literature on neurobehavioralmore » outcomes, including suicide and depression. Methodological issues in exposure assessment are discussed, focusing on the challenges in residential exposure assessment and interpretation of wire configuration codes. An overview offers recommendations for priorities across these topic areas, emphasizing the importance of resolving the question of wire codes and childhood cancer. Collectively, these articles provide an array of observations and suggestions regarding the epidemiologic literature, recognizing the potential benefits to science and public policy. 10 refs.« less

Qualitative Epidemiologic Methods Can Improve Local Prevention Programming among Adolescents

ERIC Educational Resources Information Center

Daniulaityte, Raminta; Siegal, Harvey A.; Carlson, Robert G.; Kenne, Deric R.; Starr, Sanford; DeCamp, Brad

2004-01-01

The Ohio Substance Abuse Monitoring Network (OSAM) is designed to provide accurate, timely, qualitatively-oriented epidemiologic descriptions of substance abuse trends and emerging problems in the state's major urban and rural areas. Use of qualitative methods in identifying and assessing substance abuse practices in local communities is one of…

The significance for epidemiological studies anti-measles antibody detection examined by enzyme immunoassay (EIA) and plaque reduction neutralization test (PRNT).

PubMed

Siennicka, Joanna; Częścik, Agnieszka; Trzcińska, Agnieszka

2014-01-01

The paper discusses the role of anti-measles antibodies for protection and significance for epidemiological studies determination of antibodies by different serological methods. The comparison of anti-measles virus antibodies levels measured by enzyme immunoassay (EIA) and Plaque Reduction Neutralization Test (PRNT) was described. It was found that the 200 mIU/ml of anti-measles activity measured by PRNT (level protection against symp- tomatic disease) is equivalent of 636 mIU/ml measured by EIA (Enzygnost®Anti-Measles Virus/IgG, Simens).

Mental illness and reduction of gun violence and suicide: bringing epidemiologic research to policy

PubMed Central

Swanson, Jeffrey W.; McGinty, E. Elizabeth; Fazel, Seena; Mays, Vickie M.

2015-01-01

Purpose This article describes epidemiologic evidence concerning risk of gun violence and suicide linked to psychiatric disorders, in contrast to media-fueled public perceptions of the dangerousness of mentally ill individuals, and evaluates effectiveness of policies and laws designed to prevent firearms injury and mortality associated with serious mental illnesses and substance use disorders. Methods Research concerning public attitudes toward persons with mental illness is reviewed and juxtaposed with evidence from benchmark epidemiologic and clinical studies of violence and mental illness and of the accuracy of psychiatrists' risk assessments. Selected policies and laws designed to reduce gun violence in relation to mental illness are critically evaluated; evidence-based policy recommendations are presented. Results Media accounts of mass shootings by disturbed individuals galvanize public attention and reinforce popular belief that mental illness often results in violence. Epidemiologic studies show that the large majority of people with serious mental illnesses are never violent. However, mental illness is strongly associated with increased risk of suicide, which accounts for over half of US firearms–related fatalities. Conclusions Policymaking at the interface of gun violence prevention and mental illness should be based on epidemiologic data concerning risk to improve the effectiveness, feasibility, and fairness of policy initiatives. PMID:24861430

The role of epidemiology in MS research: Past successes, current challenges and future potential.

PubMed

Simpson, Steve; Taylor, Bruce V; van der Mei, Ingrid

2015-07-01

Multiple sclerosis (MS) is a multifaceted condition, with a range of environmental, behavioural and genetic factors implicated in its aetiology and clinical course. Successes in advancing our appreciation of the roles of Epstein-Barr virus, vitamin D/UV and the HLA-DRB1 locus; and our greater understanding of these and related factors' modes of action in MS and other conditions, can be attributed in no small part to the work of generations of epidemiologists. Hardly content to rest on our laurels, however, there are yet a range of unsolved conundrums in MS, including some changes in epidemiological characteristics (e.g. increasing incidence and sex ratio), to say nothing of the unresolved parts regarding what underlies MS risk and its clinical course. There is evidence that epidemiology will continue to play a crucial role in unravelling the architecture of MS causation and clinical course. While classic epidemiological methods are ongoing, novel avenues for research include gene-environment interaction studies, the world of '-omic' research, and the utilisation of mobile and social media tools to both access and track study populations, which means that the epidemiological discoveries of the past century may be but a glimpse of our understanding in the next few decades. © The Author(s), 2015.

Evaluation of an Optimal Epidemiological Typing Scheme for Legionella pneumophila with Whole-Genome Sequence Data Using Validation Guidelines

PubMed Central

Mentasti, Massimo; Tewolde, Rediat; Aslett, Martin; Harris, Simon R.; Afshar, Baharak; Underwood, Anthony; Harrison, Timothy G.

2016-01-01

Sequence-based typing (SBT), analogous to multilocus sequence typing (MLST), is the current “gold standard” typing method for investigation of legionellosis outbreaks caused by Legionella pneumophila. However, as common sequence types (STs) cause many infections, some investigations remain unresolved. In this study, various whole-genome sequencing (WGS)-based methods were evaluated according to published guidelines, including (i) a single nucleotide polymorphism (SNP)-based method, (ii) extended MLST using different numbers of genes, (iii) determination of gene presence or absence, and (iv) a kmer-based method. L. pneumophila serogroup 1 isolates (n = 106) from the standard “typing panel,” previously used by the European Society for Clinical Microbiology Study Group on Legionella Infections (ESGLI), were tested together with another 229 isolates. Over 98% of isolates were considered typeable using the SNP- and kmer-based methods. Percentages of isolates with complete extended MLST profiles ranged from 99.1% (50 genes) to 86.8% (1,455 genes), while only 41.5% produced a full profile with the gene presence/absence scheme. Replicates demonstrated that all methods offer 100% reproducibility. Indices of discrimination range from 0.972 (ribosomal MLST) to 0.999 (SNP based), and all values were higher than that achieved with SBT (0.940). Epidemiological concordance is generally inversely related to discriminatory power. We propose that an extended MLST scheme with ∼50 genes provides optimal epidemiological concordance while substantially improving the discrimination offered by SBT and can be used as part of a hierarchical typing scheme that should maintain backwards compatibility and increase discrimination where necessary. This analysis will be useful for the ESGLI to design a scheme that has the potential to become the new gold standard typing method for L. pneumophila. PMID:27280420

Evaluation of an Optimal Epidemiological Typing Scheme for Legionella pneumophila with Whole-Genome Sequence Data Using Validation Guidelines.

PubMed

David, Sophia; Mentasti, Massimo; Tewolde, Rediat; Aslett, Martin; Harris, Simon R; Afshar, Baharak; Underwood, Anthony; Fry, Norman K; Parkhill, Julian; Harrison, Timothy G

2016-08-01

Sequence-based typing (SBT), analogous to multilocus sequence typing (MLST), is the current "gold standard" typing method for investigation of legionellosis outbreaks caused by Legionella pneumophila However, as common sequence types (STs) cause many infections, some investigations remain unresolved. In this study, various whole-genome sequencing (WGS)-based methods were evaluated according to published guidelines, including (i) a single nucleotide polymorphism (SNP)-based method, (ii) extended MLST using different numbers of genes, (iii) determination of gene presence or absence, and (iv) a kmer-based method. L. pneumophila serogroup 1 isolates (n = 106) from the standard "typing panel," previously used by the European Society for Clinical Microbiology Study Group on Legionella Infections (ESGLI), were tested together with another 229 isolates. Over 98% of isolates were considered typeable using the SNP- and kmer-based methods. Percentages of isolates with complete extended MLST profiles ranged from 99.1% (50 genes) to 86.8% (1,455 genes), while only 41.5% produced a full profile with the gene presence/absence scheme. Replicates demonstrated that all methods offer 100% reproducibility. Indices of discrimination range from 0.972 (ribosomal MLST) to 0.999 (SNP based), and all values were higher than that achieved with SBT (0.940). Epidemiological concordance is generally inversely related to discriminatory power. We propose that an extended MLST scheme with ∼50 genes provides optimal epidemiological concordance while substantially improving the discrimination offered by SBT and can be used as part of a hierarchical typing scheme that should maintain backwards compatibility and increase discrimination where necessary. This analysis will be useful for the ESGLI to design a scheme that has the potential to become the new gold standard typing method for L. pneumophila. Copyright © 2016 David et al.

Medical examiner/coroner records: uses and limitations in occupational injury epidemiologic research.

PubMed

Conroy, C; Russell, J C

1990-07-01

Epidemiologic research often relies on existing data, collected for nonepidemiologic reasons, to support studies. Data are obtained from hospital records, police reports, labor reports, death certificates, or other sources. Medical examiner/coroner records are, however, not often used in epidemiologic studies. The National Institute for Occupational Safety and Health's Division of Safety Research has begun using these records in its research program on work-related trauma. Because medical examiners and coroners have the legal authority and responsibility to investigate all externally caused deaths, these records can be used in surveillance of these deaths. Another use of these records is to validate cases identified by other case ascertainment methods, such as death certificates. Using medical examiner/coroner records also allows rapid identification of work-related deaths without waiting several years for mortality data from state offices of vital statistics. Finally, the records are an invaluable data source since they contain detailed information on the nature of the injury, external cause of death, and results of toxicologic testing, which is often not available from other sources. This paper illustrates some of the ways that medical examiner/coroner records are a valuable source of information for epidemiologic studies and makes recommendations to improve their usefulness.

Systemic review of the epidemiology of autism in Arab Gulf countries

PubMed Central

Salhia, Huda O.; Al-Nasser, Lubna A.; Taher, Lama S.; Al-Khathaami, Ali M.; El-Metwally, Ashraf A.

2014-01-01

Objective: To assess the current state of knowledge on the epidemiology of autism in Arab Gulf countries, and identify gaps for future research. Methods: PubMed and ScienceDirect databases were used to identify relevant articles published until the 3rd of April 2013 (date of search). The search was conducted using the electronic library of King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia. Studies were eligible for inclusion if they concerned the epidemiology of autism, conducted in any Arab Gulf country, and published in English. Results: Twelve articles met the inclusion criteria. Studies showed a prevalence ranging from 1.4 to 29 per 10,000 persons. Identified risk factors were metabolic, autoimmune, and environmental in nature. The following determinants were found as possible contributing factors for autism: suboptimal breast-feeding, advanced maternal and paternal age, cesarean section, and prenatal complications. Conclusion: Only a few studies explored the epidemiology of autism in Arab Gulf countries and none have investigated the burden of the disease on the child, family, or society. More research is needed to better identify the burden and risk factors of autism in Gulf countries. PMID:25274588

A Systematic Review of the Epidemiology of Echinococcosis in Domestic and Wild Animals

PubMed Central

Otero-Abad, Belen; Torgerson, Paul R.

2013-01-01

Background Human echinococcosis is a neglected zoonosis caused by parasites of the genus Echinococcus. The most frequent clinical forms of echinococcosis, cystic echinococcosis (CE) and alveolar echinococcosis (AE), are responsible for a substantial health and economic burden, particularly to low-income societies. Quantitative epidemiology can provide important information to improve the understanding of parasite transmission and hence is an important part of efforts to control this disease. The purpose of this review is to give an insight on factors associated with echinococcosis in animal hosts by summarising significant results reported from epidemiological studies identified through a systematic search. Methodology and Principal Findings The systematic search was conducted mainly in electronic databases but a few additional records were obtained from other sources. Retrieved entries were examined in order to identify available peer-reviewed epidemiological studies that found significant risk factors for infection using associative statistical methods. One hundred studies met the eligibility criteria and were suitable for data extraction. Epidemiological factors associated with increased risk of E. granulosus infection in dogs included feeding with raw viscera, possibility of scavenging dead animals, lack of anthelmintic treatment and owners' poor health education and indicators of poverty. Key factors associated with E. granulosus infection in intermediate hosts were related to the hosts' age and the intensity of environmental contamination with parasite eggs. E. multilocularis transmission dynamics in animal hosts depended on the interaction of several ecological factors, such as hosts' population densities, host-prey interactions, landscape characteristics, climate conditions and human-related activities. Conclusions/Significance Results derived from epidemiological studies provide a better understanding of the behavioural, biological and ecological factors involved in the transmission of this parasite and hence can aid in the design of more effective control strategies. PMID:23755310

Research Methods in Healthcare Epidemiology and Antimicrobial Stewardship: Use of Administrative and Surveillance Databases.

PubMed

Drees, Marci; Gerber, Jeffrey S; Morgan, Daniel J; Lee, Grace M

2016-11-01

Administrative and surveillance data are used frequently in healthcare epidemiology and antimicrobial stewardship (HE&AS) research because of their wide availability and efficiency. However, data quality issues exist, requiring careful consideration and potential validation of data. This methods paper presents key considerations for using administrative and surveillance data in HE&AS, including types of data available and potential use, data limitations, and the importance of validation. After discussing these issues, we review examples of HE&AS research using administrative data with a focus on scenarios when their use may be advantageous. A checklist is provided to help aid study development in HE&AS using administrative data. Infect Control Hosp Epidemiol 2016;1-10.

Conduct Disorder and Oppositional Defiant Disorder in a National Sample: Developmental Epidemiology

ERIC Educational Resources Information Center

Maughan, Barbara; Rowe, Richard; Messer, Julie; Goodman, Robert; Meltzer, Howard

2004-01-01

Background: Despite an expanding epidemiological evidence base, uncertainties remain over key aspects of the epidemiology of the "antisocial" disorders in childhood and adolescence. Methods: We used cross-sectional data on a nationally representative sample of 10,438 5-15-year-olds drawn from the 1999 British Child Mental Health Survey…

[A literature review on epidemiologic research on sleep disturbances in the elderly].

PubMed

Doi, Yuriko

2015-06-01

One of the issues facing our super-aging society of Japan is to secure the elderly's safety and health. According to the latest 10-year statistics of the National Police Agency, the number of elderly driving deaths 75 years of age and over has risen 1.3 times from 2003 to 2013, whereas driving deaths decreased by less than half among the people under age 75 during the same period of time. This paper reviews the current literature on epidemiologic studies investigating the associations of sleep disturbances with adverse driving events and driving practice among elderly drivers. The results suggest a cognitive behavioral therapy for insomnia as a promising method for improving their driving capacity. Key words: elderly driving, epidemiology, sleep disturbances

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

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

DOE PAGES

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua; ...

2015-11-27

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

The utility of web mining for epidemiological research: studying the association between parity and cancer risk [Web Mining for Epidemiological Research. Assessing its Utility in Exploring the Association Between Parity and Cancer Risk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tourassi, Georgia; Yoon, Hong-Jun; Xu, Songhua

Background: The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods: Using advanced web crawling and tailored information extraction procedures we automatically collected and analyzed the text content of 79,394 online obituary articles published between 1998 and 2014. The collected data included 51,911 cancer (27,330 breast; 9,470 lung; 6,496 pancreatic; 6,342 ovarian; 2,273 colon) and 27,483 non-cancer cases. With the derived information, we replicated a case-control study design to investigate the association between parity and cancer risk. Age-adjusted odds ratiosmore » (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results: Parity was found to be associated with a significantly reduced risk of breast cancer (OR=0.78, 95% CI = 0.75 to 0.82), pancreatic cancer (OR=0.78, 95% CI = 0.72 to 0.83), colon cancer (OR=0.67, 95% CI = 0.60 to 0.74), and ovarian cancer (OR=0.58, 95% CI = 0.54 to 0.62). Marginal association was found for lung cancer prevalence (OR=0.87, 95% CI = 0.81 to 0.92). The linear trend between multi-parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion: This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies.« less

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.

Neisseria gonorrhoeae molecular typing for understanding sexual networks and antimicrobial resistance transmission: A systematic review.

PubMed

Town, Katy; Bolt, Hikaru; Croxford, Sara; Cole, Michelle; Harris, Simon; Field, Nigel; Hughes, Gwenda

2018-06-01

Neisseria gonorrhoeae (NG) is a significant global public health concern due to rising diagnoses rates and antimicrobial resistance. Molecular combined with epidemiological data have been used to understand the distribution and spread of NG, as well as relationships between cases in sexual networks, but the public health value gained from these studies is unclear. We conducted a systematic review to examine how molecular epidemiological studies have informed understanding of sexual networks and NG transmission, and subsequent public health interventions. Five research databases were systematically searched up to 31st March 2017 for studies that used sequence-based DNA typing methods, including whole genome sequencing, and linked molecular data to patient-level epidemiological data. Data were extracted and summarised to identify common themes. Of the 49 studies included, 82% used NG Multi-antigen Sequence Typing. Gender and sexual orientation were commonly used to characterise sexual networks that were inferred using molecular clusters; clusters predominantly of one patient group often contained a small number of isolates from other patient groups. Suggested public health applications included using these data to target interventions at specific populations, confirm outbreaks, and inform partner management, but these were mainly untested. Combining molecular and epidemiological data has provided insight into sexual mixing patterns, and dissemination of NG, but few studies have applied these findings to design or evaluate public health interventions. Future studies should focus on the application of molecular epidemiology in public health practice to provide evidence for how to prevent and control NG. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Differentiation of Staphylococcus aureus isolates based on phenotypical characters].

PubMed

Miedzobrodzki, Jacek; Małachowa, Natalia; Markiewski, Tomasz; Białecka, Anna; Kasprowicz, Andrzej

2008-06-30

Typing of Staphylococcus aureus isolates is a necessary procedure for monitoring the transmission of S. aureus among carriers and in epidemiology. Evaluation of the range of relationship among isolates rely on epidemiological markers and is possible because of the clonal character of S. aureus species. Effective typing shows the scheme of transmission of infection in a selected area, enables identifying the reservoir of the microorganism, and may enhance effective eradication. A set of typing methods for use in analyses of epidemiological correlations and the identification of S. aureus isolates is presented. The following methods of typing are described: biotyping, serotyping, antibiogram, protein electrophoresis, cell protein profiles (proteom), immunoblotting, multilocus enzyme electrophoresis (MLEE), zymotyping, and standard species identification of S. aureus in the diagnostic laboratory. Phenotyping methods for S. aureus isolates used in the past and today in epidemiological investigations and in analyses of correlations among S. aureus isolates are presented in this review. The presented methods use morphological characteristics, physiological properties, and chemical structures of the bacteria as criteria for typing. The precision of these standard methods is not always satisfactory as S. aureus strains with atypical biochemical characters have evolved recently. Therefore it is essential to introduce additional typing procedures using molecular biology methods without neglecting phenotypic methods.

Developing the WCRF International/University of Bristol Methodology for Identifying and Carrying Out Systematic Reviews of Mechanisms of Exposure-Cancer Associations.

PubMed

Lewis, Sarah J; Gardner, Mike; Higgins, Julian; Holly, Jeff M P; Gaunt, Tom R; Perks, Claire M; Turner, Suzanne D; Rinaldi, Sabina; Thomas, Steve; Harrison, Sean; Lennon, Rosie J; Tan, Vanessa; Borwick, Cath; Emmett, Pauline; Jeffreys, Mona; Northstone, Kate; Mitrou, Giota; Wiseman, Martin; Thompson, Rachel; Martin, Richard M

2017-11-01

Background: Human, animal, and cell experimental studies; human biomarker studies; and genetic studies complement epidemiologic findings and can offer insights into biological plausibility and pathways between exposure and disease, but methods for synthesizing such studies are lacking. We, therefore, developed a methodology for identifying mechanisms and carrying out systematic reviews of mechanistic studies that underpin exposure-cancer associations. Methods: A multidisciplinary team with expertise in informatics, statistics, epidemiology, systematic reviews, cancer biology, and nutrition was assembled. Five 1-day workshops were held to brainstorm ideas; in the intervening periods we carried out searches and applied our methods to a case study to test our ideas. Results: We have developed a two-stage framework, the first stage of which is designed to identify mechanisms underpinning a specific exposure-disease relationship; the second stage is a targeted systematic review of studies on a specific mechanism. As part of the methodology, we also developed an online tool for text mining for mechanism prioritization (TeMMPo) and a new graph for displaying related but heterogeneous data from epidemiologic studies (the Albatross plot). Conclusions: We have developed novel tools for identifying mechanisms and carrying out systematic reviews of mechanistic studies of exposure-disease relationships. In doing so, we have outlined how we have overcome the challenges that we faced and provided researchers with practical guides for conducting mechanistic systematic reviews. Impact: The aforementioned methodology and tools will allow potential mechanisms to be identified and the strength of the evidence underlying a particular mechanism to be assessed. Cancer Epidemiol Biomarkers Prev; 26(11); 1667-75. ©2017 AACR . ©2017 American Association for Cancer Research.

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2012 CFR

2012-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2013 CFR

2013-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2014 CFR

2014-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

38 CFR 1.17 - Evaluation of studies relating to health effects of radiation exposure.

Code of Federal Regulations, 2011 CFR

2011-07-01

... health effects of radiation exposure. (a) From time to time, the Secretary shall publish evaluations of... paragraph a valid study is one which: (i) Has adequately described the study design and methods of data... studies affecting epidemiological assessments including case series, correlational studies and studies...

New Exposure Biomarkers as Tools for Breast Cancer Epidemiology, Biomonitoring, and Prevention: A Systematic Approach Based on Animal Evidence

PubMed Central

Ackerman, Janet M.; Attfield, Kathleen R.; Brody, Julia Green

2014-01-01

Background: Exposure to chemicals that cause rodent mammary gland tumors is common, but few studies have evaluated potential breast cancer risks of these chemicals in humans. Objective: The goal of this review was to identify and bring together the needed tools to facilitate the measurement of biomarkers of exposure to potential breast carcinogens in breast cancer studies and biomonitoring. Methods: We conducted a structured literature search to identify measurement methods for exposure biomarkers for 102 chemicals that cause rodent mammary tumors. To evaluate concordance, we compared human and animal evidence for agents identified as plausibly linked to breast cancer in major reviews. To facilitate future application of exposure biomarkers, we compiled information about relevant cohort studies. Results: Exposure biomarkers have been developed for nearly three-quarters of these rodent mammary carcinogens. Analytical methods have been published for 73 of the chemicals. Some of the remaining chemicals could be measured using modified versions of existing methods for related chemicals. In humans, biomarkers of exposure have been measured for 62 chemicals, and for 45 in a nonoccupationally exposed population. The Centers for Disease Control and Prevention has measured 23 in the U.S. population. Seventy-five of the rodent mammary carcinogens fall into 17 groups, based on exposure potential, carcinogenicity, and structural similarity. Carcinogenicity in humans and rodents is generally consistent, although comparisons are limited because few agents have been studied in humans. We identified 44 cohort studies, with a total of > 3.5 million women enrolled, that have recorded breast cancer incidence and stored biological samples. Conclusions: Exposure measurement methods and cohort study resources are available to expand biomonitoring and epidemiology related to breast cancer etiology and prevention. Citation: Rudel RA, Ackerman JM, Attfield KR, Brody JG. 2014. New exposure biomarkers as tools for breast cancer epidemiology, biomonitoring, and prevention: a systematic approach based on animal evidence. Environ Health Perspect 122:881–895; http://dx.doi.org/10.1289/ehp.1307455 PMID:24818537

An assessment of the possible extent of confounding in epidemiological studies of lung cancer risk among roofers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mundt, D.J.; van Wijngaarden, E.; Mundt, K.A.

2007-07-01

We evaluated the likelihood and extent to which the observed increased risk of lung cancer may be due to confounding (a mixing of effects of multiple exposures) by co-exposure to other potential carcinogens present in roofing or to lifestyle variables. We conducted a review of the epidemiological and industrial hygiene literature of asphalt-exposed workers. Peer-reviewed epidemiological studies of asphalt fumes, related occupational exposures, and confounding factors were identified from MEDLINE (1966 early 2004). Industrial hygiene studies of asphalt workers were identified through MEDLINE, publicly available government documents, and asphalt industry documents. Using well established statistical methods, we quantified the extentmore » to which lung cancer relative risk estimates among roofers reflect confounding from other exposures, using different prevalence and risk scenarios. The relative risk of lung cancer varied from 1.2 to 5.0 in 13 epidemiological studies of roofers; most studies reported a relative risk between 1.2 and 1.4. Smoking, asbestos and coal tar were the most likely confounders, but the prevalence of these factors varied over time. The results of the study indicate that much of the observed risk reported in epidemiological studies of cancer among roofers is well within the range of what may have resulted from confounding by reasonable and expected levels of smoking, asbestos or coal tar. This may be particularly true for those studies that did not adjust for these confounders and where the exposure was defined as employment in the roofing industry. In addition to poorly defined asphalt exposure, uncontrolled confounding cannot reliably be ruled out in studies of lung cancer among asphalt-exposed roofers. Therefore, it is not possible to conclude whether roofers are at increased risk of lung cancer due to asphalt exposure.« less

Challenges on the epidemiological and economic burden of diabetes and hypertension in Mexico.

PubMed

Arredondo, Armando; Orozco, Emanuel; Alcalde-Rabanal, Jaqueline; Navarro, Juan; Azar, Alejandra

2018-01-01

OBJECTIVE To analyze the epidemiological and economic burden of the health services demand due to diabetes and hypertension in Mexico. METHODS Evaluation study based on a time series study that had as a universe of study the assured and uninsured population that demands health services from the three main institutions of the Health System in Mexico: The Health Department, the Mexican Institute of Social Security, and Institute of Services and Social Security for State Workers. The financing method was based on instrumentation and consensus techniques for medium case management. In order to estimate the epidemiological changes and financial requirements, a time series of observed cases for diabetes and hypertension 1994-2013 was integrated. Probabilistic models were developed based on the Box-Jenkins technique for the period of 2013-2018 with 95% confidence intervals and p < 0.05. RESULTS Comparing results from 2013 versus 2018, in the five regions, different incremental trends of 14%-17% in epidemiological changes and 58%-66% in the economic burden for both diseases were observed. CONCLUSIONS If the risk factors and the different models of care remained as they currently are in the three institutions analyzed, the financial consequences would be of greater impact for the Mexican Institute of Social Security, following in order of importance the Institute of Services and Social Security for State Workers and lastly the Health Department. The financial needs for both diseases will represent approximately 13%-15% of the total budget allocated to the uninsured population and 15%-17% for the population insured depending on the region.

Challenges on the epidemiological and economic burden of diabetes and hypertension in Mexico

PubMed Central

Arredondo, Armando; Orozco, Emanuel; Alcalde-Rabanal, Jaqueline; Navarro, Juan; Azar, Alejandra

2018-01-01

ABSTRACT OBJECTIVE To analyze the epidemiological and economic burden of the health services demand due to diabetes and hypertension in Mexico. METHODS Evaluation study based on a time series study that had as a universe of study the assured and uninsured population that demands health services from the three main institutions of the Health System in Mexico: The Health Department, the Mexican Institute of Social Security, and Institute of Services and Social Security for State Workers. The financing method was based on instrumentation and consensus techniques for medium case management. In order to estimate the epidemiological changes and financial requirements, a time series of observed cases for diabetes and hypertension 1994–2013 was integrated. Probabilistic models were developed based on the Box-Jenkins technique for the period of 2013–2018 with 95% confidence intervals and p < 0.05. RESULTS Comparing results from 2013 versus 2018, in the five regions, different incremental trends of 14%–17% in epidemiological changes and 58%-66% in the economic burden for both diseases were observed. CONCLUSIONS If the risk factors and the different models of care remained as they currently are in the three institutions analyzed, the financial consequences would be of greater impact for the Mexican Institute of Social Security, following in order of importance the Institute of Services and Social Security for State Workers and lastly the Health Department. The financial needs for both diseases will represent approximately 13%–15% of the total budget allocated to the uninsured population and 15%–17% for the population insured depending on the region. PMID:29489993

Epidemiologic methods in clinical trials.

PubMed

Rothman, K J

1977-04-01

Epidemiologic methods developed to control confounding in non-experimental studies are equally applicable for experiments. In experiments, most confounding is usually controlled by random allocation of subjects to treatment groups, but randomization does not preclude confounding except for extremely large studies, the degree of confounding expected being inversely related to the size of the treatment groups. In experiments, as in non-experimental studies, the extent of confounding for each risk indicator should be assessed, and if sufficiently large, controlled. Confounding is properly assessed by comparing the unconfounded effect estimate to the crude effect estimate; a common error is to assess confounding by statistical tests of significance. Assessment of confounding involves its control as a prerequisite. Control is most readily and cogently achieved by stratification of the data, though with many factors to control simultaneously, multivariate analysis or a combination of multivariate analysis and stratification might be necessary.

Pushing and pulling in relation to musculoskeletal disorders: a review of risk factors.

PubMed

Hoozemans, M J; van der Beek, A J; Frings-Dresen, M H; van Dijk, F J; van der Woude, L H

1998-06-01

The objective was to review the literature on risk factors for musculoskeletal disorders related to pushing and pulling. The risk factors have been described and evaluated from four perspectives: epidemiology, psychophysics, physiology, and biomechanics. Epidemiological studies have shown, based on cross-sectional data, that pushing and pulling is associated with low back pain. Evidence with respect to complaints of other parts of the musculoskeletal system is lacking. Risk factors have been found to influence the maximum (acceptable) push or pull forces as well as the physiological and mechanical strain on the human body. The risk factors have been divided into: (a) work situation, such as distance, frequency, handle height, and cart weight, (b) actual working method and posture/movement/exerted forces, such as foot distance and velocity, and (c) worker's characteristics, such as body weight. Longitudinal epidemiological studies are needed to relate pushing and pulling to musculoskeletal disorders.

Missing data in FFQs: making assumptions about item non-response.

PubMed

Lamb, Karen E; Olstad, Dana Lee; Nguyen, Cattram; Milte, Catherine; McNaughton, Sarah A

2017-04-01

FFQs are a popular method of capturing dietary information in epidemiological studies and may be used to derive dietary exposures such as nutrient intake or overall dietary patterns and diet quality. As FFQs can involve large numbers of questions, participants may fail to respond to all questions, leaving researchers to decide how to deal with missing data when deriving intake measures. The aim of the present commentary is to discuss the current practice for dealing with item non-response in FFQs and to propose a research agenda for reporting and handling missing data in FFQs. Single imputation techniques, such as zero imputation (assuming no consumption of the item) or mean imputation, are commonly used to deal with item non-response in FFQs. However, single imputation methods make strong assumptions about the missing data mechanism and do not reflect the uncertainty created by the missing data. This can lead to incorrect inference about associations between diet and health outcomes. Although the use of multiple imputation methods in epidemiology has increased, these have seldom been used in the field of nutritional epidemiology to address missing data in FFQs. We discuss methods for dealing with item non-response in FFQs, highlighting the assumptions made under each approach. Researchers analysing FFQs should ensure that missing data are handled appropriately and clearly report how missing data were treated in analyses. Simulation studies are required to enable systematic evaluation of the utility of various methods for handling item non-response in FFQs under different assumptions about the missing data mechanism.

Foodborne Infectious Diseases Mediated by Inappropriate Infection Control in Food Service Businesses and Relevant Countermeasures in Korea

PubMed Central

Park, Jong Myong; You, Young-Hyun; Cho, Hyun-Min; Hong, Ji Won; Ghim, Sa-Youl

2017-01-01

Objectives The objective of this review is to propose an appropriate course of action for improving the guidelines followed by food handlers for control of infection. For this purpose, previous epidemiological reports related to acute gastroenteritis in food service businesses mediated by food handlers were intensively analyzed. Methods Relevant studies were identified in international databases. We selected eligible papers reporting foodborne infectious disease outbreaks. Among primary literature collection, the abstract of each article was investigated to find cases that absolutely identified a causative factor to be food handlers’ inappropriate infection control and the taxon of causative microbial agents by epidemiological methodologies. Information about the sites (type of food business) where the outbreaks occurred was investigated. Results A wide variety of causative microbial agents has been investigated, using several epidemiological methods. These agents have shown diverse propagation pathways based on their own molecular pathogenesis, physiology, taxonomy, and etiology. Conclusion Depending on etiology, transmission, propagation, and microbiological traits, we can predict the transmission characteristics of pathogens in food preparation areas. The infected food workers have a somewhat different ecological place in infection epidemiology as compared to the general population. However, the current Korean Food Safety Act cannot propose detailed guidelines. Therefore, different methodologies have to be made available to prevent further infections. PMID:28781938

Development, reproducibility and validity of the food frequency questionnaire in the Poland arm of the Prospective Urban and Rural Epidemiological (PURE) study.

PubMed

Dehghan, M; Ilow, R; Zatonska, K; Szuba, A; Zhang, X; Mente, A; Regulska-Ilow, B

2012-06-01

A food frequency questionnaire (FFQ) is the most commonly used method in large epidemiological studies. The validation of an FFQ is essential for specific populations because foods are culture-dependent. The present study aimed to develop an FFQ and evaluate its validity and reproducibility in estimating the intake of nutrients in urban and rural areas of Poland. Adult participants (n = 146) in the Polish arm of the ongoing Prospective Urban and Rural Epidemiological (PURE) study completed FFQs on two occasions, as well as four 24-h dietary recalls (DRs) during a 12-month period. Correlation coefficients (r) and de-attenuated correlation coefficients between dietary recalls and both FFQs were calculated for selected macro- and micronutrients. Agreement between the two methods was evaluated by classification into quartiles and the Bland-Altman method. Reproducibility was assessed by the intra-class correlation coefficient (ICC). The final food list contained 134 food items. For urban participants, FFQ2 generally underestimated energy, protein and fat compared to the FFQ1 and mean of DRs. In rural areas, compared to DRs, both FFQs overestimated energy and macronutrients. For both urban and rural settings, de-attenuated correlation exceeded 0.4 for almost all nutrients and the exact agreement in quartile categorisation was >66%. When assessing repeatability, ICC varied from 0.39-0.63 in an urban setting and 0.19-0.45 in a rural setting. This 134-item FFQ has good validity and reproducibility in relation to the reference method and can be used to rank individuals based on their macro- and micronutrient intake. © 2012 The Authors. Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.

The NHLBI Retrovirus Epidemiology Donor Studies (REDS and REDS-II): Twenty years of research to advance blood product safety and availability

PubMed Central

Kleinman, Steven; King, Melissa R; Busch, Michael P; Murphy, Edward L; Glynn, Simone A.

