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- 1. 1/11/2011 Introduction 1 Principles of Epidemiology for Public Health (EPID600) Introduction to the course Faculty: Victor J. Schoenbach, PhD home page Lorraine K. Alexander, PhD Department of Epidemiology Gillings School of Global Public Health University of North Carolina at Chapel Hill www.unc.edu/epid600/ (Note: these slides have verbatim speaker notes.)
- 2. 8/15/2007 Introduction 2 Safety warnings (actual instructions on products) Marks and Spencer bread pudding: “Product will be hot after heating” Rowenta iron: “Do not iron clothes on body” Nytol (a sleep aid): “Warning: may cause drowsiness” Kitchen knife: “Warning: keep out of children”
- 3. Introduction 3 Safety warning: Don’t believe everything you read Are the Durham Public Schools that bad?
- 4. Introduction 4 From Consumer Reports, Selling It
- 5. Introduction 5 EPID600, Principles of Epidemiology
- 6. Introduction 6 EPID600 Instructors Faculty Victor Schoenbach (“Vic”) EPID600(160) classroom since fall 2001 Internet since summer 2002 Lorraine Alexander EPID600(160) since 1994 (Carl M. Shy) 1/11/2011
- 8. 8/15/2007 Introduction 8 John C. Cassel, M.D.
- 9. 5/12/2010 Introduction 9 John C. Cassel, M.D. “Epidemiology is fundamentally engaged in the broader quest for social justice and equality.”
- 10. 7/24/2010 Introduction 10 August, 1973
- 11. 8/15/2007 Introduction 11 “I’m studying epidemiology”: 3 responses - You're studying what?” - “Does that have something to do with skin?” - “Uh-huh. And what else are you studying?”
- 12. 1/11/2011 Introduction 12 The epidemiologic perspective • Epidemiology is a way of thinking about health – human ecology • Much more than a collection of methods – a way of using them • Epidemiologists consider context, heterogeneity, dynamics, inference
- 13. 8/15/2007 Introduction 13 What is epidemiology? “The study of the distribution and determinants of health related states and events in populations, and the application of this study to control health problems” John M. Last, Dictionary of Epidemiology
- 14. 8/15/2007 Introduction 14 What is epidemiology?(con’t) “The study of the distribution and determinants of health related states and events in populations, and the application of this study to control health problems” John M. Last, Dictionary of Epidemiology
- 15. 8/15/2007 Introduction 15 What is epidemiology, really? • Study of the health and disease of the “body politic” – the population. • Basic science of public health •What causes disease? •How does disease spread? •What prevents disease? •What works in controlling disease?
- 16. 8/15/2007 Introduction 16 What for? 1. Provide the scientific basis to prevent disease & injury and promote health. 2. Determine relative importance to establish priorities for research & action. 3. Identify sections of the population at greatest risk to target interventions. 4. Evaluate effectiveness of programs in improving the health of the population.
- 17. 8/15/2007 Introduction 17 What for? – more 5. Study natural history of disease from precursor states through clinical course 6. Conduct surveillance of disease and injury occurrence in populations 7. Investigate disease outbreaks – Milton Terris, The Society for Epidemiologic Research (SER) and the future of epidemiology. Am J Epidemiol 1992; 136(8):909-915, p 912
- 18. 8/15/2007 Introduction 18 Natural history of disease • Disease is a process • Natural history is the entire process of development of a disease • Tells us what we can expect to happen • Fundamental concept for studying and controlling disease
- 20. 8/15/2007 Introduction 20 Plague! September 30, 1993 earthquake levels over one million homes in Maharashtra State, in India, with powerful aftershocks. Peasants harvest and store their crops, then decamp. August 1994, farmers return to stored grains, rats, fleas & Yersinia pestis.
- 21. 8/15/2007 Introduction 21 Plague! September 14, 1994 – four cases of bubonic plague in Mamala, Beed District, Maharashtra State. Health care infrastructure still disrupted from earthquake. September 18, Festival of Ganesh in Surat, hundreds of miles to northwest, rapidly growing and crowded city.
- 22. 8/15/2007 Introduction 22 Plague! September 21, cases of pneumonic plague in Surat. Public hospital doctors alert private doctors, but 80% flee Surat, closing all private clinics and hospitals September 22 – media barrage in India and outside – “Surat Fever”. 500,000 Surati’s depart in one week.
- 23. 8/15/2007 Introduction 23 Plague! Suratis take trains all over India, disappearing into densely-packed cities. Five Indian states go on emergency health alert status. Actions by Indian federal government are slow in coming and ineffectual; Minister of Health is not even a physician. WHO also ineffectual.
- 24. 8/15/2007 Introduction 24 Plague! Remaining medical personnel in Surat work round the clock, suffer exhaustion. Sales of tetracycline soar and become depleted. Plague expertise in short supply throughout the world (CDC has a half- time scientist).
