EPIDEMIOLOGY EPIDEMIOLOGY COURSE.COURSE.

LECTURER :Dra Tania Morejon.LECTURER :Dra Tania Morejon.

COURSE DESCRIPTIONCOURSE DESCRIPTION

The epidemiology course covers application The epidemiology course covers application of epidemiologic procedures to the of epidemiologic procedures to the understanding of the occurrence and control understanding of the occurrence and control of the conditions such as infections and of the conditions such as infections and chronic diseases , mental disorders, chronic diseases , mental disorders, community and environmental health community and environmental health hazards , accidents , and geriatric problems.hazards , accidents , and geriatric problems.

Credits hours:60Credits hours:60

COURSE OBJETIVESCOURSE OBJETIVES► Upon completion of this course, each student should possess the following Upon completion of this course, each student should possess the following

areas of subject mastery:areas of subject mastery:1.1. Epidemiology as a tool for assessing potential causal associations, health Epidemiology as a tool for assessing potential causal associations, health

needs of a population, delivery of services, program planning, and social needs of a population, delivery of services, program planning, and social policy.policy.

2.2. Assessment of the validity and reliability of such data collection mechanisms Assessment of the validity and reliability of such data collection mechanisms as death certificates, patient charts, agency records, and personal surveys.as death certificates, patient charts, agency records, and personal surveys.

3.3. Measurements of mortality and morbidity (rates, ratios, and adjusted rates) Measurements of mortality and morbidity (rates, ratios, and adjusted rates) and the major sources of error in measurement of disease.and the major sources of error in measurement of disease.

4.4. Descriptive epidemiology: the amount and distribution of disease within a Descriptive epidemiology: the amount and distribution of disease within a population by person, place, and time.population by person, place, and time.

5.5. Research designs such as retrospective (case-control), prospective (cohort), Research designs such as retrospective (case-control), prospective (cohort), historical prospective, cross-sectional, and experimental (clinical and historical prospective, cross-sectional, and experimental (clinical and community trials).community trials).

6.6. Evaluation of screening programs in the detection of disease; terminology of Evaluation of screening programs in the detection of disease; terminology of screening including determinants of sensitivity and specificity.screening including determinants of sensitivity and specificity.

7.7. Population dynamics and health with respect to the stages in demographic Population dynamics and health with respect to the stages in demographic transition and trends in the U.S. and world populations.transition and trends in the U.S. and world populations.

8.8. Epidemiologic aspects of infectious disease (variations in severity of illness, Epidemiologic aspects of infectious disease (variations in severity of illness, components of the infectious disease process, mechanism of disease components of the infectious disease process, mechanism of disease transmission, and common source versus propagated).transmission, and common source versus propagated).

9.9. Epidemiologic aspects of chronic disease (multi-factorial nature of etiology, Epidemiologic aspects of chronic disease (multi-factorial nature of etiology, long latency period, indefinite onset, and differential effect of factors on long latency period, indefinite onset, and differential effect of factors on incidence and course of disease).incidence and course of disease).

ATTENDANCEATTENDANCE

Your presence at a minimum of 80% of the Your presence at a minimum of 80% of the Epidemiology and Public HealthEpidemiology and Public Health lectures is lectures is mandatory. The role will be taken on a daily mandatory. The role will be taken on a daily basis. basis. Failure to attend 80% of the Failure to attend 80% of the lectures wil l result in your withdrawal lectures wil l result in your withdrawal from the course (W)from the course (W) , which will require , which will require you to repeat the Epidemiology and Public you to repeat the Epidemiology and Public HealthHealth course.course.

GRADINGGRADING► There will be three integrated sectional examinations during the There will be three integrated sectional examinations during the

trimester. trimester. ► Final grades are calculated as follows:Final grades are calculated as follows:► Sectional examination ISectional examination I 33%33%► Sectional examination IISectional examination II 34%34%► Sectional examination IIISectional examination III 33%33%► Final grades are determined as follows:Final grades are determined as follows:► Honors=Honors= 90 - 100 90 - 100 ► PassPass== 75 – 8975 – 89► FailFail == 74 and below74 and below► Examinations can be postponed only for legitimate reasons including Examinations can be postponed only for legitimate reasons including

health problems or sickness in the immediate family. health problems or sickness in the immediate family. Notif ication of Notif ication of an absence from an exam must be made in advance by an absence from an exam must be made in advance by contacting the Dean of Students and the Professor of contacting the Dean of Students and the Professor of Epidemiology and Public Health.Epidemiology and Public Health.