2012-01-01

The Retrovirus Epidemiology Donor Study (REDS), conducted from 1989–2001, and the Retrovirus Epidemiology Donor Study-II (REDS-II), conducted from 2004–2012, were National Heart Lung and Blood Institute (NHLBI) funded multicenter programs focused on improving blood safety and availability in the United States. REDS-II also included international study sites in Brazil and China. The three major research domains of REDS/REDS-II have been infectious disease risk evaluation, blood donation availability, and blood donor characterization. Both programs have made significant contributions to transfusion medicine research methodology by the use of mathematical modeling, large-scale donor surveys, innovative methods of repository sample storage, and establishing an infrastructure that responded to potential emerging blood safety threats such as XMRV. Blood safety studies have included protocols evaluating epidemiologic and/or laboratory aspects of HIV, HTLV I/II, HCV, HBV, WNV, CMV, HHV-8, B19V, malaria, CJD, influenza, and T. cruzi infections. Other analyses have characterized: blood donor demographics, motivations to donate, factors influencing donor return, behavioral risk factors, donors’ perception of the blood donation screening process, and aspects of donor deferral. In REDS-II, two large-scale blood donor protocols examined iron deficiency in donors and the prevalence of leukocyte antibodies. This review describes the major study results from over 150 peer-reviewed articles published by these two REDS programs. In 2011, a new seven year program, the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III), was launched. REDS-III expands beyond donor-based research to include studies of blood transfusion recipients in the hospital setting, and adds a third country, South Africa, to the international program. PMID:22633182

The utility of web mining for epidemiological research: studying the association between parity and cancer risk

PubMed Central

Yoon, Hong-Jun; Xu, Songhua; Han, Xuesong

2016-01-01

Background The World Wide Web has emerged as a powerful data source for epidemiological studies related to infectious disease surveillance. However, its potential for cancer-related epidemiological discoveries is largely unexplored. Methods Using advanced web crawling and tailored information extraction procedures, the authors automatically collected and analyzed the text content of 79 394 online obituary articles published between 1998 and 2014. The collected data included 51 911 cancer (27 330 breast; 9470 lung; 6496 pancreatic; 6342 ovarian; 2273 colon) and 27 483 non-cancer cases. With the derived information, the authors replicated a case-control study design to investigate the association between parity (i.e., childbearing) and cancer risk. Age-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each cancer type and compared to those reported in large-scale epidemiological studies. Results Parity was found to be associated with a significantly reduced risk of breast cancer (OR = 0.78, 95% CI, 0.75-0.82), pancreatic cancer (OR = 0.78, 95% CI, 0.72-0.83), colon cancer (OR = 0.67, 95% CI, 0.60-0.74), and ovarian cancer (OR = 0.58, 95% CI, 0.54-0.62). Marginal association was found for lung cancer risk (OR = 0.87, 95% CI, 0.81-0.92). The linear trend between increased parity and reduced cancer risk was dramatically more pronounced for breast and ovarian cancer than the other cancers included in the analysis. Conclusion This large web-mining study on parity and cancer risk produced findings very similar to those reported with traditional observational studies. It may be used as a promising strategy to generate study hypotheses for guiding and prioritizing future epidemiological studies. PMID:26615183

Circular epidemiology.

PubMed

Kuller, L H

1999-11-01

Circular epidemiology can be defined as the continuation of specific types of epidemiologic studies beyond the point of reasonable doubt of the true existence of an important association or the absence of such an association. Circular epidemiology is an extreme example of studies of the consistency of associations. A basic problem for epidemiology is the lack of a systematic approach to acquiring new knowledge to reach a goal of improving public health and preventive medicine. For epidemiologists, research support unfortunately is biased toward the continued study of already proven hypotheses. Circular epidemiology, however, freezes at one point in the evolution of epidemiologic studies, failing to move from descriptive to analytical case-control and longitudinal studies, for example, to experimental, clinical trials. Good epidemiology journals are filled with very well-conducted epidemiologic studies that primarily repeat the obvious or are variations on the theme.

A comparison between self-reported and GIS-based proxies of residential exposure to environmental pollution in a case-control study on lung cancer.

PubMed

Cordioli, M; Ranzi, A; Freni Sterrantino, A; Erspamer, L; Razzini, G; Ferrari, U; Gatti, M G; Bonora, K; Artioli, F; Goldoni, C A; Lauriola, P

2014-06-01

In epidemiological studies both questionnaire results and GIS modeling have been used to assess exposure to environmental risk factors. Nevertheless, few studies have used both these techniques to evaluate the degree of agreement between different exposure assessment methodologies. As part of a case-control study on lung cancer, we present a comparison between self-reported and GIS-derived proxies of residential exposure to environmental pollution. 649 subjects were asked to fill out a questionnaire and give information about residential history and perceived exposure. Using GIS, for each residence we evaluated land use patterns, proximity to major roads and exposure to industrial pollution. We then compared the GIS exposure-index values among groups created on the basis of questionnaire responses. Our results showed a relatively high agreement between the two methods. Although none of these methods is the "exposure gold standard", understanding similarities, weaknesses and strengths of each method is essential to strengthen epidemiological evidence. Copyright © 2014 Elsevier Ltd. All rights reserved.

Panic disorder and its subtypes: a comprehensive analysis of panic symptom heterogeneity using epidemiological and treatment seeking samples

PubMed Central

Roberson-Nay, R.; Kendler, K. S.

2014-01-01

Background Panic disorder (PD) is a heterogeneous syndrome that can present with a variety of symptom profiles that potentially reflect distinct etiologic pathways. The present study represents the most comprehensive examination of phenotypic variance in PD with and without agoraphobia for the purpose of identifying clinically relevant and etiologically meaningful subtypes. Method Latent class (LC) and factor mixture analysis were used to examine panic symptom data ascertained from three national epidemiologic surveys [Epidemiological Catchment Area (ECA), National Comorbidity Study (NCS), National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), Wave 1], a twin study [Virginia Adult Twin Study of Psychiatric and Substance Use Disorders (VATSPSUD)] and a clinical trial (Cross-National Collaborative Panic Study [CNCPS]). Results Factor mixture models (versus LC) generally provided better fit to panic symptom data and suggested two panic classes for the ECA, VATSPSUD and CNCPS, with one class typified by prominent respiratory symptoms. The NCS yielded two classes, but suggested both qualitative and quantitative differences. The more contemporary NESARC sample supported a two and three class model, with the three class model suggesting two variants of respiratory panic. The NESARC’s three class model continued to provide the best fit when the model was restricted to a more severe form of PD/panic disorder with agoraphobia. Conclusions Results from epidemiologic and clinical samples suggest two panic subtypes, with one subtype characterized by a respiratory component and a second class typified by general somatic symptoms. Results are discussed in light of their relevance to the etiopathogenesis of PD. PMID:21557895

[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.

Identification, typing, ecology and epidemiology of coagulase negative staphylococci associated with ruminants.

PubMed

Vanderhaeghen, Wannes; Piepers, Sofie; Leroy, Frédéric; Van Coillie, Els; Haesebrouck, Freddy; De Vliegher, Sarne

2015-01-01

Since phenotypic methods to identify coagulase negative staphylococci (CNS) from the milk of ruminants often yield unreliable results, methods for molecular identification based on gene sequencing or fingerprinting techniques have been developed. In addition to culture-based detection of isolates, culture-independent methods may be of interest. On the basis of molecular studies, the five CNS species commonly causing intramammary infections (IMI) are Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus simulans and Staphylococcus xylosus. Current knowledge suggests that S. chromogenes is a bovine-adapted species, with most cases of IMI due to this bacterium being opportunistic. S. haemolyticus also appears to be an opportunistic pathogen, but this bacterium occupies a variety of habitats, the importance of which as a source of IMI remains to be elucidated. S. xylosus appears to be a versatile species, but little is known of its epidemiology. S. epidermidis is considered to be a human-adapted species and most cases of IMI appear to arise from human sources, but the organism is capable of residing in other habitats. S. simulans typically causes contagious IMI, but opportunistic cases also occur and the ecology of this bacterium requires further study. Further studies of the ecology and epidemiology of CNS as a cause of IMI in cattle are required, along with careful attention to classification of these bacteria and the diseases they cause. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Epidemiological Perspective of Obsessive-Compulsive Disorder in Children and Adolescents

PubMed Central

Fogel, Joshua

2003-01-01

Obsessive-compulsive disorder (OCD) is reviewed from an epidemiological perspective. OCD is defined according to the DSM-IV and ICD-10, with differences noted between these two classification systems. The epidemiological rubrics of quantity (prevalence), location (genetic methods and gender differences), cause (genetic etiology), and causal mechanisms (natural history and clinical course) are reviewed. The review concludes that more research is needed to further understand the epidemiology of OCD in children and adolescents, both from a Canadian and worldwide perspective. PMID:19030478

Beverage and water intake of healthy adults in some European countries.

PubMed

Nissensohn, Mariela; Castro-Quezada, Itandehui; Serra-Majem, Lluis

2013-11-01

Nutritional surveys frequently collect some data of consumption of beverages; however, information from different sources and different methodologies raises issues of comparability. The main objective of this review was to examine the available techniques used for assessing beverage intake in European epidemiological studies and to describe the most frequent method applied to assess it. Information of beverage intake available from European surveys and nutritional epidemiological investigations was obtained from gray literature. Twelve articles were included and relevant data were extracted. The studies were carried out on healthy adults by different types of assessments. The most frequent tool used was a 7-d dietary record. Only Germany used a specific beverage assessment tool (Beverage Dietary History). From the limited data available and the diversity of the methodology used, the results show that consumption of beverages is different between countries. Current epidemiological studies in Europe focusing on beverage intake are scarce. Further research is needed to clarify the amount of beverage intake in European population.

MATERIALS SUPPORTING THE NEW RECREATIONAL ...

EPA Pesticide Factsheets

EPA is developing new, rapid methods for monitoring water quality at beaches to determine adequacy of water quality for swimming. The methods being developed rely upon quantitive polymerase chain reaction technology. They will permit real time decisions regarding beach closures. The methods are supported by a series of epidemiology studies evaluating the rate of GI illness resulting from swimming events. Implementation of BEACH Act amendments

Arsenic metabolism and cancer risk: A meta-analysis.

PubMed

Gamboa-Loira, Brenda; Cebrián, Mariano E; Franco-Marina, Francisco; López-Carrillo, Lizbeth

2017-07-01

To describe the studies that have reported association measures between risk of cancer and the percentage distribution of urinary inorganic arsenic (iAs) metabolites by anatomical site, in non-ecological epidemiological studies. Studies were identified in the PubMed database in the period from 1990 to 2015. Inclusion criteria were: non-ecological epidemiological study, with histologically confirmed cancer cases, reporting the percentage distribution of inorganic arsenic (iAs), monomethylated (MMA) and dimethylated (DMA) metabolites, as well as association measures with confidence intervals (CI) between cancer and %iAs and/or %MMA and/or %DMA. A descriptive meta-analysis was performed by the method of the inverse of the variance for the fixed effects model and the DerSimonian and Laird's method for the random effects model. Heterogeneity was tested using the Q statistic and stratifying for epidemiological design and total As in urine. The possibility of publication bias was assessed through Begg's test. A total of 13 eligible studies were found, most of them were performed in Taiwan and focused on skin and bladder cancer. The positive association between %MMA and various types of cancer was consistent, in contrast to the negative relationship between %DMA and cancer that was inconsistent. The summary risk of bladder (OR=1.79; 95% CI: 1.42, 2.26, n=4 studies) and lung (OR=2.44; 95% CI: 1.57, 3.80, n=2 studies) cancer increased significantly with increasing %MMA, without statistical heterogeneity. In contrast, lung cancer risk was inversely related to %DMA (OR=0.58; 95% CI: 0.36, 0.93, n=2 studies), also without significant heterogeneity. These results were similar after stratifying by epidemiological design and total As in urine. No evidence of publication bias was found. These findings provide additional support that methylation needs to be taken into account when assessing the potential iAs carcinogenicity risk. Copyright © 2017. Published by Elsevier Inc.

Response rate differences between web and alternative data collection methods for public health research: a systematic review of the literature.

PubMed

Blumenberg, Cauane; Barros, Aluísio J D

2018-07-01

To systematically review the literature and compare response rates (RRs) of web surveys to alternative data collection methods in the context of epidemiologic and public health studies. We reviewed the literature using PubMed, LILACS, SciELO, WebSM, and Google Scholar databases. We selected epidemiologic and public health studies that considered the general population and used two parallel data collection methods, being one web-based. RR differences were analyzed using two-sample test of proportions, and pooled using random effects. We investigated agreement using Bland-and-Altman, and correlation using Pearson's coefficient. We selected 19 studies (nine randomized trials). The RR of the web-based data collection was 12.9 percentage points (p.p.) lower (95% CI = - 19.0, - 6.8) than the alternative methods, and 15.7 p.p. lower (95% CI = - 24.2, - 7.3) considering only randomized trials. Monetary incentives did not reduce the RR differences. A strong positive correlation (r = 0.83) between the RRs was observed. Web-based data collection present lower RRs compared to alternative methods. However, it is not recommended to interpret this as a meta-analytical evidence due to the high heterogeneity of the studies.

College Health Surveillance Network: Epidemiology and Health Care Utilization of College Students at US 4-Year Universities

PubMed Central

Turner, James C.; Keller, Adrienne

2015-01-01

Abstract Objective: This description of the College Health Surveillance Network (CHSN) includes methodology, demography, epidemiology, and health care utilization. Participants: Twenty-three universities representing approximately 730,000 enrolled students contributed data from January 1, 2011, through May 31, 2014. Methods: Participating schools uploaded de-identified electronic health records from student health services monthly. Results: During this study, just over 800,000 individuals used the health centers, comprising 4.17 million patient encounters. Sixty percent of visits included primary care, 13% mental health, 9% vaccination, and 31% other miscellaneous services. The 5 most common specific diagnostic categories (with annual rates per 100 enrolled students) were preventive (16); respiratory (12); skin, hair, and nails; infectious non–sexually transmitted infection (5 each); and mental health (4). Utilization and epidemiologic trends are identified among subpopulations of students. Conclusions: CHSN data establish trends in utilization and epidemiologic patterns by college students and the importance of primary and behavioral health care services on campuses. PMID:26086428

Emerging trends in geospatial artificial intelligence (geoAI): potential applications for environmental epidemiology.

PubMed

VoPham, Trang; Hart, Jaime E; Laden, Francine; Chiang, Yao-Yi

2018-04-17

Geospatial artificial intelligence (geoAI) is an emerging scientific discipline that combines innovations in spatial science, artificial intelligence methods in machine learning (e.g., deep learning), data mining, and high-performance computing to extract knowledge from spatial big data. In environmental epidemiology, exposure modeling is a commonly used approach to conduct exposure assessment to determine the distribution of exposures in study populations. geoAI technologies provide important advantages for exposure modeling in environmental epidemiology, including the ability to incorporate large amounts of big spatial and temporal data in a variety of formats; computational efficiency; flexibility in algorithms and workflows to accommodate relevant characteristics of spatial (environmental) processes including spatial nonstationarity; and scalability to model other environmental exposures across different geographic areas. The objectives of this commentary are to provide an overview of key concepts surrounding the evolving and interdisciplinary field of geoAI including spatial data science, machine learning, deep learning, and data mining; recent geoAI applications in research; and potential future directions for geoAI in environmental epidemiology.

Causality and causal inference in epidemiology: the need for a pluralistic approach

PubMed Central

Vandenbroucke, Jan P; Broadbent, Alex; Pearce, Neil

2016-01-01

Abstract Causal inference based on a restricted version of the potential outcomes approach reasoning is assuming an increasingly prominent place in the teaching and practice of epidemiology. The proposed concepts and methods are useful for particular problems, but it would be of concern if the theory and practice of the complete field of epidemiology were to become restricted to this single approach to causal inference. Our concerns are that this theory restricts the questions that epidemiologists may ask and the study designs that they may consider. It also restricts the evidence that may be considered acceptable to assess causality, and thereby the evidence that may be considered acceptable for scientific and public health decision making. These restrictions are based on a particular conceptual framework for thinking about causality. In Section 1, we describe the characteristics of the restricted potential outcomes approach (RPOA) and show that there is a methodological movement which advocates these principles, not just for solving particular problems, but as ideals for which epidemiology as a whole should strive. In Section 2, we seek to show that the limitation of epidemiology to one particular view of the nature of causality is problematic. In Section 3, we argue that the RPOA is also problematic with regard to the assessment of causality. We argue that it threatens to restrict study design choice, to wrongly discredit the results of types of observational studies that have been very useful in the past and to damage the teaching of epidemiological reasoning. Finally, in Section 4 we set out what we regard as a more reasonable ‘working hypothesis’ as to the nature of causality and its assessment: pragmatic pluralism. PMID:26800751

The ZInEP Epidemiology Survey: background, design and methods.

PubMed

Ajdacic-Gross, Vladeta; Müller, Mario; Rodgers, Stephanie; Warnke, Inge; Hengartner, Michael P; Landolt, Karin; Hagenmuller, Florence; Meier, Magali; Tse, Lee-Ting; Aleksandrowicz, Aleksandra; Passardi, Marco; Knöpfli, Daniel; Schönfelder, Herdis; Eisele, Jochen; Rüsch, Nicolas; Haker, Helene; Kawohl, Wolfram; Rössler, Wulf

2014-12-01

This article introduces the design, sampling, field procedures and instruments used in the ZInEP Epidemiology Survey. This survey is one of six ZInEP projects (Zürcher Impulsprogramm zur nachhaltigen Entwicklung der Psychiatrie, i.e. the "Zurich Program for Sustainable Development of Mental Health Services"). It parallels the longitudinal Zurich Study with a sample comparable in age and gender, and with similar methodology, including identical instruments. Thus, it is aimed at assessing the change of prevalence rates of common mental disorders and the use of professional help and psychiatric sevices. Moreover, the current survey widens the spectrum of topics by including sociopsychiatric questionnaires on stigma, stress related biological measures such as load and cortisol levels, electroencephalographic (EEG) and near-infrared spectroscopy (NIRS) examinations with various paradigms, and sociophysiological tests. The structure of the ZInEP Epidemiology Survey entails four subprojects: a short telephone screening using the SCL-27 (n of nearly 10,000), a comprehensive face-to-face interview based on the SPIKE (Structured Psychopathological Interview and Rating of the Social Consequences for Epidemiology: the main instrument of the Zurich Study) with a stratified sample (n = 1500), tests in the Center for Neurophysiology and Sociophysiology (n = 227), and a prospective study with up to three follow-up interviews and further measures (n = 157). In sum, the four subprojects of the ZInEP Epidemiology Survey deliver a large interdisciplinary database. Copyright © 2014 John Wiley & Sons, Ltd.

[The role of the Aedes aegypti vector in the epidemiology of dengue in Mexico].

PubMed

Fernández-Salas, I; Flores-Leal, A

1995-01-01

The role of Aedes aegypti (Lineo) in the epidemiology of dengue fever in Mexico is herein discussed based on the vectorial capacity model. Comments on the advantages and disadvantages of each model component at the time of field determinations are also presented. Emphasis is made on the impact of sampling and method bias on the results of vectorial capacity studies. The paper also addresses the need to increase vector biology knowledge as an input for epidemiological work to explain and predict dengue fever outbreaks. Comments on potential entomological variables not considered by the quantitative model are included. Finally, we elaborate on the introduction of Aedes albopictus (Skuse) in Mexico as a new risk factor and on its implications for the understanding of dengue fever transmission in Mexico.

Using Inverse Problem Methods with Surveillance Data in Pneumococcal Vaccination

PubMed Central

Sutton, Karyn L.; Banks, H. T.; Castillo-Chavez, Carlos

2010-01-01

The design and evaluation of epidemiological control strategies is central to public health policy. While inverse problem methods are routinely used in many applications, this remains an area in which their use is relatively rare, although their potential impact is great. We describe methods particularly relevant to epidemiological modeling at the population level. These methods are then applied to the study of pneumococcal vaccination strategies as a relevant example which poses many challenges common to other infectious diseases. We demonstrate that relevant yet typically unknown parameters may be estimated, and show that a calibrated model may used to assess implemented vaccine policies through the estimation of parameters if vaccine history is recorded along with infection and colonization information. Finally, we show how one might determine an appropriate level of refinement or aggregation in the age-structured model given age-stratified observations. These results illustrate ways in which the collection and analysis of surveillance data can be improved using inverse problem methods. PMID:20209093

The Checkered History of American Psychiatric Epidemiology

PubMed Central

Horwitz, Allan V; Grob, Gerald N

2011-01-01

Context American psychiatry has been fascinated with statistics ever since the specialty was created in the early nineteenth century. Initially, psychiatrists hoped that statistics would reveal the benefits of institutional care. Nevertheless, their fascination with statistics was far removed from the growing importance of epidemiology generally. The impetus to create an epidemiology of mental disorders came from the emerging social sciences, whose members were concerned with developing a scientific understanding of individual and social behavior and applying it to a series of pressing social problems. Beginning in the 1920s, the interest of psychiatric epidemiologists shifted to the ways that social environments contributed to the development of mental disorders. This emphasis dramatically changed after 1980 when the policy focus of psychiatric epidemiology became the early identification and prevention of mental illness in individuals. Methods This article reviews the major developments in psychiatric epidemiology over the past century and a half. Findings The lack of an adequate classification system for mental illness has precluded the field of psychiatric epidemiology from providing causal understandings that could contribute to more adequate policies to remediate psychiatric disorders. Because of this gap, the policy influence of psychiatric epidemiology has stemmed more from institutional and ideological concerns than from knowledge about the causes of mental disorders. Conclusion Most of the problems that have bedeviled psychiatric epidemiology since its inception remain unresolved. In particular, until epidemiologists develop adequate methods to measure mental illnesses in community populations, the policy contributions of this field will not be fully realized. PMID:22188350

Describing the epidemiology of rheumatic diseases: methodological aspects.

PubMed

Guillemin, Francis

2012-03-01

Producing descriptive epidemiology data is essential to understand the burden of rheumatic diseases (prevalence) and their dynamic in the population (incidence). No matter how simple such indicators may look, the correct collection of data and the appropriate interpretation of the results face several challenges: distinguishing indicators, facing the costs of obtaining data, using appropriate definition, identifying optimal sources of data, choosing among many survey methods, dealing with estimates precision, and standardizing results. This study describes the underlying methodological difficulties to be overcome so as to make descriptive indicators reliable and interpretable.

JPRS Report, Science and Technology USSR: Life Sciences.

DTIC Science & Technology

1990-10-02

13 Epidemiology of HIV Infection in USSR [V. V. Pokrovskiy, L Yu. Yeramova, et al...tetracycline- resistant clones of this plasmid, obtained in vitro by the This paper examines the molecular epidemiological fea- prescribed method...noted in the last decade; it cases of illness, and a high proportion of late diagnoses is associated with a decline in epidemiological alertness owing

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Review of Exposure Assessment Methods in Epidemiological Studies on Incinerators

PubMed Central

Ranzi, Andrea; De Leo, Giulio A.; Lauriola, Paolo

2013-01-01

Incineration is a common technology for waste disposal, and there is public concern for the health impact deriving from incinerators. Poor exposure assessment has been claimed as one of the main causes of inconsistency in the epidemiological literature. We reviewed 41 studies on incinerators published between 1984 and January 2013 and classified them on the basis of exposure assessment approach. Moreover, we performed a simulation study to explore how the different exposure metrics may influence the exposure levels used in epidemiological studies. 19 studies used linear distance as a measure of exposure to incinerators, 11 studies atmospheric dispersion models, and the remaining 11 studies a qualitative variable such as presence/absence of the source. All reviewed studies utilized residence as a proxy for population exposure, although residence location was evaluated with different precision (e.g., municipality, census block, or exact address). Only one study reconstructed temporal variability in exposure. Our simulation study showed a notable degree of exposure misclassification caused by the use of distance compared to dispersion modelling. We suggest that future studies (i) make full use of pollution dispersion models; (ii) localize population on a fine-scale; and (iii) explicitly account for the presence of potential environmental and socioeconomic confounding. PMID:23840228

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

NASA Astrophysics Data System (ADS)

Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

2014-02-01

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

Epidemiology for the nuclear medicine technologist.

PubMed

Bolus, N E

2001-09-01

The purpose of this article is to introduce the nuclear medicine technologist to the field of epidemiology. There are many applications of epidemiology in nuclear medicine, including research studies that deal with the causes of disease or ways to prevent disease from occurring and investigating the possible effects of ionizing radiation on occupational workers and the general public. One use of an epidemiologic study is to suggest ways to reduce the occurrence of a disease. After reading this article, the nuclear medicine technologist will be familiar with: a) the history and underlying assumptions of epidemiology, b) types of epidemiologic studies, c) what is a valid statistical association for an epidemiologic study, d) proper judgment of cause and effect relationships, e) definitions of epidemiologic terms, and f) an example of a nuclear medicine research study.

Computational Evolutionary Methodology for Knowledge Discovery and Forecasting in Epidemiology and Medicine

NASA Astrophysics Data System (ADS)

Rao, Dhananjai M.; Chernyakhovsky, Alexander; Rao, Victoria

2008-05-01

Humanity is facing an increasing number of highly virulent and communicable diseases such as avian influenza. Researchers believe that avian influenza has potential to evolve into one of the deadliest pandemics. Combating these diseases requires in-depth knowledge of their epidemiology. An effective methodology for discovering epidemiological knowledge is to utilize a descriptive, evolutionary, ecological model and use bio-simulations to study and analyze it. These types of bio-simulations fall under the category of computational evolutionary methods because the individual entities participating in the simulation are permitted to evolve in a natural manner by reacting to changes in the simulated ecosystem. This work describes the application of the aforementioned methodology to discover epidemiological knowledge about avian influenza using a novel eco-modeling and bio-simulation environment called SEARUMS. The mathematical principles underlying SEARUMS, its design, and the procedure for using SEARUMS are discussed. The bio-simulations and multi-faceted case studies conducted using SEARUMS elucidate its ability to pinpoint timelines, epicenters, and socio-economic impacts of avian influenza. This knowledge is invaluable for proactive deployment of countermeasures in order to minimize negative socioeconomic impacts, combat the disease, and avert a pandemic.

Computational Evolutionary Methodology for Knowledge Discovery and Forecasting in Epidemiology and Medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Dhananjai M.; Chernyakhovsky, Alexander; Rao, Victoria

2008-05-08

Humanity is facing an increasing number of highly virulent and communicable diseases such as avian influenza. Researchers believe that avian influenza has potential to evolve into one of the deadliest pandemics. Combating these diseases requires in-depth knowledge of their epidemiology. An effective methodology for discovering epidemiological knowledge is to utilize a descriptive, evolutionary, ecological model and use bio-simulations to study and analyze it. These types of bio-simulations fall under the category of computational evolutionary methods because the individual entities participating in the simulation are permitted to evolve in a natural manner by reacting to changes in the simulated ecosystem. Thismore » work describes the application of the aforementioned methodology to discover epidemiological knowledge about avian influenza using a novel eco-modeling and bio-simulation environment called SEARUMS. The mathematical principles underlying SEARUMS, its design, and the procedure for using SEARUMS are discussed. The bio-simulations and multi-faceted case studies conducted using SEARUMS elucidate its ability to pinpoint timelines, epicenters, and socio-economic impacts of avian influenza. This knowledge is invaluable for proactive deployment of countermeasures in order to minimize negative socioeconomic impacts, combat the disease, and avert a pandemic.« less

Panel 1: Epidemiology and Diagnosis.

PubMed

Homøe, Preben; Kværner, Kari; Casey, Janet R; Damoiseaux, Roger A M J; van Dongen, Thijs M A; Gunasekera, Hasantha; Jensen, Ramon G; Kvestad, Ellen; Morris, Peter S; Weinreich, Heather M

2017-04-01

Objective To create a literature review between 2011 and June 1, 2015, on advances in otitis media (OM) epidemiology and diagnosis (including relevant audiology studies). Data Sources Electronic search engines (PubMed, EMBASE, and Cochrane Library) with a predefined search strategy. Review Methods Articles with appropriate epidemiologic methodology for OM, including acute mastoiditis and eustachian tube dysfunction. Items included OM worldwide and in high-risk populations, OM-related hearing loss, news in OM diagnostics, prenatal risk factors and comorbidities, postnatal risk factors, genetics, microbiological epidemiology, guidelines, and quality of life. Conclusions Diagnostic evidence and genetic studies are increasing; guidelines are introduced worldwide; and there is evidence of benefit of pneumococcal conjugate vaccines. New risk factors and comordities are identified in the study period, and quality of life is affected in children and their families. Implications for Practice Chronic suppurative OM occurs worldwide and contributes to lifelong hearing loss. Uniform definitions are still lacking and should be provided. An association between HIV and chronic suppurative OM has been found. Tympanometry is recommended for diagnosis, with or without pneumatic otoscopy. Video otoscopy, algorithms, and validated questionnaires may assist clinicians. Childhood obesity is associated with OM. Heritability accounts for 20% to 50% of OM diagnoses. OM-prone children seem to produce weaker immunologic responses to pneumococcal conjugate vaccines. Clinicians tend to individualize treatment without adhering to guidelines.

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

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

[Challenges to implementation of the ECG reading center in ELSA-Brasil].

PubMed

Ribeiro, Antonio Luiz; Pereira, Samuel Vianney da Cunha; Bergmann, Kaiser; Ladeira, Roberto Marini; Oliveira, Rackel Aguiar Mendes; Lotufo, Paulo A; Mill, José Geraldo; Barreto, Sandhi Maria

2013-06-01

Electrocardiography is an established low-cost method of cardiovascular assessment, utilized for decades large epidemiological studies. Nonetheless, its use in large epidemiological studies presents challenges, especially when seeking to develop a reading center. This article describes the process, difficulties and challenges of implementing an electrocardiogram reading center in Brazilian Longitudinal Study for Adult Health (ELSA-Brasil). Among the issues discussed, we have emphasized: the criteria for selection of the electrocardiography machine and the central for storage and management of the machines; the required personnel; the procedures for acquisition and transmission of electrocardiographs to the Reading Center; coding systems, with emphasis on the Minnesota code; ethical and practical issues regarding the delivery of reports to study participants; and aspects related to quality control.

The Epidemiology of Substance Use Disorders in US Veterans: A Systematic Review and Analysis of Assessment Methods

PubMed Central

Lan, Chiao-Wen; Fiellin, David A.; Barry, Declan T.; Bryant, Kendall J.; Gordon, Adam J.; Edelman, E. Jennifer; Gaither, Julie R.; Maisto, Stephen A.; Marshall, Brandon D.L.

2016-01-01

Background Substance use disorders (SUDs), which encompass alcohol and drug use disorders (AUDs, DUDs), constitute a major public health challenge among US veterans. SUDs are among the most common and costly of all health conditions among veterans. Objectives This study sought to examine the epidemiology of SUDs among US veterans, compare the prevalence of SUDs in studies using diagnostic and administrative criteria assessment methods, and summarize trends in the prevalence of SUDs reported in studies sampling US veterans over time. Methods Comprehensive electronic database searches were conducted. A total of 3,490 studies were identified. We analyzed studies sampling US veterans and reporting prevalence, distribution, and examining AUDs and DUDs. Results Of the studies identified, 72 met inclusion criteria. The studies were published between 1995 and 2013. Studies using diagnostic criteria reported higher prevalence of AUDs (32% vs. 10%) and DUDs (20% vs. 5%) than administrative criteria, respectively. Regardless of assessment method, both the lifetime and past year prevalence of AUDs in studies sampling US veterans has declined gradually over time. Conclusion The prevalence of SUDs reported in studies sampling US veterans are affected by assessment method. Given the significant public health problems of SUDs among US veterans, improved guidelines for clinical screening using validated diagnostic criteria to assess AUDs and DUDs in US veteran populations are needed. Scientific Significance These findings may inform VA and other healthcare systems in prevention, diagnosis, and intervention for SUDs among US veterans. PMID:26693830

Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler.

PubMed Central

Colt, J S

1998-01-01

Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods. Images Figure 1 PMID:9799187

Dissecting effects of complex mixtures: who's afraid of informative priors?

PubMed

Thomas, Duncan C; Witte, John S; Greenland, Sander

2007-03-01

Epidemiologic studies commonly investigate multiple correlated exposures, which are difficult to analyze appropriately. Hierarchical modeling provides a promising approach for analyzing such data by adding a higher-level structure or prior model for the exposure effects. This prior model can incorporate additional information on similarities among the correlated exposures and can be parametric, semiparametric, or nonparametric. We discuss the implications of applying these models and argue for their expanded use in epidemiology. While a prior model adds assumptions to the conventional (first-stage) model, all statistical methods (including conventional methods) make strong intrinsic assumptions about the processes that generated the data. One should thus balance prior modeling assumptions against assumptions of validity, and use sensitivity analyses to understand their implications. In doing so - and by directly incorporating into our analyses information from other studies or allied fields - we can improve our ability to distinguish true causes of disease from noise and bias.

Molecular epidemiology for vector research on leishmaniasis.

PubMed

Kato, Hirotomo; Gomez, Eduardo A; Cáceres, Abraham G; Uezato, Hiroshi; Mimori, Tatsuyuki; Hashiguchi, Yoshihisa

2010-03-01

Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.

Molecular Epidemiology for Vector Research on Leishmaniasis

PubMed Central

Kato, Hirotomo; Gomez, Eduardo A; Cáceres, Abraham G; Uezato, Hiroshi; Mimori, Tatsuyuki; Hashiguchi, Yoshihisa

2010-01-01

Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches. PMID:20617005

Retrospective epidemiological study of Latin American patients with transfusional hemosiderosis: the first Latin American epidemiological study in iron overload--the RELATH study.

PubMed

Lobo, Clarisse; Angulo, Ivan L; Aparicio, Lidia R; Drelichman, Guillermo I; Zanichelli, Maria A; Cancado, Rodolfo

2011-09-01

The retrospective epidemiological study of Latin Americans with transfusional hemosiderosis is the first regional patient registry to gather data regarding the burden of transfusional hemosiderosis and patterns of care in these patients. Retrospective and cross-sectional data were collected on patients ≥2 years with selected chronic anemias and minimum 20 transfusions. In the 960 patients analyzed, sickle-cell disease (48·3%) and thalassemias (24·0%) were the most frequent underlying diagnoses. The registry enrolled 355 pediatric patients (187 with sickle-cell disease/94 with thalassemia). Serum ferritin was the most frequent method used to detect iron overload. Complications from transfusional hemosiderosis were reported in ~80% of patients; hepatic (65·3%), endocrine (27·5%), and cardiac (18·2%) being the most frequent. These data indicate that hemoglobinopathies and complications due to transfusional hemosiderosis are a significant clinical problem in the Latin American population with iron overload. Chelation therapy is used insufficiently and has a high rate of discontinuation.