- 25. 8/15/2007 Introduction 25 Plague! Indian and multinational drug companies promote anitibiotics, cleansers, pesticides, rat poison. 20% of tourism packages canceled; Gulf State Nations, Pakistan, and Sri Lanka ban all flights, citizens, goods, and postal communications (!) with India. Bombay stock market crashes.
- 26. 8/15/2007 Introduction 26 Plague! Russia, China, Egypt, Malaysia, Bangladesh close all connections to India; others inspect all Indian travellers (10 suspected cases in NYC had malaria, typhoid, viruses, liver dis.). KLM sprays pesticides in plane cabins. Delhi closes all public schools. October 2 – Indian federal officials announce over 4,000 cases.
- 27. 8/15/2007 Introduction 27 Plague! India’s National Institute of Communicable Diseases and All India Institute of Medical Sciences engage in stand-off over specimens and decline outside laboratory assistance despite limited equipment and no air- conditioning. Most of original specimens deteriorate through lack of proper handling.
- 28. 8/15/2007 Introduction 28 Plague! Lack of definitive laboratory diagnosis undercuts governmental public health authority. Alternative theories abound – hantavirus, melioidosis, Burkholderia pseudomallei, leptospirosis, tularemia, Pseudomonas pseudomallei, conspiracy theories (rebels, U.S.). Ministry of Defense takes over all remaining blood and sputum samples.
- 29. 8/15/2007 Introduction 29 Plague! Thousands of worried well fill hospitals. Widespread inappropriate use of antibiotics, DDT. $1.3 billion lost trade and tourism. Lessons learned: Public health matters.
- 30. Introduction 30 About EPID600 Cooperative learning model designed by Carl M. Shy in 1990s - structured learning tasks where students • apply concepts and methods • exercise critical judgment • confront complexities of real life Small group with TA consultant Resources 1/11/2011
- 31. Introduction 31 Learning resources • Lectures – live, recorded, Powerpoint slides with verbatim speaker notes, and audio tutorials (web searchable) • Textbook (see www.unc.edu/epid600/ for information) • Case studies, approximately weekly 1/11/2011
- 32. 8/15/2007 Introduction 32 Learning resources – con’t • Course websites (just Google “EPID600”): • http://blackboard.unc.edu – announcements, all materials organized by course module, and links to everything • http://www.unc.edu/epid600/ – most of the content and submission forms that are displayed in Blackboard – for when you can’t or don’t want to log in to Blackboard • Instructors – your TA, Vic, Lorraine • Each other
- 33. 1/11/2011 Introduction 33 Finding information • Search the net – open or targeted, e.g. predictive value site:epidemiolog.net/epid160/lectures • www.epidemiolog.net: Understanding the fundamentals of epidemiology – an evolving text (includes problems and answers), old EPID168 exercises, examinations, spreadsheets, more …
- 34. 8/15/2007 Introduction 34 Course schedule • 9-12 hours/week (including class attendance) • Most weeks – 1-2 textbook chapter(s), a case study article with questions, small group discussion • Three examinations interspersed • Suggestion to spread out the workload: - Before Exam 1 read ahead in textbook - After Exam 1 begin your final paper (Exam 3)
- 35. 1/11/2011 Introduction 35 Course schedule EPID600 spring 2011 classroom course schedule (Tuesday lab) Sun Mon Tue lecture (3:30p) Tues lab (5:00p) Thu Fri Sat 1/9/2011 1/10/2011 1/11/2011 1/11/2011 1/13/2011 ###### 1/15/2011 Blackboard site open by today Start Module I: Introduction Lab - DVD: Part I The Age of AIDS Online discussion of The Age of AIDS Indiv. cs01 due: 1/16/2011 1/17/2011 1/18/2011 1/18/2011 1/20/2011 ###### 1/22/2011 Martin Luther King, Jr. Holiday Start Module II: Studying populations Lab: Introduction 1/23/2011 1/24/2011 1/25/2011 1/25/2011 1/27/2011 ###### 1/29/2011 Indiv. cs02 due: Studying populations Start Module III: Incidence Lab: Studying populations Group cs02 due: Studying 1/30/2011 1/31/2011 2/1/2011 2/1/2011 2/3/2011 ###### 2/5/2011 Indiv. cs03 due: Incidence Start Module IV: Screening Lab: Incidence Group cs03 due: Incidence 2/6/2011 2/7/2011 2/8/2011 2/8/2011 2/10/2011 ###### 2/12/2011 Indiv. cs04 due: Screening Start Module V: Intervention studies Lab: Screening Group cs04 due: Screening Peer and TA evaluations due2/13/2011 2/14/2011 2/15/2011 2/15/2011 2/17/2011 ###### 2/19/2011 Indiv. cs05 due: Interventions studies Start Module VI: Cohort studies Lab: Intervention studies Group cs05 due: Intervention studies Exam 1 posted
- 36. 8/15/2007 Introduction 36 Challenges in an introductory course • Diversity of backgrounds – biology, physiology, math/statistics, public health, epidemiology • Diversity of interest – from: “I epidemiology” to: “Let me out of here!” • Basic epidemiologic concepts are still evolving
- 37. 8/15/2007 Introduction 37 Course objectives 1. Explain the population perspective, access population data, describe public health problems 2. Apply and interpret measures of disease occurrence and correlates in populations 3. Use basic methods for investigating disease outbreaks 4. Explain relative strengths and limitations of different epidemiologic study designs 5. Identify and control major sources of error in community health studies