SCHEDULE ISCHEDULE IHOURSHOURS LECTURELECTURE

11 Introduction and orientationIntroduction and orientation

33 The history and scope of epidemiology.The history and scope of epidemiology.

33 Practical applications of epidemiology.Practical applications of epidemiology.

44 Measures of morbidity and mortality.Measures of morbidity and mortality.

44 Descriptive epidemiology :person ,place, Descriptive epidemiology :person ,place, time. time.

11 Review.Review.

22 EXAM IEXAM I

SCHEDULE IISCHEDULE IIHOURHOURSS

LECTURELECTURE

22 Sources of data for use in epidemiology.Sources of data for use in epidemiology.44 Study designs :ecologic and cross-Study designs :ecologic and cross-

sectional.sectional.33 Study designs :case-controlStudy designs :case-control33 Study designs : cohort studies.Study designs : cohort studies.33 Experimental study designs.Experimental study designs.22 Measures of effect.Measures of effect.22 Data interpretation issues.Data interpretation issues.11 Review.Review.22 EXAM IIEXAM II

SCHEDULE IIISCHEDULE IIIHOURHOURSS

LECTURELECTURE

44 Screening for disease in the community.Screening for disease in the community.44 Epidemiology of infectious diseases.Epidemiology of infectious diseases.33 Epidemiologic aspects of work and Epidemiologic aspects of work and

environment.environment.33 Molecular and genetic epidemiology.Molecular and genetic epidemiology.33 Psychologic , behavioral , and social Psychologic , behavioral , and social

epidemiology.epidemiology.11 Review.Review.22 EXAM IIIEXAM III

INTRODUCTION TO INTRODUCTION TO EPIDEMIOLOGY.EPIDEMIOLOGY.

►Epidemiology is a fundamental medical Epidemiology is a fundamental medical science that focuses on the distribution and science that focuses on the distribution and determinants of disease frequency in determinants of disease frequency in human populations. Specifically , human populations. Specifically , epidemiologist examine patterns of illness in epidemiologist examine patterns of illness in the population and then try to determine the population and then try to determine why certain groups or individuals develop a why certain groups or individuals develop a particular disease whereas others do not .particular disease whereas others do not .

The history and scope of The history and scope of epidemiology.epidemiology.

►Epidemiology defined.Epidemiology defined.►Foundations of epidemiology .Foundations of epidemiology .►Historical antecedents of epidemiology.Historical antecedents of epidemiology.►Recent applications of epidemiology .Recent applications of epidemiology .

EPIDEMIOLOGY DEFINED.EPIDEMIOLOGY DEFINED. Definition of epidemiology is "the study of the distribution and determinants of health-related states in Definition of epidemiology is "the study of the distribution and determinants of health-related states in

specified populations, and the application of this study to control health problems." A look at the key specified populations, and the application of this study to control health problems." A look at the key words will help illuminate the meaning: words will help illuminate the meaning:

► StudyStudy —Epidemiology is the basic science of public health. It's a highly quantitative discipline based —Epidemiology is the basic science of public health. It's a highly quantitative discipline based on principles of statistics and research methodologieson principles of statistics and research methodologies

► DistributionDistribution —Epidemiologists study the distribution of frequencies and patterns of health events —Epidemiologists study the distribution of frequencies and patterns of health events within groups in a population. To do this, they use descriptive epidemiology, which characterizes within groups in a population. To do this, they use descriptive epidemiology, which characterizes health events in terms of time, place, and personhealth events in terms of time, place, and person

► DeterminantsDeterminants —Epidemiologists also attempt to search for causes or factors that are associated —Epidemiologists also attempt to search for causes or factors that are associated with increased risk or probability of disease. This type of epidemiology, where we move from with increased risk or probability of disease. This type of epidemiology, where we move from questions of "who," "what," "where," and "when" and start trying to answer "how" and "why," is questions of "who," "what," "where," and "when" and start trying to answer "how" and "why," is referred to as analytical epidemiology.referred to as analytical epidemiology.

► Health-related statesHealth-related states —Although infectious diseases were clearly the focus of much of the early —Although infectious diseases were clearly the focus of much of the early epidemiological work, this is no longer true. Epidemiology as it is practiced today is applied to the epidemiological work, this is no longer true. Epidemiology as it is practiced today is applied to the whole spectrum of health-related events, which includes chronic disease, environmental problems, whole spectrum of health-related events, which includes chronic disease, environmental problems, behavioral problems, and injuries in addition to infectious disease.behavioral problems, and injuries in addition to infectious disease.

► PopulationsPopulations —One of the most important distinguishing characteristics of epidemiology is that it —One of the most important distinguishing characteristics of epidemiology is that it deals with groups of people rather than with individual patients.deals with groups of people rather than with individual patients.

► ControlControl —Finally, although epidemiology can be used simply as an analytical tool for studying —Finally, although epidemiology can be used simply as an analytical tool for studying diseases and their determinants, it serves a more active role. Epidemiological data steers public diseases and their determinants, it serves a more active role. Epidemiological data steers public health decision making and aids in developing and evaluating interventions to control and prevent health decision making and aids in developing and evaluating interventions to control and prevent health problems. This is the primary function of applied, or fieldhealth problems. This is the primary function of applied, or field

FOUNDATIONS OF FOUNDATIONS OF EPIDEMIOLOGY.EPIDEMIOLOGY.

► Epidemiology is an interdisciplinary field that Epidemiology is an interdisciplinary field that draws from biostatistics and social and behavioral draws from biostatistics and social and behavioral sciences as well as from the medically related sciences as well as from the medically related fields of toxicology , pathology , virology ,genetics , fields of toxicology , pathology , virology ,genetics , microbiology , and clinical medical.microbiology , and clinical medical.

► To elaborate some of the contributions of To elaborate some of the contributions of microbiology include information about specific microbiology include information about specific disease agents , including their morphology and disease agents , including their morphology and modes of transmission .modes of transmission .

► The investigation of anthrax ,legionnaires disease , and The investigation of anthrax ,legionnaires disease , and infant botulism utilized microbiologic techniques to identify infant botulism utilized microbiologic techniques to identify possible infectious agents . When the infectious agent is possible infectious agents . When the infectious agent is virus the expertise of a virologist may be required . Clinical virus the expertise of a virologist may be required . Clinical medicine is involved in the diagnosis of the patients state of medicine is involved in the diagnosis of the patients state of health , that is defining whether the patient has a particular health , that is defining whether the patient has a particular disease or condition. A pathologist expertise may help disease or condition. A pathologist expertise may help differentiate between diagnosed the individuals symptoms differentiate between diagnosed the individuals symptoms or signs of ill health .Astute physicians may suggest or signs of ill health .Astute physicians may suggest epidemiologic research on the basis of clinical observations epidemiologic research on the basis of clinical observations .Toxicology is concerned with the presence and health .Toxicology is concerned with the presence and health effects and chemical agents.effects and chemical agents.

HISTORICAL ANTECEDENTS OF HISTORICAL ANTECEDENTS OF EPIDEMIOLOGY.EPIDEMIOLOGY.

► The epidemiology began with the Greeks, who in their The epidemiology began with the Greeks, who in their concern for the ancient epidemics and deadly toll of the concern for the ancient epidemics and deadly toll of the diseases , attributed disease casualty to environmental diseases , attributed disease casualty to environmental factors . Early causal explanations for epidemics included factors . Early causal explanations for epidemics included various events, such as the wrath of the gods , the various events, such as the wrath of the gods , the breakdown of religious beliefs and morality , the influence breakdown of religious beliefs and morality , the influence of the weather , and “bad air” .Much later during the late of the weather , and “bad air” .Much later during the late Renaissance , pioneer biostatisticians quantified morbidity Renaissance , pioneer biostatisticians quantified morbidity and mortality trends. During the 19and mortality trends. During the 19 thth century, early century, early microbiologists formalized the germ theory of disease , microbiologists formalized the germ theory of disease , which attributed diseases to specific organisms . Each of which attributed diseases to specific organisms . Each of the stages in the genesis of epidemiology is discussed in the stages in the genesis of epidemiology is discussed in turn below . turn below .

RECENT APPLICATIONS OF RECENT APPLICATIONS OF EPIDEMIOLOGY .EPIDEMIOLOGY .

► The Biological Concept of Race and its Application to The Biological Concept of Race and its Application to Public Health and EpidemiologyPublic Health and Epidemiology

► Richard Cooper and Richard David Richard Cooper and Richard David Cook County HospitalCook County HospitalChildren's Memorial Hospital (Chicago) The category of race is widely Children's Memorial Hospital (Chicago) The category of race is widely used in public health. Although its significance may be clear-cut in used in public health. Although its significance may be clear-cut in some practical situations, an adequate theoretical construct for the some practical situations, an adequate theoretical construct for the concept of race does not exist. Public health appears to lag far behind concept of race does not exist. Public health appears to lag far behind the other biological sciences in the effort to grapple with the idea of the other biological sciences in the effort to grapple with the idea of race and its implications for the nature-nurture question. This paper race and its implications for the nature-nurture question. This paper outlines the current anthropological and social perspective on race, outlines the current anthropological and social perspective on race, and applies this view to problems of disease epidemiology. It is and applies this view to problems of disease epidemiology. It is proposed that uncritical use of the traditional biological concept of race proposed that uncritical use of the traditional biological concept of race has distorted etiological thinking in public health and has proven an has distorted etiological thinking in public health and has proven an obstacle in the development of effective intervention strategies. The obstacle in the development of effective intervention strategies. The pragmatism of medicine and its isolation from social science may pragmatism of medicine and its isolation from social science may account for much of this backwardness. account for much of this backwardness.

Molecular Epidemiology and Molecular Epidemiology and Cancer PreventionCancer Prevention

Molecular epidemiology: recent Molecular epidemiology: recent advances and future directionsadvances and future directions► RecentRecent advances in genomics, microassay technologies and advances in genomics, microassay technologies and

informatics hold promise for rapid identification informatics hold promise for rapid identification ofof polymorphic variants polymorphic variants or changes in expression or changes in expression ofof genes influencing both response and genes influencing both response and susceptibility to carcinogens. Another emerging area susceptibility to carcinogens. Another emerging area ofof molecular molecular epidemiologyepidemiology concerns the role concerns the role ofof nutrition and specific dietary nutrition and specific dietary factors (including studies on antioxidants, energy metabolism, insulin factors (including studies on antioxidants, energy metabolism, insulin and various growth factors) and the modulating effect and various growth factors) and the modulating effect ofof genetic genetic polymorphisms. Finally, molecular polymorphisms. Finally, molecular epidemiologyepidemiology has enormous has enormous potential in cancer prevention through the early identification potential in cancer prevention through the early identification ofof `at risk' `at risk' populations and the rapid assessment populations and the rapid assessment ofof intervention efficacy. Its intervention efficacy. Its success in fully reaching this potential will depend on the application success in fully reaching this potential will depend on the application ofof validated biomarkers, with adherence to sound epidemiologic and validated biomarkers, with adherence to sound epidemiologic and ethical principles. ethical principles.

►

An application of density estimation An application of density estimation to geographical epidemiologyto geographical epidemiology

► Relative risk function over a geographical region is defined Relative risk function over a geographical region is defined and it is shown that it can be estimated effectively using and it is shown that it can be estimated effectively using kernel density estimation separately for the spatial kernel density estimation separately for the spatial distribution of disease cases and for a sample of controls. distribution of disease cases and for a sample of controls. This procedure is demonstrated using data on childhood This procedure is demonstrated using data on childhood leukaemia in the vicinity of the Sellafield nuclear leukaemia in the vicinity of the Sellafield nuclear reprocessing plant in Cumbria, U.K. Various modifications reprocessing plant in Cumbria, U.K. Various modifications to the method are proposed, including the use of an to the method are proposed, including the use of an adaptive kernel. The final plot demonstrates a sharp peak adaptive kernel. The final plot demonstrates a sharp peak at Sellafield and a reasonably smooth surface over the rest at Sellafield and a reasonably smooth surface over the rest of the region, despite the small number of cases in the of the region, despite the small number of cases in the series. series.