Intricacies of assessing the human microbiome in epidemiological studies

PubMed Central

Robinson, Courtney K.; Brotman, Rebecca M.; Ravel, Jacques

2016-01-01

Purpose In the past decade, remarkable relationships have been documented between dysbiosis of the human microbiota and adverse health outcomes. This review seeks to highlight some of the challenges and pitfalls that may be encountered during all stages of microbiota research, from study design and sample collection, to nucleic acid extraction and sequencing, and bioinformatic and statistical analysis. Methods Literature focused on human microbiota research was reviewed and summarized. Results While most studies have focused on surveying the composition of the microbiota, fewer have explored the causal roles of these bacteria, archaea, viruses, and fungi in affecting disease states. Microbiome research is in its relatively early years and many aspects remain challenging, including the complexity and personalized aspects of microbial communities, the influence of exogenous and often confounding factors, the need to apply fundamental principles of ecology and epidemiology, the necessity for new software tools, and the rapidly evolving genomic, technological, and analytical landscapes. Conclusions Incorporating human microbiome research in large epidemiological studies will soon help us unravel the intricate relationships that we have with our microbial partners and provide interventional opportunities to improve human health. PMID:27180112

[Epidemiologic diagnostic of nosocomial suppurative-septic infections of Pseudomonas etiology based on intraspecies typing of causative agent].

PubMed

Fel'dblium, I V; Zakharova, Iu A; Nikolaeva, A M; Fedotova, O S

2013-01-01

Scientific justification of optimization of epidemiologic diagnostic of suppurative-septic infection (SSI) caused by Pseudomonas aeruginosa based on comparability of antibiotic sensitivity and beta-lactamase production. Intraspecies typing of 37 P. aeruginosa strains isolated during microbiological monitoring of 106 patients and 131 objects of clinical environment of surgical and obstetrician hospitals by using a complex ofphenotypic and molecular-biological methods including determination of sensitivity to antibiotics by serial dilutions method and PCR-diagnostics with determination of TEM, SHV, CTX, OXA, MBL, VIM genes was performed. P. aeruginosa strains combined into groups by isolation location during studies turned out to be heterogeneous by sensitivity to antibiotics and beta-lactamase production that allowed to form subgroups of strains by focality attribute. Isolates recovered from different SSI foci had significant differences in minimal inhibitory concentration (MIC) reaching 1024 times. MIC parameter within subgroups did not exceed 8 - 16 consequent dilutions. Use of a complex of phenotypic and molecular-biologic methods of causative agent typing including determination of sensitivity to antibiotics by serial dilutions method and evaluation of beta-lactamase production allowed to establish a mechanism of development of SSI epidemic process caused by P. aeruginosa, detect origins and reservoirs of infection in hospital, modes and factors of transmission and reach maximum justification of epidemiologic control and prophylaxis measures of localization of foci of nosocomial infections of pseudomonas etiology.

Automated detection of hospital outbreaks: A systematic review of methods.

PubMed

Leclère, Brice; Buckeridge, David L; Boëlle, Pierre-Yves; Astagneau, Pascal; Lepelletier, Didier

2017-01-01

Several automated algorithms for epidemiological surveillance in hospitals have been proposed. However, the usefulness of these methods to detect nosocomial outbreaks remains unclear. The goal of this review was to describe outbreak detection algorithms that have been tested within hospitals, consider how they were evaluated, and synthesize their results. We developed a search query using keywords associated with hospital outbreak detection and searched the MEDLINE database. To ensure the highest sensitivity, no limitations were initially imposed on publication languages and dates, although we subsequently excluded studies published before 2000. Every study that described a method to detect outbreaks within hospitals was included, without any exclusion based on study design. Additional studies were identified through citations in retrieved studies. Twenty-nine studies were included. The detection algorithms were grouped into 5 categories: simple thresholds (n = 6), statistical process control (n = 12), scan statistics (n = 6), traditional statistical models (n = 6), and data mining methods (n = 4). The evaluation of the algorithms was often solely descriptive (n = 15), but more complex epidemiological criteria were also investigated (n = 10). The performance measures varied widely between studies: e.g., the sensitivity of an algorithm in a real world setting could vary between 17 and 100%. Even if outbreak detection algorithms are useful complementary tools for traditional surveillance, the heterogeneity in results among published studies does not support quantitative synthesis of their performance. A standardized framework should be followed when evaluating outbreak detection methods to allow comparison of algorithms across studies and synthesis of results.

Epidemiology as a liberal art.

PubMed

Fraser, D W

1987-02-05

Epidemiology has features that resemble those of the traditional liberal arts. This makes it fit both for inclusion in an undergraduate curriculum and as an example in medical school of the continuing value of a liberal education. As a "low-technology" science, epidemiology is readily accessible to nonspecialists. Because it is useful for taking a first look at a new problem, it is applicable to a broad range of interesting phenomena. Furthermore, it emphasizes method rather than arcane knowledge and illustrates the approaches to problems and the kinds of thinking that a liberal education should cultivate: the scientific method, analogic thinking, deductive reasoning, problem solving within constraints, and concern for aesthetic values.

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

10 CFR 602.5 - Epidemiology and Other Health Studies Financial Assistance Program.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Epidemiology and Other Health Studies Financial Assistance... AND OTHER HEALTH STUDIES FINANCIAL ASSISTANCE PROGRAM § 602.5 Epidemiology and Other Health Studies... toxic substances; (5) Epidemiology and other health studies relating to energy production, transmission...

The Emerging HIV Epidemic on the Mexico-US Border: An International Case Study Characterizing the Role of Epidemiology in Surveillance and Response

PubMed Central

Strathdee, Steffanie A.; Magis-Rodriguez, Carlos; Mays, Vickie M.; Jimenez, Richard; Patterson, Thomas L.

2012-01-01

Purpose HIV/AIDS surveillance data are critical for monitoring epidemic trends, but can mask dynamic sub-epidemics, especially in vulnerable populations that under-utilize HIV testing. In this case study, we describe community-based epidemiologic data among injection drug users (IDU) and female sex workers (FSWs) in two northern Mexico-US Border States that identified an emerging HIV epidemic and generated a policy response. Methods We draw from quantitative and qualitative cross-sectional and prospective epidemiologic studies and behavioral intervention studies among IDUs and FSWs in Tijuana, Baja California and Ciudad Juarez, Chihuahua. Results Recognition that the HIV epidemic on Mexico’s northern border was already well established in subgroups where it had been presumed to be insignificant was met with calls for action and enhanced prevention efforts from researchers, NGOs and policy makers. Conclusions Successful policies and program outcomes included expansion of needle exchange programs, a nation-wide mobile HIV prevention program targeting marginalized populations, a successful funding bid from the Global Fund for HIV, TB and Malaria to scale up targeted HIV prevention programs and the establishment of binational training programs on prevention of HIV and substance use. We discuss how epidemiologic data informed HIV prevention policies and suggest how other countries may learn from Mexico’s experience. PMID:22626001

Epidemiology and risk factors for drug allergy

PubMed Central

Thong, Bernard Y-H; Tan, Teck-Choon

2011-01-01

The aim of this review was to describe the current evidence-based knowledge of the epidemiology, prevalence, incidence, risk factors and genetic associations of drug allergy. Articles published between 1966 and 2010 were identified in MEDLINE using the key words adult, adverse drug reaction reporting systems, age factors, anaphylactoid, anaphylaxis, anaesthetics, antibiotics, child, drug allergy, drug eruptions, ethnic groups, hypersensitivity, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, sex factors, Stevens Johnson syndrome and toxic epidermal necrolysis. Additional studies were identified from article reference lists. Relevant, peer-reviewed original research articles, case series and reviews were considered for review. Current epidemiological studies on adverse drug reactions (ADRs) have used different definitions for ADR-related terminology, often do not differentiate immunologically and non-immunologically mediated drug hypersensitivity, study different study populations (different ethnicities, inpatients or outpatients, adults or children), utilize different methodologies (spontaneous vs. non-spontaneous reporting, cohort vs. case-control studies), different methods of assessing drug imputability and different methods of data analyses. Potentially life-threatening severe cutaneous adverse reactions (SCAR) are associated with a high risk of morbidity and mortality. HLA associations for SCAR associated with allopurinol, carbamazepine and abacavir have been reported with the potential for clinical use in screening prior to prescription. Identification of risk factors for drug allergy and appropriate genetic screening of at-risk ethnic groups may improve the outcomes of drug-specific SCAR. Research and collaboration are necessary for the generation of clinically-relevant, translational pharmacoepidemiological and pharmacogenomic knowledge, and success of health outcomes research and policies on drug allergies. PMID:21480948

Reproducing Epidemiologic Research and Ensuring Transparency.

PubMed

Coughlin, Steven S

2017-08-15

Measures for ensuring that epidemiologic studies are reproducible include making data sets and software available to other researchers so they can verify published findings, conduct alternative analyses of the data, and check for statistical errors or programming errors. Recent developments related to the reproducibility and transparency of epidemiologic studies include the creation of a global platform for sharing data from clinical trials and the anticipated future extension of the global platform to non-clinical trial data. Government agencies and departments such as the US Department of Veterans Affairs Cooperative Studies Program have also enhanced their data repositories and data sharing resources. The Institute of Medicine and the International Committee of Medical Journal Editors released guidance on sharing clinical trial data. The US National Institutes of Health has updated their data-sharing policies. In this issue of the Journal, Shepherd et al. (Am J Epidemiol. 2017;186:387-392) outline a pragmatic approach for reproducible research with sensitive data for studies for which data cannot be shared because of legal or ethical restrictions. Their proposed quasi-reproducible approach facilitates the dissemination of statistical methods and codes to independent researchers. Both reproducibility and quasi-reproducibility can increase transparency for critical evaluation, further dissemination of study methods, and expedite the exchange of ideas among researchers. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

DEVELOPMENT OF A NOVEL METHOD FOR ANALYSIS OF TRANSCRIPTIONAL CHANGES IN TRANSITIONAL EPITHELIUM FROM URINARY BLADDERS OF RATS EXPOSED TO DRINKING WATER DISINFECTION BY-PRODUCTS

EPA Science Inventory

Development of a Novel Method for Analysis of Transcriptional Changes in Transitional Epithelium from Urinary Bladders of Rats Exposed to Drinking Water Disinfection By- products.

Epidemiologic studies in human populations that drink chemically disinfected drinking wa...

Application of the epidemiological model in studying human error in aviation

NASA Technical Reports Server (NTRS)

Cheaney, E. S.; Billings, C. E.

1981-01-01

An epidemiological model is described in conjunction with the analytical process through which aviation occurrence reports are composed into the events and factors pertinent to it. The model represents a process in which disease, emanating from environmental conditions, manifests itself in symptoms that may lead to fatal illness, recoverable illness, or no illness depending on individual circumstances of patient vulnerability, preventive actions, and intervention. In the aviation system the analogy of the disease process is the predilection for error of human participants. This arises from factors in the operating or physical environment and results in errors of commission or omission that, again depending on the individual circumstances, may lead to accidents, system perturbations, or harmless corrections. A discussion of the previous investigations, each of which manifests the application of the epidemiological method, exemplifies its use and effectiveness.

Protecting privacy of shared epidemiologic data without compromising analysis potential.

PubMed

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

2012-01-01

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. 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. 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. 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.

Automated detection of hospital outbreaks: A systematic review of methods

PubMed Central

Buckeridge, David L.; Lepelletier, Didier

2017-01-01

Objectives Several automated algorithms for epidemiological surveillance in hospitals have been proposed. However, the usefulness of these methods to detect nosocomial outbreaks remains unclear. The goal of this review was to describe outbreak detection algorithms that have been tested within hospitals, consider how they were evaluated, and synthesize their results. Methods We developed a search query using keywords associated with hospital outbreak detection and searched the MEDLINE database. To ensure the highest sensitivity, no limitations were initially imposed on publication languages and dates, although we subsequently excluded studies published before 2000. Every study that described a method to detect outbreaks within hospitals was included, without any exclusion based on study design. Additional studies were identified through citations in retrieved studies. Results Twenty-nine studies were included. The detection algorithms were grouped into 5 categories: simple thresholds (n = 6), statistical process control (n = 12), scan statistics (n = 6), traditional statistical models (n = 6), and data mining methods (n = 4). The evaluation of the algorithms was often solely descriptive (n = 15), but more complex epidemiological criteria were also investigated (n = 10). The performance measures varied widely between studies: e.g., the sensitivity of an algorithm in a real world setting could vary between 17 and 100%. Conclusion Even if outbreak detection algorithms are useful complementary tools for traditional surveillance, the heterogeneity in results among published studies does not support quantitative synthesis of their performance. A standardized framework should be followed when evaluating outbreak detection methods to allow comparison of algorithms across studies and synthesis of results. PMID:28441422

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

21 CFR 25.30 - General.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of recalls. (d) Destruction or disposition of any FDA-regulated article condemned after seizure or... if the method of destruction or disposition of the article, including packaging material, is in... grants for statistical and epidemiological studies, surveys and inventories, literature searches, and...

Integrating workplace exposure databases for occupational medicine services and epidemiologic studies at a former nuclear weapons facility.

PubMed

Ruttenber, A J; McCrea, J S; Wade, T D; Schonbeck, M F; LaMontagne, A D; Van Dyke, M V; Martyny, J W

2001-02-01

We outline methods for integrating epidemiologic and industrial hygiene data systems for the purpose of exposure estimation, exposure surveillance, worker notification, and occupational medicine practice. We present examples of these methods from our work at the Rocky Flats Plant--a former nuclear weapons facility that fabricated plutonium triggers for nuclear weapons and is now being decontaminated and decommissioned. The weapons production processes exposed workers to plutonium, gamma photons, neutrons, beryllium, asbestos, and several hazardous chemical agents, including chlorinated hydrocarbons and heavy metals. We developed a job exposure matrix (JEM) for estimating exposures to 10 chemical agents in 20 buildings for 120 different job categories over a production history spanning 34 years. With the JEM, we estimated lifetime chemical exposures for about 12,000 of the 16,000 former production workers. We show how the JEM database is used to estimate cumulative exposures over different time periods for epidemiological studies and to provide notification and determine eligibility for a medical screening program developed for former workers. We designed an industrial hygiene data system for maintaining exposure data for current cleanup workers. We describe how this system can be used for exposure surveillance and linked with the JEM and databases on radiation doses to develop lifetime exposure histories and to determine appropriate medical monitoring tests for current cleanup workers. We also present time-line-based graphical methods for reviewing and correcting exposure estimates and reporting them to individual workers.

Approaches to Teaching Biometry and Epidemiology at Two Veterinary Schools in Germany.

PubMed

Zeimet, Ramona; Kreienbrock, Lothar; Doherr, Marcus G

In a thematically broad and highly condensed curriculum like veterinary medicine, it is essential to pay close attention to the didactic and methodical approaches used to deliver that content. The course topics ideally should be selected for their relevance but also for the target audience and their previous knowledge. The overall objective is to improve the long-term availability of what has been learned. For this reason, an evaluation among lecturers of German-speaking veterinary schools was carried out in 2012 to consider which topics in biometry and epidemiology they found relevant to other subject areas. Based on this survey, two veterinary schools (Berlin and Hannover) developed a structured approach for the introductory course in biometry and epidemiology. By means of an appropriate choice of topics and the use of adequate teaching methods, the quality of the lecture course could be significantly increased. Appropriately communicated learning objectives as well as a high rate of student activity resulted in increased student satisfaction. A certain degree of standardization of teaching approaches and material resulted in a comparison between the study sites and reduced variability in the content delivered at different schools. Part of this was confirmed by the high consistency in the multiple-choice examination results between the study sites. The results highlight the extent to which didactic and methodical restructuring of teaching affects the learning success and satisfaction of students. It can be of interest for other courses in veterinary medicine, human medicine, and biology.

Epidemiology of hypertension in Northern Tanzania: a community-based mixed-methods study.

PubMed

Galson, Sophie W; Staton, Catherine A; Karia, Francis; Kilonzo, Kajiru; Lunyera, Joseph; Patel, Uptal D; Hertz, Julian T; Stanifer, John W

2017-11-09

Sub-Saharan Africa is particularly vulnerable to the growing global burden of hypertension, but epidemiological studies are limited and barriers to optimal management are poorly understood. Therefore, we undertook a community-based mixed-methods study in Tanzania to investigate the epidemiology of hypertension and barriers to care. In Northern Tanzania, between December 2013 and June 2015, we conducted a mixed-methods study, including a cross-sectional household epidemiological survey and qualitative sessions of focus groups and in-depth interviews. For the survey, we assessed for hypertension, defined as a single blood pressure ≥160/100 mm Hg, a two-time average of ≥140/90 mm Hg or current use of antihypertensive medications. To investigate relationships with potential risk factors, we used adjusted generalised linear models. Uncontrolled hypertension was defined as a two-time average measurement of ≥160/100 mm Hg irrespective of treatment status. Hypertension awareness was defined as a self-reported disease history in a participant with confirmed hypertension. To explore barriers to care, we identified emerging themes using an inductive approach within the framework method. We enrolled 481 adults (median age 45 years) from 346 households, including 123 men (25.6%) and 358 women (74.4%). Overall, the prevalence of hypertension was 28.0% (95% CI 19.4% to 38.7%), which was independently associated with age >60 years (prevalence risk ratio (PRR) 4.68; 95% CI 2.25 to 9.74) and alcohol use (PRR 1.72; 95% CI 1.15 to 2.58). Traditional medicine use was inversely associated with hypertension (PRR 0.37; 95% CI 0.26 to 0.54). Nearly half (48.3%) of the participants were aware of their disease, but almost all (95.3%) had uncontrolled hypertension. In the qualitative sessions, we identified barriers to optimal care, including poor point-of-care communication, poor understanding of hypertension and structural barriers such as long wait times and undertrained providers. In Northern Tanzania, the burden of hypertensive disease is substantial, and optimal hypertension control is rare. Transdisciplinary strategies sensitive to local practices should be explored to facilitate early diagnosis and sustained care delivery. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Iliotibial band friction syndrome

PubMed Central

2010-01-01

Published articles on iliotibial band friction syndrome have been reviewed. These articles cover the epidemiology, etiology, anatomy, pathology, prevention, and treatment of the condition. This article describes (1) the various etiological models that have been proposed to explain iliotibial band friction syndrome; (2) some of the imaging methods, research studies, and clinical experiences that support or call into question these various models; (3) commonly proposed treatment methods for iliotibial band friction syndrome; and (4) the rationale behind these methods and the clinical outcome studies that support their efficacy. PMID:21063495

Does G6PD deficiency protect against cancer? A critical review.

PubMed Central

Cocco, P

1987-01-01

Previous observations on the lower mortality for cancer experienced in populations with a higher frequency of G6PD deficiency support biochemical studies on the role of G6PD during cell proliferation. The general agreement among experimental studies prevented a deeper analysis of the sources of what has been called "epidemiological evidence of the protective role of G6PD deficiency against cancer". This review analyses the methods and findings in those papers, stressing their limitations and emphasising that no final conclusions can be drawn from them. Preliminary results of ongoing epidemiological studies of G6PD deficiency and cancer are presented, although they do not prove or disprove the hypothesis that G6PD deficiency protects against cancer. PMID:3309118

Epidemiologic studies of the human microbiome and cancer.

PubMed

Vogtmann, Emily; Goedert, James J

2016-02-02

The human microbiome, which includes the collective genome of all bacteria, archaea, fungi, protists, and viruses found in and on the human body, is altered in many diseases and may substantially affect cancer risk. Previously detected associations of individual bacteria (e.g., Helicobacter pylori), periodontal disease, and inflammation with specific cancers have motivated studies considering the association between the human microbiome and cancer risk. This short review summarises microbiome research, focusing on published epidemiological associations with gastric, oesophageal, hepatobiliary, pancreatic, lung, colorectal, and other cancers. Large, prospective studies of the microbiome that employ multidisciplinary laboratory and analysis methods, as well as rigorous validation of case status, are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, screening, and treatment.

Epidemiologic studies of the human microbiome and cancer

PubMed Central

Vogtmann, Emily; Goedert, James J

2016-01-01

The human microbiome, which includes the collective genome of all bacteria, archaea, fungi, protists, and viruses found in and on the human body, is altered in many diseases and may substantially affect cancer risk. Previously detected associations of individual bacteria (e.g., Helicobacter pylori), periodontal disease, and inflammation with specific cancers have motivated studies considering the association between the human microbiome and cancer risk. This short review summarises microbiome research, focusing on published epidemiological associations with gastric, oesophageal, hepatobiliary, pancreatic, lung, colorectal, and other cancers. Large, prospective studies of the microbiome that employ multidisciplinary laboratory and analysis methods, as well as rigorous validation of case status, are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, screening, and treatment. PMID:26730578

Epidemiology and Antimicrobial Resistance of International Travel-Associated Campylobacter Infections in the United States, 2005–2011

PubMed Central

Palmer, Amanda; Wymore, Katie; Clogher, Paula; Oosmanally, Nadine; Robinson, Trisha; Lathrop, Sarah; Karr, Jillian; Hatch, Julie; Dunn, John; Ryan, Patricia; Blythe, David

2014-01-01

Objectives. The objective of this study was to determine the role international travel plays in US Campylobacter epidemiology and antimicrobial resistance. Methods. In this study, epidemiological and antimicrobial resistance data, encompassing the years 2005 to 2011, from 10 sites participating in the Foodborne Diseases Active Surveillance Network were linked. The 10 sites are represented by 7 states that conducted surveillance on a statewide level, and 3 states which conducted county-level surveillance. Cases of Campylobacter among persons with history of international travel in the week prior to illness were compared with cases among individuals with no international travel. Results. Approximately 18% of Campylobacter infections were estimated to be associated with international travel, and 60% of international travel-associated infections had a quinolone-resistant Campylobacter isolate. Conclusions. We confirm that international travel plays a significant role in campylobacteriosis diagnosed in the United States. Recognizing this is important to both medical management decisions and understanding burden and attribution estimates of US campylobacteriosis and antibiotic-resistant campylobacteriosis. PMID:24832415

The Role of In Vitro Susceptibility Testing in the Management of Candida and Aspergillus.

PubMed

Ostrosky-Zeichner, Luis; Andes, David

2017-08-15

Antifungal susceptibility testing has evolved from a research technique to a standardized and well-validated tool for the clinical management of fungal infections and for epidemiological studies. Genetic mutations and phenotypic resistance in vitro have been shown to correlate with clinical outcomes and treatment failures, and this in turn has led to the creation of clinical breakpoints and, more recently, epidemiological cutoff values for clinically relevant fungal pathogens. Resistance mechanisms for Candida and Aspergillus species have been extensively described and their corresponding genetic mutations can now be readily detected. Epidemiological studies have been able to detect the emergence of regional clonal and nonclonal resistance in several countries. The clinical microbiology laboratory is expected to transition from culture and traditional susceptibility testing to molecular methods for detection, identification, and resistance profiling over the next 5-10 years. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

The power and pitfalls of HIV phylogenetics in public health.

PubMed

Brooks, James I; Sandstrom, Paul A

2013-07-25

Phylogenetics is the application of comparative studies of genetic sequences in order to infer evolutionary relationships among organisms. This tool can be used as a form of molecular epidemiology to enhance traditional population-level communicable disease surveillance. Phylogenetic study has resulted in new paradigms being created in the field of communicable diseases and this commentary aims to provide the reader with an explanation of how phylogenetics can be used in tracking infectious diseases. Special emphasis will be placed upon the application of phylogenetics as a tool to help elucidate HIV transmission patterns and the limitations to these methods when applied to forensic analysis. Understanding infectious disease epidemiology in order to prevent new transmissions is the sine qua non of public health. However, with increasing epidemiological resolution, there may be an associated potential loss of privacy to the individual. It is within this context that we aim to promote the discussion on how to use phylogenetics to achieve important public health goals, while at the same time protecting the rights of the individual.

Epidemiologic Analysis of Onychomycosis in the San Diego Pediatric Population.

PubMed

Totri, Christine R; Feldstein, Stephanie; Admani, Shehla; Friedlander, Sheila F; Eichenfield, Lawrence F

2017-01-01

Onychomycosis (OM) is thought to be a rare disease in children, although there are few epidemiologic studies. This 3-year retrospective case series of nearly 400 children seen at Rady Children's Hospital-San Diego (RCHSD) describes the characteristics of OM found in this pediatric population. From 2011 to 2013, the Pediatric and Adolescent Dermatology Clinic at RCHSD saw a total of 36,634 unique patients, of whom 433 were unique patients with OM. Thirty-four patients met exclusion criteria, leaving 399 (1.1%) with a diagnosis of OM by a pediatric dermatologist. Nail cultures were obtained in 242 cases (60.7%), 116 (48.0%) of which were positive. Trichophyton rubrum was the most commonly isolated pathogen, responsible for 106 cases (91.3%) of positive cultures in the cohort. Our study provides important regional information regarding epidemiologic data in pediatric onychomycosis, highlighting the diagnostic methods most commonly used and the pathogens most frequently encountered in our practice. © 2016 Wiley Periodicals, Inc.

The measurement of poverty in psychiatric epidemiology in LMICs: critical review and recommendations.

PubMed

Cooper, Sara; Lund, Crick; Kakuma, Ritsuko

2012-09-01

Studies exploring the relationship between poverty and mental health in low and middle income countries (LMICs) have produced somewhat conflicting results. This has partly been attributed to poorly operationalized and oversimplified poverty measures. This paper has two aims: (1) to review how socio-economic outcomes in psychiatric epidemiology in LMICs are measured; (2) based on this review, to provide a set of generic recommendations for measuring poverty in psychiatric epidemiology in LMIC. This is relevant for mental health researchers, and for practitioners and policy makers who use mental health research findings. This review was part of a broader systematic review examining the association between poverty and mental illness. An analytic framework was developed to examine the definition and measurement of poverty in these studies. The majority of studies provided no definition for the concept of poverty being used, and very few measured poverty through standardized or validated methods. Many poverty indicators were broken down into extremely open-ended and vague categories, with no details on how the parameters were defined or derived, and no documentation of the time period and unit of analysis for which the poverty variable was measured. This review revealed that using poverty as an indicator in mental health research in LMIC is still in its infancy, with much room for improvement. The implications of poor measurement of poverty in psychiatric epidemiology are discussed. The recommendations provided will hopefully help researchers in psychiatric epidemiology use the concept of poverty in a much more critical, systematic and appropriate manner.

Phylogenetic studies of transmission dynamics in generalized HIV epidemics: An essential tool where the burden is greatest?

PubMed Central

Dennis, Ann M.; Herbeck, Joshua T.; Brown, Andrew Leigh; Kellam, Paul; de Oliveira, Tulio; Pillay, Deenan; Fraser, Christophe; Cohen, Myron S.

2014-01-01

Efficient and effective HIV prevention measures for generalized epidemics in sub-Saharan Africa have not yet been validated at the population-level. Design and impact evaluation of such measures requires fine-scale understanding of local HIV transmission dynamics. The novel tools of HIV phylogenetics and molecular epidemiology may elucidate these transmission dynamics. Such methods have been incorporated into studies of concentrated HIV epidemics to identify proximate and determinant traits associated with ongoing transmission. However, applying similar phylogenetic analyses to generalized epidemics, including the design and evaluation of prevention trials, presents additional challenges. Here we review the scope of these methods and present examples of their use in concentrated epidemics in the context of prevention. Next, we describe the current uses for phylogenetics in generalized epidemics, and discuss their promise for elucidating transmission patterns and informing prevention trials. Finally, we review logistic and technical challenges inherent to large-scale molecular epidemiological studies of generalized epidemics, and suggest potential solutions. PMID:24977473

Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

PubMed Central

2012-01-01

Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage). The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic) or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49), P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl bromide exposure and serious health problems, including prostate cancer risk from occupational and community exposure. The environmental risks of methyl bromide are not in doubt, but also its health risks, especially for genetically predisposed subjects, should not be underestimated. PMID:22284215

[Epidemiological methods used in studies in the prevalence of Tourette syndrome].

PubMed

Stefanoff, Paweł; Mazurek, Jacek

2003-01-01

Tourette syndrome (TS) prevalence was studied since the early 80-ies. Its clinical course is characterised by co-occurrence of motor and vocal tics. Results of previous epidemiological studies were surprisingly divergent: the prevalence varied from 0.5 to 115 cases per 10,000 population. The disease previously recognised as extremely rare and severe is now considered as quite common, with often moderate course. Selected methods used in studies of TS prevalence and analysis of their possible impact on study results are presented. The studies were divided into 3 groups: studies of the hospitalised population, large-scale screenings and studies involving school population, basing on characteristic and size of population, methods of selection of subjects, diagnostic and screening methods used. Studies of the hospitalised population involved patients with most severe symptoms, in different age groups, different methods of final diagnosis confirmation were used. TS prevalence varied from 0.5 up to 15 cases per 10,000 population. Procedures used in large-scale screening studies made possible the elimination of potential selection bias. Large populations were studied using transparent and repetitive confirmation of diagnoses. Their validity was additionally checked in parallel validity studies. TS prevalence was in the range 4.3 to 10 cases per 10,000 population. The highest TS prevalence was obtained in studies involving schoolchildren. Data were gathered from multiple sources: from parents, teachers and children, as well as from classroom observation. Diagnoses were made by experienced clinicians. TS prevalence obtained in school population studies was between 36.2 up to 115 per 10,000 population.

Effects of noise and electromagnetic fields on reproductive outcomes.

PubMed Central

Meyer, R E; Aldrich, T E; Easterly, C E

1989-01-01

Much public health research has been directed to studies of cancer risks due to chemical agents. Recently, increasing attention has been given to adverse reproductive outcomes as another, shorter-term biologic indicator of public health impact. Further, several low-level ubiquitous physical agents have been implicated recently as possibly affecting human health. These physical factors (noise and electromagnetic fields) represent difficult topics for research with epidemiologic study methods. This paper provides a brief review of the published data related to the risk of adverse reproductive outcomes and exposure to noise or electromagnetic fields. The discussion includes ideas for possible biologic mechanisms, considerations for exposure assessment, and suggestions for epidemiologic research. PMID:2667980

High Resolution Melting as a rapid, reliable, accurate and cost-effective emerging tool for genotyping pathogenic bacteria and enhancing molecular epidemiological surveillance: a comprehensive review of the literature.

PubMed

Tamburro, M; Ripabelli, G

2017-01-01

Rapid, reliable and accurate molecular typing methods are essential for outbreaks detection and infectious diseases control, for monitoring the evolution and dynamics of microbial populations, and for effective epidemiological surveillance. The introduction of a novel method based on the analysis of melting temperature of amplified products, known as High Resolution Melting (HRM) since 2002, has found applications in epidemiological studies, either for identification of bacterial species or molecular typing, as well as an extensive and increasing use in many research fields. HRM method is based on the use of saturating third generation dyes, advanced real-time PCR platforms, and bioinformatics tools. To describe, by a comphrehensive review of the literature, the use, application and usefulness of HRM for the genotyping of bacterial pathogens in the context of epidemiological surveillance and public health. A literature search was carried out during July-August 2016, by consulting the biomedical databases PubMed/Medline, Scopus, EMBASE, and ISI Web of Science without limits. The search strategy was performed according to the following keywords: high resolution melting analysis and bacteria and genotyping or molecular typing. All the articles evaluating the application of HRM for bacterial pathogen genotyping were selected and reviewed, taking into account the objective of each study, the rationale explaining the use of this technology, and the main results obtained in comparison with gold standards and/or alternative methods, when available. HRM method was extensively used for molecular typing of both Gram-positive and Gram-negative bacterial pathogens, representing a versatile genetic tool: a) to evaluate genetic diversity and subtype at species/subspecies level, based also on allele discrimination/identification and mutation screening; b) to recognize phylogenetic groupings (lineage, sublineage, subgroups); c) to identify antimicrobial resistance; d) to detect and screen for mutations related to drug-resistance; e) to discriminate gene isoforms. HRM method showed, in almost all instances, excellent typeability and discriminatory power, with high concordance of typing results obtained with gold standards or comparable methods. Conversely, for the evaluation of genetic determinants associated to antibiotic-resistance or for screening of associated mutations in key gene fragments, the sensitivity and specificity was not optimal, because the targeted amplicons did not encompass all the crucial mutations. Despite the recent introduction of sequencing-based methods, the HRM method deserves consideration in research fields of infectious diseases, being characterized by low cost, rapidity, flexibility and versatility. However, there are some limitations to HRM assays development, which should be carefully considered. The most common application of HRM for bacterial typing is related to Single Nucleotide Polymorphism (SNP)-based genotyping with the analysis of gene fragments within the multilocus sequence typing (MLST) loci, following an approach termed mini-MLST or Minim typing. Although the resolving power is not totally correspondent to MLST, the Simpson's Index of Diversity provided by HRM method typically >0.95. Furthermore, the cost of this approach is less than MLST, enabling low cost surveillance and rapid response for outbreak control. Hence, the potential of HRM technology can strongly facilitate routine research and diagnostics in the epidemiological studies, as well as advance and streamline the genetic characterization of bacterial pathogens.

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

VISUALLY OBSERVED MOLD AND MOLDY ODOR VERSUS QUANTITATIVELY MEASURED MICROBIAL EXPOSURE IN HOMES

EPA Science Inventory

The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children's asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child's age 1 (Year ...

Development and application of Human Genome Epidemiology

NASA Astrophysics Data System (ADS)

Xu, Jingwen

2017-12-01

Epidemiology is a science that studies distribution of diseases and health in population and its influencing factors, it also studies how to prevent and cure disease and promote health strategies and measures. Epidemiology has developed rapidly in recent years and it is an intercross subject with various other disciplines to form a series of branch disciplines such as Genetic epidemiology, molecular epidemiology, drug epidemiology and tumor epidemiology. With the implementation and completion of Human Genome Project (HGP), Human Genome Epidemiology (HuGE) has emerged at this historic moment. In this review, the development of Human Genome Epidemiology, research content, the construction and structure of relevant network, research standards, as well as the existing results and problems are briefly outlined.

Molecular epidemiological study of HIV-1 CRF01_AE transmission in Hong Kong.