- 38. 8/15/2007 Introduction 38 Course objectives – continued 6. Evaluate epidemiologic evidence by applying criteria for causal inference 7. Use epidemiologic methods in evaluating public health interventions 8. Comprehend basic ethical and legal principles related to epidemiologic data 9. Appreciate complexities in applying scientific evidence in making policy
- 39. 1/11/2011 Introduction 39 Evaluation and grading Several examinations: • Two with multiple choice / calculation / short answer • One with essay questions (the “final paper”) Class participation / group work See Blackboard | Syllabus | Grading & Evaluation
- 40. 8/15/2007 Introduction 40 UNC-CH Honor Code • Integrity of academic work is vital to scholarly activity • Integrity of academic work is an individual and collective responsibility • Your participation in EPID600 implies full observance of the Honor Code
- 41. 8/15/2007 Introduction 41 What is prohibited? Academic cheating includes unauthorized copying, collaboration on examinations, and plagiarism. Plagiarism is the intentional representation of another person's words, thoughts, or ideas as one's own. If you are uncertain in a specific instance, ask an instructor.
- 42. 1/11/2011 Introduction 42 What students say about EPID600 “EPID600 was an excellent overview of the methods.” “Epi was great, and Bios was also good” “EPID600 was very interesting and probably one of the most valuable as epidemiology is a foundation of public health and through that course you learned history and practical knowledge.”
- 43. 1/11/2011 Introduction 43 What students say about EPID600 “. . . Extremely difficult to follow due to the cluttered and disorganized nature of the course website (there was a BlackBoard site AND a class website . . .)” “I was expecting to take an Epid class that discussed the prevalence and spread of major (and less known) diseases throughout the world . . .”
- 44. 1/11/2011 Introduction 44 What students say about EPID600 “I’ve heard horror stories about EPID 600, and I fear taking it.” “. . . Make Bios and EPID more challenging, we can take it . . .” “I don’t feel at all prepared with regard to my knowledge of epidemiology . . .” “I basically taught myself the material . . .”
- 45. 1/11/2011 Introduction 45 What students say about EPID600 “I do not feel that I have a good grasp of concepts still.” “I almost feel like I need to take it again to really absorb all the information.” “I don’t feel confident about any of the material.” “The course was great. My main problem was that I already knew everything.”
- 46. 2/21/2011 Introduction 46 Thank you Xie xie ni Asante Gracias, grazie Dhanyawad Spacibo Merci, Danke Naishitz Arigato, Shohkrahn Gàn xìe Multu^mesc Hvala Ngiyabonga Cám o*n Kamsa hamnida
Editor's Notes
- Welcome, bienvenidos, bienvenue, ni-hau, huan-ying, karibuni, salam malekum, wilkommen, drasvuitya, namaste, merhaba, shalom, sawadee-hlap, ya’h te habeen, xin chao. Welcome to EPID600, Principles of Epidemiology for Public Health. I would like to begin by congratulating you on your decision to learn epidemiology. Even if you are taking this course only because it is required for your program, I congratulate you for signing up for a program that requires epidemiology.
- Whenever you open the box of a new product you have purchased, the first thing you encounter is a set of cautions for using the product safely. I haven't had the opportunity yet to write a set of cautions for EPID600, so I'm providing several that I found in a column by Ann Landers. These were allegedly actual instructions: For a Marks and Spencer bread pudding: “Product will be hot after heating” For a Rowenta iron: “Do not iron clothes on body” For Nytol (a sleep aid): “Warning: may cause drowsiness” For a kitchen knife: “Warning: keep out of children” So, with these warnings in mind, let me share a photography with you.
- You may be troubled by the information on this slide. I’m assuming that it reflects a lapse in proofing rather than a desperate state of affairs!
- Recently I’ve learned that modern marketing makes use of photos that have no particular relation to the product being sold.
- So, in that sprit, welcome to EPID600, Principles of Epidemiology for Public Health.
- And now some introductions. My name is Victor Schoenbach (please call me “Vic”). I've been a member of the faculty in the Department of Epidemiology since 1980 and have taught an introductory epidemiology course here every year since then. For the first 20 years I taught EPID168 (now EPID710), the introductory course for epidemiology majors, and since fall 2001 I’ve taught EPID600 (formerly known as EPID160) every semester. The second EPID600 faculty member is Lorraine Alexander, who is also the Department of Epidemiology’s Associate Chair for Distance Learning and co-leads the Certificate Program in Field Epidemiology. Lorraine has been with this course since 1994. In fact, she and Carl Shy, with the help of a number of our ablest doctoral students and specialists in distance learning and information technology, developed the Internet version of the course in the 1990s. The rest of the instructor team are our very bright, knowledgeable, organized, helpful, dedicated, and congenial teaching assistants. They are the key to the success of this course.
