EpiLEC Session 7 Spatial Patterns of Disease PDF

Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ______...

Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ Lesson title: Presentation of the Spatial Distribution of Materials: Disease - Paper and Pen - Desktop Computer or Lesson Objectives: Smart Phone with internet access At the end of this period, the students are expected to: - pdf file copy of 1. Explain the distribution and patterns of disease reference book occurrence in space. 2. Apply epidemiologic principles in relating disease Reference: spread in a geographical area 1. Thrusfield, Michael (1995). Veterinary Epidemiology. Third edition. Oxford: 1. Blackwell Science Ltd. Productivity Tip: Have enough sleep and healthy diet each day. A. LESSON PREVIEW/REVIEW 1) Introduction (2 mins) We learned in the previous session that the patterns of disease occurrence can provide useful clues as to which factors may be affecting the health of the population, by answering questions on the 'animal, place, time' concept. Hippocrates (5th Century BC) stated, “If you want to learn about the health of a population, look at the air they breathe, the water they drink and the places where they live.” Though such statement refers to human population, it aptly applies to animal population as well. The temporal distribution of disease was already covered in previous lesson. Now, we will learn that disease occurrence can also be characterized through its spatial pattern. It is usually of interest to determine whether disease occurs in a spatially clustered pattern which may be the result of transmission of infectious disease amongst animals in close proximity from each other or of presence of risk factors in the location of the cluster. Spatial epidemiology is the description and analysis of geographic variations in disease with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors.” [Elliott P, Wartenberg D. Spatial Epidemiology: Current Approaches and Future Challenges. Environ Health Perspect. 2004; 112(9): 998–1006.] FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 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. What is the most common way to present the spatial distribution of disease? 2. How is GIS significant in epidemiologic investigation of a disease? B.MAIN LESSON 1) Activity 2: Content Notes (20 mins) Read the full content of this lesson in the following sources: Thrusfield, Michael (1995). Veterinary Epidemiology Third Edition, p 65-73 The spatial pattern of disease is typically a consequence of environmental factors. Environmental factors include: aspects of climate (temperature, humidity, rainfall); aspects of animal management (management of animals in a certain area of a country may result in high rates of disease that may not be seen in other areas). Clustering of disease events in space are often demonstrated by the use of conventional mapping techniques. Geographic Information Systems (GIS) and easy access to spatial data (e.g. satellite images) have facilitated the ability to conduct spatial epidemiological analyses in recent years. Classification of Maps o Geographic base maps - constructed according to the shape of a country or region o Demographic base maps - drawn to represent the size of the population. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ o Isodemographic base maps - morbidity and mortality information is presented in relation to population size. Geographical information system (GIS) o Computerized system for collecting, sorting, managing, interrogating and displaying spatial data. o Have a range of powerful functions that include graphical analysis based on spatial location, statistical analysis, and modelling o Applications of GIS 1. Cartography 2. Neighbourhood analysis 3. Buffer generation 4. Overlay analysis 5. Network analysis 6. Three-dimensional surface modelling Types of Geographic Base Maps Point (dot or location ) maps - Illustrate outbreaks of disease in discrete locations, by circles, squares, dots or other symbol. Distribution maps - Constructed to show the area over which disease occurs. Proportional circle maps - Morbidity and mortality can be depicted using circles whose area is proportional to the amount of disease or deaths. Choropletic maps - Displays quantitative information as discrete shaded units of area, graded in intensity to represent the variability of the mapped data. Quantitative data are displayed but the boundaries artificial and does not show actual boundaries between high and low prevalence o Choroplethic Grid-based Maps - The units can be formed from gridlines, but are commonly administrative areas such as parishes, shires, counties or states. Isopletic maps - True boundaries between different values can be depicted by joining all points of equal value by a line, such as joining points of equal height to produce the familiar contour map. o Isomorbs are lines joining points of equal morbidity o Isomorts are lines joining points of equal mortality Demographic Base Map o Demographic map require accurate information on both numerators and denominators in morbidity and mortality values and are not common in veterinary medicine because the information is often missing. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ 2) Activity 3: Skill-building Activities The above figure is a hypothetical map of positive dog rabies cases in the different cities and municipalities in Cebu. Provide brief answers to the following: A. How can this map be of significance in describing disease spatial distribution of rabies in Cebu? B. What are pitfalls or disadvantages of this kind of presentation on the spatial distribution of the disease? FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH  Course Code: PHLT 2 Veterinary Epidemiology Student’s Activity sheet for Session #7 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) Link to short quiz is 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 #7 Name: _____________________________________________________________ Class number: _______ Section: ____________ Schedule: ________________________________________ Date: ________________ FAQs What is geotagging and how can it be of significance in epidemiology? Geotagging is the process of adding geographical information to various media in the form of metadata. The data usually consists of coordinates like latitude and longitude, but may even include bearing, altitude, distance and place names. Geotagging is most commonly used for photographs and can help people get a lot of specific information about where the picture was taken or the exact location of a friend who logged on to a service. Geotagging location services can be used to find location-specific websites, news and other information. It is based on positions and coordinates and is often directly taken from a global positioning system (GPS). -https://www.techopedia.com/definition/86/geotagging There are varied uses of geotagging. Through geotagging, the location of livestock farms and complete livestock population can be recorded in a database. Besides data of farms, the status of domestic animals and birds, the information of veterinary hospitals and related offices would also be linked through the GIS technology. The data would be useful to plot locations thus can be essential during times of outbreak of any diseases among domestic animals and birds. Thereby geotagging helps improve livestock management system and will help prevent or contain the spread of infectious diseases. FLM 1.0 Prepared by Daniel C. Ventura, Jr., DVM, PhD., DipVPH