PubMed

Chen, J H K; Wong, K H; Li, P; Chan, K C; Lee, M P; Lam, H Y; Cheng, V C C; Yuen, K Y; Yam, W C

2009-08-15

The objective of this study was to investigate the transmission history of the HIV-1 CRF01_AE epidemics in Hong Kong between 1994 and 2007. A total of 465 HIV-1 CRF01_AE pol sequences were derived from an in-house or a commercial HIV-1 genotyping system. Phylogenies of CRF01_AE sequences were analyzed by the Bayesian coalescent method. CRF01_AE patient population included 363 males (78.1%) and 102 females (21.9%), whereas 65% (314 of 465) were local Chinese. Major transmission routes were heterosexual contact (63%), followed by intravenous drug use (IDU) (19%) and men having sex with men (MSM) (17%). From phylogenetic analysis, local CRF01_AE strains were from multiple origins with 3 separate transmission clusters identified. Cluster 1 consisted mainly of Chinese male IDUs and heterosexuals. Clusters 2 and 3 included mainly local Chinese MSM and non-Chinese Asian IDUs, respectively. Chinese reference isolates available from China (Fujian, Guangxi, or Liaoning) were clonally related to our transmission clusters, demonstrating the epidemiological linkage of CRF01_AE infections between Hong Kong and China. The 3 individual local transmission clusters were estimated to have initiated since late 1980s and late 1990s, causing subsequent epidemics in the early 2000s. This is the first comprehensive molecular epidemiological study of HIV-1 CRF01_AE in Hong Kong. It revealed that MSM contact is becoming a major route of local CRF01_AE transmission in Hong Kong. Epidemiological linkage of CRF01_AE between Hong Kong and China observed in this study indicates the importance of regular molecular epidemiological surveillance for the HIV-1 epidemic in our region.

Diagnostic criteria for neurocysticercosis, revisited

PubMed Central

Del Brutto, Oscar H

2012-01-01

Diagnosis of neurocysticercosis (NCC) can be a challenge. Clinical manifestations are non-specific, most neuroimaging findings are non-pathognomonic, and some serologic tests have low sensitivity or specificity. A set of diagnostic criteria was proposed in 2001 to avoid the over diagnosis of NCC that occurs in epidemiologic surveys, and to help clinicians evaluating patients with suspected NCC. The set included four stratified categories of criteria, including: (1) absolute: histological demonstration of cysticerci, cystic lesions showing the scolex on neuroimaging studies, and direct visualization of subretinal parasites by fundoscopic examination; (2) major: lesions highly suggestive of NCC on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot (EITB) for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after cysticidal drug therapy, and spontaneous resolution of single enhancing lesions; (3) minor: lesions compatible with NCC on neuroimaging studies, suggestive clinical manifestations, positive cerebrospinal fluid (CSF) ELISA for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the nervous system; and (4) epidemiological: evidence of a household contact with Taenia solium infection, individuals coming from or living in cysticercosis endemic areas, and history of travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: (1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiological criteria; and (2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiological criteria, and in those who have three minor plus one epidemiological criteria. After 10 years of usage, this set has been proved useful in both, field studies, and hospital settings. Recent advances in neuroimaging and immune diagnostic methods have enhanced its accuracy for the diagnosis of NCC. PMID:23265554

The Clinical Profile of Patients with Psoriasis in Korea: A Nationwide Cross-Sectional Study (EPI-PSODE)

PubMed Central

Song, Hae Jun; Park, Chul Jong; Kim, Tae Yoon; Choe, Yong Beom; Lee, Seok-Jong; Kim, Nack In; Cho, Jae We; Jeon, Jie Hyun; Jang, Min Soo; Youn, Jai Il; Kim, Myung Hwa; Park, Joonsoo; Kim, Ki Ho; Kim, Byung Soo; Youn, Sang Woong; Lee, Joo-Heung; Lee, Min-Geol; Ahn, Sung Ku; Won, Young Ho; Yun, Seok Kweon; Shin, Bong Seok; Seo, Seong Jun; Lee, Ji Yeoun; Kim, Kwang Joong; Ro, Young Suck; Kim, Youngdoe; Yu, Dae Young

2017-01-01

Background Psoriasis is an immune-mediated, chronic inflammatory disease affecting multiple aspects of patients' lives. Its epidemiology varies regionally; however, nationwide epidemiologic data on psoriasis depicting profile of Korean patients has not been available to date. Objective To understand nationwide epidemiologic characteristics and clinical features of adult patients with psoriasis visited university hospitals in Korea. Methods This multicenter, non-interventional, cross-sectional study recruited 1,278 adult patients with psoriasis across 25 centers in Korea in 2013. Various clinical data including PASI, BSA, DLQI, SF-36 and PASE were collected. Results A total of 1,260 patients completed the study (male:female=1.47:1). The mean age was 47.0 years with a distribution mostly in the 50s (24.9%). Early onset (<40 years) of psoriasis accounted for 53.9% of patients. The mean disease duration was 109.2 months; mean body mass index was 23.9 kg/m2; and 12.7% of patients had a family history of psoriasis. Plaque and guttate types of psoriasis accounted for 85.8% and 8.4%, respectively. Patients with PASI ≥10 accounted for 24.9%; patients with body surface area ≥10 were 45.9%. Patients with DLQI ≥6 accounted for 78.8%. Between PASI <10 and PASI ≥10 groups, significant difference was noted in age at diagnosis, disease duration, blood pressure, waist circumference of female, and treatment experiences with phototherapy, systemic agents, and biologics. Conclusion This was the first nationwide epidemiologic study of patients with psoriasis in Korea and provides an overview of the epidemiologic characteristics and clinical profiles of this patient population. PMID:28761295

Variable Number Of Tandem Repeats (VNTR) and its application in bacterial epidemiology.

PubMed

Ramazanzadeh, Rashid; McNerney, Ruth

2007-08-15

Molecular epidemiology is the using of molecular techniques to study bacterial distribution in human populations. Recently molecular epidemiologist benefit from several techniques such as Variable Number Tandem Repeat (VNTR) typing method to typing bacterial strains. Variable Number Tandem Repeat (VNTR) typing is a tool for genotyping and provides data in a simple and numeric format based on the number of repetitive sequences. VNTR for first time identified in M. tuberculosis as Mycobacterial Interspersed Repeat Units (MIRUs). General terms of VNTR have now been reported in Bacillus anthracis, Legionella pneumophila, Pseudomonas aeruginosa, Salmonella enterica and Escherichia coli O157.

TEAM Webinar Series | EGRP/DCCPS/NCI/NIH

Cancer.gov

View archived webinars from the Transforming Epidemiology through Advanced Methods (TEAM) Webinar Series, hosted by NCI's Epidemiology and Genomics Research Program. Topics include participant engagement, data coordination, mHealth tools, sample selection, and instruments for diet & physical activity assessment.

[Use of molecular genetic diagnostic methods in periodontology and implantology].

PubMed

Shcherbo, S N; Choniashvili, D Z; De, D A; Sadovskiĭ, V V; Toguzov, R T

2009-11-01

The authors have studied the species-specific composition of major periodontopathogenic bacteria (P. gingivalis, P. intermedia, B. forsythus, A. actinomycetemcomitans, and T. denticola), by applying the Russian reagent kit developed and made by HPF "GENETECH", and some fungi, microorganisms, and viruses among the Moscow Region inhabitants with chronic generalized periodontitis in 2006-2008. The studies have shown it possible to use molecular genetic methods for diagnosis, drug therapy monitoring, and epidemiological studies in periodontology and implantology.

Seasonality of Violent Suicides in the Athens Greater Area

ERIC Educational Resources Information Center

Christodoulou, C.; Papadopoulos, I. N.; Douzenis, A.; Kanakaris, N.; Leukidis, C.; Gournellis, R.; Vlachos, K.; Papadopoulos, F. C.; Lykouras, L.

2009-01-01

The aim of the study was to ascertain suicide seasonality in the Greek population and to associate this seasonal variation with age, sex, and suicide method. Studying seasonality can be of help in establishing a public health policy, related with suicide prevention. This is an epidemiologic study based on forensic evidence. We studied the deaths…

The World Health Organization and the contested beginnings of psychiatric epidemiology as an international discipline: one rope, many strands.

PubMed

Lovell, Anne M

2014-08-01

This paper focuses on the relatively late emergence of psychiatric epidemiology as an international discipline, through local-global exchanges during the first 15 years of the World Health Organization (WHO). Building an epidemiological canon within WHO's Mental Health Programme faced numerous obstacles. First, an idealist notion of mental health inherent in WHO's own definition of health contributed to tensions around the object of psychiatric epidemiology. Second, the transfer of methods from medical epidemiology to research on mental disorders required mobilizing conceptual justifications, including a 'contagion argument'. Third, epidemiological research at WHO was stymied by other public health needs, resource scarcity and cultural barriers. This history partly recapitulates the development of psychiatric epidemiology in North America and Europe, but is also shaped by concerns in the developing world, translated through first-world 'experts'. Resolving the tensions arising from these obstacles allowed WHO to establish its international schizophrenia research, which in turn provided proof of concept for psychiatric epidemiology in the place of scepticism within and without psychiatry. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Actual data on epidemiological evolution and prevention endeavours regarding traumatic brain injury

PubMed Central

Popescu, C; Anghelescu, A; Daia, C; Onose, G

2015-01-01

Background: Knowledge of the epidemiology of traumatic brain injury (TBI) is required both to prevent this disorder and to develop effective care and rehabilitation approaches for patients. Objective: The aim of this article is to find solutions to decrease the incidence of TBI and offer recommendations for their prevention. Material and methods: We analyzed epidemiological studies on TBI by performing a systematic review of literature, using information reported by different centers, collecting data on demographics, showing characteristics of TBI including incidence, identification of risk groups on differences in age, gender, geographical variation, severity and mortality. Results: Studies suggest that the incidence of TBI is between 18 and 250 per 100,000 persons per year. Men and people living in social and economical deprived areas, usually young adults and the elderly are high-risk groups for TBI. Discussion: Prevention remains the “key point” in medicine and especially for TBI, saving the patient from unnecessary often-harsh sufferance. Conclusions: Most public epidemiological data showed that TBI is a major cause of mortality and disability. The effort to understand TBI and the available strategies to treat this lesion, in order to improve clinical outcomes after TBI, may be based on an increase in research on the epidemiology of TBI. A coordinated strategy to evaluate this public health problem in Romania would first of all rely on a related advanced monitoring system, to provide precise information about the epidemiology, clinical and paraclinical data, but concerning the social and economic connected consequences, too. Abbreviations: CNS = central nervous system, ED = emergency department, EU = European Union, FTE = Full Time Employees, GCS = Glasgow Coma Scale, TBI = traumatic brain injury, US = United States, WHO = World Health Organization. PMID:26351526

Application of advanced data collection and quality assurance methods in open prospective study - a case study of PONS project.

PubMed

Wawrzyniak, Zbigniew M; Paczesny, Daniel; Mańczuk, Marta; Zatoński, Witold A

2011-01-01

Large-scale epidemiologic studies can assess health indicators differentiating social groups and important health outcomes of the incidence and mortality of cancer, cardiovascular disease, and others, to establish a solid knowledgebase for the prevention management of premature morbidity and mortality causes. This study presents new advanced methods of data collection and data management systems with current data quality control and security to ensure high quality data assessment of health indicators in the large epidemiologic PONS study (The Polish-Norwegian Study). The material for experiment is the data management design of the large-scale population study in Poland (PONS) and the managed processes are applied into establishing a high quality and solid knowledge. The functional requirements of the PONS study data collection, supported by the advanced IT web-based methods, resulted in medical data of a high quality, data security, with quality data assessment, control process and evolution monitoring are fulfilled and shared by the IT system. Data from disparate and deployed sources of information are integrated into databases via software interfaces, and archived by a multi task secure server. The practical and implemented solution of modern advanced database technologies and remote software/hardware structure successfully supports the research of the big PONS study project. Development and implementation of follow-up control of the consistency and quality of data analysis and the processes of the PONS sub-databases have excellent measurement properties of data consistency of more than 99%. The project itself, by tailored hardware/software application, shows the positive impact of Quality Assurance (QA) on the quality of outcomes analysis results, effective data management within a shorter time. This efficiency ensures the quality of the epidemiological data and indicators of health by the elimination of common errors of research questionnaires and medical measurements.

Epidemiology of sport-related spinal cord injuries: A systematic review

PubMed Central

Chan, Christie WL; Tator, Charles H.

2016-01-01

Context Despite the recognition of sports as a significant contributor in the etiology of spinal cord injury (SCI), no studies have systematically explored the epidemiology of SCI caused by sports. Objective This paper aims to give a systematic overview of the epidemiology of sport-related spinal cord injury around the world. Methods A systematic review was conducted to identify published literature reporting the epidemiology of SCI caused by sports. The literature search was conducted in MEDLINE/PubMed, CINAHL, EMBASE, PsycINFO and Sportdiscus with date limits 1980 through to July 2015. Data from 54 studies covering 25 countries was extracted and collated. Results Important findings include identification of 6 countries in which sports accounts for over 13% of SCI (highest to lowest: Russia, Fiji, New Zealand, Iceland, France and Canada); individual sports with high risk for SCI (diving, skiing, rugby, and horseback riding); and the most common level of injury for various sports (almost entirely cervical for hockey, skiing, diving and American football, while over half of horseback riding and snowboarding injuries are thoracic or lumbosacral). Conclusion This paper identifies countries and sports with higher rates of sport-related SCIs where implementation of prevention programs and reporting systems to track SCI epidemiology may be helpful, and highlights gaps in our current knowledge for further investigation. The comparison of SCI occurrence for each sport across countries, as well as examination of the specific characteristics of SCI incurred for individual sports will assist in directing efforts for prevention. PMID:26864974

Human Health Effects of Trichloroethylene: Key Findings and Scientific Issues

PubMed Central

Jinot, Jennifer; Scott, Cheryl Siegel; Makris, Susan L.; Cooper, Glinda S.; Dzubow, Rebecca C.; Bale, Ambuja S.; Evans, Marina V.; Guyton, Kathryn Z.; Keshava, Nagalakshmi; Lipscomb, John C.; Barone, Stanley; Fox, John F.; Gwinn, Maureen R.; Schaum, John; Caldwell, Jane C.

2012-01-01

Background: In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) completed a toxicological review of trichloroethylene (TCE) in September 2011, which was the result of an effort spanning > 20 years. Objectives: We summarized the key findings and scientific issues regarding the human health effects of TCE in the U.S. EPA’s toxicological review. Methods: In this assessment we synthesized and characterized thousands of epidemiologic, experimental animal, and mechanistic studies, and addressed several key scientific issues through modeling of TCE toxicokinetics, meta-analyses of epidemiologic studies, and analyses of mechanistic data. Discussion: Toxicokinetic modeling aided in characterizing the toxicological role of the complex metabolism and multiple metabolites of TCE. Meta-analyses of the epidemiologic data strongly supported the conclusions that TCE causes kidney cancer in humans and that TCE may also cause liver cancer and non-Hodgkin lymphoma. Mechanistic analyses support a key role for mutagenicity in TCE-induced kidney carcinogenicity. Recent evidence from studies in both humans and experimental animals point to the involvement of TCE exposure in autoimmune disease and hypersensitivity. Recent avian and in vitro mechanistic studies provided biological plausibility that TCE plays a role in developmental cardiac toxicity, the subject of substantial debate due to mixed results from epidemiologic and rodent studies. Conclusions: TCE is carcinogenic to humans by all routes of exposure and poses a potential human health hazard for noncancer toxicity to the central nervous system, kidney, liver, immune system, male reproductive system, and the developing embryo/fetus. PMID:23249866

Panel discussion review: session 1--exposure assessment and related errors in air pollution epidemiologic studies.

PubMed

Sarnat, Jeremy A; Wilson, William E; Strand, Matthew; Brook, Jeff; Wyzga, Ron; Lumley, Thomas

2007-12-01

Examining the validity of exposure metrics used in air pollution epidemiologic models has been a key focus of recent exposure assessment studies. The objective of this work has been, largely, to determine what a given exposure metric represents and to quantify and reduce any potential errors resulting from using these metrics in lieu of true exposure measurements. The current manuscript summarizes the presentations of the co-authors from a recent EPA workshop, held in December 2006, dealing with the role and contributions of exposure assessment in addressing these issues. Results are presented from US and Canadian exposure and pollutant measurement studies as well as theoretical simulations to investigate what both particulate and gaseous pollutant concentrations represent and the potential errors resulting from their use in air pollution epidemiologic studies. Quantifying the association between ambient pollutant concentrations and corresponding personal exposures has led to the concept of defining attenuation factors, or alpha. Specifically, characterizing pollutant-specific estimates for alpha was shown to be useful in developing regression calibration methods involving PM epidemiologic risk estimates. For some gaseous pollutants such as NO2 and SO2, the associations between ambient concentrations and personal exposures were shown to be complex and still poorly understood. Results from recent panel studies suggest that ambient NO2 measurements may, in some locations, be serving as surrogates to traffic pollutants, including traffic-related PM2.5, hopanes, steranes, and oxidized nitrogen compounds (rather than NO2).

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

Experience of 16 years and its associated challenges in the Field Epidemiology Training Program in Korea.

PubMed

Lee, Moo-Sik; Kim, Eun-Young; Lee, Sang-Won

2017-01-01

The field epidemiologist system of South Korea, which employs public health doctors who are relatively more readily available, was created in 1999 to ensure a ready supply of experts for epidemiological investigations and enable an effective response for new and reemerging infectious diseases. However, the 2015 outbreak of Middle East Respiratory Syndrome revealed limitations in the existing systems of management of field epidemiologists and communicable diseases. The present study aims to evaluate data on current states, administrative reports, and other literature on the field epidemiologist system that has been in place in South Korea for 16 years since 1999 and to suggest appropriate future improvements in this system. By suggesting methods to evaluate the field epidemiologist system and training programs and by suggesting ways for the Korea Centers for Disease Control and Prevention to conduct evaluations on its own, the present study provides supporting evidence for improvement of systems for training of experts in epidemiological investigations. Moreover, based on the findings, this study also suggests methods to systematically train experts in communicable diseases management and a sustainable system to establish the basis of and develop strategies for a systematic and phased management of field epidemiologist training programs. The present study suggests the possibility of establishing dedicated training facilities, revising the guidelines on training and improvement of the competency of public health experts, while not limiting the scope of application to communicable diseases.

Should the history of epidemiology be taught in epidemiology training programs?

PubMed

Laskaris, Zoey; Morabia, Alfredo

2015-01-01

Currently, there is no evidence concerning the presence of historical content in the epidemiology curricula of the United States and abroad. Similarly, it is not known how epidemiologists view this topic in the context of master's or doctoral level course work. We attempted to fill these knowledge gaps with data from 2 online surveys-Survey I administered to persons in charge of all epidemiology training programs in North America and Survey II to epidemiologists practicing around the world. A substantial minority (39%) of graduate programs in epidemiology in the United States teach a course on the history of the field. In both surveys, the most common reasons selected for teaching such a course were "To build a sense of identity as an epidemiologist" and "As a tool for achieving a deeper understanding into specific methods and concepts." The majority of respondents, from 63 countries, agreed that the history of epidemiology should be included in curricula for graduate students in epidemiology.

Impact of gastrointestinal parasitic nematodes of sheep, and the role of advanced molecular tools for exploring epidemiology and drug resistance - an Australian perspective

PubMed Central

2013-01-01

Parasitic nematodes (roundworms) of small ruminants and other livestock have major economic impacts worldwide. Despite the impact of the diseases caused by these nematodes and the discovery of new therapeutic agents (anthelmintics), there has been relatively limited progress in the development of practical molecular tools to study the epidemiology of these nematodes. Specific diagnosis underpins parasite control, and the detection and monitoring of anthelmintic resistance in livestock parasites, presently a major concern around the world. The purpose of the present article is to provide a concise account of the biology and knowledge of the epidemiology of the gastrointestinal nematodes (order Strongylida), from an Australian perspective, and to emphasize the importance of utilizing advanced molecular tools for the specific diagnosis of nematode infections for refined investigations of parasite epidemiology and drug resistance detection in combination with conventional methods. It also gives a perspective on the possibility of harnessing genetic, genomic and bioinformatic technologies to better understand parasites and control parasitic diseases. PMID:23711194

History matching of a complex epidemiological model of human immunodeficiency virus transmission by using variance emulation.

PubMed

Andrianakis, I; Vernon, I; McCreesh, N; McKinley, T J; Oakley, J E; Nsubuga, R N; Goldstein, M; White, R G

2017-08-01

Complex stochastic models are commonplace in epidemiology, but their utility depends on their calibration to empirical data. History matching is a (pre)calibration method that has been applied successfully to complex deterministic models. In this work, we adapt history matching to stochastic models, by emulating the variance in the model outputs, and therefore accounting for its dependence on the model's input values. The method proposed is applied to a real complex epidemiological model of human immunodeficiency virus in Uganda with 22 inputs and 18 outputs, and is found to increase the efficiency of history matching, requiring 70% of the time and 43% fewer simulator evaluations compared with a previous variant of the method. The insight gained into the structure of the human immunodeficiency virus model, and the constraints placed on it, are then discussed.

Cancer Risk Assessment Primer.

ERIC Educational Resources Information Center

Aidala, Jim

1985-01-01

Describes the scientific basis of cancer risk assessment, outlining the dominant controversies surrounding the use of different methods for identifying carcinogens (short-term tests, animal bioassays, and epidemiological studies). Points out that risk assessment is as much an art as it is a science. (DH)

Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome

PubMed Central

Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

2016-01-01

Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method. PMID:27006375

Bayesian dose-response analysis for epidemiological studies with complex uncertainty in dose estimation.

PubMed

Kwon, Deukwoo; Hoffman, F Owen; Moroz, Brian E; Simon, Steven L

2016-02-10

Most conventional risk analysis methods rely on a single best estimate of exposure per person, which does not allow for adjustment for exposure-related uncertainty. Here, we propose a Bayesian model averaging method to properly quantify the relationship between radiation dose and disease outcomes by accounting for shared and unshared uncertainty in estimated dose. Our Bayesian risk analysis method utilizes multiple realizations of sets (vectors) of doses generated by a two-dimensional Monte Carlo simulation method that properly separates shared and unshared errors in dose estimation. The exposure model used in this work is taken from a study of the risk of thyroid nodules among a cohort of 2376 subjects who were exposed to fallout from nuclear testing in Kazakhstan. We assessed the performance of our method through an extensive series of simulations and comparisons against conventional regression risk analysis methods. When the estimated doses contain relatively small amounts of uncertainty, the Bayesian method using multiple a priori plausible draws of dose vectors gave similar results to the conventional regression-based methods of dose-response analysis. However, when large and complex mixtures of shared and unshared uncertainties are present, the Bayesian method using multiple dose vectors had significantly lower relative bias than conventional regression-based risk analysis methods and better coverage, that is, a markedly increased capability to include the true risk coefficient within the 95% credible interval of the Bayesian-based risk estimate. An evaluation of the dose-response using our method is presented for an epidemiological study of thyroid disease following radiation exposure. Copyright © 2015 John Wiley & Sons, Ltd.

Injury and illness epidemiology in soccer – effects of global geographical differences – a call for standardized and consistent research studies

PubMed Central

Gillogly, Scott; Singh, Gurcharan; Chamari, Karim

2017-01-01

Soccer is the most popular sport in the world. While injuries and illnesses can affect the players’ health and performance, they can also have a major economic impact on teams. Moreover, several studies have shown the favourable association between higher player availability and team success. Therefore, injury prevention could directly impact clubs’ financial balance and teams’ performance via increased player availability. To be able to develop effective methods of injury prevention, it is vital to first determine the scope and the degree of the problem: the mechanisms and types of injuries, their frequency and severity, etc. According to the most widely known prevention model, systematic injury surveillance is the first and most fundamental step towards injury prevention. Since epidemiological studies have shown that injuries and illnesses in soccer players differ from region to region, it is important to establish a specific injuries and illness database in order to guide specific preventive actions. Since Asia is the largest continent, with the highest number of soccer players, and in the light of the long-term research on injuries performed in UEFA clubs, the authors of the present article present the AFC surveillance. Some methodological issues related to this prospective design study are discussed. The definition of injury and illness and the methods to track players’ exposure are described along with the potential challenges related to such a vast scale study. This article is also a call for action to have consistent and standardized epidemiological studies on soccer injuries and illnesses, with the aim to improve their prevention. PMID:29158618

What matters most: quantifying an epidemiology of consequence.

PubMed

Keyes, Katherine; Galea, Sandro

2015-05-01

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Microbiologic tests in epidemiologic studies: are they reproducible?

PubMed

Aass, A M; Preus, H R; Zambon, J J; Gjermo, P

1994-12-01

Microbiologic assessments are often included in longitudinal studies to elucidate the significance of the association of certain Gram-negative bacteria and the development of periodontal diseases. In such studies, the reliability of methods is crucial. There are several methods to identify putative pathogens, and some of them are commercially available. The purpose of the present study was to compare the reproducibility of four different methods for detecting Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in order to evaluate their usefulness in epidemiologic studies. The test panel consisted of 10 young subjects and 10 adult periodontitis patients. Subgingival plaque was sampled from sites showing bone loss and "healthy" control sites. The four different methods for detecting the target bacteria were 1) cultivation, 2) Evalusite (a chair-side kit based on ELISA), 3) OmniGene, Inc, based on DNA probes, and 4) indirect immunofluorescence (IIF). The test procedure was repeated after a 1-wk interval and was performed by one examiner. Sites reported to be positive for a microorganism by any of the four methods at one or both examinations were considered to be positive for that organism and included in the analysis. The reproducibility of the four methods was low. The IIF and the cultivation methods showed somewhat higher reproducibility than did the commercial systems. A second test was done for Evalusite, three paper points for sampling being used instead of one as described in the manual. The reproducibility of the second test was improved, indicating that the detection level of the system may influence the reliability.

Epidemiological Outbreaks of Pneumocystis jirovecii Pneumonia Are Not Limited to Kidney Transplant Recipients: Genotyping Confirms Common Source of Transmission in a Liver Transplantation Unit

PubMed Central

Dominique, Manon; Morio, Florent; Thepault, Rose-Anne; Franck-Martel, Claire; Tellier, Anne-Charlotte; Ferrandière, Martine; Hennequin, Christophe; Bernard, Louis; Salamé, Ephrem; Bailly, Éric; Chandenier, Jacques

2016-01-01

Over a 5-month period, four liver transplant patients at a single hospital were diagnosed with Pneumocystis jirovecii pneumonia (PCP). This unusually high incidence was investigated using molecular genotyping. Bronchoalveolar lavage fluids (BALF) obtained from the four liver recipients diagnosed with PCP were processed for multilocus sequence typing (MLST) at three loci (SOD, mt26s, and CYB). Twenty-four other BALF samples, which were positive for P. jirovecii and collected from 24 epidemiologically unrelated patients with clinical signs of PCP, were studied in parallel by use of the same method. Pneumocystis jirovecii isolates from the four liver recipients all had the same genotype, which was different from those of the isolates from all the epidemiologically unrelated individuals studied. These findings supported the hypothesis of a common source of contamination or even cross-transmission of a single P. jirovecii clone between the four liver recipients. Hospitalization mapping showed several possible encounters between these four patients, including outpatient consultations on one particular date when they all possibly met. This study demonstrates the value of molecular genotyping of P. jirovecii isolated from clinical samples for epidemiological investigation of PCP outbreaks. It is also the first description of a common source of exposure to a single P. jirovecii clone between liver transplant recipients and highlights the importance of prophylaxis in such a population. PMID:26935726

The Genetics of Obsessive-Compulsive Disorder and Tourette Syndrome: An Epidemiological and Pathway-Based Approach for Gene Discovery

ERIC Educational Resources Information Center

Grados, Marco A.

2010-01-01

Objective: To provide a contemporary perspective on genetic discovery methods applied to obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). Method: A review of research trends in genetics research in OCD and TS is conducted, with emphasis on novel approaches. Results: Genome-wide association studies (GWAS) are now in progress in OCD…

Donor-Recipient Identification in Para- and Poly-phyletic Trees Under Alternative HIV-1 Transmission Hypotheses Using Approximate Bayesian Computation

PubMed Central

Romero-Severson, Ethan O.; Bulla, Ingo; Hengartner, Nick; Bártolo, Inês; Abecasis, Ana; Azevedo-Pereira, José M.; Taveira, Nuno; Leitner, Thomas

2017-01-01

Diversity of the founding population of Human Immunodeficiency Virus Type 1 (HIV-1) transmissions raises many important biological, clinical, and epidemiological issues. In up to 40% of sexual infections, there is clear evidence for multiple founding variants, which can influence the efficacy of putative prevention methods, and the reconstruction of epidemiologic histories. To infer who-infected-whom, and to compute the probability of alternative transmission scenarios while explicitly taking phylogenetic uncertainty into account, we created an approximate Bayesian computation (ABC) method based on a set of statistics measuring phylogenetic topology, branch lengths, and genetic diversity. We applied our method to a suspected heterosexual transmission case involving three individuals, showing a complex monophyletic-paraphyletic-polyphyletic phylogenetic topology. We detected that seven phylogenetic lineages had been transmitted between two of the individuals based on the available samples, implying that many more unsampled lineages had also been transmitted. Testing whether the lineages had been transmitted at one time or over some length of time suggested that an ongoing superinfection process over several years was most likely. While one individual was found unlinked to the other two, surprisingly, when evaluating two competing epidemiological priors, the donor of the two that did infect each other was not identified by the host root-label, and was also not the primary suspect in that transmission. This highlights that it is important to take epidemiological information into account when analyzing support for one transmission hypothesis over another, as results may be nonintuitive and sensitive to details about sampling dates relative to possible infection dates. Our study provides a formal inference framework to include information on infection and sampling times, and to investigate ancestral node-label states, transmission direction, transmitted genetic diversity, and frequency of transmission. PMID:28912340

Advancing the research agenda for diagnostic error reduction.

PubMed

Zwaan, Laura; Schiff, Gordon D; Singh, Hardeep

2013-10-01

Diagnostic errors remain an underemphasised and understudied area of patient safety research. We briefly summarise the methods that have been used to conduct research on epidemiology, contributing factors and interventions related to diagnostic error and outline directions for future research. Research methods that have studied epidemiology of diagnostic error provide some estimate on diagnostic error rates. However, there appears to be a large variability in the reported rates due to the heterogeneity of definitions and study methods used. Thus, future methods should focus on obtaining more precise estimates in different settings of care. This would lay the foundation for measuring error rates over time to evaluate improvements. Research methods have studied contributing factors for diagnostic error in both naturalistic and experimental settings. Both approaches have revealed important and complementary information. Newer conceptual models from outside healthcare are needed to advance the depth and rigour of analysis of systems and cognitive insights of causes of error. While the literature has suggested many potentially fruitful interventions for reducing diagnostic errors, most have not been systematically evaluated and/or widely implemented in practice. Research is needed to study promising intervention areas such as enhanced patient involvement in diagnosis, improving diagnosis through the use of electronic tools and identification and reduction of specific diagnostic process 'pitfalls' (eg, failure to conduct appropriate diagnostic evaluation of a breast lump after a 'normal' mammogram). The last decade of research on diagnostic error has made promising steps and laid a foundation for more rigorous methods to advance the field.

Clinical and epidemiological characteristics of Korean patients with hepatitis C virus genotype 6

PubMed Central

Seong, Mun Hyuk; Kil, Ho; Kim, Jong Yeop; Lee, Sang Soo; Jang, Eun Sun; Kim, Jin-Wook; Kim, Young Seok; Bae, Si Hyun; Lee, Youn Jae; Lee, Han Chu; Yun, Haesun; Kang, Byung Hak; Kim, Kisang

2013-01-01

Background/Aims The distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2. Methods This was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared. Results The patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2. Conclusions The epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring. PMID:23593609

Problems and Benefits Reported by Stroke Family Caregivers: Results from a Prospective Epidemiological Study

PubMed Central

Haley, William E.; Allen, Jessica Y.; Grant, Joan S.; Clay, Olivio J.; Perkins, Martinique; Roth, David L.

2009-01-01

Background and Purpose Stroke symptoms can be very stressful for family caregivers, but most knowledge about the prevalence and stressfulness of stroke-related patient problems is derived from convenience samples. In addition, little is known about perceived benefits of the stroke caregiving experience. The purpose of this study was to determine the prevalence and stressfulness of stroke-related problems, and perceived benefits of caregiving, as reported by an epidemiologically-derived sample of caregivers of stroke survivors. Methods Stroke survivors (N=75) from a prospective epidemiological study of stroke, the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, and their family caregivers were followed. Caregivers were given a comprehensive telephone interview 8 to 12 months after the stroke, using measures of stroke patient problems, caregiver appraisals of the stressfulness of these problems, and perceived benefits of caregiving. Results Caregivers rated patient problems with mood (depression, loneliness and anxiety), memory, and physical care (bowel control), as the most stressful, but reported prevalence of these problems was lower than those reported previously in studies using clinical samples. Caregivers also reported many benefits from caregiving, with over 90% reporting that caregiving enabled them to appreciate life more. Conclusions Epidemiologically based studies of stroke caregiving provide a unique picture of caregiver strains and benefits compared with clinical studies, which tend to over-represent more impaired patients. Support for caregivers should include interventions to aid their coping with highly stressful mood, physical care, and cognitive problems of stroke patients, but should also attend to perceived benefits of caregiving. PMID:19407230

Lessons Learned From Methodological Validation Research in E-Epidemiology.