- Teaching this course has a special meaning for me. I took EPID160 – for the first time – in the fall of 1972, when I was a masters student in the Department of Health Education (now HBHE). The course was taught by John Cassel, who was then chair of the Department of Epidemiology.
- John Cassel was an inspiring man. He pioneered community-oriented primary care in South Africa in the 1940s and 50s. His work in providing health care to Africans, however, was not appreciated by the apartheid government, so he left South Africa and came to Chapel Hill, as the first permanent chairperson of the Department of Epidemiology. A believer in multidisciplinary perspectives, Dr. Cassel broadened the Department by bringing in social scientists and practicing physicians. He launched the first community-based cardiovascular disease cohort study in a biracial community (the Evans County Study) and was one of the founders of the field of social epidemiology. I recently came across John Cassel’s EPID160 lectures from fall 1972. I scanned them and posted rough versions of the files at www.unc.edu/~vschoenb/EPIDhistory/JohnCassel-MarionLectures/
- “Epidemiology is fundamentally engaged in the broader quest for social justice and equality.” This is the way that John Cassel characterized epidemiology during the discussion in which he invited Sherman James to join the Epidemiology faculty at UNC. Dr. James recounted the incident when he presented the 1999 John Cassel Seminar (1/20/1999). John Cassel’s perspective is not always prominent in epidemiology discussions, but it defines a mission for our field that we should never lose sight of. (To learn more about John Cassel, see Michel A. Ibrahim, Berton H. Kaplan, Ralph C. Patrick, Cecil Slome, Herman A. Tyroler and Robert N. Wilson. The legacy of John C. Cassel. Am J Epidemiol 1980(July);112(1):1-7 (http://aje.oxfordjournals.org/cgi/reprint/112/1/1.pdf)
- This is a picture of my wife and me the year after we were students in EPID160. She was an MPH student in Health Administration (now called HPM). We met in PUBH 100 (Principles of Public Health), a School-wide required core course that no longer exists. I’m sorry they eliminated that course – I certainly got a lot out of it. (The photo is probably from an SPH fall picnic in 1973.)
- But let’s think about you. I imagine that someone – perhaps a friend, relative, or co-worker – has asked you what you are taking this semester. When you said “epidemiology”, you probably received one of these typical responses. “You're studying what?”, or "Does that have something to do with skin?”, or perhaps just, “Uh-huh. And what else are you studying?” So one thing that I hope you will learn in this course is a way to explain epidemiology to normal people.
- Epidemiology is fundamentally a perspective, a way of thinking about health and disease – a type of human ecology. Health in an individual is studied in relation to the environment, including the rest of the population. Many students see epidemiology as a collection of methods – but most of epidemiologic methods are drawn from other disciplines – particularly demography, biostatistics, medicine, biology, psychology, and sociology. Epidemiologists consider context, heterogeneity, dynamics, inference, with a strong awareness of the limitations of empirical data.
- There are a number of definitions of epidemiology. One of my favorites is the one in John Last’s Dictionary of Epidemiology: “The study of the distribution and determinants of health related states and events in populations, and the application of this study to control health problems” (3rd edition). Let’s examine the definition phrase by phrase. The definition refers to the distribution of health-related states. Epidemiology studies where diseases are found in the population – who gets them (e.g., young people, older people, women, men), where they occur (e.g., in urban areas, rural areas, industrialized countries, developing countries), and the patterns of disease occurrence by season and over time. “Distribution and determinants” – we say “determinants” because epidemiology is interested in the factors that influence the occurrence of disease – risk factors, environmental factors, and preventive factors. The object is to prevent disease, and in order to do that we need to identify the factors that affect its occurrence. I’ve been saying “disease” as a short-hand for “health-related states and events”. Epidemiology can be used to study any phenomena that exist (“states”) or occur (“events”). Besides disease, epidemiology can study positive conditions (e.g., immunity) and positive behaviors (e.g., physical activity) as well as adverse ones. Epidemiologists are usually most interested in studying events, since once a condition has existed for some time, its antecedents are often harder to discern. However, health-related states are also important to study, since with some conditions, e.g., anxiety, depression, and immunity, their duration may be as important as their occurrence.
