EpiLEC Session 2 Definition and Scope PDF

Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ____...

Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Lesson title: Definition and Scope of Veterinary Materials: Epidemiology - Paper and Pen Lesson Objectives: - Desktop Computer or Smart Phone with At the end of this period, the students are expected to: internet access 1. distinguish the unique attributes of epidemiology - pdf file copy of rendering it distinct science. reference book 2. Compare and contrast clinical approaches and epidemiological approaches to disease management. References: 3. Appraise the one health approach to diseases. 1. Thrusfield, Michael (1995). Veterinary Epidemiology. Third edition. Oxford: 1. Blackwell Science Ltd. 2. Schwabe, Riemann, Franti (1977). Veterinary Epidemiology in Veterinary Practice, Philadelphia: Lea & Febiger. Productivity Tip: Have an open communication with friends and share. Find out on your common needs. A. LESSON PREVIEW/REVIEW 1) Introduction (2 mins) Epidemiology is defined is defined in various ways by different authors, mostly describing the term in the context of a particular interest or needs. The general definition by Schwabe et.al. (1977), “the study of disease in populations,” reflects that this discipline differs from conventional or traditional medical approaches to the study of disease that normally are concerned with the disease processes in affected individuals. Along with the clinical findings and pathology, the epidemiology of a disease is an integral part of its basic description. Epidemiology has its special techniques of data collection and interpretation, and vocabulary of technical terms. It will be the aim of this lesson to provide an overview of the epidemiological terminologies, its approaches and methods. Further, this session endeavors to describe some of the distinctive characteristics of the epidemiological approach, especially those which differ from the familiar clinical descriptive methods. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ 2) Activity 1: What I Know Chart, part 1 (3 mins) Consider the following questions on the table below. On the first column briefly write in bullet points what you know about the question. Meanwhile, leave the third column blank until you have completed going through the whole lesson. What I Know Questions: What I Learned (Activity 4) 1. Name two unique attributes of epidemiology rendering it distinct science? 2. Why is Epidemiology also regarded as “medicine in the field” approach? 3. What is a “One Health” approach in disease management? B.MAIN LESSON 1) Activity 2: Content Notes (20 mins) In addition to the discussions below which were summarized from various chapters of Epidemiology in Veterinary Practice by Schwabe, Riemann, and Franti (1977), read the whole contents of Chapter 2 (pages 22-33) in Veterinary Epidemiology, Third Edition by Michael Thrusfield. The Definition and Scope of Epidemiology The definitions of Epidemiology by Blackmore and Harris (1979) encompass the scope of epidemiology that is basically, the “study of distribution, determinants, and dynamics of disease in a population, or in more simple terms, the study of factors determining the occurrence of a disease in a population.” Probably the earliest use of the word "epidemiology" was in Spain as contained in a 1598 book about plague called Epidemiología. The ancient Greek physician Hippocrates (born around 460 BC) used the word epidemeion to refer to diseases that visit the community, FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ meaning they occurred from time to time, in contrast to endemeion, diseases which resided within the community. The expression "endemic disease" comes from this word. The word derives from the Greek word epidemos - epi meaning "upon" and demos meaning "people". Theoretically therefore, the term epidemiology refers to study of disease in human population and the most appropriate term is epizootiology when the population comprises of non-human animals. Considering however that veterinary public health is equally concerned with diseases of both animals and man, the term epidemiology is generally accepted to both population and as synonym for epizootiology. There are five objectives of epidemiology: (Thrusfield, (1995)) 1. Determination of the origin of a disease whose cause is known; 2. Investigation and control of a disease whose cause is either unknown or poorly understood; 3. Acquisition of information on the ecology and natural history of a disease; 4. Planning and monitoring of disease control programmes; 5. Assessment of the economic effects of a disease and analysis of the costs and economic benefits of alternative control programmes Approaches to Epidemiology o Medical Detection The Medical detection was the original “school” of epidemiology. This avenue grew mostly from experiences of clinicians and pathologists in the 18th century as they first considered population aspects of commonly occurring diseases of man and other animals. As they began to follow up cases of diseases in animals and man in the field, they evolved methods to investigate contacts and outbreaks and to carry out systematic case-finding surveys. Owing to the fact that this school of epidemiology is a field-based activity, thereby mass case-finding techniques was familiarly dubbed “down the road’ testing. Further, with such labels as “gumshoe” and “flatfoot”, this medical detection approach came to be known as “shoe-leather” epidemiology. o Medical Ecology The traditional exponents of this approach were veterinarians and physicians who first discovered that: 1) The life cycles of parasites of vertebrates often are biologically complex; 2) Zoonoses and many other infections shared among vertebrate species were relatively nonspecific, and FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ 3) Some infections were transmitted from vertebrate to vertebrate by invertebrate vectors. Ecologists, entomologists, parasitologists, zoologists, and others have all contributed both to the efforts to unravel the intricacies of such biologically complicated diseases and to the development of the ecological study of