PubMed

Kesse-Guyot, Emmanuelle; Assmann, Karen; Andreeva, Valentina; Castetbon, Katia; Méjean, Caroline; Touvier, Mathilde; Salanave, Benoît; Deschamps, Valérie; Péneau, Sandrine; Fezeu, Léopold; Julia, Chantal; Allès, Benjamin; Galan, Pilar; Hercberg, Serge

2016-10-18

Traditional epidemiological research methods exhibit limitations leading to high logistics, human, and financial burden. The continued development of innovative digital tools has the potential to overcome many of the existing methodological issues. Nonetheless, Web-based studies remain relatively uncommon, partly due to persistent concerns about validity and generalizability. The objective of this viewpoint is to summarize findings from methodological studies carried out in the NutriNet-Santé study, a French Web-based cohort study. On the basis of the previous findings from the NutriNet-Santé e-cohort (>150,000 participants are currently included), we synthesized e-epidemiological knowledge on sample representativeness, advantageous recruitment strategies, and data quality. Overall, the reported findings support the usefulness of Web-based studies in overcoming common methodological deficiencies in epidemiological research, in particular with regard to data quality (eg, the concordance for body mass index [BMI] classification was 93%), reduced social desirability bias, and access to a wide range of participant profiles, including the hard-to-reach subgroups such as young (12.30% [15,118/122,912], <25 years) and old people (6.60% [8112/122,912], ≥65 years), unemployed or homemaker (12.60% [15,487/122,912]), and low educated (38.50% [47,312/122,912]) people. However, some selection bias remained (78.00% (95,871/122,912) of the participants were women, and 61.50% (75,590/122,912) had postsecondary education), which is an inherent aspect of cohort study inclusion; other specific types of bias may also have occurred. Given the rapidly growing access to the Internet across social strata, the recruitment of participants with diverse socioeconomic profiles and health risk exposures was highly feasible. Continued efforts concerning the identification of specific biases in e-cohorts and the collection of comprehensive and valid data are still needed. This summary of methodological findings from the NutriNet-Santé cohort may help researchers in the development of the next generation of high-quality Web-based epidemiological studies.

[Exploring multiple trajectories of causality: collaboration between Anthropology and Epidemiology in the 1982 birth cohort, Pelotas, Southern Brazil].

PubMed

Béhague, Dominique P; Gonçalves, Helen

2008-12-01

Although the relationship between epidemiology and anthropology has a long history, it has generally been comprised of the integration of quantitative and qualitative methods. Only recently have the two fields begun to converge along theoretical lines, leading to a growing mutual interest in explaining rather than simply describing phenomena. This paper aimed to illustrate how ethnographic analyses can be used to assist with the in-depth and theoretically-imbued interpretation of epidemiological results. The anthropological analysis presented in this paper used ethnographic data collected as part of the ongoing 1982 birth cohort study, between 1997 and 2007 in Pelotas, Southern Brazil. Analyses were framed according to the results presented in two of the epidemiological articles published in this series on the determinants of mental morbidity and age of sexual initiation. The ethnographic results show that statistical associations consist of multiple pathways of influence and causality that generally correspond to the unique experiences of specific subgroups. In exploring these pathways, the paper highlights the importance of an additional set of mediating factors that account for epidemiological results; these include the awareness and experience of inequities, the role of violence in everyday life, traumatic life events, increasing social isolation and emotional introversion as a response to life's difficulties, and differing approaches towards socio-psychological maturation. Theoretical and methodological collaboration between anthropology and epidemiology is important for public health, as it has positively modified both fields.

Soy intake is associated with lower lung cancer risk: results from a meta-analysis of epidemiologic studies123

PubMed Central

Yang, Wan-Shui; Va, Puthiery; Wong, Man-Yu; Zhang, Huan-Ling

2011-01-01

Background: Although several in vitro and animal in vivo studies have suggested that soy or soy isoflavones may exert inhibitory effects on lung carcinogenesis, epidemiologic studies have reported inconclusive results on the association between soy intake and lung cancer. Objective: The aim of this meta-analysis was to investigate whether an association exists between soy and lung cancer in epidemiologic studies. Design: We searched PubMed, EMBASE, and the Cochrane Library from their inception to February 2011 for both case-control and cohort studies that assessed soy consumption and lung cancer risk. Study-specific risk estimates were combined by using fixed-effect or random-effect models. Results: A total of 11 epidemiologic studies that consisted of 8 case-control and 3 prospective cohort studies were included. A significantly inverse association was shown between soy intake and lung cancer with an overall RR of 0.77 (95% CI: 0.65, 0.92). Findings were slightly different when analyses were restricted to 5 high-quality studies (RR: 0.70; 95% CI: 0.45, 0.99). In a subgroup meta-analysis, a statistically significant protective effect of soy consumption was observed in women (RR: 0.79; 95% CI: 0.67, 0.93), never smokers (RR: 0.62; 95% CI: 0.51, 0.76), and Asian populations (RR: 0.86; 95% CI: 0.74, 0.98). Conclusions: Our findings indicate that the consumption of soy food is associated with lower lung cancer risk. Because of different methods used to assess soy consumption across studies, more well-designed cohort studies or intervention studies that use unified measures of soy intake are needed to fully characterize such an association. PMID:22071712

Cancer risk in the rubber industry: a review of the recent epidemiological evidence

PubMed Central

Kogevinas, M.; Sala, M.; Boffetta, P.; Kazerouni, N.; Kromhout, H.; Hoar-Zahm, S.

1998-01-01

OBJECTIVES: To examine the recent epidemiological evidence on cancer risk among workers in the rubber industry. METHODS: Epidemiological studies published after the last detailed review by the International Agency for Research on Cancer (IARC) in 1982 were reviewed. 12 cohort studies in nine countries that examined distinct populations of workers in the rubber industry, seven industry based nested case-control studies, 48 community based case-control studies in 16 countries, and 23 studies based on administrative data that reported risks for employment in the rubber industry were identified. RESULTS: Excess risks of bladder cancer, lung cancer, and leukaemia were found in most studies, with risks above 1.5 in about half of the studies. A moderate excess risk for laryngeal cancer was consistent across studies. Excess risks were found in a few studies for cancers of the oesophagus, stomach, colon, liver, pancreas, skin, prostate, kidney, brain, and thyroid, and for malignant lymphoma and multiple myeloma, but overall results were not consistent for these neoplasms. CONCLUSIONS: Magnitude of the observed risks varied considerably between studies, but overall the findings indicate the presence of a widespread moderate increased cancer risk among rubber workers. The most consistent results were for bladder, laryngeal, and lung cancer and for leukaemia. Excess risks were also found for other neoplasms but an evaluation of the consistency of the findings is difficult because of the possible selective reporting of results. Recent studies do not provide information associating specific exposures with cancer risk. The preventive measures taken in the rubber industry in recent years may decrease risks, but this has not been documented yet in epidemiological studies.   PMID:9536156

Critical Appraisal Skills Among Canadian Obstetrics and Gynaecology Residents: How Do They Fare?

PubMed

Bougie, Olga; Posner, Glenn; Black, Amanda Y

2015-07-01

Evidence-based medicine has become the standard of care in clinical practice. In this study, our objectives were to (1) determine the type of epidemiology and/or biostatistical training being given in Canadian obstetrics and gynaecology post-graduate programs, (2) determine obstetrics and gynaecology residents' level of confidence with critical appraisal, and (3) assess knowledge of fundamental biostatistical and epidemiological principles among Canadian obstetrics and gynaecology trainees. During a national standardized in-training examination, all Canadian obstetrics and gynaecology residents were invited to complete an anonymous cross-sectional survey to determine their levels of confidence with critical appraisal. Fifteen critical appraisal questions were integrated into the standardized examination to assess critical appraisal skills objectively. Primary outcomes were the residents' level of confidence interpreting biostatistical results and applying research findings to clinical practice, their desire for more biostatistics/epidemiological training in residency, and their performance on knowledge questions. A total of 301 of 355 residents completed the survey (response rate=84.8%). Most (76.7%) had little/no confidence interpreting research statistics. Confidence was significantly higher in those with increased seniority (OR=1.93), in those who had taken a previous epidemiology/statistics course (OR=2.65), and in those who had prior publications (OR=1.82). Many (68%) had little/no confidence applying research findings to clinical practice. Confidence increased significantly with increasing training year (P<0.001) and with formal epidemiology training during residency (OR=2.01). The mean score of the 355 residents on the knowledge assessment questions was 69.8%. Increasing seniority was associated with improved overall test performance (P=0.02). Poorer performance topics included analytical study method (9.9%), study design (36.9%), and sample size (42.0%). Most (84.4%) wanted more epidemiology teaching. Canadian obstetrics and gynaecology residents may have the biostatistical and epidemiological knowledge to interpret results published in the literature, but lack confidence applying these skills in clinical settings. Most residents want additional training in these areas, and residency programs should include training in formal curriculums to improve their confidence and prepare them for a lifelong practice of evidence-based medicine.

[Causal inference in medicine: a reaction to the report, "incidence of Minamata disease in communities along the Agano River, Niigata, Japan--patterns of the exposure and official diagnosis of patients"].

PubMed

Tsuda, T; Mino, Y; Yamamoto, E; Matsuoka, H; Babazono, A; Shigemi, J; Miyai, M

1997-07-01

Kondo's "Incidence of Minamata Disease in Communities along the Agano River, Niigata, Japan (Jap. J. Hyg. 51:599-611;1996)" is critically reviewed. The data of the article were obtained from most of the residents living in the Agano river villages where Minamata disease was discovered in June, 1965. However, sampling proportions were much different between in the population base and in the cases. The method of identification of cases from the data and the reason for the difference were not clearly demonstrated. The citations of reference articles are insufficient despite the fact that other epidemiologic studies on methyl-mercury poisoning have been reported not only in Japan, but also around the world. His "analysis of the recognized patients" is erroneous. Both the sampling scheme of information of hair mercury and the modeling of the analysis are based on Kondo's arbitrary interpretation, not on epidemiologic theory. His "analysis of the rejected applicants" is also erroneous. His calculations of the attributable proportion are incorrect and self-induced in both the assignments of data and analysis of data. Kondo has failed to study the epidemiologic theories in light of changes in the field. Therefore, his article is lacking in epidemiologic theory, a logical base and scientific inference. In Japan, epidemiologic methodology has rarely been used in studies on Minamata Disease in either Kumamoto and Niigata. The government has used neurologically specific diagnosis based on combinations of symptoms to judge the causality between each of symptoms and methyl-mercury poisoning. Epidemiologic data obtained in Minamata, Kumamoto in 1971 indicate that the criteria set by the government in 1977 have produced much more false-negative patients than false-positive patients. As a result, a huge number of symptomatic patients, including those with peripheral neuropathy or with constriction of the visual field, did not receive any help or compensation until 1995. The authors emphasize that the causal relationship between each symptom and methyl-mercury exposure should be reevaluated epidemiologically in Japan.

Hormonal contraceptive use and women's risk of HIV acquisition: priorities emerging from recent data.

PubMed

Ralph, Lauren J; Gollub, Erica L; Jones, Heidi E

2015-12-01

Understanding whether hormonal contraception increases women's risk of HIV acquisition is a public health priority. This review summarizes recent epidemiologic and biologic data, and considers the implications of new evidence on research and programmatic efforts. Two secondary analyses of HIV prevention trials demonstrated increased HIV risk among depot medroxyprogesterone acetate (DMPA) users compared with nonhormonal/no method users and norethisterone enanthate (NET-EN) users. A study of women in serodiscordant partnerships found no significant association for DMPA or implants. Two meta-analyses found elevated risks of HIV among DMPA users compared with nonhormonal/no method users, with no association for NET-EN or combined oral contraceptive pills. In-vitro and animal model studies identified plausible biological mechanisms by which progestin exposure could increase risk of HIV, depending on the type and dose of progestin, but such mechanisms have not been definitively observed in humans. Recent epidemiologic and biologic evidence on hormonal contraception and HIV suggests a harmful profile for DMPA but not combined oral contraceptives. In limited data, NET-EN appears safer than DMPA. More research is needed on other progestin-based methods, especially implants and Sayana Press. Future priorities include updating modeling studies with new pooled estimates, continued basic science to understand biological mechanisms, expanding contraceptive choice, and identifying effective ways to promote dual method use.

An approach to checking case-crossover analyses based on equivalence with time-series methods.

PubMed

Lu, Yun; Symons, James Morel; Geyh, Alison S; Zeger, Scott L

2008-03-01

The case-crossover design has been increasingly applied to epidemiologic investigations of acute adverse health effects associated with ambient air pollution. The correspondence of the design to that of matched case-control studies makes it inferentially appealing for epidemiologic studies. Case-crossover analyses generally use conditional logistic regression modeling. This technique is equivalent to time-series log-linear regression models when there is a common exposure across individuals, as in air pollution studies. Previous methods for obtaining unbiased estimates for case-crossover analyses have assumed that time-varying risk factors are constant within reference windows. In this paper, we rely on the connection between case-crossover and time-series methods to illustrate model-checking procedures from log-linear model diagnostics for time-stratified case-crossover analyses. Additionally, we compare the relative performance of the time-stratified case-crossover approach to time-series methods under 3 simulated scenarios representing different temporal patterns of daily mortality associated with air pollution in Chicago, Illinois, during 1995 and 1996. Whenever a model-be it time-series or case-crossover-fails to account appropriately for fluctuations in time that confound the exposure, the effect estimate will be biased. It is therefore important to perform model-checking in time-stratified case-crossover analyses rather than assume the estimator is unbiased.

[How to write high-quality epidemiological research paper Ⅵ. Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut)].

PubMed

Ding, C Y; Cao, Y; Yang, C; Sun, F; Zhan, S Y

2017-01-10

Concerns have been raised about the reporting quality in nutritional epidemiology. Therefore, strengthening the reporting of observational studies in epidemiology-nutritional epidemiology (STROBE-nut) has been proposed by extending the STROBE statement to include additional recommendations on issues related to nutritional epidemiology and dietary assessment, aiming to provide more specific guidelines on how to report observational research in the field. This paper presents a brief introduction to STROBE-nut and also an explanation of the key points in the additional items, with an example illustrating the application of the checklist.

Identifying socioeconomic, epidemiological and operational scenarios for tuberculosis control in Brazil: an ecological study.

PubMed

Pelissari, Daniele Maria; Rocha, Marli Souza; Bartholomay, Patricia; Sanchez, Mauro Niskier; Duarte, Elisabeth Carmen; Arakaki-Sanchez, Denise; Dantas, Cíntia Oliveira; Jacobs, Marina Gasino; Andrade, Kleydson Bonfim; Codenotti, Stefano Barbosa; Andrade, Elaine Silva Nascimento; Araújo, Wildo Navegantes de; Costa, Fernanda Dockhorn; Ramalho, Walter Massa; Diaz-Quijano, Fredi Alexander

2018-06-06

To identify scenarios based on socioeconomic, epidemiological and operational healthcare factors associated with tuberculosis incidence in Brazil. Ecological study. The study was based on new patients with tuberculosis and epidemiological/operational variables of the disease from the Brazilian National Information System for Notifiable Diseases and the Mortality Information System. We also analysed socioeconomic and demographic variables. The units of analysis were the Brazilian municipalities, which in 2015 numbered 5570 but 5 were excluded due to the absence of socioeconomic information. Tuberculosis incidence rate in 2015. We evaluated as independent variables the socioeconomic (2010), epidemiological and operational healthcare indicators of tuberculosis (2014 or 2015) using negative binomial regression. Municipalities were clustered by the k-means method considering the variables identified in multiple regression models. We identified two clusters according to socioeconomic variables associated with the tuberculosis incidence rate (unemployment rate and household crowding): a higher socioeconomic scenario (n=3482 municipalities) with a mean tuberculosis incidence rate of 16.3/100 000 population and a lower socioeconomic scenario (2083 municipalities) with a mean tuberculosis incidence rate of 22.1/100 000 population. In a second stage of clusterisation, we defined four subgroups in each of the socioeconomic scenarios using epidemiological and operational variables such as tuberculosis mortality rate, AIDS case detection rate and proportion of vulnerable population among patients with tuberculosis. Some of the subscenarios identified were characterised by fragility in their information systems, while others were characterised by the concentration of tuberculosis cases in key populations. Clustering municipalities in scenarios allowed us to classify them according to the socioeconomic, epidemiological and operational variables associated with tuberculosis risk. This classification can support targeted evidence-based decisions such as monitoring data quality for improving the information system or establishing integrative social protective policies for key populations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Molecular diagnosis of toxoplasmosis in immunocompromised patients.

PubMed

Robert-Gangneux, Florence; Belaz, Sorya

2016-08-01

Toxoplasmosis in immunocompromised patients is associated with a high mortality rate. Molecular techniques are important tools to diagnose acute disease in immunocompromised patients, but there are various methods with variable efficiency. Some of them have been validated for the diagnosis of congenital toxoplasmosis, but the impact of their use has not been evaluated in immunocompromised patients. Toxoplasmosis is of increasing importance in non-HIV immunocompromised patients. In addition, the picture of disease shows greater severity in South America, both in immunocompetent study participants and in congenitally infected infants. These epidemiological differences could influence the sensitivity of diagnostic methods. This review analyzes recent data on molecular diagnosis and compares them with older ones, in light of progress gained in molecular techniques and of recent epidemiological findings. Most recent studies were conducted in South America and used PCR targeting the B1 gene. PCR on blood could allow diagnosing a significant proportion of patients with ocular toxoplasmosis in Brazil. Quantitative PCR methods with specific probes should be used to improve sensitivity and warrant specificity. Performance of quantitative PCR targeting the repeated 529 bp sequence for the diagnosis of toxoplasmosis in immunocompromised patients needs evaluation in field studies in South America and in western countries.

A METHOD FOR EXPOSING RODENTS TO RESUSPENDED PARTICLES USING WHOLE-BODY PLETHYSMOGRAPHY

EPA Science Inventory

Background: Epidemiological studies have reported increased risks of cardiopulmonary-related hospitalization and death in association with exposure to elevated levels of particulate matter (PM) across a wide range of urban areas. In response to these findings, researchers have c...

The Biomarkers of Exposure and Effect in Agriculture (BEEA) Study: Rationale, design, methods, and participant characteristics

EPA Science Inventory

Agricultural exposures including pesticides, endotoxin, and allergens have been associated with risk of various cancers and other chronic diseases, although the biological mechanisms underlying these associations are generally unclear. To facilitate future molecular epidemiologic...

RECREATIONAL WATER QUALITY AND SWIMMING ASSOCIATED HEALTH EFFECTS

EPA Science Inventory

The U.S. EPA's National Epidemiological and Environmental Assessment of Recreational Water study is currently underway with the goal of determining if new rapid methods for measuring water quality can be used to predict illness in swimmers. This lecture will provide a historical...

NATIONAL EPIDEMIOLOGICAL AND ENVIRONMENTAL ASSESSMENT OF RECREATIONAL WATER STUDY

EPA Science Inventory

Evidence from various sources around the world indicate that there is a relationship between gastroenteritis in swimmers and the quality of the bathing water as measured with bacterial indicators of fecal contamination. Current EPA guidelines recommend the use of cultural method...

Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates

USDA-ARS?s Scientific Manuscript database

Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by th...

More evidence of unpublished industry studies of lead smelter/refinery workers

PubMed Central

2015-01-01

Background Lead smelter/refinery workers in the US have had significant exposure to lead and are an important occupational group to study to understand the health effects of chronic lead exposure in adults. Recent research found evidence that studies of lead smelter/refinery workers have been conducted but not published. This paper presents further evidence for this contention. Objectives To present further evidence of industry conducted, unpublished epidemiologic studies of lead smelter/refinery workers and health outcomes. Methods Historical research relying on primary sources such as internal industry documents and published studies. Results ASARCO smelter/refinery workers were studied in the early 1980s and found to have increased risk of lung cancer and stroke in one study, but not in another. Conclusions Because occupational lead exposure is an on-going concern for US and overseas workers, all epidemiologic studies should be made available to evaluate and update occupational health and safety standards. PMID:26070220

Measurement of spices and seasonings in India: Opportunities for cancer epidemiology and prevention

PubMed Central

Ferrucci, Leah M.; Daniel, Carrie R.; Kapur, Kavita; Chadha, Puneet; Shetty, Hemali; Graubard, Barry I.; George, Preethi S.; Osborne, Whitney; Yurgalevitch, Susan; Devasenapathy, Niveditha; Chatterjee, Nilanjan; Prabhakaran, Dorairaj; Gupta, Prakash C.; Mathew, Aleyamma; Sinha, Rashmi

2011-01-01

Bioactive components of many foods added during cooking have potential antioxidant, anti-inflammatory, antimicrobial, antibacterial and chemopreventive properties. However, epidemiologic studies generally do not collect detailed information on these items which include spices, chilies, coconuts, garlic, onions, and oils. Since India has some of the highest spice consumption in the world, we developed a computer-based food preparer questionnaire to estimate per capita consumption of 19 spices, chilies, coconuts, garlic, onions, and 13 cooking oils among 3,625 participants in the India Health Study, a multicenter pilot study in three regions of India. We observed notable regional differences in consumption of spices, chilies, coconut, garlic, and onions. In Trivandrum, over 95 percent of the participants consumed 12 different spices, while in New Delhi and Mumbai, 95 percent of participants consumed only four and five spices, respectively. Cooking oil use also varied, as ghee was most common in New Delhi (96.8%) followed by mustard seed oil (78.0%), while in Trivandrum the primary oil was coconut (88.5%) and in Mumbai it was peanut (68.5%). There was some variation in consumption by education, income, and religion. Using a novel method for assessing food items primarily added during cooking, we successfully estimated per capita consumption within an epidemiologic study. Based on basic science research and suggestive ecologic level data on cancer incidence and spice consumption, improving epidemiologic assessment of these potentially chemopreventive food items may enhance our understanding of diet and cancer risk. PMID:21338207

A Scan of CDC-Authored Articles on Legal Epidemiology, 2011-2015

PubMed Central

Martini, Leila; Presley, David; Klieger, Sarah

2016-01-01

Objective: The Centers for Disease Control and Prevention (CDC) conducts research on legal epidemiology, the scientific study of law as a factor in the cause, distribution, and prevention of disease. This study describes a scan of articles written by CDC staff members to characterize the frequency and key features of legal epidemiology articles and their distribution across CDC departments and divisions. Methods: CDC librarians searched an internal repository for journal articles by CDC staff published from January 1, 2011, to May 31, 2015. Researchers reviewed and coded the abstracts to produce data on key features of the articles. Results: Researchers identified 158 CDC-authored legal epidemiology articles published in 83 journals, most frequently in Preventing Chronic Disease (14 publications), Journal of Public Health Management Practice (10 publications), and Morbidity and Mortality Weekly Report (9 publications). Most articles concerned the use and impact of law as a deliberate tool of intervention. Thirteen articles addressed the legal infrastructure of public health, and 3 assessed the incidental or unintended effects of nonhealth laws. CDC-authored articles encompassed policy making, implementation, and impact. Literature reviews and studies mapping laws across multiple jurisdictions constituted one-quarter of all publications. Studies addressed laws at the international, national, state, local, and organizational levels. Conclusion: Results of the scan can be used to identify opportunities for the agency to better support research, professional development, networking, publication, and tracking of publication in this emerging field. PMID:28123227

Measurement of spices and seasonings in India: opportunities for cancer epidemiology and prevention.

PubMed

Ferrucci, Leah M; Daniel, Carrie R; Kapur, Kavita; Chadha, Puneet; Shetty, Hemali; Graubard, Barry I; George, Preethi S; Osborne, Whitney; Yurgalevitch, Susan; Devasenapathy, Niveditha; Chatterjee, Nilanjan; Prabhakaran, Dorairaj; Gupta, Prakash C; Mathew, Aleyamma; Sinha, Rashmi

2010-01-01

Bioactive components of many foods added during cooking have potential antioxidant, anti-inflammatory, antimicrobial, antibacterial and chemopreventive properties. However, epidemiologic studies generally do not collect detailed information on these items, which include spices, chilies, coconuts, garlic, onions, and oils. Since India has some of the highest spice consumption in the world, we developed a computer-based food preparer questionnaire to estimate per capita consumption of 19 spices, chilies, coconuts, garlic, onions, and 13 cooking oils among 3,625 participants in the India Health Study, a multicenter pilot study in three regions of India. We observed notable regional differences in consumption of spices, chilies, coconut, garlic, and onions. In Trivandrum, over 95 percent of the participants consumed 12 different spices, while in New Delhi and Mumbai, 95 percent of participants consumed only four and five spices, respectively. Cooking oil use also varied, as ghee was most common in New Delhi (96.8%) followed by mustard seed oil (78.0%), while in Trivandrum the primary oil was coconut (88.5%) and in Mumbai it was peanut (68.5%). There was some variation in consumption by education, income, and religion. Using a novel method for assessing food items primarly added during cooking, we successfully estimated per capita consumption within an epidemiologic study. Based on basic science research and suggestive ecologic level data on cancer incidence and spice consumption, improving epidemiologic assessment of these potentially chemopreventive food items may enhance our understanding of diet and cancer risk.

Suicidal Phenomena and Abuse in Adolescents: A Review of Epidemiological Studies

ERIC Educational Resources Information Center

Evans, E.; Hawton, K.; Rodham, K.

2005-01-01

Objective:: To conduct a systematic review of the international literature to determine whether adolescents who had experienced abuse were more likely to also experience suicidal thoughts and behaviors than other adolescents, and to investigate the nature of this association. Method:: Reports of community- or school-based studies of adolescents on…

[Monitoring methods and their results in environmental medicine - implications for medical counsellors].

PubMed

Wolter, E; Neumann, A; Straff, W

2017-06-01

Besides effect and environmental monitoring, human biomonitoring (HBM) offers an attractive method for analyzing the distribution and intensity of anthropogenic environmental pollutants in individuals or in particular groups of the population. However, no assessment values of comparable reliability are available to enable an interpretation of the results of environmental studies from the viewpoint of environmental health. This must be taken into account when reporting findings of such studies as well as in medical consultation, in order to avoid overdiagnosis and unnecessary anxiety for the participant. In medical practice, care should be taken when dealing with monitoring results outside the normal range! Environmental or biomonitoring results provide only a part of the available information alongside medical history and clinical examinations. In the case of tests performed for private interests as well as tests carried out within the framework of an epidemiological environmental survey, communication of results and findings can be problematic. In epidemiological studies, a close co-operation between the participant's consultant physician and physicians conducting the study is beneficial in order to ensure professional advisory counselling for subjects with results outside the normal range.

Epidemiology and risk factors for drug allergy.

PubMed

Thong, Bernard Y-H; Tan, Teck-Choon

2011-05-01

The aim of this review was to describe the current evidence-based knowledge of the epidemiology, prevalence, incidence, risk factors and genetic associations of drug allergy. Articles published between 1966 and 2010 were identified in MEDLINE using the key words adult, adverse drug reaction reporting systems, age factors, anaphylactoid, anaphylaxis, anaesthetics, antibiotics, child, drug allergy, drug eruptions, ethnic groups, hypersensitivity, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, sex factors, Stevens Johnson syndrome and toxic epidermal necrolysis. Additional studies were identified from article reference lists. Relevant, peer-reviewed original research articles, case series and reviews were considered for review. Current epidemiological studies on adverse drug reactions (ADRs) have used different definitions for ADR-related terminology, often do not differentiate immunologically and non-immunologically mediated drug hypersensitivity, study different study populations (different ethnicities, inpatients or outpatients, adults or children), utilize different methodologies (spontaneous vs. non-spontaneous reporting, cohort vs. case-control studies), different methods of assessing drug imputability and different methods of data analyses. Potentially life-threatening severe cutaneous adverse reactions (SCAR) are associated with a high risk of morbidity and mortality. HLA associations for SCAR associated with allopurinol, carbamazepine and abacavir have been reported with the potential for clinical use in screening prior to prescription. Identification of risk factors for drug allergy and appropriate genetic screening of at-risk ethnic groups may improve the outcomes of drug-specific SCAR. Research and collaboration are necessary for the generation of clinically-relevant, translational pharmacoepidemiological and pharmacogenomic knowledge, and success of health outcomes research and policies on drug allergies. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

Teratogenicity of depleted uranium aerosols: A review from an epidemiological perspective

PubMed Central

Hindin, Rita; Brugge, Doug; Panikkar, Bindu

2005-01-01

Background Depleted uranium is being used increasingly often as a component of munitions in military conflicts. Military personnel, civilians and the DU munitions producers are being exposed to the DU aerosols that are generated. Methods We reviewed toxicological data on both natural and depleted uranium. We included peer reviewed studies and gray literature on birth malformations due to natural and depleted uranium. Our approach was to assess the "weight of evidence" with respect to teratogenicity of depleted uranium. Results Animal studies firmly support the possibility that DU is a teratogen. While the detailed pathways by which environmental DU can be internalized and reach reproductive cells are not yet fully elucidated, again, the evidence supports plausibility. To date, human epidemiological data include case examples, disease registry records, a case-control study and prospective longitudinal studies. Discussion The two most significant challenges to establishing a causal pathway between (human) parental DU exposure and the birth of offspring with defects are: i) distinguishing the role of DU from that of exposure to other potential teratogens; ii) documentation on the individual level of extent of parental DU exposure. Studies that use biomarkers, none yet reported, can help address the latter challenge. Thoughtful triangulation of the results of multiple studies (epidemiological and other) of DU teratogenicity contributes to disentangling the roles of various potentially teratogenic parental exposures. This paper is just such an endeavor. Conclusion In aggregate the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU. PMID:16124873

Biomarker as a Research Tool in Linking Exposure to Air Particles and Respiratory Health

PubMed Central

2015-01-01

Some of the environmental toxicants from air pollution include particulate matter (PM10), fine particulate matter (PM2.5), and ultrafine particles (UFP). Both short- and long-term exposure could result in various degrees of respiratory health outcomes among exposed persons, which rely on the individuals' health status. Methods. In this paper, we highlight a review of the studies that have used biomarkers to understand the association between air particles exposure and the development of respiratory problems resulting from the damage in the respiratory system. Data from previous epidemiological studies relevant to the application of biomarkers in respiratory system damage reported from exposure to air particles are also summarized. Results. Based on these analyses, the findings agree with the hypothesis that biomarkers are relevant in linking harmful air particles concentrations to increased respiratory health effects. Biomarkers are used in epidemiological studies to provide an understanding of the mechanisms that follow airborne particles exposure in the airway. However, application of biomarkers in epidemiological studies of health effects caused by air particles in both environmental and occupational health is inchoate. Conclusion. Biomarkers unravel the complexity of the connection between exposure to air particles and respiratory health. PMID:25984536

How to study the aetiology of burn injury: the epidemiological approach.

PubMed

Bouter, L M; Knipschild, P G; van Rijn, J L; Meertens, R M

1989-06-01

Effective prevention of burn injury should be based on sound aetiological knowledge. This article deals with epidemiological methods to study the incidence of burn injury as a function of its risk factors. Central methodological issues are comparability of baseline prognosis, comparability of measurements (of effects in cohort studies and of risk factors in case-control studies), and comparability of external circumstances. These principles are clarified with a number of fictitious examples of risk factors for burn injury. It is explained that in preventive trials comparability may be achieved by randomization, blinding and placebo intervention. The main tools in non-experimental studies are deliberate selection and multivariate analysis. Special attention is given to the definition of the source population and to reducing measurement incomparability in case-control studies. Some well-designed case-control studies following these principles might bring effective prevention of burn injury some steps nearer.

Association between Recruitment Methods and Attrition in Internet-Based Studies

PubMed Central

Bajardi, Paolo; Paolotti, Daniela; Vespignani, Alessandro; Eames, Ken; Funk, Sebastian; Edmunds, W. John; Turbelin, Clement; Debin, Marion; Colizza, Vittoria; Smallenburg, Ronald; Koppeschaar, Carl; Franco, Ana O.; Faustino, Vitor; Carnahan, AnnaSara; Rehn, Moa; Merletti, Franco; Douwes, Jeroen; Firestone, Ridvan; Richiardi, Lorenzo

2014-01-01

Internet-based systems for epidemiological studies have advantages over traditional approaches as they can potentially recruit and monitor a wider range of individuals in a relatively inexpensive fashion. We studied the association between communication strategies used for recruitment (offline, online, face-to-face) and follow-up participation in nine Internet-based cohorts: the Influenzanet network of platforms for influenza surveillance which includes seven cohorts in seven different European countries, the Italian birth cohort Ninfea and the New Zealand birth cohort ELF. Follow-up participation varied from 43% to 89% depending on the cohort. Although there were heterogeneities among studies, participants who became aware of the study through an online communication campaign compared with those through traditional offline media seemed to have a lower follow-up participation in 8 out of 9 cohorts. There were no clear differences in participation between participants enrolled face-to-face and those enrolled through other offline strategies. An Internet-based campaign for Internet-based epidemiological studies seems to be less effective than an offline one in enrolling volunteers who keep participating in follow-up questionnaires. This suggests that even for Internet-based epidemiological studies an offline enrollment campaign would be helpful in order to achieve a higher participation proportion and limit the cohort attrition. PMID:25490045

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...

Integrating Phylodynamics and Epidemiology to Estimate Transmission Diversity in Viral Epidemics

PubMed Central

Magiorkinis, Gkikas; Sypsa, Vana; Magiorkinis, Emmanouil; Paraskevis, Dimitrios; Katsoulidou, Antigoni; Belshaw, Robert; Fraser, Christophe; Pybus, Oliver George; Hatzakis, Angelos

2013-01-01

The epidemiology of chronic viral infections, such as those caused by Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV), is affected by the risk group structure of the infected population. Risk groups are defined by each of their members having acquired infection through a specific behavior. However, risk group definitions say little about the transmission potential of each infected individual. Variation in the number of secondary infections is extremely difficult to estimate for HCV and HIV but crucial in the design of efficient control interventions. Here we describe a novel method that combines epidemiological and population genetic approaches to estimate the variation in transmissibility of rapidly-evolving viral epidemics. We evaluate this method using a nationwide HCV epidemic and for the first time co-estimate viral generation times and superspreading events from a combination of molecular and epidemiological data. We anticipate that this integrated approach will form the basis of powerful tools for describing the transmission dynamics of chronic viral diseases, and for evaluating control strategies directed against them. PMID:23382662

Population Genomics of Francisella tularensis subsp. holarctica and its Implication on the Eco-Epidemiology of Tularemia in Switzerland

PubMed Central

Wittwer, Matthias; Altpeter, Ekkehard; Pilo, Paola; Gygli, Sebastian M.; Beuret, Christian; Foucault, Frederic; Ackermann-Gäumann, Rahel; Karrer, Urs; Jacob, Daniela; Grunow, Roland; Schürch, Nadia

2018-01-01

Whole genome sequencing (WGS) methods provide new possibilities in the field of molecular epidemiology. This is particularly true for monomorphic organisms where the discriminatory power of traditional methods (e.g., restriction enzyme length polymorphism typing, multi locus sequence typing etc.) is inadequate to elucidate complex disease transmission patterns, as well as resolving the phylogeny at high resolution on a micro-geographic scale. In this study, we present insights into the population structure of Francisella tularensis subsp. holarctica, the causative agent of tularemia in Switzerland. A total of 59 Fth isolates were obtained from castor bean ticks (Ixodes ricinus), animals and humans and a high resolution phylogeny was inferred using WGS methods. The majority of the Fth population in Switzerland belongs to the west European B.11 clade and shows an extraordinary genetic diversity underlining the old evolutionary history of the pathogen in the alpine region. Moreover, a new B.11 subclade was identified which was not described so far. The combined analysis of the epidemiological data of human tularemia cases with the whole genome sequences of the 59 isolates provide evidence that ticks play a pivotal role in transmitting Fth to humans and other vertebrates in Switzerland. This is further underlined by the correlation of disease risk estimates with climatic and ecological factors influencing the survival of ticks. PMID:29623260

Epidemiology and detection as options for control of viral and parasitic foodborne disease.