- Epidemiology studies populations. This aspect is one of the defining characteristics of epidemiology. In fact, the word for “people” is part of the derivation of the word “epidemiology” (from the Greek: epi - upon, demos = people, logy = study). However, there are also veterinary epidemiologists, who study populations of other animals. Take a look now at the last part of the definition, the application of this study to control health problems. This component of the definition is actually a point of some debate among epidemiologists, and not all definitions include it. In fact, three of my colleagues, including our past Department chair, published an article several years ago in the American Journal of Public Health in which they argued that the application of the results of epidemiologic studies to disease control should not be part of epidemiology. Policymakers and health education specialists are better prepared to do that, their argument went, and though epidemiologists can become involved in disease control and advocacy as individuals when they do so they are not acting as epidemiologists. Others (e.g., UNC EPID alumnus Douglas Weed, in an article in the Annals of Epidemiology) counter that drawing implications and advocating for policy changes should indeed be part of epidemiology, since epidemiologists are the ones most equipped to interpret the data they generate. Since some decisions involving resources, and approvals are based on what is or is not epidemiology (e.g., acceptable topics for an epidemiology dissertation or appointment to an epidemiology position), the question is somewhat consequential.
- What is epidemiology, really? Epidemiology is the study of the health and disease of the “body politic” – the population. Clinicians prevent, detect, monitor, and treat diseases in individual patients; epidemiologists prevent, detect, monitor, and “treat” epidemic and endemic diseases, in populations. Epidemiology is a basic science of public health. Epidemiologic studies provide the basis for public health practice and policymaking, by attempting to find out what causes disease, how does disease spread, what prevents disease, and what works in controlling disease? Of course, other disciplines are concerned with these questions, too. Many fields evaluate programs, for example. One difference is that epidemiologists emphasize evaluation in relation to health outcomes, rather than to processes, such as utilization of services. However, epidemiologists are by no means the only professionals concerned with health outcomes, nor with the causes and dissemination of disease. But when other people study health and disease in populations, then they are practicing epidemiology. I am beating the drum not so much for epidemiologists as I am for epidemiology.
- So what is epidemiology good for? Milton Terris (1992), one of the leaders in the development of the modern profession of epidemiology, summarized the uses of the field in an article published on the 25th anniversary of the founding of the Society for Epidemiologic Research. Terris’ listed 7 primary uses of epidemiology: 1. To provide the scientific basis to prevent disease & injury and promote health. 2. To determine the relative importance of different health needs, to establish priorities for research & action. 3. To identify sections of the population at greatest risk, to enable targeting of interventions. To evaluate effectiveness of programs in improving the health of the population. (continues on next slide)
- 5. To study the natural history of disease from precursor states through clinical course. 6. To conduct surveillance of disease and injury occurrence in populations To investigate disease outbreaks to determine their source and how to control them. – Milton Terris, The Society for Epidemiologic Research (SER) and the future of epidemiology. Am J Epidemiol 1992; 136(8):909-915, p 912
- Let me elaborate briefly on the concept of natural history of disease, a fundamental concept in epidemiology and public health. Disease is generally best understood as a process that unfolds over time. “Natural history” refers to the entire process of the development of a disease, and its course after it manifests. In principle, “natural” refers to that process in the absence of intervention. Why is that important? In order to know if an intervention could make a difference, it is necessary to know what would happen without intervention. For example, screening programs for early detection of chronic diseases must be based on an accurate understanding of the natural history of the condition. As we shall see in an upcoming lecture, early detection and screening requires that the disease have a stage during which it can be detected but would not ordinarily come to medical attention. Moreover, treatment during this presymptomatic stage must be more effective than treatment after the disease becomes symptomatic. Why? If the treatment is no more efficacious before symptoms appear, then why bother to screen? If the same health outcomes could be obtained without the costs and logistical challenges of screening by just waiting for symptoms to bring the patient to the clinic, then why bother to screen?
- During her doctoral studies in bacteriology and immunology, Laurie Garrett began working as a journalist to earn some extra money. She was so good at it and enjoyed it so much that she left microbiology for journalism, where she has been extremely successful. After a best-selling book The Coming Plague presented the problem of emerging and re-emerging infectious diseases and how the world was ill-prepared to cope with them, Garrett turned her attention to the collapse of the public health institutional infrastructure around the world. In the Betrayal of Trust, Laurie Garrett chronicles two major disease outbreaks that were exacerbated by the lack of an effective public health system. She then chronicles the deterioration of the public health infrastructure in Russia and the United States. The following account of the 1994 outbreak of plague in India vividly illustrates how disease outbreaks can unfold and the importance of public health for modern society. The bubonic plague is caused by a bacterium called Yersinia pestis. Since only recently have the genetic sequences of bacteria become known, they are characterized most often by how they appear through a microscope. Yersinia pestis is shaped like a rod and is “gram-negative”, i.e., it belongs to a group of bacteria that have cell walls that prevent them from absorbing a commonly used dye (a “Gram stain”).
- Yersinia pestis was responsible for the Black Death in Europe in the Middle Ages and has killed many millions of people throughout the world. The bacteria are transmitted primarily through the bite of a flea that infests black rats. Fortunately, the plague is readily treated with antibiotics, but when treatment does not begin in time, the bacteria produces a pneumonia (pneumonic plague) that progresses very rapidly – and that can spread from person-to-person. On September 30, 1993, a powerful earthquake leveled a million homes in Maharashtra State, in India. The peasants quickly harvested their crops, stored them, and then fled. A year later, in summer 1994, the peasants returned to retrieve their stored grain, which had since been colonized by rats, who in turn were infested with fleas, which in turn were infected with Yersinia pestis.