The Biological Concept of The Biological Concept of Race and its Application to Race and its Application to

Public Health and Public Health and EpidemiologyEpidemiology

► The category of race is widely used in public health. Although its The category of race is widely used in public health. Although its significance may be clear-cut in some practical situations, an adequate significance may be clear-cut in some practical situations, an adequate theoretical construct for the concept of race does not exist. Public theoretical construct for the concept of race does not exist. Public health appears to lag far behind the other biological sciences in the health appears to lag far behind the other biological sciences in the effort to grapple with the idea of race and its implications for the effort to grapple with the idea of race and its implications for the nature-nurture question. This paper outlines the current nature-nurture question. This paper outlines the current anthropological and social perspective on race, and applies this view to anthropological and social perspective on race, and applies this view to problems of disease epidemiology. It is proposed that uncritical use of problems of disease epidemiology. It is proposed that uncritical use of the traditional biological concept of race has distorted etiological the traditional biological concept of race has distorted etiological thinking in public health and has proven an obstacle in the thinking in public health and has proven an obstacle in the development of effective intervention strategies. The pragmatism of development of effective intervention strategies. The pragmatism of medicine and its isolation from social science may account for much of medicine and its isolation from social science may account for much of this backwardness. this backwardness.

►

The Epidemiology of Childhood The Epidemiology of Childhood Psychiatric Disorders:Psychiatric Disorders:

► While sharing a new emphasis upon identifying discrete While sharing a new emphasis upon identifying discrete psychiatric disorders in children and adolescents, psychiatric disorders in children and adolescents, epidemiological field studies conducted during the past epidemiological field studies conducted during the past decade have used diverse methods of case ascertainment decade have used diverse methods of case ascertainment and definition. Half used the multimethod-multistage and definition. Half used the multimethod-multistage approach to ascertain cases. Severity rating scales and approach to ascertain cases. Severity rating scales and measures of pervasiveness, parent-child concordance, and measures of pervasiveness, parent-child concordance, and global functional impairment were employed to enhance global functional impairment were employed to enhance the specificity of case definition. The majority of overall the specificity of case definition. The majority of overall prevalence estimates of moderate to severe disorder range prevalence estimates of moderate to severe disorder range from 14 to 20%. Those investigations that use multiple from 14 to 20%. Those investigations that use multiple methods to define caseness show greatest promise in methods to define caseness show greatest promise in identifying true cases in community samples. identifying true cases in community samples.

Molecular epidemiology of Molecular epidemiology of tuberculosis: recent tuberculosis: recent

developments and applicationsdevelopments and applications ► The standard method for the typing of Mycobacterium The standard method for the typing of Mycobacterium

tuberculosis is still IS 6110 restriction fragment length tuberculosis is still IS 6110 restriction fragment length polymorphism (RFLP). This method has been widely used polymorphism (RFLP). This method has been widely used and has provided information on the variety and distribution and has provided information on the variety and distribution of tuberculosis strain types across the globe. Recently, IS of tuberculosis strain types across the globe. Recently, IS 6110 RFLP has been used to investigate the question of 6110 RFLP has been used to investigate the question of reinfection versus reactivation, examine the existence of reinfection versus reactivation, examine the existence of multiple infection, and track the spread of multidrug-multiple infection, and track the spread of multidrug-resistant tuberculosis. There have also been efforts to resistant tuberculosis. There have also been efforts to increase our understanding of the biologic characteristics increase our understanding of the biologic characteristics of IS 6110. These studies have resulted in a clearer of IS 6110. These studies have resulted in a clearer understanding of fingerprinting data and increased our understanding of fingerprinting data and increased our understanding of the evolution and pathogenicity of this understanding of the evolution and pathogenicity of this organism. organism.

Recent trends in the Recent trends in the epidemiology of sexually epidemiology of sexually

transmitted infections in the transmitted infections in the European Union European Union

►Sexually transmitted infections (STIs) are a Sexually transmitted infections (STIs) are a major public health problem in Europe. We major public health problem in Europe. We review recent trends in the epidemiology of review recent trends in the epidemiology of the major acute STIs in the European Union the major acute STIs in the European Union and Norway, their key determinants, and and Norway, their key determinants, and opportunities for enhancing STI prevention opportunities for enhancing STI prevention interventions in the region interventions in the region