PubMed Central

Jaykus, L. A.

1997-01-01

Human enteric viruses and protozoal parasites are important causes of emerging food and waterborne disease. Epidemiologic investigation and detection of the agents in clinical, food, and water specimens, which are traditionally used to establish the cause of disease outbreaks, are either cumbersome, expensive, and frequently unavailable or unattempted for the important food and waterborne enteric viruses and protozoa. However, the recent introduction of regulatory testing mandates, alternative testing strategies, and increased epidemiologic surveillance for food and waterborne disease should significantly improve the ability to detect and control these agents. We discuss new methods of investigating foodborne viral and parasitic disease and the future of these methods in recognizing, identifying, and controlling disease agents. PMID:9366607

[BRILL-ZINSER DISEASE AS A CONSEQUENCE OF RICKETTSIA PROWAZEKII PERSISTENCE IN PREVIOUSLY ILL WHO HAVE HAD EPIDEMIC TYPHUS (EPIDEMIOLOGIC ASPECTS)].

PubMed

Tarasevich, I V; Shpynov, S N; Pantyukhina, A N

2015-01-01

Materials, that summarize data of original research and scientific literature on epidemiology and problems of persistence during epidemic typhus, whose causative agent (Rickettsia prowazekii) is reactivated in the organism of the previously ill and is manifested as Brill-Zinser disease, are presented. A retrospective analysis was carried out with the data obtained by Russian (All-Union) Centre for Rickettsioses during study of epidemiologic examination maps of 5705 typhus nidi and results of 19 463 blood sera analysis during study of immunologic structure of population in the territories of the former USSR for the period from 1970 to 1992. A decrease of epidemic typhus morbidity and an increase of the fraction of Brill-Zinser disease took place as a result of pediculosis corporis control. In separate territories specific weight of Brill-Zinser disease was 48% in 1952, up to 80% in 1969, and from 1977 all the ill were previously ill. However, during the perestroika period and afterwards, due to a reduction of economic and hygienic living conditions, appearance of refugees, the immune structure regarding typhus began to change. Due to the buildup of the population migration process and the presence of risk groups (refugees, homeless) among population of regions, where local wars are waged, the enhancement of methods of epidemic typhus and Brill-Zinser disease diagnostics and pediculosis corporis eradication is necessary. Study of R. prowazekii by molecular-genetics methods is necessary for complete understanding of its mechanism of persistence.

Bacterial CRISPR Regions: General Features and their Potential for Epidemiological Molecular Typing Studies

PubMed Central

Karimi, Zahra; Ahmadi, Ali; Najafi, Ali; Ranjbar, Reza

2018-01-01

Introduction: CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) loci as novel and applicable regions in prokaryotic genomes have gained great attraction in the post genomics era. Methods: These unique regions are diverse in number and sequence composition in different pathogenic bacteria and thereby can be a suitable candidate for molecular epidemiology and genotyping studies. Results:Furthermore, the arrayed structure of CRISPR loci (several unique repeats spaced with the variable sequence) and associated cas genes act as an active prokaryotic immune system against viral replication and conjugative elements. This property can be used as a tool for RNA editing in bioengineering studies. Conclusion: The aim of this review was to survey some details about the history, nature, and potential applications of CRISPR arrays in both genetic engineering and bacterial genotyping studies. PMID:29755603

Validation methodology in publications describing epidemiological registration methods of dental caries: a systematic review.

PubMed

Sjögren, P; Ordell, S; Halling, A

2003-12-01

The aim was to describe and systematically review the methodology and reporting of validation in publications describing epidemiological registration methods for dental caries. BASIC RESEARCH METHODOLOGY: Literature searches were conducted in six scientific databases. All publications fulfilling the predetermined inclusion criteria were assessed for methodology and reporting of validation using a checklist including items described previously as well as new items. The frequency of endorsement of the assessed items was analysed. Moreover, the type and strength of evidence, was evaluated. Reporting of predetermined items relating to methodology of validation and the frequency of endorsement of the assessed items were of primary interest. Initially 588 publications were located. 74 eligible publications were obtained, 23 of which fulfilled the inclusion criteria and remained throughout the analyses. A majority of the studies reported the methodology of validation. The reported methodology of validation was generally inadequate, according to the recommendations of evidence-based medicine. The frequencies of reporting the assessed items (frequencies of endorsement) ranged from four to 84 per cent. A majority of the publications contributed to a low strength of evidence. There seems to be a need to improve the methodology and the reporting of validation in publications describing professionally registered caries epidemiology. Four of the items assessed in this study are potentially discriminative for quality assessments of reported validation.

Multiplicity and molecular epidemiology of Plasmodium vivax and Plasmodium falciparum infections in East Africa.

PubMed

Zhong, Daibin; Lo, Eugenia; Wang, Xiaoming; Yewhalaw, Delenasaw; Zhou, Guofa; Atieli, Harrysone E; Githeko, Andrew; Hemming-Schroeder, Elizabeth; Lee, Ming-Chieh; Afrane, Yaw; Yan, Guiyun

2018-05-02

Parasite genetic diversity and multiplicity of infection (MOI) affect clinical outcomes, response to drug treatment and naturally-acquired or vaccine-induced immunity. Traditional methods often underestimate the frequency and diversity of multiclonal infections due to technical sensitivity and specificity. Next-generation sequencing techniques provide a novel opportunity to study complexity of parasite populations and molecular epidemiology. Symptomatic and asymptomatic Plasmodium vivax samples were collected from health centres/hospitals and schools, respectively, from 2011 to 2015 in Ethiopia. Similarly, both symptomatic and asymptomatic Plasmodium falciparum samples were collected, respectively, from hospitals and schools in 2005 and 2015 in Kenya. Finger-pricked blood samples were collected and dried on filter paper. Long amplicon (> 400 bp) deep sequencing of merozoite surface protein 1 (msp1) gene was conducted to determine multiplicity and molecular epidemiology of P. vivax and P. falciparum infections. The results were compared with those based on short amplicon (117 bp) deep sequencing. A total of 139 P. vivax and 222 P. falciparum samples were pyro-sequenced for pvmsp1 and pfmsp1, yielding a total of 21 P. vivax and 99 P. falciparum predominant haplotypes. The average MOI for P. vivax and P. falciparum were 2.16 and 2.68, respectively, which were significantly higher than that of microsatellite markers and short amplicon (117 bp) deep sequencing. Multiclonal infections were detected in 62.2% of the samples for P. vivax and 74.8% of the samples for P. falciparum. Four out of the five subjects with recurrent P. vivax malaria were found to be a relapse 44-65 days after clearance of parasites. No difference was observed in MOI among P. vivax patients of different symptoms, ages and genders. Similar patterns were also observed in P. falciparum except for one study site in Kenyan lowland areas with significantly higher MOI. The study used a novel method to evaluate Plasmodium MOI and molecular epidemiological patterns by long amplicon ultra-deep sequencing. The complexity of infections were similar among age groups, symptoms, genders, transmission settings (spatial heterogeneity), as well as over years (pre- vs. post-scale-up interventions). This study demonstrated that long amplicon deep sequencing is a useful tool to investigate multiplicity and molecular epidemiology of Plasmodium parasite infections.

Use of emergency department electronic medical records for automated epidemiological surveillance of suicide attempts: a French pilot study.

PubMed

Metzger, Marie-Hélène; Tvardik, Nastassia; Gicquel, Quentin; Bouvry, Côme; Poulet, Emmanuel; Potinet-Pagliaroli, Véronique

2017-06-01

The aim of this study was to determine whether an expert system based on automated processing of electronic health records (EHRs) could provide a more accurate estimate of the annual rate of emergency department (ED) visits for suicide attempts in France, as compared to the current national surveillance system based on manual coding by emergency practitioners. A feasibility study was conducted at Lyon University Hospital, using data for all ED patient visits in 2012. After automatic data extraction and pre-processing, including automatic coding of medical free-text through use of the Unified Medical Language System, seven different machine-learning methods were used to classify the reasons for ED visits into "suicide attempts" versus "other reasons". The performance of these different methods was compared by using the F-measure. In a test sample of 444 patients admitted to the ED in 2012 (98 suicide attempts, 48 cases of suicidal ideation, and 292 controls with no recorded non-fatal suicidal behaviour), the F-measure for automatic detection of suicide attempts ranged from 70.4% to 95.3%. The random forest and naïve Bayes methods performed best. This study demonstrates that machine-learning methods can improve the quality of epidemiological indicators as compared to current national surveillance of suicide attempts. Copyright © 2016 John Wiley & Sons, Ltd.

A METHOD OF ASSESSING AIR TOXICS CONCENTRATIONS IN URBAN AREAS USING MOBILE PLATFORM MEASUREMENTS

EPA Science Inventory

The objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxic assessments in Environmental Justice applications, epidemiological studies...

The limitations of opportunistic epidemiology, pseudopod epidemiology.

PubMed

Kuller, Lewis H

2016-10-01

Epidemiology has been remarkably successful in the past in identifying the important agents of disease, the impact of the environment, both physical and social, and interrelationship with host susceptibility (genomics). Many of the advances in improving the health of individuals and populations have been the result of epidemiology studies that have identified the specific "agents" of disease and application of public health and preventive medicine. In recent years, large longitudinal studies have dominated epidemiology research, especially long incubation period chronic diseases. The initial hypotheses in these studies have been expanded by vertical extension studies using newer technologies to measure independent variables, vertical pseudopods, and additional studies of other diseases, horizontal pseudopods, of the original longitudinal study. Host susceptibility, i.e. genomics, has also become a prominent component of these longitudinal studies. The critical question addressed in this paper is whether these "pseudopod" epidemiology approaches have enhanced public health or generated a large number of studies of little impact.

A Review of Adult Obesity Prevalence, Trends, Risk Factors, and Epidemiologic Methods in Kuwait

PubMed Central

Alsmadi, Osama; Behbehani, Kazem

2013-01-01

Objective. Kuwait is among the countries with the highest obesity rates worldwide; however, little is known about the state of obesity epidemiology research in Kuwait. In this paper, we therefore review the findings and methodology of studies on the prevalence, trends and risk factors of obesity in Kuwait. Methods. The PubMed database was searched using the keyword combination: obesity and adults and Kuwait. Out of 111 articles, 39 remained after abstract review, and 18 were selected after full-text review. Results. The studies were all cross-sectional and published in the last fifteen years (1997–2012). The sample size ranged from 177 to 38,611 individuals. Only 30% of studies used random sampling. The prevalence (BMI ≥ 30) in studies with a nationally representative sample ranged from 24% to 48% overall and in adults >50 years was greater than 52%. Rates were significantly higher in women than those in men. Studies that examined trends showed an increase in obesity prevalence between 1980 and 2009. Multiple risk factors including sociocultural factors were investigated in the studies; however, factors were only crudely assessed. Conclusion. There is a need for future studies, particularly surveillance surveys and prospective cohort studies utilizing advanced methods, to monitor trends and to comprehensively assess the factors contributing to the obesity epidemic in Kuwait. PMID:24455212

Radiofrequency exposure on fast patrol boats in the Royal Norwegian Navy--an approach to a dose assessment.

PubMed

Baste, Valborg; Mild, Kjell Hansson; Moen, Bente E

2010-07-01

Epidemiological studies related to radiofrequency (RF) electromagnetic fields (EMF) have mainly used crude proxies for exposure, such as job titles, distance to, or use of different equipment emitting RF EMF. The Royal Norwegian Navy (RNoN) has measured RF field emitted from high-frequency antennas and radars on several spots where the crew would most likely be located aboard fast patrol boats (FPB). These boats are small, with short distance between the crew and the equipment emitting RF field. We have described the measured RF exposure aboard FPB and suggested different methods for calculations of total exposure and annual dose. Linear and spatial average in addition to percentage of ICNIRP and squared deviation of ICNIRP has been used. The methods will form the basis of a job exposure matrix where relative differences in exposure between groups of crew members can be used in further epidemiological studies of reproductive health. 2010 Wiley-Liss, Inc.

[Monitoring of Mycobacterium tuberculosis infections in Iaşi County in 2009].

PubMed

Luncă, Cătălina; Enache, Ecaterina; Olaru, Simona Peter; Diculencu, Daniela; Iancu, Luminiţa Smaranda

2011-01-01

Tuberculosis is a major public health problem worldwide. Our study aimed to investigate epidemiological and demographic characteristics of tuberculosis infection and resistance to antituberculous drugs in Iasi County in 2009. We have analysed the epidemiological parameters for 687 patients with pulmonary tuberculosis, new cases confirmed by microscopy and cultivation on Lowenstein Jensen. First and second-line antituberculous susceptibility testing was done for 130 strains, using agar proportion method and absolute-concentration method. The number of new cases of tuberculosis was higher in rural areas and in males 41-50 years old (sex ratio=2.22). The proportion of positive cases in microscopy was 81.51%. Drug resistance was as follows: 16 isolates (12.3%) to isoniazid, 5 (3.84%) to rifampin, 2 (1.53%) to ethambutol, 2 (1.53%) to streptomycin and 4 (3.07%) were multidrug-resistant. In this study we found high resistance rates to isoniazid, streptomycin and ethambutol. This requires increasing efficiency of tuberculosis diagnosis and susceptibility testing.

Characterization and Epidemiology of Pigeon Paramyxovirus Type-1 Viruses (PPMV-1) Isolated in Macedonia.

PubMed

Dodovski, A; Cvetkovikj, I; Krstevski, K; Naletoski, I; Savić, Vladimir

2017-06-01

We have characterized in this study 10 PPMV-1 isolated from domestic pigeons and one PPMV-1 isolated from a feral pigeon in the period 2007-2012, using both classical methods (HI test and ICPI test) and molecular methods (RT-qPCR, RT-PCR, and nucleotide sequencing). Using phylogenetic analysis of partial fusion gene sequences, these viruses clustered with recent European PPMV-1 isolates (EU/re) within the genotype VIb/1. All isolates possessed virulent cleavage site motifs with variable morbidity and mortality in pigeons. The intracerebral pathogenecity indices of the five isolates ranged from 0.59 to 1.53. The repetitive isolation of PPMV-1 viruses for several consecutive years led toward establishing enzootic presence of the disease in pigeons. A high nucleotide sequence homology between the Macedonian isolates and EU/re isolates was shown. Co-circulation of different isolates in the same holdings was detected. This is the first study to extensively describe the molecular epidemiology of PPMV-1 isolated in Macedonia.

Epidemiology of Glaucoma in Sub-Saharan Africa: Prevalence, Incidence and Risk Factors

PubMed Central

Kyari, Fatima; Abdull, Mohammed M.; Bastawrous, Andrew; Gilbert, Clare E.; Faal, Hannah

2013-01-01

Purpose: The purpose of this study is to review the epidemiology of different types of glaucoma relevant to Sub-Saharan Africa (SSA) and to discuss the evidence regarding the risk factors for onset and progression of glaucoma, including risk factors for glaucoma blindness. Methods: Electronic databases (PubMed, MedLine, African Journals Online- AJOL) were searched using the full text, Medical Subject Headings (MeSH) terms, author(s) and title to identify publications since 1982 in the following areas: population-based glaucoma prevalence and incidence studies in SSA and in African-derived black populations outside Africa; population-based prevalence and incidence of blindness and visual impairment studies in SSA including rapid assessment methods, which elucidate the glaucoma-specific blindness prevalence; studies of risk factors for glaucoma; and publications that discussed public health approaches for the control of glaucoma in Africa. Results: Studies highlighted that glaucoma in SSA is a public health problem and predominantly open-angle glaucoma. It is the second-leading cause of blindness, has a high prevalence, an early onset and progresses more rapidly than in Caucasians. These factors are further compounded by poor awareness and low knowledge about glaucoma even by persons affected by the condition. Conclusion: Glaucoma care needs to be given high priority in Vision 2020 programs in Africa. Many questions remain unanswered and there is a need for further research in glaucoma in SSA in all aspects especially epidemiology and clinical care and outcomes involving randomized controlled trials. Genetic and genome-wide association studies may aid identification of high-risk groups. Social sciences and qualitative studies, health economics and health systems research will also enhance public health approaches for the prevention of blindness due to glaucoma. PMID:23741130

Breast Cancer and Modifiable Lifestyle Factors in Argentinean Women: Addressing Missing Data in a Case-Control Study

PubMed Central

Coquet, Julia Becaria; Tumas, Natalia; Osella, Alberto Ruben; Tanzi, Matteo; Franco, Isabella; Diaz, Maria Del Pilar

2016-01-01

A number of studies have evidenced the effect of modifiable lifestyle factors such as diet, breastfeeding and nutritional status on breast cancer risk. However, none have addressed the missing data problem in nutritional epidemiologic research in South America. Missing data is a frequent problem in breast cancer studies and epidemiological settings in general. Estimates of effect obtained from these studies may be biased, if no appropriate method for handling missing data is applied. We performed Multiple Imputation for missing values on covariates in a breast cancer case-control study of Córdoba (Argentina) to optimize risk estimates. Data was obtained from a breast cancer case control study from 2008 to 2015 (318 cases, 526 controls). Complete case analysis and multiple imputation using chained equations were the methods applied to estimate the effects of a Traditional dietary pattern and other recognized factors associated with breast cancer. Physical activity and socioeconomic status were imputed. Logistic regression models were performed. When complete case analysis was performed only 31% of women were considered. Although a positive association of Traditional dietary pattern and breast cancer was observed from both approaches (complete case analysis OR=1.3, 95%CI=1.0-1.7; multiple imputation OR=1.4, 95%CI=1.2-1.7), effects of other covariates, like BMI and breastfeeding, were only identified when multiple imputation was considered. A Traditional dietary pattern, BMI and breastfeeding are associated with the occurrence of breast cancer in this Argentinean population when multiple imputation is appropriately performed. Multiple Imputation is suggested in Latin America’s epidemiologic studies to optimize effect estimates in the future. PMID:27892664

[Drinking water hardness and chronic degenerative diseases. I. Analysis of epidemiological research].

PubMed

Nardi, G; Donato, F; Monarca, S; Gelatti, U

2003-01-01

For many years a causal relation between drinking water hardness and cardiovascular or other chronic degenerative diseases in humans has been hypothesized. In order to evaluate the association between the concentration of minerals (calcium and magnesium) responsible for the hardness of drinking water and human health, a review of all the articles published on the subject from 1980 up to today has been carried out. The retrieved articles have been divided into 4 categories: geographic correlation studies, cross-sectional studies, case-control and cohort studies, and clinical trials. The methods for the selection of the articles and the extraction and analysis of the data are detailed in this paper. Epidemiological studies have been reviewed critically, and some conclusions have been drawn taking into account the research in basic sciences and experimental studies. However, a formal meta-analysis has not been performed, due to the heterogeneity of measures of effect among the different studies.

Suicidal behaviour on subway systems: a review of the epidemiology.

PubMed

Ratnayake, Ruwan; Links, Paul S; Eynan, Rahel

2007-11-01

Suicide on subway systems is a public health challenge that has been reported in urban centers worldwide. Our objective was to analyze studies of suicide on subway systems, develop a profile of characteristics that are suggestive of association with suicides or attempts, and show how this profile can inform prevention. A literature review involving epidemiology studies and studies relating to subway suicide was conducted. Twenty-eight studies were included in this review. Across studies, characteristics were not often assessed for risk factor status, although several characteristics were remarkably similar. Those attempting suicide on the subway appear to be affected by serious mental illness and have contact with mental health services before the suicidal behavior. Several characteristics may be shared among this population, emphasizing the potential for prevention in clinical and public health domains. Well-designed studies that utilize robust data collection and statistical methods are needed to establish the risk status associated with these characteristics.

Development and validation of a new method for the registration of overuse injuries in sports injury epidemiology: the Oslo Sports Trauma Research Centre (OSTRC) overuse injury questionnaire.

PubMed

Clarsen, Benjamin; Myklebust, Grethe; Bahr, Roald

2013-05-01

Current methods for injury registration in sports injury epidemiology studies may substantially underestimate the true burden of overuse injuries due to a reliance on time-loss injury definitions. To develop and validate a new method for the registration of overuse injuries in sports. A new method, including a new overuse injury questionnaire, was developed and validated in a 13-week prospective study of injuries among 313 athletes from five different sports, cross-country skiing, floorball, handball, road cycling and volleyball. All athletes completed a questionnaire by email each week to register problems in the knee, lower back and shoulder. Standard injury registration methods were also used to record all time-loss injuries that occurred during the study period. The new method recorded 419 overuse problems in the knee, lower back and shoulder during the 3-month-study period. Of these, 142 were classified as substantial overuse problems, defined as those leading to moderate or severe reductions in sports performance or participation, or time loss. Each week, an average of 39% of athletes reported having overuse problems and 13% reported having substantial problems. In contrast, standard methods of injury registration registered only 40 overuse injuries located in the same anatomical areas, the majority of which were of minimal or mild severity. Standard injury surveillance methods only capture a small percentage of the overuse problems affecting the athletes, largely because few problems led to time loss from training or competition. The new method captured a more complete and nuanced picture of the burden of overuse injuries in this cohort.

A comparative epidemiologic study of specific antibodies (IgM and IgA) and parasitological findings in an endemic area of low transmission of schistosoma mansoni.

PubMed

Kanamura, H Y; Dias, L C; da Silva, R M; Glasser, C M; Patucci, R M; Vellosa, S A; Antunes, J L

1998-01-01

The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT) on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil) with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.

The Ins and Outs of DNA Fingerprinting the Infectious Fungi

PubMed Central

Soll, David R.

2000-01-01

DNA fingerprinting methods have evolved as major tools in fungal epidemiology. However, no single method has emerged as the method of choice, and some methods perform better than others at different levels of resolution. In this review, requirements for an effective DNA fingerprinting method are proposed and procedures are described for testing the efficacy of a method. In light of the proposed requirements, the most common methods now being used to DNA fingerprint the infectious fungi are described and assessed. These methods include restriction fragment length polymorphisms (RFLP), RFLP with hybridization probes, randomly amplified polymorphic DNA and other PCR-based methods, electrophoretic karyotyping, and sequencing-based methods. Procedures for computing similarity coefficients, generating phylogenetic trees, and testing the stability of clusters are then described. To facilitate the analysis of DNA fingerprinting data, computer-assisted methods are described. Finally, the problems inherent in the collection of test and control isolates are considered, and DNA fingerprinting studies of strain maintenance during persistent or recurrent infections, microevolution in infecting strains, and the origin of nosocomial infections are assessed in light of the preceding discussion of the ins and outs of DNA fingerprinting. The intent of this review is to generate an awareness of the need to verify the efficacy of each DNA fingerprinting method for the level of genetic relatedness necessary to answer the epidemiological question posed, to use quantitative methods to analyze DNA fingerprint data, to use computer-assisted DNA fingerprint analysis systems to analyze data, and to file data in a form that can be used in the future for retrospective and comparative studies. PMID:10756003

Four years into the Indian ocean field epidemiology training programme.

PubMed

Halm, Ariane; Seyler, Thomas; Mohamed, Sainda; Ali Mbaé, Saindou Ben; Randrianarivo-Solofoniaina, Armand Eugène; Ratsitorahina, Maherisoa; Nundlall, Ram; Aboobakar, Shahina; Bibi, Jastin; Filleul, Laurent; Piola, Patrice; Razafimandimby, Harimahefa; Rasamoelina, Harena; Valenciano, Marta; Moren, Alain; Cardinale, Eric; Lepec, Richard; Flachet, Loïc

2017-01-01

Following the 2005-6 chikungunya outbreak, a project to strengthen regional Public Health preparedness in the Indian Ocean was implemented. It includes the Comoros, Madagascar, Mauritius, Reunion (France) and Seychelles. A Field Epidemiology Training Programme (FETP-OI) was started in 2011 to develop a pool of well-trained intervention epidemiologists. The FETP-OI consists of two years of supervised, learning-by-doing, on-the-job training at national sites involved in disease surveillance and response. It includes work placements at the Madagascar Pasteur Institute and the French regional epidemiology unit in Reunion and up to three training courses per year. Training objectives include epidemiological surveillance, outbreak investigations, research studies, scientific communication and transfer of competencies. In four years, two cohorts of in total 15 fellows originating from four countries followed the FETP-OI. They led 42 surveillance projects (71% routine management, 14% evaluations, 12% setup, 3% other) and investigated 36 outbreak alerts, 58% of them in Madagascar; most investigations (72%) concerned foodborne pathogens, plague or malaria. Fellows performed 18 studies (44% descriptive analyses, 22% disease risk factors, and 34% on other subjects), and presented results during regional and international conferences through 26 oral and 15 poster presentations. Four articles were published in regional Public Health bulletins and several scientific manuscripts are in process. The FETP-OI has created a regional force of intervention consisting of field epidemiologists and trained supervisors using the same technical language and epidemiological methods. The third cohort is now ongoing. Technically and financially sustainable FETP-OI projects help addressing public health priorities of the Indian Ocean.

Los Alamos National Laboratory: A guide to records series supporting epidemiologic studies conducted for the Department of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-01-01

The purpose of this guide is to describe each series of records that pertains to the epidemiologic studies conducted by the Epidemiology Section of the Occupational Medicine Group (ESH-2) at the Department of Energy`s (DOE) Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico. The records described in this guide relate to occupational studies performed by the Epidemiology Section, including those pertaining to workers at LANL, Mound Plant, Oak Ridge Reservation, Pantex Plant, Rocky Flats Plant, and Savannah River Site. Also included are descriptions of other health-related records generated or collected by the Epidemiology Section and a small setmore » of records collected by the Industrial Hygiene and Safety Group. This guide is not designed to describe the universe of records generated by LANL which may be used for epidemiologic studies of the LANL work force. History Associates Incorporated (HAI) prepared this guide as part of its work as the support services contractor for DOE`s Epidemiologic Records Inventory Project. This introduction briefly describes the Epidemiologic Records Inventory Project, HAI`s role in the project, the history of LANL the history and functions of LANL`s Health Division and Epidemiology Section, and the various epidemiologic studies performed by the Epidemiology Section. It provides information on the methodology that HAI used to inventory and describe records housed in the offices of the LANL Epidemiology Section in Technical Area 59 and at the LANL Records Center. Other topics include the methodology used to produce the guide, the arrangement of the detailed record series descriptions, and information concerning access to records repositories.« less

Becoming the Framingham Study 1947–1950

PubMed Central

Oppenheimer, Gerald M.

2005-01-01

In the epidemiological imagination, the Framingham Heart Study has attained iconic status, both as the prototype of the cohort study and as a result of its scientific success. When the Public Health Service launched the study in 1947, epidemiological knowledge of coronary heart disease was poor, and epidemiology primarily involved the study of infectious disease. In constructing their investigation, Framingham’s initiators had to invent new approaches to epidemiological research. These scientific goals were heavily influenced by the contending institutional and personal interests buffeting the study. The study passed through vicissitudes and stages during its earliest years as its organizers grappled to define its relationship to medicine, epidemiology, and the local community. PMID:15798116

Using geographic information systems for radon exposure assessment in dwellings in the Oslo region, Norway

NASA Astrophysics Data System (ADS)

Kollerud, R.; Blaasaas, K.; Ganerød, G.; Daviknes, H. K.; Aune, E.; Claussen, B.

2014-04-01

Radon exposures were assigned to each residential address in the Oslo region using a geographic information system (GIS) that included indoor radon measurements. The results will be used in an epidemiologic study regarding leukemia and brain cancer. The model is based on 6% of measured residential buildings. High density of indoor radon measurements allowed us to develop a buffer model where indoor radon measurements found around each dwelling were used to assign a radon value for homes lacking radon measurement. Intraclass correlation coefficients (ICCs) were used to study the agreement between radon values from the buffer method, from indoor radon values of measured houses, and from a regression model constructed with radiometric data (eTh, eU) and bedrock geology. We obtained good agreement for both comparisons with ICC values between 0.54 and 0.68. GIS offers a useful variety of tools to study the indoor-radon exposure assessment. By using the buffer method it is more likely that geological conditions are similar within the buffer and this may take more into account the variation of radon over short distances. It is also probable that short-distance-scale correlation patterns express similarities in building styles and living habits. Although the method has certain limitations, we regard it as acceptable for use in epidemiological studies.

[Gender-sensitive epidemiological data analysis: methodological aspects and empirical outcomes. Illustrated by a health reporting example].

PubMed

Jahn, I; Foraita, R

2008-01-01

In Germany gender-sensitive approaches are part of guidelines for good epidemiological practice as well as health reporting. They are increasingly claimed to realize the gender mainstreaming strategy in research funding by the federation and federal states. This paper focuses on methodological aspects of data analysis, as an empirical data example of which serves the health report of Bremen, a population-based cross-sectional study. Health reporting requires analysis and reporting methods that are able to discover sex/gender issues of questions, on the one hand, and consider how results can adequately be communicated, on the other hand. The core question is: Which consequences do a different inclusion of the category sex in different statistical analyses for identification of potential target groups have on the results? As evaluation methods logistic regressions as well as a two-stage procedure were exploratively conducted. This procedure combines graphical models with CHAID decision trees and allows for visualising complex results. Both methods are analysed by stratification as well as adjusted by sex/gender and compared with each other. As a result, only stratified analyses are able to detect differences between the sexes and within the sex/gender groups as long as one cannot resort to previous knowledge. Adjusted analyses can detect sex/gender differences only if interaction terms have been included in the model. Results are discussed from a statistical-epidemiological perspective as well as in the context of health reporting. As a conclusion, the question, if a statistical method is gender-sensitive, can only be answered by having concrete research questions and known conditions. Often, an appropriate statistic procedure can be chosen after conducting a separate analysis for women and men. Future gender studies deserve innovative study designs as well as conceptual distinctiveness with regard to the biological and the sociocultural elements of the category sex/gender.

Salmonella epidemiology: A whirlwind of change.

PubMed

Besser, John M

2018-05-01

The field of infectious disease epidemiology for Salmonella and other enteric pathogens is undergoing some of the most profound changes since the time of Kauffman and White. Rapid advances in "big data" technologies such as genomics and metagenomics are making it possible to monitor and control salmonellosis in new and exciting ways. Epidemiological methods are becoming increasingly robust through the routine use of standardized hypothesis-generating questionnaires, iterative open-ended interviewing, informational trace-backs and new modeling techniques for describing the attribution of disease to food sources. In addition, Salmonella epidemiology is facing important challenges and new opportunities due to the rapid adoption of culture independent diagnostic test panels by clinical laboratories. Where is this unprecedented wave of change taking us? This chapter will examine emerging trends in Salmonella epidemiology, and take a peek into the not-so-distant future. Published by Elsevier Ltd.

[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. © 2016 médecine/sciences – Inserm.

Evaluation of the Association between Persistent Organic ...

EPA Pesticide Factsheets

Background: Diabetes is a major threat to public health in the United States and worldwide. Understanding the role of environmental chemicals in the development or progression of diabetes is an emerging issue in environmental health.Objective: We assessed the epidemiologic literature for evidence of associations between persistent organic pollutants (POPs) and type 2 diabetes.Methods: Using a PubMed search and reference lists from relevant studies or review articles, we identified 72 epidemiological studies that investigated associations of persistent organic pollutants (POPs) with diabetes. We evaluated these studies for consistency, strengths and weaknesses of study design (including power and statistical methods), clinical diagnosis, exposure assessment, study population characteristics, and identification of data gaps and areas for future research.Conclusions: Heterogeneity of the studies precluded conducting a meta-analysis, but the overall evidence is sufficient for a positive association of some organochlorine POPs with type 2 diabetes. Collectively, these data are not sufficient to establish causality. Initial data mining revealed that the strongest positive correlation of diabetes with POPs occurred with organochlorine compounds, such as trans-nonachlor, dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), and dioxins and dioxin-like chemicals. There is less indication of an association between other nonorganochlorine POPs, such as

Analysis of Spatiotemporal Characteristics of Pandemic SARS Spread in Mainland China.

PubMed

Cao, Chunxiang; Chen, Wei; Zheng, Sheng; Zhao, Jian; Wang, Jinfeng; Cao, Wuchun

2016-01-01

Severe acute respiratory syndrome (SARS) is one of the most severe emerging infectious diseases of the 21st century so far. SARS caused a pandemic that spread throughout mainland China for 7 months, infecting 5318 persons in 194 administrative regions. Using detailed mainland China epidemiological data, we study spatiotemporal aspects of this person-to-person contagious disease and simulate its spatiotemporal transmission dynamics via the Bayesian Maximum Entropy (BME) method. The BME reveals that SARS outbreaks show autocorrelation within certain spatial and temporal distances. We use BME to fit a theoretical covariance model that has a sine hole spatial component and exponential temporal component and obtain the weights of geographical and temporal autocorrelation factors. Using the covariance model, SARS dynamics were estimated and simulated under the most probable conditions. Our study suggests that SARS transmission varies in its epidemiological characteristics and SARS outbreak distributions exhibit palpable clusters on both spatial and temporal scales. In addition, the BME modelling demonstrates that SARS transmission features are affected by spatial heterogeneity, so we analyze potential causes. This may benefit epidemiological control of pandemic infectious diseases.

Analysis of Spatiotemporal Characteristics of Pandemic SARS Spread in Mainland China

PubMed Central

Cao, Chunxiang; Zheng, Sheng; Zhao, Jian; Wang, Jinfeng; Cao, Wuchun

2016-01-01

Severe acute respiratory syndrome (SARS) is one of the most severe emerging infectious diseases of the 21st century so far. SARS caused a pandemic that spread throughout mainland China for 7 months, infecting 5318 persons in 194 administrative regions. Using detailed mainland China epidemiological data, we study spatiotemporal aspects of this person-to-person contagious disease and simulate its spatiotemporal transmission dynamics via the Bayesian Maximum Entropy (BME) method. The BME reveals that SARS outbreaks show autocorrelation within certain spatial and temporal distances. We use BME to fit a theoretical covariance model that has a sine hole spatial component and exponential temporal component and obtain the weights of geographical and temporal autocorrelation factors. Using the covariance model, SARS dynamics were estimated and simulated under the most probable conditions. Our study suggests that SARS transmission varies in its epidemiological characteristics and SARS outbreak distributions exhibit palpable clusters on both spatial and temporal scales. In addition, the BME modelling demonstrates that SARS transmission features are affected by spatial heterogeneity, so we analyze potential causes. This may benefit epidemiological control of pandemic infectious diseases. PMID:27597972

The use of genetic markers in the molecular epidemiology of histoplasmosis: a systematic review.