- On September 14, 1994, four cases of bubonic plague were reported in Mamala, in the Beed District of Maharashtra State. There were undoubtedly other cases as well, but the health care infrastructure had been severely disrupted by the earthquake. As a result, bubonic plague cases went undetected - and untreated - and developed into pneumonic plague. Several days later in Surat, a city hundreds of miles away, people gathered by the Tapti River to celebrate the Festival of Ganesh. Due to particularly heavy rains during the monsoon season that had just ended, the ground was still soft in many places, so hundreds of thousands of people crowded into a narrow area. Among them must have been someone infected with pneumonic plague.
- By September 21, cases of pneumonic plague began to appear in Surat. As a result of cutbacks in funding, the public hospitals now treated a minority of patients, so the public health physicians quietly passed the word to their private colleagues to be on the lookout for plague. The reaction was not one that brought credit to the medical profession. 80% of the private physicians fled Surat, closing all private clinics and hospitals. As word of the outbreak spread, the middle class followed their lead, and the media – local, national, and then international – trumpeted the story: “Surat Fever”. A half-million people – one quarter of Surat’s population – departed in one week.
- People from Surat quickly dispersed around the country, disappearing into India’s densely packed cities. Even without epidemiology training, you probably realize that this is not a good way to contain an outbreak of a communicable disease. Soon, cases of pneumonic plague began appearing in widely separated locations. Five Indian states went on emergency health alert status. Unfortunately, the Indian federal government was slow to act and ineffectual when it did. The Minister of Health was a political appointee and not even a physician. However, the World Health Organization was also ineffectual in gauging the nature of the situation and in orchestrating an appropriate international response.
- Meanwhile in Surat, the remaining medical personnel worked round the clock to care for the growing number of cases – and became exhausted in the process. Sales of tetracycline – the primary antibiotic used against plague – soared, so that supplies quickly became depleted. As the international community became increasingly concerned, it emerged that there was a severe shortage of plague expertise throughout the world. The U.S. Centers for Disease Control and Prevention, for example, had only a half-time scientist who was an expert in this disease.
- There was no shortage of “expertise” in the private sector, however. Indian and multinational drug companies stepped in to promote their antibiotics, cleansers, pesticides, and rat poison – even though Yersinia were being carried by untreated people rather than by rats and fleas. As fear spread, one-fifth of tourism packages to India were cancelled. India’s traditional opponents took the opportunity to ban all commerce with India, even postal communications. Then, the Bombay stock market crashed.
- In the face of bland reassurances from the WHO, countries around the world took measures to protect themselves from infected travellers from India. Russia, China, Egypt, Malaysia, and Bangladesh closed all connections to India, while Britain and other countries inspected all Indian travelers. The Royal Dutch Airline (KLM) sprayed pesticides in cabins of planes arriving from India – a puzzling containment strategy, since the infected carriers were people, not insects. In India, public schools were being closed, and as of October 2nd – less than two months after the first four cases were reported, Indian federal officials announced over 4,000 cases.
- The Indian federal government proved inept at dealing with the epidemic. The National Institute of Communicable Diseases and the All India Institute of Medical Sciences engaged in a stand-off over custody of specimens from suspected plague victims. The government declined the assistance of outside laboratories even though their own equipment was limited and laboratory conditions were inadequate. Most of the original specimens deteriorated through the lack of proper handling, so that it would prove impossible to conduct an accurate analysis of the extent of the epidemic.
- The lack of definitive laboratory diagnosis undercut the authority of governmental public health agencies. Alternative theories of the cause of the illnesses abounded. Some thought that the outbreak was due really to various other diseases. Others proposed that the outbreak was the result of a conspiracy by rebels or by the U.S. Central Intelligence Agency. These theories prompted the Ministry of Defense to take custody of the remaining blood and sputum samples, cutting out public health completely.
- Fortunately for India – and the rest of the world – the outbreak subsided. But in the process thousands of worried well filled the hospitals, there was widespread inappropriate use of antibiotics and pesticides, and losses in trade and tourism alone exceeded $1 billion. The lessons learned from this experience? Public health matters! If you feel that I have singled out the Indian government unfairly, it is only that I did not have the time to provide a synopsis of the chapters on Zaire, Russia, and the United States.
- Now we should talk a little about the course. EPID600 is based on a cooperative learning model of adult education, in which students work on structured learning tasks so that they can apply the concepts and methods they are learning, exercise critical judgment, and confront some of the complexities of real life epidemiology. Students will work in small groups, or “teams”, of about 10 members each. Each teaching assistant will act as a consultant to several teams.
- We also offer numerous learning resources. First is a set of stimulating, thought-provoking lectures, such as this one. These are presented live at the UNC Gillings School of Global Public Health and are available as Powerpoint slides with verbatim speaker notes. The lectures have been recorded as audio tutorials that can be streamed or downloaded from the web. Because of the lag involved in re-recording, though, I encourage you to use them in conjunction with the separately posted Powerpoint slides, which will always be the most up-to-date. (Note that each lecture slide has a date in the lower left-hand corner; the date gets changed when I update the slide or speaker notes.) We also use a published textbook (see the EPID600 webpage at www.unc.edu/epid600/ ). My lectures are designed to complement the textbook and in some cases to comment on it. Epidemiology is a relatively new field, and even its fundamentals are still evolving. This evolution can make for considerable confusion, since different authors and investigators use terms in different ways and make statements that reflect the era in which the writer learned epidemiology. Fortunately the newer conceptual framework provides greater clarity than the earlier ones. The lectures will try to provide the benefit of these recent developments. The course is organized into weekly modules. Most modules contain, besides the lecture, a case study consisting of a reading or two and a dozen or so questions taken largely from past examinations.
- We provide Two course websites, where you can find the class schedule, lecture slides, case studies, and information about the conduct of the course and its policies, including grading, plus links to other Internet resources (be sure to check out Epigrad Today). One course website is in Blackboard (http://blackboard.unc.edu), and the other is open to the public. The Blackboard site has everything you will need for the course, including announcements, a folder for each weekly module to hold all of the materials and links for that module including the lecture slides, case studies, and supplementary materials, and links to submission forms. The public website, at www.unc.edu/epid600/, has most of the content and submission forms that are available in the Blackboard site. The public website is available when you cannot cannot login to Blackboard. A teaching assistant and the course faculty, who will answer your questions, make suggestions, and provide feedback about your answers on case study and examination questions. Your fellow students, many of whom have public health and other relevant training and/or experience. You will work in a small group on case studies and other tasks to gain experience working on epidemiologic questions of the sort that arise in the lives of public health professionals.
- If you would like to read more of what I would say than is presented in the lectures, take a look at my Evolving Text, which I was developing during my years of teaching EPID168, the introductory course for Epidemiology majors at UNC. You can find it and other resources at www.epidemiolog.net With all these resources, how can one find anything? Try search the lectures through a search website. Use the advanced search option and specify the domain to be searched as: predictive value site:epidemiolog.net/epid160/lectures You can then open the document(s) located and search with Edit | Find Search the Evolving Text in the same way; use the domain epidemiolog.net/evolving or epidemiolog.net/es/endesarrollo Search the case study answers by downloading the instructor answers to a folder on your disk drive, as they are posted; then use your operating system’s search tool or another program. (Please remember that instructor answers are not to be given to others.)
- A word about the course schedule. All versions of EPID600 are designed to provide a 3-credit graduate level introductory epidemiology course that satisfies the accreditation requirements for masters and doctoral degrees in public health. The rule of thumb for UNC-CH graduate courses is 3 or 4 hours of in-class or outside work for each credit hour, so the estimated workload for EPID600 is about 9-12 hours/ week. Besides the lecture, most weeks will involve reading a chapter or two in the textbook, reading a published article and answering questions for the Case Study, and participating in discussions with your small group. In addition, there are three examinations, the last of which is an article critique often called “the final paper”. To balance your workload across the semester, we suggest that you read ahead in the textbook, at least to familiarize yourself with it, during the weeks before the posting of the first examination. After the first examination is over, read over the article you will be critiquing for the final paper (Exam 3) and begin drafting your answers (instructions will be posted on the web site). Then work on the second examination when it is posted, and after it is finished, go back and complete your paper. With this schedule you can spread the workload over the entire semester and can have the benefit of time and reflection in writing your article critique.
- A word about the course schedule. All versions of EPID600 are designed to provide a 3-credit graduate level introductory epidemiology course that satisfies the accreditation requirements for masters and doctoral degrees in public health. The rule of thumb for UNC-CH graduate courses is 3 or 4 hours of in-class or outside work for each credit hour, so the estimated workload for EPID600 is about 9-12 hours/ week. Besides the lecture, most weeks will involve reading a chapter or two in the textbook, reading a published article and answering questions for the Case Study, and participating in discussions with your small group. In addition, there are three examinations, the last of which is an article critique often called “the final paper”. To balance your workload across the semester, we suggest that you read ahead in the textbook, at least to familiarize yourself with it, during the weeks before the posting of the first examination. After the first examination is over, read over the article you will be critiquing for the final paper (Exam 3) and begin drafting your answers (instructions will be posted on the web site). Then work on the second examination when it is posted, and after it is finished, go back and complete your paper. With this schedule you can spread the workload over the entire semester and can have the benefit of time and reflection in writing your article critique.
- And now, to elicit your sympathy and understanding, I want to call your attention to some of the challenges of teaching an introductory course in epidemiology. First, since this graduate level course does not follow an undergraduate epidemiology course, students vary greatly in their previous exposure to epidemiology and to the many related fields. That means that nearly everything I might say is going to be too familiar to some of you and too unfamiliar to others. Second, since EPID600 is a required course, there is a diversity of interest, from those who are excited at the opportunity to learn epidemiology to those who are taking the course “under duress”. Third, as I mentioned earlier, epidemiologic concepts are still evolving. So there remains more inconsistency and confusion than will be the case in another decade or two.