epidemiology. o Mathematical approach Applied mostly in identifying the determinants of “disease of unknown etiology.” Used primarily by statisticians and public health workers. The mathematical, also biostatistical epidemiology is the newest school of epidemiology. It provides several broad classes of investigating procedures. These include methods for: 1) Designing and conducting studies; 2) Developing and presenting data; and 3) Analyzing data to make comparisons, determine associations, interpret results, and draw inferences or conclusions o Modern epidemiologic approaches emerge from practitioners whose training or interest have been more geographical or economic than medical, from geneticists, and from individuals in specific specialties such as occupational medicine in human practice The two principal uses of epidemiology are: 1. Serves as the investigative or diagnostic discipline for population or herd medicine; 2. Supports various forms of directed action against disease. Epidemiology as Diagnostic Discipline (Medical Detection Approach) The epidemiologic approach to diagnosis is a holistic one, which contrasts with the more reductionistic approaches of clinical diagnosis and pathology; that is, epidemiology is concerned with the whole forest as well as with the tress and the leaves. Is basic unit of concern -the population, include the healthy animals as well as the sick and dead ones. The three parent diagnostic disciplines – clinical diagnosis, pathology, and epidemiology, complement one another and their distinctly different tools may be applied sequentially to the solution of diagnostic problems. Some of the characteristics of these disciplines are presented in the slides that follow: FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Diagnostic uses of Epidemiology have two interrelated avenues; Intensive follow-up and Surveillance. Intensive follow-up is a detailed, multifaceted study of all seemingly relevant aspects of a disease event in a population unit. One of its commonest forms is the outbreak investigation. Surveillance is an active disease accounting process, i.e. a broad overall, organized approach to the collection, collation, analysis, expression, and dissemination of data about disease in large or small populations. Some like to call it “information for action.” Surveillance is made up by at least three components (1) a defined disease monitoring system, (2) a predefined disease intervention strategy (directed action), and (3) a defined threshold of disease frequency Definitions of Surveillance and Monitoring from the Dictionary of Epidemiology (2008) Fifth Edition, edited for the International Epidemiological Association by Miquel Porta, Oxford University Press: Surveillance - Systematic and continuous collection, analysis, and interpretation of data, closely integrated with the timely and coherent dissemination of the results and assessment to those who have the right to know so that action can be taken. It is an essential feature of epidemiological and public health practice. The final phase in the surveillance chain is the application of information to health promotion and to disease prevention and control. A surveillance system includes a functional capacity for data collection, analysis, and dissemination linked to public health programs. It is often distinguished from monitoring by the notion FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ that surveillance is continuous and ongoing, whereas monitoring tends to be more intermittent or episodic. Monitoring - The intermittent performance and analysis of measurements aimed at detecting changes in the health status of populations or in the physical or social environment. It may also imply intervention in the light of observed measurements and analysis of the effect of the intervention (e.g., on the health status of a population or on an environmental compartment). The process of collecting and analyzing information about the implementation and effects of a public health program. Active Surveillance data Detailed information resulting from instances of intensive follow-up of cases or outbreaks Results of special on-time or repeated prevalence surveys Evaluation reports and other active feedback from continuous disease control or prevalence monitoring programs Passive Surveillance data Reports of cases of disease or causes of deaths from individual veterinary clinics, diagnostic laboratories, and food protection services Morbidity reports from livestock disease control personnel; Reports of invaders detected or intercepted by international quarantine authorities Epidemiology as Directed Action Directed actions in epidemiological sense are doing things about herd disease in systematic and logical ways. These Actions include: 1. Studies on the nature and extent of the disease problems present in a given population; 2. Studies on the overall behaviour of particular diseases in different populations, with investigation of their determinants and patterns of occurrence; 3. Planning, and evaluation of efforts to prevent or control diseases; and 4. Research on new methods or approaches for the investigation and control of crowd diseases. The methods of directed action to disease will be covered in a separate session. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Types of Epidemiological Investigation The overall strategy of epidemiology is the “scientific method” applied to problems of diseases in populations. The stages in the overall epidemiologic process are described below: 1. Descriptive Epidemiology Means making observations in the field in order to describe a particular disease event or disease phenomenon as fully as necessary. 2. Experimental Epidemiology Involves designing specific population experiments to test epidemiological hypotheses. Often, prospective and proceed from the postulated cause to the observable effect 3. Analytical Epidemiology Strategy goes beyond purely descriptive process to draw statistical inferences about diseases in populations from available samples of the populations. Mathematical tools help determine the statistical significance of hypothesized associations between possible determinants of disease and observed rates of disease frequency. 