PubMed

Damasceno, L S; Leitão, T M J S; Taylor, M L; Muniz, M M; Zancopé-Oliveira, R M

2016-01-01

Histoplasmosis is a systemic mycosis caused by Histoplasma capsulatum, a dimorphic fungal pathogen that can infect both humans and animals. This disease has worldwide distribution and affects mainly immunocompromised individuals. In the environment, H. capsulatum grows as mold but undergoes a morphologic transition to the yeast morphotype under special conditions. Molecular techniques are important tools to conduct epidemiologic investigations for fungal detection, identification of infection sources, and determination of different fungal genotypes associated to a particular disease symptom. In this study, we performed a systematic review in the PubMed database to improve the understanding about the molecular epidemiology of histoplasmosis. This search was restricted to English and Spanish articles. We included a combination of specific keywords: molecular typing [OR] genetic diversity [OR] polymorphism [AND] H. capsulatum; molecular epidemiology [AND] histoplasmosis; and molecular epidemiology [AND] Histoplasma. In addition, we used the specific terms: histoplasmosis [AND] outbreaks. Non-English or non-Spanish articles, dead links, and duplicate results were excluded from the review. The results reached show that the main methods used for molecular typing of H. capsulatum were: restriction fragment length polymorphism, random amplified polymorphic DNA, microsatellites polymorphism, sequencing of internal transcribed spacers region, and multilocus sequence typing. Different genetic profiles were identified among H. capsulatum isolates, which can be grouped according to their source, geographical origin, and clinical manifestations.

Comparison of normal tissue dose calculation methods for epidemiological studies of radiotherapy patients.

PubMed

Mille, Matthew M; Jung, Jae Won; Lee, Choonik; Kuzmin, Gleb A; Lee, Choonsik

2018-06-01

Radiation dosimetry is an essential input for epidemiological studies of radiotherapy patients aimed at quantifying the dose-response relationship of late-term morbidity and mortality. Individualised organ dose must be estimated for all tissues of interest located in-field, near-field, or out-of-field. Whereas conventional measurement approaches are limited to points in water or anthropomorphic phantoms, computational approaches using patient images or human phantoms offer greater flexibility and can provide more detailed three-dimensional dose information. In the current study, we systematically compared four different dose calculation algorithms so that dosimetrists and epidemiologists can better understand the advantages and limitations of the various approaches at their disposal. The four dose calculations algorithms considered were as follows: the (1) Analytical Anisotropic Algorithm (AAA) and (2) Acuros XB algorithm (Acuros XB), as implemented in the Eclipse treatment planning system (TPS); (3) a Monte Carlo radiation transport code, EGSnrc; and (4) an accelerated Monte Carlo code, the x-ray Voxel Monte Carlo (XVMC). The four algorithms were compared in terms of their accuracy and appropriateness in the context of dose reconstruction for epidemiological investigations. Accuracy in peripheral dose was evaluated first by benchmarking the calculated dose profiles against measurements in a homogeneous water phantom. Additional simulations in a heterogeneous cylinder phantom evaluated the performance of the algorithms in the presence of tissue heterogeneity. In general, we found that the algorithms contained within the commercial TPS (AAA and Acuros XB) were fast and accurate in-field or near-field, but not acceptable out-of-field. Therefore, the TPS is best suited for epidemiological studies involving large cohorts and where the organs of interest are located in-field or partially in-field. The EGSnrc and XVMC codes showed excellent agreement with measurements both in-field and out-of-field. The EGSnrc code was the most accurate dosimetry approach, but was too slow to be used for large-scale epidemiological cohorts. The XVMC code showed similar accuracy to EGSnrc, but was significantly faster, and thus epidemiological applications seem feasible, especially when the organs of interest reside far away from the field edge.

The genetic epidemiology of personality disorders

PubMed Central

Reichborn-Kjennerud, Ted

2010-01-01

Genetic epidemiologic studies indicate that all ten personality disorders (PDs) classified on the DSM-IV axis II are modestly to moderately heritable. Shared environmental and nonadditive genetic factors are of minor or no importance. No sex differences have been identified. Multivariate studies suggest that the extensive comorbidity between the PDs can be explained by three common genetic and environmental risk factors. The genetic factors do not reflect the DSM-IV cluster structure, but rather: i) broad vulnerability to PD pathology or negative emotionality; ii) high impulsivity/low agreeableness; and iii) introversion. Common genetic and environmental liability factors contribute to comorbidity between pairs or clusters of axis I and axis II disorders. Molecular genetic studies of PDs, mostly candidate gene association studies, indicate that genes linked to neurotransmitter pathways, especially in the serotonergic and dopaminergic systems, are involved. Future studies, using newer methods like genome-wide association, might take advantage of the use of endophenotypes. PMID:20373672

Considerations for conducting epidemiologic case-control studies of cancer in developing countries.

PubMed

Brinton, L A; Herrero, R; Brenes, M; Montalván, P; de la Guardia, M E; Avila, A; Domínguez, I L; Basurto, E; Reeves, W C

1991-01-01

The challenges involved in conducting epidemiologic studies of cancer in developing countries can be and often are unique. This article reports on our experience in performing a case-control study of invasive cervical cancer in four Latin American countries (Columbia, Costa Rica, Mexico, and Panama), the summary medical results of which have been published in a previous issue of this journal (1). The study involved a number of principal activities--mainly selecting, conducting interviews with, and obtaining appropriate biologic specimens from 759 cervical cancer patients, 1,467 matched female controls, and 689 male sex partners of monogamous female subjects. This presentation provides an overview of the planning and methods used to select the subjects, conduct the survey work, and obtain complete and effectively unbiased data. It also points out some of the important advantages and disadvantages of working in developing areas similar to those serving as locales for this study.

Against Popperized epidemiology.

PubMed

Jacobsen, M

1976-03-01

The recommendation of Popper's philosophy of science should be adopted by epidemiologists is disputed. Reference is made to other authors who have shown that the most constructive elements in Popper's ideas have been advocated by earlier philosophers and have been used in epidemiology without abandoning inductive reasoning. It is argued that Popper's denigration of inductive methods is particularly harmful to epidemiology. Inductive reasoning and statistical inference play a key role in the science; it is suggested that unfamiliarity with these ideas contributes to widespread misunderstanding of the function of epidemiology. Attention is drawn to a common fallacy involving correlations between three random variables. The prevalence of the fallacy may be related to confusion between deductive and inductive logic.

Improved Variable Selection Algorithm Using a LASSO-Type Penalty, with an Application to Assessing Hepatitis B Infection Relevant Factors in Community Residents

PubMed Central

Guo, Pi; Zeng, Fangfang; Hu, Xiaomin; Zhang, Dingmei; Zhu, Shuming; Deng, Yu; Hao, Yuantao

2015-01-01

Objectives In epidemiological studies, it is important to identify independent associations between collective exposures and a health outcome. The current stepwise selection technique ignores stochastic errors and suffers from a lack of stability. The alternative LASSO-penalized regression model can be applied to detect significant predictors from a pool of candidate variables. However, this technique is prone to false positives and tends to create excessive biases. It remains challenging to develop robust variable selection methods and enhance predictability. Material and methods Two improved algorithms denoted the two-stage hybrid and bootstrap ranking procedures, both using a LASSO-type penalty, were developed for epidemiological association analysis. The performance of the proposed procedures and other methods including conventional LASSO, Bolasso, stepwise and stability selection models were evaluated using intensive simulation. In addition, methods were compared by using an empirical analysis based on large-scale survey data of hepatitis B infection-relevant factors among Guangdong residents. Results The proposed procedures produced comparable or less biased selection results when compared to conventional variable selection models. In total, the two newly proposed procedures were stable with respect to various scenarios of simulation, demonstrating a higher power and a lower false positive rate during variable selection than the compared methods. In empirical analysis, the proposed procedures yielding a sparse set of hepatitis B infection-relevant factors gave the best predictive performance and showed that the procedures were able to select a more stringent set of factors. The individual history of hepatitis B vaccination, family and individual history of hepatitis B infection were associated with hepatitis B infection in the studied residents according to the proposed procedures. Conclusions The newly proposed procedures improve the identification of significant variables and enable us to derive a new insight into epidemiological association analysis. PMID:26214802

Fine Particle Sources and Cardiorespiratory Morbidity: An Application of Chemical Mass Balance and Factor Analytical Source-Apportionment Methods

PubMed Central

Sarnat, Jeremy A.; Marmur, Amit; Klein, Mitchel; Kim, Eugene; Russell, Armistead G.; Sarnat, Stefanie E.; Mulholland, James A.; Hopke, Philip K.; Tolbert, Paige E.

2008-01-01

Background Interest in the health effects of particulate matter (PM) has focused on identifying sources of PM, including biomass burning, power plants, and gasoline and diesel emissions that may be associated with adverse health risks. Few epidemiologic studies, however, have included source-apportionment estimates in their examinations of PM health effects. We analyzed a time-series of chemically speciated PM measurements in Atlanta, Georgia, and conducted an epidemiologic analysis using data from three distinct source-apportionment methods. Objective The key objective of this analysis was to compare epidemiologic findings generated using both factor analysis and mass balance source-apportionment methods. Methods We analyzed data collected between November 1998 and December 2002 using positive-matrix factorization (PMF), modified chemical mass balance (CMB-LGO), and a tracer approach. Emergency department (ED) visits for a combined cardiovascular (CVD) and respiratory disease (RD) group were assessed as end points. We estimated the risk ratio (RR) associated with same day PM concentrations using Poisson generalized linear models. Results There were significant, positive associations between same-day PM2.5 (PM with aero-dynamic diameter ≤ 2.5 μm) concentrations attributed to mobile sources (RR range, 1.018–1.025) and biomass combustion, primarily prescribed forest burning and residential wood combustion, (RR range, 1.024–1.033) source categories and CVD-related ED visits. Associations between the source categories and RD visits were not significant for all models except sulfate-rich secondary PM2.5 (RR range, 1.012–1.020). Generally, the epidemiologic results were robust to the selection of source-apportionment method, with strong agreement between the RR estimates from the PMF and CMB-LGO models, as well as with results from models using single-species tracers as surrogates of the source-apportioned PM2.5 values. Conclusions Despite differences among the source-apportionment methods, these findings suggest that modeled source-apportioned data can produce robust estimates of acute health risk. In Atlanta, there were consistent associations across methods between PM2.5 from mobile sources and biomass burning with both cardiovascular and respiratory ED visits, and between sulfate-rich secondary PM2.5 with respiratory visits. PMID:18414627

Should Child Protection Services Respond Differently to Maltreatment, Risk of Maltreatment, and Risk of Harm?

ERIC Educational Resources Information Center

Fallon, Barbara; Trocme, Nico; MacLaurin, Bruce

2011-01-01

Objective: To examine evidence available in large-scale North American datasets on child abuse and neglect that can assist in understanding the complexities of child protection case classifications. Methods: A review of child abuse and neglect data from large North American epidemiological studies including the Canadian Incidence Study of Reported…

Poisoning and Intoxication by Trace Elements in Children. An Abstract Review of the Worldwide Medical Literature 1966-1971.

ERIC Educational Resources Information Center

Public Health Service (DHEW), Washington, DC. Bureau of Community Environmental Management.

This annotated bibliography of 247 entries is divided into the following categories: (a) general aspects and reviews; (b) sources of poisoning, epidemiology, and pica studies; (c) clinico-pathological studies; (d) diagnosis and screening; (e) laboratory methods; and (f) treatment and prevention. A subject and author index is included. (PD)

Race and Gender Differences in Perceived Caregiver Availability for Community-Dwelling Middle-Aged and Older Adults

ERIC Educational Resources Information Center

Roth, David L.; Haley, William E.; Wadley, Virginia G.; Clay, Olivio J.; Howard, George

2007-01-01

Purpose: Informal family caregivers are increasingly recognized as critical for meeting the needs of individuals with chronic diseases associated with aging. This study examined race and gender differences in perceived informal caregiver availability for participants aged 45 and older in a large national epidemiological study. Design and Methods:…

The Adolescent Outcome of Hyperactive Girls: Self-Report of Psychosocial Status

ERIC Educational Resources Information Center

Young, Susan; Heptinstall, Ellen; Sonuga-Barke, Edmund J. S.; Chadwick, Oliver; Taylor, Eric

2005-01-01

Background: The aim of the study was to clarify the developmental risk associated with hyperactive behaviour in girls in a longitudinal epidemiological design. Methods: This was investigated in a follow-up study of girls who were identified by parent and teacher ratings in a large community survey of 6- and 7-year-olds as showing pervasive…

Incidence of Hospitalization Due to Child Maltreatment in Taiwan, 1996-2007: A Nationwide Population-Based Study

ERIC Educational Resources Information Center

Chiang, Wan-Lin; Huang, Yu-Tung; Feng, Jui-Ying; Lu, Tsung-Hsueh

2012-01-01

Objectives: Little is known regarding the epidemiology of child maltreatment in Asian countries. This study aimed to examine the incidence of hospitalization coded as due to child maltreatment in Taiwan. Methods: We used inpatient claims data of the National Health Insurance for the years 1996 through 2007 for estimation. Hospitalization of…

Cancer Survival in California Hispanic Farmworkers, 1988-2001

ERIC Educational Resources Information Center

Dodge, Jennifer L.; Mills, Paul K.; Riordan, Deborah G.

2007-01-01

Context: Although epidemiologic studies have identified elevated cancer risk in farmworkers for some cancer types, little is known about cancer survival in this population. Purpose: To determine if cancer survival differs between a Hispanic farmworker population and the general Hispanic population in California. Methods: Hispanic United Farm…

Genotyping of Mycobacterium tuberculosis: application in epidemiologic studies

PubMed Central

Kato-Maeda, Midori; Metcalfe, John Z.; Flores, Laura

2014-01-01

Genotyping is used to track specific isolates of Mycobacterium tuberculosis in a community. It has been successfully used in epidemiologic research (termed ‘molecular epidemiology’) to study the transmission dynamics of TB. In this article, we review the genetic markers used in molecular epidemiologic studies including the use of whole-genome sequencing technology. We also review the public health application of molecular epidemiologic tools. PMID:21366420

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...

College Health Surveillance Network: Epidemiology and Health Care Utilization of College Students at US 4-Year Universities

ERIC Educational Resources Information Center

Turner, James C.; Keller, Adrienne

2015-01-01

Objective: This description of the College Health Surveillance Network (CHSN) includes methodology, demography, epidemiology, and health care utilization. Participants: Twenty-three universities representing approximately 730,000 enrolled students contributed data from January 1, 2011, through May 31, 2014. Methods: Participating schools uploaded…

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…

Epidemiology of prostate and kidney cancer in the Aboriginal population of Canada: A systematic review

PubMed Central

Wong, Emily Chu Lee; Kapoor, Anil

2017-01-01

Introduction Prostate and kidney cancer rates in the Aboriginal population of Canada is a growing issue. Methods A systematic review of prostate and kidney cancer epidemiology in the Aboriginal population of Canada was performed with international comparison and evaluation of present epidemiological disparities. PubMed, Medline, and Embase (from January 1946 to June 2016), relevant government-published reports, and the websites of organizations contributing to prostate or kidney cancer guidelines were searched. We included studies that informed any of the three epidemiological questions this review is focused on answering. Results Two systematic reviews, two meta-analyses, five literature reviews, and 21 single-study papers were included. The incidence and mortality rates of kidney cancer were elevated among Canadian Aboriginals when compared to the provincial or national population and to several international regions. No studies reported data on survival. Prostate cancer incidence, mortality, and survival rates were lower in Aboriginals provincially, nationally, and internationally, with incidence and survival reaching statistical significance. Elevated rate of risk factors for kidney cancer was a significant finding among Canadian Aboriginals. Aboriginals were screened for prostate cancer less than the general Canadian population, a trend also observed in the U.S. Conclusions The elevated incidence and mortality of kidney cancer among Canadian Aboriginals is most likely attributable to the rise in lifestyle-based risk factors. Two correlations concerning prostate cancer are made. However, due to temporal and regional disparities in data, further investigation is required to elucidate these observations. PMID:28503238

Characteristics of the Japanese Diet Described in Epidemiologic Publications: A Qualitative Systematic Review.

PubMed

Suzuki, Nozomu; Goto, Yoshihito; Ota, Haruka; Kito, Kumiko; Mano, Fumika; Joo, Erina; Ikeda, Kaori; Inagaki, Nobuya; Nakayama, Takeo

2018-01-01

International interest in the Japanese diet has grown in recent years. The aim of this systematic review was to evaluate and organize the Japanese diet and dietary characteristics from an epidemiological perspective, mainly focusing on the nutritional and dietary elements. PubMed, Web of Science, Japan Medical Abstracts Society, JDream III, and CiNii databases were searched. The eligibility criteria included research with an epidemiological study design that was either cross-sectional, cohort, or case-control-based that defined the dietary patterns of the Japanese diet using dietary pattern analysis. A total of 39 research articles that described the Japanese diet were included. The data that were extracted included the following: implementing country, location, study design, participant characteristics, key outcomes, methods used in the analysis of dietary patterns, and descriptions of the Japanese diet. As a result of the systematic review analyzing the descriptions of the Japanese diet from 39 selected articles, we were able to aggregate the descriptions into 16 categories from 33 factors. After performing a content analysis using a further aggregation of categories, we found that the top three applicable categories were soybeans/soybean-derived products, seafood, and vegetables; these were followed by rice and miso soup. The Japanese dietary content was found to be diverse based on an examination of epidemiological studies; however, we were able to aggregate the content into 16 categories. The Japanese diet is considered to be a dietary pattern that contains a combination of factors: the dietary staple, side dishes, and soup.

Epidemiological Outbreaks of Pneumocystis jirovecii Pneumonia Are Not Limited to Kidney Transplant Recipients: Genotyping Confirms Common Source of Transmission in a Liver Transplantation Unit.

PubMed

Desoubeaux, Guillaume; Dominique, Manon; Morio, Florent; Thepault, Rose-Anne; Franck-Martel, Claire; Tellier, Anne-Charlotte; Ferrandière, Martine; Hennequin, Christophe; Bernard, Louis; Salamé, Ephrem; Bailly, Éric; Chandenier, Jacques

2016-05-01

Over a 5-month period, four liver transplant patients at a single hospital were diagnosed with Pneumocystis jirovecii pneumonia (PCP). This unusually high incidence was investigated using molecular genotyping. Bronchoalveolar lavage fluids (BALF) obtained from the four liver recipients diagnosed with PCP were processed for multilocus sequence typing (MLST) at three loci (SOD, mt26s, and CYB). Twenty-four other BALF samples, which were positive for P. jirovecii and collected from 24 epidemiologically unrelated patients with clinical signs of PCP, were studied in parallel by use of the same method. Pneumocystis jirovecii isolates from the four liver recipients all had the same genotype, which was different from those of the isolates from all the epidemiologically unrelated individuals studied. These findings supported the hypothesis of a common source of contamination or even cross-transmission of a single P. jirovecii clone between the four liver recipients. Hospitalization mapping showed several possible encounters between these four patients, including outpatient consultations on one particular date when they all possibly met. This study demonstrates the value of molecular genotyping of P. jirovecii isolated from clinical samples for epidemiological investigation of PCP outbreaks. It is also the first description of a common source of exposure to a single P. jirovecii clone between liver transplant recipients and highlights the importance of prophylaxis in such a population. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Biomarkers for Uranium Risk Assessment for the Development of the CURE (Concerted Uranium Research in Europe) Molecular Epidemiological Protocol.

PubMed

Guéguen, Yann; Roy, Laurence; Hornhardt, Sabine; Badie, Christophe; Hall, Janet; Baatout, Sarah; Pernot, Eileen; Tomasek, Ladislav; Laurent, Olivier; Ebrahimian, Teni; Ibanez, Chrystelle; Grison, Stephane; Kabacik, Sylwia; Laurier, Dominique; Gomolka, Maria

2017-01-01

Despite substantial experimental and epidemiological research, there is limited knowledge of the uranium-induce health effects after chronic low-dose exposures in humans. Biological markers can objectively characterize pathological processes or environmental responses to uranium and confounding agents. The integration of such biological markers into a molecular epidemiological study would be a useful approach to improve and refine estimations of uranium-induced health risks. To initiate such a study, Concerted Uranium Research in Europe (CURE) was established, and involves biologists, epidemiologists and dosimetrists. The aims of the biological work package of CURE were: 1. To identify biomarkers and biological specimens relevant to uranium exposure; 2. To define standard operating procedures (SOPs); and 3. To set up a common protocol (logistic, questionnaire, ethical aspects) to perform a large-scale molecular epidemiologic study in uranium-exposed cohorts. An intensive literature review was performed and led to the identification of biomarkers related to: 1. retention organs (lungs, kidneys and bone); 2. other systems/organs with suspected effects (cardiovascular system, central nervous system and lympho-hematopoietic system); 3. target molecules (DNA damage, genomic instability); and 4. high-throughput methods for the identification of new biomarkers. To obtain high-quality biological materials, SOPs were established for the sampling and storage of different biospecimens. A questionnaire was developed to assess potential confounding factors. The proposed strategy can be adapted to other internal exposures and should improve the characterization of the biological and health effects that are relevant for risk assessment.

Molecular and epidemiological study of enterovirus D68 in Taiwan.

PubMed

Huang, Yuan-Pin; Lin, Tsuey-Li; Lin, Ting-Han; Wu, Ho-Sheng

2017-08-01

As an immunofluorescence assay for enterovirus D68 (EV-D68) is not available in the enteroviruses surveillance network in Taiwan, EV-D68 may be the actual pathogen of untypeable enterovirus-suspected isolates. The untypeable isolates collected from 2007 through 2014 were identified by nucleic acid amplification-based methods and sequencing of the VP1 region to analyze the phylogeny and epidemiology of EV-D68 in Taiwan. Twenty-nine EV-D68 isolates were sequenced, including 15 Cluster 3 and 14 Cluster 1 viruses. Approximately 41% of the patients were children under 5 years of age and their infections peaked in August. The ratio of male to female patients was 1.5 and 3.67 for Cluster 3 and Cluster 1, respectively. Fever and respiratory symptoms were commonly reported in EV-D68-infected patients. The results of phylogenetic analyses showed that EV-D68 isolates between 2007 and 2014 belonged to different clusters and existed for years, indicating that endemic circulation of EV-D68 existed in Taiwan. This study showed that EV-D68 has been endemic in Taiwan for some years despite a small number of positive cases. The continuous monitoring and efforts towards the improvement of diagnostic techniques are required to complete the surveillance system. This study provided the genetic and epidemiological information which could contribute to understanding the etiology and epidemiology of EV-D68. Copyright © 2015. Published by Elsevier B.V.

Maxillofacial fracture epidemiology and treatment plans in the Northeast of Iran: A retrospective study

PubMed Central

Samieirad, Sahand; Aboutorabzade, Mohammad-Reza; Tohidi, Elahe; Shaban, Baratollah; Khalife, Hussein; Salami, Hamid-Reza

2017-01-01

Background The epidemiology of facial injuries varies based on lifestyle, cultural background and socioeconomic status in different countries and geographic zones. This study evaluated the epidemiology of maxillofacial fractures and treatment plans in hospitalized patients in Northeast of Iran (2015-2016). Material and Methods In this retrospective study, the medical records of 502 hospitalized patients were evaluated in the Department of Maxillofacial Surgery in Kamyab Hospital in Mashhad, Iran. The type and cause of fractures and treatment plans were recorded in a checklist. Data were analyzed with Mann–Whitney test, chi-squared test and Fisher’s exact test, using SPSS 21. Results The majority of patients were male (80.3%). Most subjects were in 20-30-year age range (43.2%). The fractures were mostly caused by accidents, particularly motorcycle accidents (MCAs), and the most common site of involvement was the body of the mandible. There was a significant association between the type of treatment and age. In fact, the age range of 16-59 years underwent open reduction internal fixation (ORIF) more than other age ranges (P=0.001). Also, there was a significant association between gender and fractures (P=0.002). Conclusions It was concluded that patient age and gender and trauma significantly affected the prevalence of maxillofacial traumas, fracture types and treatment plans. This information would be useful for making better health policy strategies. Key words:Epidemiology, treatment, facial injuries, maxillofacial fractures, trauma. PMID:28809369

Linking Meteorology, Air Quality Models and Observations to ...

EPA Pesticide Factsheets

Epidemiologic studies are critical in establishing the association between exposure to air pollutants and adverse health effects. Results of epidemiologic studies are used by U.S. EPA in developing air quality standards to protect the public from the health effects of air pollutants. A major challenge in environmental epidemiology is adequate exposure characterization. Numerous health studies have used measurements from a few central-site ambient monitors to characterize air pollution exposures. Relying solely on central-site ambient monitors does not account for the spatial-heterogeneity of ambient air pollution patterns, the temporal variability in ambient concentrations, nor the influence of infiltration and indoor sources. Central-site monitoring becomes even more problematic for certain air pollutants that exhibit significant spatial heterogeneity. Statistical interpolation techniques and passive monitoring methods can provide additional spatial resolution in ambient concentration estimates. In addition, spatio-temporal models, which integrate GIS data and other factors, such as meteorology, have also been developed to produce more resolved estimates of ambient concentrations. Models, such as the Community Multi-Scale Air Quality (CMAQ) model, estimate ambient concentrations by combining information on meteorology, source emissions, and chemical-fate and transport. Hybrid modeling approaches, which integrate regional scale models with local scale dispersion

A normalization method for combination of laboratory test results from different electronic healthcare databases in a distributed research network.

PubMed

Yoon, Dukyong; Schuemie, Martijn J; Kim, Ju Han; Kim, Dong Ki; Park, Man Young; Ahn, Eun Kyoung; Jung, Eun-Young; Park, Dong Kyun; Cho, Soo Yeon; Shin, Dahye; Hwang, Yeonsoo; Park, Rae Woong

2016-03-01

Distributed research networks (DRNs) afford statistical power by integrating observational data from multiple partners for retrospective studies. However, laboratory test results across care sites are derived using different assays from varying patient populations, making it difficult to simply combine data for analysis. Additionally, existing normalization methods are not suitable for retrospective studies. We normalized laboratory results from different data sources by adjusting for heterogeneous clinico-epidemiologic characteristics of the data and called this the subgroup-adjusted normalization (SAN) method. Subgroup-adjusted normalization renders the means and standard deviations of distributions identical under population structure-adjusted conditions. To evaluate its performance, we compared SAN with existing methods for simulated and real datasets consisting of blood urea nitrogen, serum creatinine, hematocrit, hemoglobin, serum potassium, and total bilirubin. Various clinico-epidemiologic characteristics can be applied together in SAN. For simplicity of comparison, age and gender were used to adjust population heterogeneity in this study. In simulations, SAN had the lowest standardized difference in means (SDM) and Kolmogorov-Smirnov values for all tests (p < 0.05). In a real dataset, SAN had the lowest SDM and Kolmogorov-Smirnov values for blood urea nitrogen, hematocrit, hemoglobin, and serum potassium, and the lowest SDM for serum creatinine (p < 0.05). Subgroup-adjusted normalization performed better than normalization using other methods. The SAN method is applicable in a DRN environment and should facilitate analysis of data integrated across DRN partners for retrospective observational studies. Copyright © 2015 John Wiley & Sons, Ltd.

Making medical decisions in dependence of genetic background: estimation of the utility of DNA testing in clinical, pharmaco-epidemiological or genetic studies.

PubMed

Nguyen, Thuy Trang; Schäfer, Helmut; Timmesfeld, Nina

2013-05-01

An index measuring the utility of testing a DNA marker before deciding between two alternative treatments is proposed which can be estimated from pharmaco-epidemiological case-control or cohort studies. In the case-control design, external estimates of the prevalence of the disease and of the frequency of the genetic risk variant are required for estimating the utility index. Formulas for point and interval estimates are derived. Empirical coverage probabilities of the confidence intervals were estimated under different scenarios of disease prevalence, prevalence of drug use, and population frequency of the genetic variant. To illustrate our method, we re-analyse pharmaco-epidemiological case-control data on oral contraceptive intake and venous thrombosis in carriers and non-carriers of the factor V Leiden mutation. We also re-analyse cross-sectional data from the Framingham study on a gene-diet interaction between an APOA2 polymorphism and high saturated fat intake on obesity. We conclude that the utility index may be helpful to evaluate and appraise the potential clinical and public health relevance of gene-environment interaction effects detected in genomic and candidate gene association studies and may be a valuable decision support for designing prospective studies on the clinical utility. © 2013 Wiley Periodicals, Inc.

Improving the Linkages between Air Pollution Epidemiology and Quantitative Risk Assessment

PubMed Central

Bell, Michelle L.; Walker, Katy; Hubbell, Bryan

2011-01-01

Background: Air pollution epidemiology plays an integral role in both identifying the hazards of air pollution as well as supplying the risk coefficients that are used in quantitative risk assessments. Evidence from both epidemiology and risk assessments has historically supported critical environmental policy decisions. The extent to which risk assessors can properly specify a quantitative risk assessment and characterize key sources of uncertainty depends in part on the availability, and clarity, of data and assumptions in the epidemiological studies. Objectives: We discuss the interests shared by air pollution epidemiology and risk assessment communities in ensuring that the findings of epidemiological studies are appropriately characterized and applied correctly in risk assessments. We highlight the key input parameters for risk assessments and consider how modest changes in the characterization of these data might enable more accurate risk assessments that better represent the findings of epidemiological studies. Discussion: We argue that more complete information regarding the methodological choices and input data used in epidemiological studies would support more accurate risk assessments—to the benefit of both disciplines. In particular, we suggest including additional details regarding air quality, demographic, and health data, as well as certain types of data-rich graphics. Conclusions: Relatively modest changes to the data reported in epidemiological studies will improve the quality of risk assessments and help prevent the misinterpretation and mischaracterization of the results of epidemiological studies. Such changes may also benefit epidemiologists undertaking meta-analyses. We suggest workshops as a way to improve the dialogue between the two communities. PMID:21816702

A nomograph method for assessing body weight.

PubMed

Thomas, A E; McKay, D A; Cutlip, M B

1976-03-01

The ratio of weight/height emerges from varied epidemiological studies as the most generally useful index of relative body mass in adults. The authors present a nomograph to facilitate use of this relationship in clinical situations. While showing the range of weight given as desirable in life insurance studies, the scale expresses relative weight as a continuous variable. This method encourages use of clinical judgment in interpreting "overweight" and "underweight" and in accounting for muscular and skeletal contributions to measured mass.

Epidemiology of Patient Harms in New Zealand: Protocol of a General Practice Records Review Study

PubMed Central

Leitch, Sharon; Wallis, Katharine A; Eggleton, Kyle S; Cunningham, Wayne K; Williamson, Martyn I; Lillis, Steven; McMenamin, Andrew W; Tilyard, Murray W; Reith, David M; Samaranayaka, Ari; Hall, Jason E

2017-01-01

Background Knowing where and why harm occurs in general practice will assist patients, doctors, and others in making informed decisions about the risks and benefits of treatment options. Research to date has been unable to verify the safety of primary health care and epidemiological research about patient harms in general practice is now a top priority for advancing health systems safety. Objective We aim to study the incidence, distribution, severity, and preventability of the harms patients experience due to their health care, from the whole-of-health-system lens afforded by electronic general practice patient records. Methods “Harm” is defined as disease, injury, disability, suffering, and death, arising from the health system. The study design is a stratified, 2-level cluster, retrospective records review study. Both general practices and patients will be randomly selected so that the study’s results will apply nationally, after weighting. Stratification by practice size and rurality will allow comparisons between 6 study groups (large, medium-sized, small; urban and rural practices). Records of equal numbers of patients from each study group will be included in the study because there may be systematic differences in patient harms in different types of practices. Eight general practitioner investigators will review 3 years of electronic general practice health records (consultation notes, prescriptions, investigations, referrals, and summaries of hospital care) from 9000 patients registered in 60 general practices. Double-blinded reviews will check the concordance of reviewers’ assessments. Study data will comprise demographic data of all 9000 patients and reviewers’ assessments of whether patients experienced harm arising from health care. Where patient harm is identified, their types, preventability, severity, and outcomes will be coded using the Medical Dictionary for Regulatory Activities (MedDRA) 18.0. Results We have recruited practices and collected electronic records from 9078 patients. Reviews of these records are under way. The study is expected to be completed in August 2017. Conclusions The design of this complex study is presented with discussion on data collection methods, sampling weights, power analysis, and statistical approach. This study will show the epidemiology of patient harms recorded in general practice records for all of New Zealand and will show whether this epidemiology differs by rural location and clinic size. PMID:28119276

Common periodontal diseases of children and adolescents.

PubMed

Al-Ghutaimel, Hayat; Riba, Hisham; Al-Kahtani, Salem; Al-Duhaimi, Saad

2014-01-01

Background. Since 2000, studies, experiments, and clinical observations revealed high prevalence of periodontal diseases among children and adolescents. Therefore, this paper was designed to provide an update for dental practitioners on epidemiology, microbiology, pathology, prevention, diagnosis, and treatment of periodontal diseases in children and adolescents. Methods. This paper reviews the current literature concerning periodontal diseases in pediatric dentistry. It includes MEDLINE database search using key terms: "periodontal diseases in children," "Periodontal diseasesin adolescents," "periodontal diseases risk factors," "microbiology of periodontal diseases," "classification of periodontal diseases," "epidemiology of periodontal diseases," and "treatment of periodontal diseases." Articles were evaluated by title and/or abstract and relevance to pediatric dentistry. Sixty-five citations were selected by this method and by the references within the chosen articles. A review of the comprehensive textbooks on pediatric dentistry and periodontology was done. Some recommendations were based on the opinions of experienced researchers and clinicians, when data were inconclusive.

Comparison of four molecular methods to type Salmonella Enteritidis strains.

PubMed

Campioni, Fábio; Pitondo-Silva, André; Bergamini, Alzira M M; Falcão, Juliana P

2015-05-01

This study compared the pulsed-field gel electrophoresis (PFGE), enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR), multilocus variable-number of tanden-repeat analysis (MLVA), and multilocus sequence typing (MLST) methods for typing 188 Salmonella Enteritidis strains from different sources isolated over a 24-year period in Brazil. PFGE and ERIC-PCR were more efficient than MLVA for subtyping the strains. However, MLVA provided additional epidemiological information for those strains. In addition, MLST showed the Brazilian strains as belonging to the main clonal complex of S. Enteritidis, CC11, and provided the first report of two new STs in the S. enterica database but could not properly subtype the strains. Our results showed that the use of PFGE or ERIC-PCR together with MLVA is suitable to efficiently subtype S. Enteritidis strains and provide important epidemiological information. © 2015 APMIS. Published by John Wiley & Sons Ltd.

Evaluating the use of friend or family controls in epidemiologic case-control studies.

PubMed

Zhong, Charlie; Cockburn, Myles; Cozen, Wendy; Voutsinas, Jenna; Lacey, James V; Luo, Jianning; Sullivan-Halley, Jane; Bernstein, Leslie; Wang, Sophia S

2017-02-01

Traditional methodologies for identifying and recruiting controls in epidemiologic case-control studies, such as random digit dialing or neighborhood walk, suffer from declining response rates. Here, we revisit the feasibility and comparability of using alternative sources of controls, specifically friend and family controls. We recruited from a recently completed case-control study of non-Hodgkin lymphoma (NHL) among women in Los Angeles County where controls from the parent study were ascertained by neighborhood walk. We calculated participation rates and compared questionnaire responses between the friend/family controls and the original matched controls from the parent study. Of the 182 NHL case patients contacted, 111 (61%) agreed to participate in our feasibility study. 70 (63%) provided contact information for potential friend and/or family member controls. We were able to successfully contact and recruit a friend/family member for 92% of the case patients. This represented 46 friend controls and 54 family controls. Family controls significantly differed from original matched controls by sex and household income. Other characteristics were similar between friend controls and the original study's neighborhood controls. The apparent comparability of neighborhood controls to friend and family controls among respondents in this study suggests that these alternative methods of control identification can serve as a complementary source of eligible controls in epidemiologic case-control studies. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Epidemiology of Cancer Among Police Officers

PubMed Central

Wirth, Michael; Vena, John E.; Smith, Emily K.; Bauer, Sarah E.; Violanti, John; Burch, James

2013-01-01

Background This review summarizes peer-reviewed studies examining cancer risks among police officers. It provides an overview of existing research limitations and uncertainties and the plausible etiologic risk factors associated with cancer in this understudied occupation. Methods Previous cancer studies among police officers were obtained via a systematic review of the MEDLINE, CABDirect, and Web of Science bibliographic databases. Results Quality observational studies of cancer among police officers are sparse and subject to limitations in exposure assessment and other methods. Results from three studies suggested possible increased mortality risks for all cancers, and cancers of the colon, kidney, digestive system, esophagus, male breast, and testis, as well as Hodgkin’s disease. Few incidence studies have been performed, and results have been mixed, although some associations with police work have been observed for thyroid, skin, and male breast cancer. Conclusions Police are exposed to a mix of known or suspected agents or activities that increase cancer risk. Epidemiologic evidence to date is sparse and inconsistent. There is a critical need for more research to understand the biological and social processes underlying exposures and the suggested disproportionate risks and to identify effective prevention strategies. PMID:23255299

A safe an easy method for building consensus HIV sequences from 454 massively parallel sequencing data.

PubMed

Fernández-Caballero Rico, Jose Ángel; Chueca Porcuna, Natalia; Álvarez Estévez, Marta; Mosquera Gutiérrez, María Del Mar; Marcos Maeso, María Ángeles; García, Federico

2018-02-01

To show how to generate a consensus sequence from the information of massive parallel sequences data obtained from routine HIV anti-retroviral resistance studies, and that may be suitable for molecular epidemiology studies. Paired Sanger (Trugene-Siemens) and next-generation sequencing (NGS) (454 GSJunior-Roche) HIV RT and protease sequences from 62 patients were studied. NGS consensus sequences were generated using Mesquite, using 10%, 15%, and 20% thresholds. Molecular evolutionary genetics analysis (MEGA) was used for phylogenetic studies. At a 10% threshold, NGS-Sanger sequences from 17/62 patients were phylogenetically related, with a median bootstrap-value of 88% (IQR83.5-95.5). Association increased to 36/62 sequences, median bootstrap 94% (IQR85.5-98)], using a 15% threshold. Maximum association was at the 20% threshold, with 61/62 sequences associated, and a median bootstrap value of 99% (IQR98-100). A safe method is presented to generate consensus sequences from HIV-NGS data at 20% threshold, which will prove useful for molecular epidemiological studies. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

[Epidemiology of arbovirus diseases: use and value of physiologic age determination of female mosquito vectors].

PubMed

Mondet, B

1996-01-01

The physiological age of Yellow Fever Aedes females in Africa was studied during four years, from 1988 to 1992. We used a method, according to Polovodova's method, which looks for the "yellow body" under natural light. Those yellow bodies exist in the old females, the "parous" ones, and not in the young females, the "nulliparous" ones. We present some results to illustrate the interest of studying the physiological age of mosquitoes in the epidemiology of the arboviral diseases. The transmission risk, in relation with abundance and parity rate was illustrated, in particular for Aedes africanus and Aedes luteocephalus, which is useful to compare species, or with a given species, to compare periods. The parity rate of Aedes furcifer females was studied on 6 points along a transect between a forest and a village. The rate and the abundance of the females caught on human bates are inversely proportional. The parity rate is minimum in the canopy forest (about 50%) and maximum inside a house (100%). The rains have different consequences on the species, according to the period of fall. At the beginning of the dry season, they bring about hatching, but not at the end of the dry season. Massive hatching, will occur just at the beginning of the rainy season, some weeks later. Studying the physiological age of Ae. africanus females, the number of nulliparous is not related to the rain. That means a possibility of "natural" hatching for part of the eggs. Among the female of the dry season, young females are found, which is important for the transmission capacity. The method, described herein, to determine the physiological age is perfectly applicable to the Yellow Fever vector Haemagogus janthinomys in Southern America. But for the Dengue vectors Aedes aegypti and probably Aedes albopictus, the Detinova's method seems better. Actually, it seems important to study the physiological age of the vectors Ae. aegypti and Ae. albopictus, as well as the evolution of the physiological age in space and time, in order to better know the epidemiology of dengue in Southern America.

Inferring epidemiological dynamics of infectious diseases using Tajima's D statistic on nucleotide sequences of pathogens.

PubMed

Kim, Kiyeon; Omori, Ryosuke; Ito, Kimihito

2017-12-01

The estimation of the basic reproduction number is essential to understand epidemic dynamics, and time series data of infected individuals are usually used for the estimation. However, such data are not always available. Methods to estimate the basic reproduction number using genealogy constructed from nucleotide sequences of pathogens have been proposed so far. Here, we propose a new method to estimate epidemiological parameters of outbreaks using the time series change of Tajima's D statistic on the nucleotide sequences of pathogens. To relate the time evolution of Tajima's D to the number of infected individuals, we constructed a parsimonious mathematical model describing both the transmission process of pathogens among hosts and the evolutionary process of the pathogens. As a case study we applied this method to the field data of nucleotide sequences of pandemic influenza A (H1N1) 2009 viruses collected in Argentina. The Tajima's D-based method estimated basic reproduction number to be 1.55 with 95% highest posterior density (HPD) between 1.31 and 2.05, and the date of epidemic peak to be 10th July with 95% HPD between 22nd June and 9th August. The estimated basic reproduction number was consistent with estimation by birth-death skyline plot and estimation using the time series of the number of infected individuals. These results suggested that Tajima's D statistic on nucleotide sequences of pathogens could be useful to estimate epidemiological parameters of outbreaks. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Combined Application of Study Design and Case-Based Learning Comprehensive Model in Epidemiology Teaching

ERIC Educational Resources Information Center

Shi, Xiuquan; Zhou, Yanna; Wang, Haiyan; Wang, Tao; Nie, Chan; Shi, Shangpeng

2017-01-01

This paper aims to conduct the SD-CBL (study design with the case based learning, SD-CBL) in Epidemiology teaching and evaluate its effect. Students from five classes were recruited, and a combined comprehensive teaching model of SD-CBL was used in the "Injury Epidemiology" chapter, while other chapters in "Epidemiology"…

Analysis of Typing Methods for Epidemiological Surveillance of both Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus Strains▿ †

PubMed Central

Faria, Nuno A.; Carrico, João A.; Oliveira, Duarte C.; Ramirez, Mário; de Lencastre, Hermínia

2008-01-01

Sequence-based methods for typing Staphylococcus aureus, such as multilocus sequence typing (MLST) and spa typing, have increased interlaboratory reproducibility, portability, and speed in obtaining results, but pulsed-field gel electrophoresis (PFGE), remains the method of choice in many laboratories due to the extensive experience with this methodology and the large body of data accumulated using the technique. Comparisons between typing methods have been overwhelmingly based on a qualitative assessment of the overall agreement of results and the relative discriminatory indexes. In this study, we quantitatively assess the congruence of the major typing methods for S. aureus, using a diverse collection of 198 S. aureus strains previously characterized by PFGE, spa typing, MLST, and, in the case of methicillin-resistant S. aureus (MRSA), SCCmec typing in order to establish the quantitative congruence between the typing methods. The results of most typing methods agree in that MRSA and methicillin-susceptible S. aureus (MSSA) differ in terms of diversity of genetic backgrounds, with MSSA being more diverse. Our results show that spa typing has a very good predictive power over the clonal relationships defined by eBURST, while PFGE is less accurate for that purpose but nevertheless provides better typeability and discriminatory power. The combination of PFGE and spa typing provided even better results. Based on these observations, we suggest the use of the conjugation of spa typing and PFGE typing for epidemiological surveillance studies, since this combination provides the ability to infer long-term relationships while maintaining the discriminatory power and typeability needed in short-term studies. PMID:17989188

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

The changing role and legitimate boundaries of epidemiology: community-based prevention programmes.

PubMed

Tuomilehto, J; Puska, P

1987-01-01

Epidemiology is the basic science of public health. It combines medical and social sciences, both of which are developing with new inventions. Therefore, the role of epidemiology and its boundaries are also changing over time. An important role of epidemiology is to develop and implement community-based control programmes for major diseases in the community. Such programmes are essential for large scale public health policy. It is necessary that epidemiological research can as freely as possible test new methods of disease prevention and health promotion. The first community-based control programme for cardiovascular diseases, the North Karelia Project is reviewed against this background. At present, it is still possible to define the boundaries of epidemiology geographically and culturally, but in the future, however, it will become more difficult. There is no doubt that epidemiology will remain as the basic science of public health but the scope of public health problems are growing much wider. These include the prevention of the final epidemic--the destruction of our planet by nuclear bombs. In the control of the existing epidemics and in the prevention of new ones the boundaries of epidemiology cannot stay rigid but they must be changing as new facts about the emerging public health problems are identified.

Global Foot-and-Mouth Disease Research Update and Gap Analysis: 2 - Epidemiology, Wildlife and Economics.

PubMed

Knight-Jones, T J D; Robinson, L; Charleston, B; Rodriguez, L L; Gay, C G; Sumption, K J; Vosloo, W

2016-06-01

We assessed knowledge gaps in foot-and-mouth disease (FMD) research, and in this study, we consider (i) epidemiology, (ii) wildlife and (iii) economics. The study took the form of a literature review (2011-2015) combined with research updates collected in 2014 from 33 institutes from across the world. Findings were used to identify priority areas for future FMD research. During 2011-2015, modelling studies were dominant in the broad field of epidemiology; however, continued efforts are required to develop robust models for use during outbreaks in FMD-free countries, linking epidemiologic and economics models. More guidance is needed for both the evaluation and the setting of targets for vaccine coverage, population immunity and vaccine field efficacy. Similarly, methods for seroprevalence studies need to be improved to obtain more meaningful outputs that allow comparison across studies. To inform control programmes in endemic countries, field trials assessing the effectiveness of vaccination in extensive smallholder systems should be performed to determine whether FMD can be controlled with quality vaccines in settings where implementing effective biosecurity is challenging. Studies need to go beyond measuring only vaccine effects and should extend our knowledge of the impact of FMD and increase our understanding of how to maximize farmer participation in disease control. Where wildlife reservoirs of virus exist, particularly African Buffalo, we need to better understand when and under what circumstances transmission to domestic animals occurs in order to manage this risk appropriately, considering the impact of control measures on livelihoods and wildlife. For settings where FMD eradication is unfeasible, further ground testing of commodity-based trade is recommended. A thorough review of global FMD control programmes, covering successes and failures, would be extremely valuable and could be used to guide other control programmes. © 2016 Blackwell Verlag GmbH.

On the equivalence of case-crossover and time series methods in environmental epidemiology.

PubMed

Lu, Yun; Zeger, Scott L

2007-04-01

The case-crossover design was introduced in epidemiology 15 years ago as a method for studying the effects of a risk factor on a health event using only cases. The idea is to compare a case's exposure immediately prior to or during the case-defining event with that same person's exposure at otherwise similar "reference" times. An alternative approach to the analysis of daily exposure and case-only data is time series analysis. Here, log-linear regression models express the expected total number of events on each day as a function of the exposure level and potential confounding variables. In time series analyses of air pollution, smooth functions of time and weather are the main confounders. Time series and case-crossover methods are often viewed as competing methods. In this paper, we show that case-crossover using conditional logistic regression is a special case of time series analysis when there is a common exposure such as in air pollution studies. This equivalence provides computational convenience for case-crossover analyses and a better understanding of time series models. Time series log-linear regression accounts for overdispersion of the Poisson variance, while case-crossover analyses typically do not. This equivalence also permits model checking for case-crossover data using standard log-linear model diagnostics.

The moving-window Bayesian maximum entropy framework: estimation of PM(2.5) yearly average concentration across the contiguous United States.

PubMed

Akita, Yasuyuki; Chen, Jiu-Chiuan; Serre, Marc L

2012-09-01

Geostatistical methods are widely used in estimating long-term exposures for epidemiological studies on air pollution, despite their limited capabilities to handle spatial non-stationarity over large geographic domains and the uncertainty associated with missing monitoring data. We developed a moving-window (MW) Bayesian maximum entropy (BME) method and applied this framework to estimate fine particulate matter (PM(2.5)) yearly average concentrations over the contiguous US. The MW approach accounts for the spatial non-stationarity, while the BME method rigorously processes the uncertainty associated with data missingness in the air-monitoring system. In the cross-validation analyses conducted on a set of randomly selected complete PM(2.5) data in 2003 and on simulated data with different degrees of missing data, we demonstrate that the MW approach alone leads to at least 17.8% reduction in mean square error (MSE) in estimating the yearly PM(2.5). Moreover, the MWBME method further reduces the MSE by 8.4-43.7%, with the proportion of incomplete data increased from 18.3% to 82.0%. The MWBME approach leads to significant reductions in estimation error and thus is recommended for epidemiological studies investigating the effect of long-term exposure to PM(2.5) across large geographical domains with expected spatial non-stationarity.

Development of a loop-mediated isothermal amplification method for rapid mass-screening of sand flies for Leishmania infection.

PubMed

Nzelu, Chukwunonso O; Gomez, Eduardo A; Cáceres, Abraham G; Sakurai, Tatsuya; Martini-Robles, Luiggi; Uezato, Hiroshi; Mimori, Tatsuyuki; Katakura, Ken; Hashiguchi, Yoshihisa; Kato, Hirotomo

2014-04-01

Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1h from a crude sand fly template without DNA purification. Amplicon detection could be accomplished by the newly developed colorimetric malachite green (MG)--mediated naked eye visualization. Pre-addition of MG to the LAMP reaction solution did not inhibit amplification efficiency. The field applicability of the colorimetric MG-based LAMP assay was demonstrated with 397 field-caught samples from the endemic areas of Ecuador and eight positive sand flies were detected. The robustness, superior sensitivity, and ability to produce better visual discriminatory reaction products than existing LAMP fluorescence and turbidity assays indicated the field potential usefulness of this new method for surveillance and epidemiological studies of leishmaniasis in developing countries. Copyright © 2013 Elsevier B.V. All rights reserved.

Assessment of the French National Health Insurance Information System as a tool for epidemiological surveillance of malaria.

PubMed

Delon, François; Mayet, Aurélie; Thellier, Marc; Kendjo, Eric; Michel, Rémy; Ollivier, Lénaïck; Chatellier, Gilles; Desjeux, Guillaume

2017-05-01

Epidemiological surveillance of malaria in France is based on a hospital laboratory sentinel surveillance network. There is no comprehensive population surveillance. The objective of this study was to assess the ability of the French National Health Insurance Information System to support nationwide malaria surveillance in continental France. A case identification algorithm was built in a 2-step process. First, inclusion rules giving priority to sensitivity were defined. Then, based on data description, exclusion rules to increase specificity were applied. To validate our results, we compared them to data from the French National Reference Center for Malaria on case counts, distribution within subgroups, and disease onset date trends. We built a reusable automatized tool. From July 1, 2013, to June 30, 2014, we identified 4077 incident malaria cases that occurred in continental France. Our algorithm provided data for hospitalized patients, patients treated by private physicians, and outpatients for the entire population. Our results were similar to those of the National Reference Center for Malaria for each of the outcome criteria. We provided a reliable algorithm for implementing epidemiological surveillance of malaria based on the French National Health Insurance Information System. Our method allowed us to work on the entire population living in continental France, including subpopulations poorly covered by existing surveillance methods. Traditional epidemiological surveillance and the approach presented in this paper are complementary, but a formal validation framework for case identification algorithms is necessary. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Information content of household-stratified epidemics.

PubMed

Kinyanjui, T M; Pellis, L; House, T

2016-09-01

Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Mediterranean studies of cardiovascular disease and hyperglycemia: analytical modeling of population socio-economic transitions (MedCHAMPS)--rationale and methods.

PubMed

Maziak, Wasim; Critchley, Julia; Zaman, Shahaduz; Unwin, Nigel; Capewell, Simon; Bennett, Kathleen; Unal, Belgin; Husseini, Abdullatif; Romdhane, Habiba Ben; Phillimore, Peter

2013-08-01

In response to the escalating epidemic of cardiovascular disease (CVD) in the Mediterranean Region (MR), an international collaboration aiming at understanding the burden of CVD and evaluating cost-effective strategies to combat it was recently established. This paper describes the rationale and methods of the project MedCHAMPS to disseminate this successful experience. The framework of MedCHAMPS is exceptional in combining multiple disciplines (e.g. epidemiology, anthropology, economics), countries [Turkey, Syria, occupied Palestinian territory (oPt), Tunisia, UK, Ireland], research methods (situational and policy analysis, quantitative and qualitative studies, statistical modeling), and involving local stakeholders at all levels to assess trends of CVD/diabetes in the society and attributes of the local health care systems to provide optimal policy recommendations to reduce the burden of CVD/diabetes. MedCHAMPS provides policy makers in the MR and beyond needed guidance about the burden of CVD, and best cost-effective ways to combat it. Our approach of building developed-developing countries collaboration also provides a roadmap for other researchers seeking to build research base into CVD epidemiology and prevention in developing countries.

Differentiation of Trypanosoma brucei, T. rhodesiense, and T. gambiense by the indirect fluorescent antibody test

PubMed Central

Latif, B. M. A.; Adam, Katherine M. G.

1973-01-01

Epidemiological studies, if they are to lead to appropriate preventive procedures, require knowledge of the host distribution of the parasite. Progress in the epidemiology of African trypanosomiasis is restricted by the lack of a reliable and simple method of differentiating Trypanosoma brucei, T. rhodesiense, and T. gambiense. The recently introduced blood inoculation infectivity test promises to fulfil this need by distinguishing T. brucei from T. rhodesiense, but it would not be suitable for separating T. brucei from T. gambiense, since rats and mice are frequently refractory to infection by fresh isolates of T. gambiense. Previous studies had indicated that the indirect fluorescent antibody test might differentiate not only the subgenera of the salivarian trypanosome species but also members of the subgenus Trypanozoon. A method of performing the test is described that enables T. brucei, T. rhodesiense, and T. gambiense to be differentiated by the titre of the sera. The method might be used in conjunction with the blood inoculation infectivity test to distinguish between new isolates of the subgenus Trypanozoon in East Africa, and also to search for possible animal reservoirs of T. gambiense in West Africa. PMID:4587481

Influence of Urbanicity and County Characteristics on the Association between Ozone and Asthma Emergency Department Visits in North Carolina

EPA Science Inventory

Background: Air pollution epidemiology studies, often conducted in large metropolitan areas due to proximity to regulatory monitors, are limited in their ability to examine potential associations between air pollution exposures and health effects in rural locations. Methods: In a...

Major Depressive Disorder in Adolescence: The Role of Subthreshold Symptoms

ERIC Educational Resources Information Center

Georgiades, Katholiki; Lewinsohn, Peter M.; Monroe, Scott M.; Seeley, John R.

2006-01-01

Objective: To examine the longitudinal association between individual subthreshold symptoms and onset of major depressive disorder (MDD) in adolescence. Method: Data for analysis come from the Oregon Adolescent Depression Project, a prospective epidemiological study of psychological disorders among adolescents, ages 14 to 18 years, from the…

Proposed key characteristics of male reproductive toxicants as a method for organizing and screening mechanistic evidence for non-cancer outcomes.

EPA Science Inventory

The adoption of systematic review practices for risk assessment includes integration of evidence obtained from experimental, epidemiological, and mechanistic studies. Although mechanistic evidence plays an important role in mode of action analysis, the process of sorting and anal...

Use of an improved atpA amplification and sequencing method to identify members of the Campylobacteraceae and Helicobacteraceae

USDA-ARS?s Scientific Manuscript database

Emerging Campylobacter spp. and arcobacters have been increasingly isolated from human clinical samples, food and the environment. Unambiguous species identification of such organisms is of obvious importance in epidemiological studies, but is also necessary to accurately assess their host range and...

Association Between Satellite-based Estimates of Long-term PM2.5 Exposure and Coronary Artery Disease

EPA Science Inventory

Background: Epidemiological studies have identified associations between long-term PM2.5 exposure and cardiovascular events, though most have relied on concentrations from central-site air quality monitors. Methods: We utilized a cohort of 5679 patients who had undergone cardiac ...

Epidemiology of Vocal Health in Young Adults Attending College in the United States

ERIC Educational Resources Information Center

Hartley, Naomi A.; Breen, Ellen; Thibeault, Susan L.

2016-01-01

Purpose: The purpose of this study was to document typical vocal health characteristics (including voice-related activities, behaviors, and symptomatology) of young adults attending college and to determine lifetime and point prevalence rates of voice disorders. Method: Undergraduates at University of Wisconsin-Madison completed an anonymous…

Urban College Student Self-Report of Hookah Use with Health Care Providers

ERIC Educational Resources Information Center

Jani, Samir Ranjit; Brown, Darryl; Berhane, Zekarias; Peter, Nadja; Solecki, Susan; Turchi, Renee

2018-01-01

Objective: This study's purpose was to describe urban college students' communication about hookah with health care providers. Participants: Participants included a random sample of undergraduate urban college students and health care providers. Methods: Students surveyed determined the epidemiology of hookah use in this population, how many…

77 FR 4046 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-26

... Evaluation of Worker Notification Program (0920-0566, Expiration 2/ 28/2011)--Reinstatement--National... and health problems. Since the Right to Know movement in the late 1970s, NIOSH has been developing methods and materials to notify subjects of its epidemiological studies. Within NIOSH, notifying workers...

Environmental pollutants and dysregulation of male puberty--a comparison among species.

PubMed

Magnusson, Ulf; Ljungvall, Karl

2014-04-01

The scientific literature on altered onset of puberty predominantly involves studies on females. This paper reviews current knowledge on the role of environmental pollutants in dysregulation of male puberty in humans, laboratory rodents and farm animals. The methods used to determine the onset of puberty are well developed in humans and farm animals, and standardized across studies in humans. In laboratory rodents standardized external morphological endpoints are used. There is an increasing weight of evidence from epidemiological studies in humans, as well as from experiments in animals, indicating that environmental pollutants dysregulate puberty in males. Most data are from studies on "classical" persistent environmental pollutants. Assessing the effect of multichemical environmental pollution on dysregulation of puberty in humans is more challenging; further solid epidemiological data would likely contribute most to our understanding, especially if combined with systematically collected field-data from selected wildlife. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Explanation and Elaboration Document for the STROBE-Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary Extension.

PubMed

O'Connor, A M; Sargeant, J M; Dohoo, I R; Erb, H N; Cevallos, M; Egger, M; Ersbøll, A K; Martin, S W; Nielsen, L R; Pearl, D L; Pfeiffer, D U; Sanchez, J; Torrence, M E; Vigre, H; Waldner, C; Ward, M P

2016-12-01

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE-Vet Statement. Thus, this is a companion document to the STROBE-Vet Statement Methods and process document, which describes the checklist and how it was developed. © 2016 The Authors. Zoonoses and Public Health published by Blackwell Verlag GmbH.

Costs and epidemiological changes of chronic diseases: implications and challenges for health systems.

PubMed

Arredondo, Armando; Aviles, Raul

2015-01-01

The need to integrate economic and epidemiological aspects in the clinical perspective leads to a proposal for the analysis of health disparities and to an evaluation of the health services and of the new challenges which are now being faced by health system reforms in middle income countries. To identify the epidemiological changes, the demand for health services and economic burden from chronic diseases (diabetes and hypertension) in a middle income county. We conducted longitudinal analyses of costs and epidemiological changes for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations. The cost-evaluation method was used, based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2014-2016, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95%, and the Box-Pierce test. Regarding epidemiological changes expected in both diseases for 2014 vs. 2016, an increase is expected, although results predict a greater increase for diabetes, 8-12% in all three studied institutions, (p < .05). Indeed, in the case of diabetes, the increase was 41469 cases for uninsured population (SSA) and 65737 for the insured population (IMSS and ISSSTE). On hypertension cases the increase was 38109 for uninsured vs 62895 for insured. Costs in US$ ranged from $699 to $748 for annual case management per patient in the case of diabetes, and from $485 to $622 in patients with hypertension. Comparing financial consequences of health services required by insured and uninsured populations, the greater increase (23%) will be for the insured population (p < .05). The financial requirements of both diseases will amount to 19.5% of the total budget for the uninsured and 12.5% for the insured population. If the risk factors and the different health care models remain as they currently are, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant challenge is the appearance of internal competition in the use and allocation of financial resources with programs for other chronic and infectious diseases.

Formalizing the Role of Agent-Based Modeling in Causal Inference and Epidemiology

PubMed Central

Marshall, Brandon D. L.; Galea, Sandro

2015-01-01

Calls for the adoption of complex systems approaches, including agent-based modeling, in the field of epidemiology have largely centered on the potential for such methods to examine complex disease etiologies, which are characterized by feedback behavior, interference, threshold dynamics, and multiple interacting causal effects. However, considerable theoretical and practical issues impede the capacity of agent-based methods to examine and evaluate causal effects and thus illuminate new areas for intervention. We build on this work by describing how agent-based models can be used to simulate counterfactual outcomes in the presence of complexity. We show that these models are of particular utility when the hypothesized causal mechanisms exhibit a high degree of interdependence between multiple causal effects and when interference (i.e., one person's exposure affects the outcome of others) is present and of intrinsic scientific interest. Although not without challenges, agent-based modeling (and complex systems methods broadly) represent a promising novel approach to identify and evaluate complex causal effects, and they are thus well suited to complement other modern epidemiologic methods of etiologic inquiry. PMID:25480821

Deterministic analysis of extrinsic and intrinsic noise in an epidemiological model.

PubMed

Bayati, Basil S

2016-05-01

We couple a stochastic collocation method with an analytical expansion of the canonical epidemiological master equation to analyze the effects of both extrinsic and intrinsic noise. It is shown that depending on the distribution of the extrinsic noise, the master equation yields quantitatively different results compared to using the expectation of the distribution for the stochastic parameter. This difference is incident to the nonlinear terms in the master equation, and we show that the deviation away from the expectation of the extrinsic noise scales nonlinearly with the variance of the distribution. The method presented here converges linearly with respect to the number of particles in the system and exponentially with respect to the order of the polynomials used in the stochastic collocation calculation. This makes the method presented here more accurate than standard Monte Carlo methods, which suffer from slow, nonmonotonic convergence. In epidemiological terms, the results show that extrinsic fluctuations should be taken into account since they effect the speed of disease breakouts and that the gamma distribution should be used to model the basic reproductive number.

Dose-effect relationships, epidemiological analysis and the derivation of low dose risk.

PubMed

Leenhouts, H P; Chadwick, K H

2011-03-01

This paper expands on our recent comments in a letter to this journal about the analysis of epidemiological studies and the determination of low dose RBE of low LET radiation (Chadwick and Leenhouts 2009 J. Radiol. Prot. 29 445-7). Using the assumption that radiation induced cancer arises from a somatic mutation (Chadwick and Leenhouts 2011 J. Radiol. Prot. 31 41-8) a model equation is derived to describe cancer induction as a function of dose. The model is described briefly, evidence is provided in support of it, and it is applied to a set of experimental animal data. The results are compared with a linear fit to the data as has often been done in epidemiological studies. The article presents arguments to support several related messages which are relevant to epidemiological analysis, the derivation of low dose risk and the weighting factor of sparsely ionising radiations. The messages are: (a) cancer incidence following acute exposure should, in principle, be fitted to a linear-quadratic curve with cell killing using all the data available; (b) the acute data are dominated by the quadratic component of dose; (c) the linear fit of any acute data will essentially be dependent on the quadratic component and will be unrelated to the effectiveness of the radiation at low doses; consequently, (d) the method used by ICRP to derive low dose risk from the atomic bomb survivor data means that it is unrelated to the effectiveness of the hard gamma radiation at low radiation doses; (e) the low dose risk value should, therefore, not be used as if it were representative for hard gamma rays to argue for an increased weighting factor for tritium and soft x-rays even though there are mechanistic reasons to expect this; (f) epidemiological studies of chronically exposed populations supported by appropriate cellular radiobiological studies have the best chance of revealing different RBE values for different sparsely ionising radiations.

Merging economics and epidemiology to improve the prediction and management of infectious disease.

PubMed

Perrings, Charles; Castillo-Chavez, Carlos; Chowell, Gerardo; Daszak, Peter; Fenichel, Eli P; Finnoff, David; Horan, Richard D; Kilpatrick, A Marm; Kinzig, Ann P; Kuminoff, Nicolai V; Levin, Simon; Morin, Benjamin; Smith, Katherine F; Springborn, Michael

2014-12-01

Mathematical epidemiology, one of the oldest and richest areas in mathematical biology, has significantly enhanced our understanding of how pathogens emerge, evolve, and spread. Classical epidemiological models, the standard for predicting and managing the spread of infectious disease, assume that contacts between susceptible and infectious individuals depend on their relative frequency in the population. The behavioral factors that underpin contact rates are not generally addressed. There is, however, an emerging a class of models that addresses the feedbacks between infectious disease dynamics and the behavioral decisions driving host contact. Referred to as "economic epidemiology" or "epidemiological economics," the approach explores the determinants of decisions about the number and type of contacts made by individuals, using insights and methods from economics. We show how the approach has the potential both to improve predictions of the course of infectious disease, and to support development of novel approaches to infectious disease management.

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 shaped in large measure by market forces, technologic advances and to a lesser extent, by habit and aesthetics.

Epidemiological risk factors for adult dengue in Singapore: an 8-year nested test negative case control study.

PubMed

Yung, Chee Fu; Chan, Siew Pang; Thein, Tun Linn; Chai, Siaw Ching; Leo, Yee Sin

2016-07-08

Understanding changes in the ecology and epidemiology of dengue is important to ensure resource intensive control programmes are targeted effectively as well as to inform future dengue vaccination strategies. We analyzed data from a multicentre longitudinal prospective study of fever in adults using a nested test negative case control approach to identify epidemiological risk factors for dengue disease in Singapore. From April 2005 to February 2013, adult patients presenting with fever within 72 h at selected public primary healthcare clinics and a tertiary hospital in Singapore were recruited. Acute and convalescent blood samples were collected and used to diagnose dengue using both PCR and serology methods. A dengue case was defined as having a positive RT-PCR result for DENV OR evidence of serological conversion between acute and convalescent blood samples. Similarly, controls were chosen from patients in the cohort who tested negative for dengue using the same laboratory methods. The host epidemiological factors which increased the likelihood of dengue disease amongst adults in Singapore were those aged between 21 and 40 years old (2 fold increase) while in contrast, Malay ethnicity was protective (OR 0.57, 95%CI 0.35 to 0.91) against dengue disease. Spatial factors which increased the odds of acquiring dengue was residing at a foreign workers dormitory or hostel (OR 3.25, 95 % CI 1.84 to 5.73) while individuals living in the North-West region of the country were less likely to get dengue (OR 0.50, 95%CI 0.29 to 0.86). Other factors such as gender, whether one primarily works indoors or outdoors, general dwelling type or floor, the type of transportation one uses to work, travel history, as well as self-reported history of mosquito bite or household dengue/fever were not useful in helping to inform a diagnosis of dengue. We have demonstrated a test negative study design to better understand the epidemiological risk factors of adult dengue over multiple seasons. We were able to discount other previously speculated factors such as gender, whether one primarily works indoors or outdoors, dwelling floor in a building and the use of public transportation as having no effect on one's risk of getting dengue.

[Scientific, practical and educational aspects of clinical epidemiology].

PubMed

Briko, N I

2012-01-01

This article defines clinical epidemiology and describes its goal and objectives. The author claims that clinical epidemiology is a section of epidemiology which underlies the development of evidence-based standards for diagnostics, treatment and prevention and helps to select the appropriate algorithm for each clinical case. The study provides a comprehensive overview of the relationship between clinical epidemiology and evidence-based medicine. Epidemiological research is shown to be methodological basis of clinical epidemiology and evidence-based medicine with randomized controlled trials being the "gold standard" for obtaining reliable data. The key stages in the history of clinical epidemiology are discussed and further development of clinical epidemiology and the integration of courses on clinical epidemiology in education is outlined for progress in medical research and health care practice.