- The objectives of this course, designed to meet the Council on Education in Public Health requirements, are to: 1. Explain the population perspective, access population data, and describe public health problems – The population perspective is at the heart of epidemiology and public health, and being able to describe populations and health problems is the first step in thinking about them effectively. 2. Apply and interpret measures of disease occurrence and correlates in populations – Since epidemiology studies populations, we need to have measures that quantify the occurrence and presence of disease, and the presence of exposures that influence them, in groups of people 3. Use basic methods for investigating disease outbreaks 4. Explain the relative strengths and limitations of different epidemiologic study designs 5. Identify and control major sources of error in community health studies – Every science has to contend with error. But since epidemiology is an observational science, our abilities to avoid and control error through experimental design – standard temperature and pressure, for example – are very limited. People are not easy to study.
- 6. Evaluate the evidence from different epidemiologic studies – Rarely does a single epidemiologic study establish anything. There are too many possible sources of error and other influences to consider. So weighing the evidence from different studies is an essential part of interpreting findings and reaching conclusions. 7. Use epidemiologic methods in evaluating public health interventions 8. Comprehend basic ethical and legal principles related to collecting, maintaining, and using epidemiologic data 9. Appreciate the complexities in applying scientific evidence in making policy – Epidemiology helps to provide the scientific basis for public health practice and policy, but the connection is often not straightforward. Appreciating the complexities is an important part of using epidemiologic data appropriately.
- The grading algorithm for EPID600 is explained in the syllabus folder in the Blackboard course website. Grades are based on indicators of learning and class participation. Even if you do not do well on examinations, you can still pass this course. For example, you can earn up points on your final grade by submitting your individual case study answers, and you receive credit on your final grade for working in your small groups.
- Speaking of grading, I need to mention that all submitted work for this course comes under the Honor Code of the University of North Carolina at Chapel Hill. Integrity of academic work is vital to scholarly activity, and this University takes the Honor Code very seriously . You as students depend on your instructors to be truthful in the material we present and to be honest with you in our interactions. All of us depend on researchers and writers to be honest in their descriptions of what they have done and what they have found. The occasional lapses of integrity serve to remind us that without it what use would the information in scientific journals be? (e.g., see http://www.nytimes.com/2010/02/03/health/research/03lancet.html ) Integrity of academic work is the responsibility of each of us as individuals and of all of us collectively. When students engage in improper collaboration or use others’ work improperly, there is a corrosive effect on the entire enterprise. Students who do play by the rules may feel they are at a disadvantage and wonder why they should observe the rules if others do not. I accept my responsibility as a faculty member to report instances where I have reason to suspect that an Honor Code violation has occurred, and I use a computer-based screening procedure to detect such situations. I have had to report a significant number of EPID600 students, and it has pained me greatly to do so. These students had various motives for engaging in the behaviors that got them in trouble, and some students were taken advantage of by other students. So please help me to protect EPID600 students’ honor.
- What does the Honor Code require? In general the Code requires that all of us avoid cheating and plagiarism. Academic cheating includes unauthorized collaboration or communication on an assignment. EPID600 provides specific guidelines for permissible and impermissible collaboration on assignments. In brief, you may not have access to instructor answers before they have been posted in Blackboard and you may not communicate about an examination except with the course instructors, including teaching assistants. Plagiarism is the intentional representation of another person's words, thoughts, or ideas as one's own. These issues are most likely not new to you, but if you are uncertain in any specific instance, ask an instructor. Since cheating and plagiarism involve misrepresentation, raising the question with an instructor demonstrates that you are not attempting to mislead or misrepresent.
- “EPID600 was an excellent overview of the methods.” “Epi was great, and Bios was also good” “EPID600 was very interesting and probably one of the most valuable as epidemiology is a foundation of public health and through that course you learned history and practical knowledge.”
- “. . . Extremely difficult to follow due to the cluttered and disorganized nature of the course website (there was a BlackBoard site AND a class website . . .)” “I was expecting to take an Epid class that discussed the prevalence and spread of major (and less known) diseases throughout the world . . .”
- “I’ve heard horror stories about EPID 600, and I fear taking it.” “. . . Make Bios and EPID more challenging, we can take it . . .” “I don’t feel at all prepared with regard to my knowledge of epidemiology . . .” “I basically taught myself the material . . .”
- “I do not feel that I have a good grasp of concepts still.” “I almost feel like I need to take it again to really absorb all the information.” “I don’t feel confident about any of the material.” “The course was great. My main problem was that I already knew everything.”
- Goodbye for now, in many languages, and I hope that you enjoy the class. [For the classroom course, discuss class size limits, waiting list and drops, procedure for labs and switching lab days, and The Age of AIDS.]