4. Theoretical Epidemiology Consists of the representation of disease using mathematical “models” that attempt to simulate natural disease occurrence. Epidemiological Subdisciplines The following recognized epidemiological subdisciplines are described by Thrusfield (1995) o Clinical epidemiology o Environmental epidemiology o Computational epidemiology o Micro-epidemiology (Comparative epidemiology) o Genetic epidemiology o Macro-epidemiology o Molecular epidemiology o Nutritional epidemiology o Chronic disease epidemiology o Subclinical epidemiology Supplemental Readings: Pearce, Neil (1999). “Epidemiology as a Population Science,” International Journal of Epidemiology, 28:S1015-S1018 file:///E:/2%20ACADEMICS/VET%20EPIDEMIOLOGY/REFERENCES/Epidemiology %20as%20Population%20Science%20(readings).pdf Martin, Meek, Willeberg (1987), Veterinary Epidemiology Principles and Methods. Ames: Iowa State University Press, p 7-9. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ One Health Approach to Disease What is One Health? (https://www.cdc.gov/onehealth/basics/index.html) One Health is an approach that recognizes that the health of people is closely connected to the health of animals and our shared environment. One Health is not new, but it has become more important in recent years. This is because many factors have changed interactions between people, animals, plants, and our environment. Human populations are growing and expanding into new geographic areas. As a result, more people live in close contact with wild and domestic animals, both livestock and pets. Close contact with animals and their environments provides more opportunities for diseases to pass between animals and people. The earth has experienced changes in climate and land use, such as deforestation and intensive farming practices. Disruptions in environmental conditions and habitats can provide new opportunities for diseases to pass to animals. The movement of people, animals, and animal products has increased from international travel and trade. As a result, diseases can spread quickly across borders and around the globe. These changes have led to the spread of existing or known (endemic) and new or merging zoonotic diseases, which are diseases that can spread between animals and people. Examples of zoonotic diseases include: Rabies, Salmonella infection, West Nile virus infection, Q Fever (Coxiella burnetii), Anthrax, Brucellosis, Lyme disease, Ringworm, Ebola Successful public health interventions require the cooperation of human, animal, and environmental health partners. Professionals in human health (doctors, nurses, public health practitioners, epidemiologists), animal health (veterinarians, paraprofessionals, agricultural workers), environment (ecologists, wildlife experts), and other areas of expertise need to communicate, collaborate on, and coordinate activities. Other relevant players in a One Health approach could include law enforcement, policymakers, agriculture, communities, and even pet owners. No one person, organization, or sector can address issues at the animal-human-environment interface alone. By promoting collaboration across all sectors, a One Health approach can achieve the best health outcomes for people, animals, and plants in a shared environment. 2) Activity 3: Skill-building Activities (18 mins + 2 mins checking) Draw a figure / diagram; or find a picture that will illustrate the either (a) interplay of Veterinary Epidemiology and other sciences, or (b) One health approach to disease. Accompany your work with brief description. Further instruction will be provided regarding submission of your work. You will earn 10 points in this activity. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ 3) Activity 4: What I Know Chart, part 2 (2 mins) You are about to complete the lesson at this point. To refresh what you have learned, review back the questions in the What I Know Chart from Activity 1 and write your answers to the questions based on what you now know in the third column of the chart. 4) Activity 5: Check for Understanding (5 mins) Take quiz uploaded in google classroom C. LESSON WRAP-UP 1) Activity 6: Thinking about Learning (5 mins) You are done with this session! Let’s track your progress. Shade the session numbers you have completed. P1 P2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ ☐ 2) My learning targets: Complete the table below. Record your scores, learning experience for the session and deliberately plan for the next session. Date Learning Target/Topic Scores Action Plan What session# did you do? What were the What were What contributed to the quality of your performance What’s the date learning targets? What activities did you your scores in today? What will you do next session to maintain today? do? the activities? your performance or improve it? FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity Sheet for Session #2 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ FAQs 1. Why is epidemiology often described as the basic science of public health? First, epidemiology is a quantitative discipline that relies on a working knowledge of probability, statistics, and sound research methods. Second, epidemiology is a method of causal reasoning based on developing and testing hypotheses grounded in such scientific fields as biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events. However, epidemiology is not just a research activity but an integral component of public health, providing the foundation for directing practical and appropriate public health action based on this science and causal reasoning. 2. Can the epidemiological approach to disease management be applied in clinical practice? Epidemiological principles are increasingly being applied in clinical practice, whether it be in the use of Evidence-Based Veterinary Medicine, in order to ensure that appropriate scientific methodology is applied in the treatment of individual animals, or through the use of aggregated animal data in the form of Herd Health Plans to advise on measures which can be applied at the farm level. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH