Lesson Title: The X-Files (Medical Geography)
Authors: Jerry Benson and Kim Thurman
Author Info:
Jerry Benson
Luverne High School
Luverne, Minnesota
Instructor Kim Thurman
9th Grade Geography Instructor
Soddy Daisy, TN
Grade: AP Geography
Key Words:
Medical Geography, Spatial Diffusion, Influenza, Ebola, Virus, Population, Epidemic,
Pandemic, Spanish Influenza, Epidemiology, Pathology, Expansion Diffusion, Hierarchical
Diffusion, Contagious Diffusion, Vectors, Nonvectored, Vehicles, Infectious Disease, Chronic or Degenerative Diseases, Genetic or Inherited Diseases, Agents, Reservoir,
Hosts, Networking, Traditional Medicine
Time Needed : Four to five class periods
Objectives: Students will be able to:
1. Acquire an understanding of applying geographical skills to modern medical problems
through the field of medical geography.
2. Discuss, describe and give examples of the spatial diffusion process (hierarchical
diffusion and contagious diffusion). Cause and effect relationships and how geographers
analyze and explain how diseases are spread and medically controlled.
3. Demonstrate their knowledge of the diffusion of disease by mapping several diseases
(Spanish Influenza of 1918 and Ebola).
a. Map making and analysis skills to show where certain diseases are
located.
b. Place-location. Why certain diseases occur where they do and how
they share a pattern of moving throughout human populations.
4. Gain an understanding and appreciation for the global medical network that has
been created to help human populations from harmful contagious disease outbreaks.
5. Examine maps to draw conclusions and describe the diffusion of the influenza pandemic
of 1918 in the United States and throughout the world.
6. Examine maps to draw conclusions and describe the diffusion of the Ebola in the United
States and throughout the world.
7. Gain an understanding how maps can provide useful information about an issue.
8. Gain an understanding of how maps can be used to solve problems.
9. Acquire and use the vocabulary in the field of medical geography.
10. Gain computer skills by using data to make a spreadsheet and analyze the information
geographically.
Materials:
1. Colored pencils
2. Pen or pencil
3. Calculator
4. Goode's World Atlas
5. Outline maps of the United States, the World and Africa
6. Computer (spread sheet activities) and access to the Internet
7. Resource sheets included in the teacher resource section
8. Background information on medical geography, influenza and Ebola
9. Vocabulary sheets of medical geography terms
10. Extension information on some suggested diseases that could be investigated geographically
(i.e., Malaria, cholera, yellow fever, cancer, heart disease and many other health
related issues)
Preparation :
Teacher Background Notes
The instructor needs to have a good understanding of the history of medical geography
and the diffusion process. This will be provided for by teacher notes.
Medical Geography
Medical geographers are interested in the distribution, process and pathways
by which diseases spread or are diffused. The diffusion process can be represented
and analyzed by cartographic methods. Medical geographers attempt to answer the
geographical questions of where and why certain disease take place on the Earth's surface.
Such discoveries enable the scientific community to make important predictions that
may prevent and reduce the damage of outbreaks of various diseases. Maps of an early
outbreak of a disease can serve as an early alert for the development of strategy to
be used in preparation for handling crisis situations. Medical geographers investigate
the geographic distribution of major diseases (places) (movement) as well as their
routes of diffusion.
Medical geographers use a three part classification system for grouping any world
or regional disease. The first category for classifying any disease are called infectious
diseases. An infectious disease is any such disease that results from an invasion of parasites and their multiplication in any human population. Infectious diseases
are broken into two separate groups of diseases; vectored and non-vectored.
The second category for classifying any world or regional diseases are grouped
into a category labeled as chronic or degenerative diseases. Chronic or degenerative
diseases are those diseases of longevity. They do not kill instantly but cause long-term deterioration of the body. Cancer and heart disease are two examples.
A third category that is used in the classification system are diseases grouped
as genetic or inherited diseases. These are diseases that can be traced directly
to one's parentage and to the chromosomes and genes that define one's makeup. Hemophilia, sickle cell anemia, and lactose intolerance are just a few examples of genetic or
inherited diseases.
Some diseases may occur in a region or maybe worldwide. When a disease of a
high percentage hits a population and is localized, the disease is labeled as an
epidemic. When a disease outbreak spreads worldwide is called a pandemic.
Medical geographers investigate a wide variety of diseases in order to improve
the quality of human life. Medical geographers investigate any disease that hits
the pool of human population. Medical geographers attempt to aide in the discovery
of the host, cause and prevention of regional and world disease.
Diffusion Process
(See Models of Diffusion)
You may have never considered geography and the medical sciences to be related,
but in fact they have an old partnership. In particular, the subfield of epidemiology
is the study of how disease spreads. Geographers have long considered the spread
or diffusion of phenomena across space. With the outbreak of cholera, yellow fever and
the various types of influenza during the late 1800's and early 1900's, geographers
have cooperated with epidemiologists.
From the American experience of the Civil War, the Union Army Corps of Engineers
and Sanitation Departments record keeping of soldiers dying from dysentery to England
Dr. John Snow, geographers and the medical sciences have worked together to network
medical system to prevent and control many major contagious outbreaks. Also, one
must not forget the United States building of the Panama Canal. Yellow fever had
to be put under control before the canal could be built.
When studying diffusion, geographers look for contagious effects and hierarchical
effects. Where something spreads from one point to another and where something spreads
by jumping first to large cities and then to even small cities.
Places can affect other places through a process called spatial diffusion. Spatial
diffusion is the spread of some phenomenon over space and through time from a limited
number of origins. Geographers have discovered that all phenomena that diffuse share general spatial patterns and processes.
There are two types of diffusion: relocation and expansion diffusion. Relocation
diffusion occurs when the items being diffused leave behind the original area as
they move to new areas.
Expansion diffusion is the process whereby the item spreads geographically by
passing from one person to another while remaining with the first person. The phenomenon
begin diffused often intensifies in the origin region as new areas are affected by
the phenomenon. An example of this type of diffusion is the diffusion of different
types of influenza or some other contagious diseases as they move from one host to
another.
The place where you live has something to do with when the diffusing disease
reach you. There are two spatial regularities to the diffusion process. The first
is a contagious effect which says that places near the origin will be affected first
(central place theory). The farther you are from the point or point of origin, the later
you will be affected.
Diffusion processes do not always follow the rule of distance. Hierarchal effects
occur when phenomena spread first to major cities, then to intermediate-size places
and then later to small rural towns.
How Diseases Spread
Infectious disease are spread by disease-causing organisms called agents. Agents
can range from viruses, bacteria and other microorganisms that can invade the body
or contaminate elements of the environment.
When we are afflicted by an infectious disease, we are hosts to that disease
organism. When a population contains a large number of hosts, a reservoir has been
formed from which the disease may expand or diffuse to additional susceptible people.
These then become additional hosts, strengthening the disease reservoir.
The spreading of a disease occurs in several ways. Some agents are transmitted
from one person directly to another by contact. Diseases that are transmitted this
way are grouped together as non-vectored diseases, because they do not need an intermediate host or vector for their propagation. The common cold, measles, mononucleosis
are among non-vectored disease.
When a disease is carried from one host to the next by an intermediate host,
the disease is considered vectored. Insects are the most common vectors, but worms,
snails and larger animals can serve as a vector.
Disease organisms are also transmitted by water, soil, food and feces. These
are non-biological vectors, sometimes called mechanical vectors, or vehicles. Infectious
diseases can thus be grouped according to whether they are vectored or non-vectored.
(See Typical Contagious Disease Diffusion)
Spanish Influenza of 1918 : A Case Study
The greatest pandemic in the history of modern world was the outbreak of the
Spanish Influenza of 1918-1919. Over 25-30 million people died worldwide from this
contagious disease. The disease started out and diffused from rural agricultural
America to all corners of the planet. From the misunderstanding of viruses and the transportation
of millions of soldiers, the world was faced with its first great medical challenge.
The influenza was called "Spanish Influenza" because in the late fall of 1918
Spanish authorities observed and reported to world officials that a suspicious disease
was killing hundreds of people. Thus, the pandemic was on its killer course but
misnamed.
At the time of the outbreak, medical officials knew very little about the scientific
nature of influenza. Many medical officials believed that influenza was caused by
bacteria. Viruses are and can be a very dangerous medical challenge if not understood and controlled in its early stages.
Influenza type A and type B are classified as non-vectored infectious diseases
by epitomologists. Influenza can and was directly transmitted from person to person
without an intermediate carrier. The worldwide pandemic of 1918 was a virulent strain
of the virus which diffused from the rural agriculture Midwest of the United States
to rest of the world. Influenza, once a new strain has begun to spread, diffuses
when people inhale the airborne virus; and it spreads rapidly.
Why do new epidemics and pandemics of influenza occur? The answer apparently
lies in the life cycle of the influenza A virus which comes from China. There the
virus resides in birds, especially in waterfowl. The virus cannot be transmitted
directly from birds to people. The virus is transmitted from to pigs and from pigs to humans.
Farming practices put ducks in close proximity to pigs and, in turn, to people.
People ill with the flu can transmit the virus to pigs. So, medical geographers
believe that pigs are host to strains of influenza A virus. So, this means that new strains
of the virus can be formed in the host. The new strain is transmitted from pigs
to people.
The Origins of the Great Pandemic
Many retrospective analyses of the Great Pandemic suggest that it originated in the
central area of the North American Continent early in the spring of 1918. The kind
of influenza found in Kansas, Missouri and other parts of the Midwest was somewhat
different from the ordinary form of the disease.
It was not until the next wave of influenza during autumn of 1918 that much attention
was paid to the nature of the spring wave and how it differed from other epidemics
in the proportions of victims who were young adults. During March and April of 1918, the disease spread from the Midwest into parts of the South and into many military
camps in various parts of the United States. Probably, troops of the American Expeditionary
Forces carried this form of influenza to Europe during the spring of 1918. As the spring epidemic waned in the United States, an even more virulent form of influenza
surfaced in the ports of France. The disease quickly spread to the western front,
which seemed to serve an even further epicenter for an incredibly lethal "second
wave" of influenza that occurred in May of 1918.
The Crack of Doom
The influenza pandemic of 1918-1920 descended upon Europe in a ruinous fashion.
In Europe, the diseases was known as "Spanish Influenza" perhaps because news from
that neutral country was not censored during the war. The Spanish Influenza spread
through much of the Mediterranean littoral. As the disease spread throughout parts of
Europe, the disease was altered and a more merciless form continued to spread farther
outward from it European epicenter, decimating many in its wake. Later that year
the disease arrived in Australia, South Africa and a few weeks later in West Africa.
By August, this more virulent form of the disease, normally considered as the
"second wave" had cut its swath among populations of the Indian subcontinent, Southeast
Asia, Japan, China and a large part of the Caribbean and large parts of Central and
South America. By September, the threat of the pandemic was clearly recognized, the
"second wave" is thought to have first arrived in the United States.
Given the annihilating propensity of the second wave, it is not difficult to
reconstruct diffusion pathways in the United States during the autumn of 1918. Since
the outbreak of this pandemic was so explosive (transportation and people from different parts of the world coming in contact with one another), it took a public health network
several weeks to formulate reporting procedures because it was not accustomed to
reporting influenza mortality from specific cities on a regular basis.
At the national level, Dr. William H. Davis, then chief statistician of the Bureau
of the Census, used data coming in from across the country to start his analysis
of the problem. Dr. Davis used September 14, 1918 as a reasonable beginning date
for weekly reporting of influenza mortality, with some allowance for cumulative pandemic
deaths prior to that date. Dr. Davis theorized that Boston was the epicenter for
the disease and from there the disease diffused rapidly to several New England cities
and New York City. By late September, several several additional influenza epicenters
had formed: these included Chicago, the Gulf Coast and Chesapeake Bay area. (See
the map, U.S. Influenza Diffusion Pathways: First Autumn Wave, Pandemic of 1918-1919)
By December of 1918, the Public Health Service had produced some maps on the
progression of the Pandemic. A map based on reports from military bases as well
as several hundred urban places was produced.
Other maps were produced showing reports from over 175 cities. A pattern soon was
discovered linking the progression of the disease across the United States. Analysis
from data of records of the first wave showed how the diffusion patterns of the disease skipped from the very largest to next largest metropolitan centers. Also, reports
showed how the disease was linked with army training camps.
According to officials at the Public Health Service, a leading biostatistician
discovered that four metropolitan centers suffered severely from the "second wave,"
they were: Philadelphia, Baltimore, Washington D.C. and San Francisco.
Philadelphia may have been one of the hardest-hit cities during the initial phases
of the pandemic. The disease seems to have spread to the civilian population of
that city from both their Philadelphia Navy Yard and Fort Dix, New Jersey. Within
a month almost 11,000 deaths were attributed to the disease. Approximately 25% of the
American population was affected by this pandemic.
Symptoms of the Spanish Influenza Disease
In addition to some of the classic symptoms of the disease- fever, headaches,
nausea, muscle pains and respiratory problems - many victims expectorated quantities
of sputum and turned purple or blue. Sometimes this syndrome occurred within two
days of the onset of symptoms. Many researchers believe that the disease may have been
more than one disease because of the circumstances and the high youthful mortality
rate. It is known that more than half-million person in the United States alone
died from this disease.
Activities:
Day One :
1. Introduce the term medical geography to students. Within this discussion include
the term spatial diffusion. (See Teacher Background Notes)
2. Discuss disease classification (See Teacher Background Notes)
3. Ask students to think about and name diseases and how people might contract those
disease. (i.e. flu, AIDS, chicken pox, mononucleosis, lime disease, etc.) Try to
lead students to name diseases that are contracted from animals, water or food, (vectors) and those that are contracted by contact with an infected person (non-vectored).
Discuss the term vector. (See Teacher Background Notes)
4. Discuss relocation and expansion diffusion. (See Teacher Background Notes and
the Models of Diffusion)
5. Discuss the two modes of diffusion, contagious and hierarchical. (See Teacher
Background Notes and the Models of Diffusion)
Day Two : Mapping Exercise
1. A good way to introduce this unit would be to start out by reading the following
song-poem about the Spanish Influenza Pandemic of
1918-1919 :
I had a little bird
And its name was Enza.
I opened the window
And in-flew Enza.
You could discuss the meaning of this little well-known song as a lead-in to the lessons
of the pandemic of 1918-1919.
2. Student will map the following data collected on total deaths from the flu outbreak.
An outline map of the United States will be needed.
| State |
No. Cases |
| California |
17880 |
| Colorado |
6266 |
| Connecticut |
8653 |
| Indiana |
10562 |
| Kansas |
7440 |
| Kentucky |
13870 |
| Maine |
3667 |
| Maryland |
9898 |
| Massachusetts |
22776 |
| Michigan |
12253 |
| Minnesota |
84842 |
| Missouri |
13202 |
| Montana |
3918 |
| New Hampshire |
2972 |
| New Jersey |
19924 |
| New York |
48945 |
| Ohio |
25275 |
| Pennsylvania |
64837 |
| Rhode Island |
3328 |
| Utah |
2343 |
| Vermont |
1816 |
| Virginia |
14184 |
| Washington |
5559 |
| Wisconsin |
9313 |
3. Students are to take the raw data that is listed above and arrange the data (cook)
in order to be mapped:
The following data needs to be arranged from highest to lowest in order to make a
histogram :
Range ________ Mean _______ Median _______ Mode______
The data can also be used in a computer program data spreadsheet.
The students are to make a map from the data that has been cooked.
The Map components can be easily checked :
Title, Orientation, Date, Author, Legend, Source and Scale
T O D A L S S
The following is an assessment sheet to grade the map:
_____ 1 pt. Title ________________________________
_____ 1 pt. Author
_____ 1 pt. Date
_____ 1 pt. Orientation (Compass Rose)
_____ 1 pt. Scale
_____ 1 pt. Source
_____ 10 pts. Legend
Classification Scheme _________
Histogram ______
Range, Mean, Medium and Mode.
______ 25 pts Mapped Data
________/ 47 Total Points
4. The students should be able to recognize several patterns from the 25 states'
data they map. Discuss some of the patterns. Ask: Where are major population deaths
from influenza located? Why?
Day 3 : Mapping the 25 Top Metropolitan (Population of 100,000 or more)
Areas for Influenza Deaths
1. Hand out the list of the following 20 cities that were hit the hardest by the
outbreak of influenza:
(This activity could be used on a computer spreadsheet).
1910 Voter Registration Numbers, deaths from Influenza, 1919
| City |
Number of Deaths |
| Detroit |
2347 |
| Minneapolis-St. Paul |
979 |
| Los Angeles |
1055 |
| San Francisco |
1927 |
| New York |
14822 |
| Philadelphia |
4034 |
| Chicago |
5122 |
| Boston |
3303 |
| New Orleans |
1284 |
| Baltimore |
1679 |
| Cleveland |
2046 |
| Pittsburgh |
2252 |
| Cleveland |
2046 |
| Washington D.C. |
976 |
| St. Louis , MO. |
965 |
| Jersey City |
1117 |
| Atlanta |
598 |
| Seattle |
591 |
| Milwaukee |
851 |
| Denver |
581 |
3. The students are to make a histogram ranking the highest to lowest and find the
range, mean, median and the mode for each.
4. Students are to locate and label each city by placing dots on a blank map of the
United States. What are some of the patterns that can be recognized? Where are
these patterns and can you speculate why?
Day Four : Recognizing the Diffusion Process of the Pandemic of
1918-1919 on A Global Scale
1. Hand out the world map to show the second wave diffusion scale.
2. Students are to label the following nations:
| United States |
France |
Great Britain |
Canada |
| Brazil |
China |
Russia |
Belgium |
| Germany |
India |
Japan |
Australia |
| Madagascar |
Peru |
Mexico |
Cuba |
| South Africa |
Spain |
Columbia |
Panama |
| Philippines |
Venezuela |
Iceland |
New Zealand |
| Morocco |
Portugal |
Turkey |
Egypt |
| Italy |
Austria |
Finland |
|
3. Discuss the many diffusion patterns on the global scale. How did the disease
get to Australia, China, India, Alaska and Japan?
Day Five : Internet Activity
1. If you have access to the Internet in a computer lab, you and your class can log
on to the World Health Web site at http://www.who. You can get into their web site
and look up information on the major contagious diseases in the world today. Students
could even go off on their own and investigate a disease of their choice. There are
many database spreadsheet activities that the student could do on their own on other
diseases such as the ones listed below:
AIDS Pneumonia
Dengue Fever
Influenza
Ebola
Alzheimer'
Cancer
Cholera
Arteriosclerosis
Sickle Cell Anemia
Bilharzia Lactose Intolerance
Tuberculosis
Malaria
Heart Disease
Yellow Fever
Seasonal Affective Disorder (SAD)
2. This would be an excellent introduction to Kim's lessons on Ebola.
Lesson Title: Models of Diffusion-An Introduction to Medical Geography
Ebola
Author: Kim Thurman
Author Info: 9th Grade Geography Instructor, Soddy Daisy, TN
Key Terms: medical geography, spatial diffusion, vector, infectious disease, chronic
disease, genetic disease, relocation diffusion, expansion diffusion, contagious diffusion,
hierarchical diffusion
Time Needed: Three to four class periods
Overview:
In 1854, Dr. Snow, a physician, decided to take a geographical approach to find the
source of the cholera epidemic sweeping the Shoho district of London. This is one
of the earliest examples of the application of geographic study; the why of where.
One tool that is used to answer why phenomena, such as disease, appears and spreads
the way it does, is the diffusion model. Like other phenomena, diseases spread in
patterns. In this lesson, students will learn two models of diffusion, contagious
and hierarchical. Students will also learn to classify disease and identify how it spread
in order to provide evidence for how it diffuses.
Objectives: Student will be able to:
1. Describe the work of a medical geographer.
2. Explain spatial diffusion.
3. Identify vectored and non-vectored diseases.
4. Classify disease as infectious, chronic, or genetic.
5. Explain two models of diffusion: contagious, hierarchical.
6. Distinguish between relocation and expansion diffusion.
Materials:
1. Teacher Background Notes (in previous lesson)
2. Overhead transparency created from Appendix 1.
3. Student access to research materials
4. Human geography text
Preparation:
1. Teacher should read the background material provided.
2. If time permits, familiarize yourself with several diseases (see list)
3. Create the transparency of the diffusion model.
Activities:
Day One:
1. Introduce the term medical geography to students. Within this discussion include
the term spatial diffusion. (See Teacher Background Notes)
2. Discuss disease classification. (See Teacher Background Notes)
3. Ask students to think about and name diseases and how people might contract those
diseases. (i.e. flu, AIDS, chicken pox, mononucleosis, lime disease, etc.) Try
to lead students to name diseases that are contracted from animals, water or food,
(vectors) and those that are contracted by contact with an infected person (non-vectored).
Discuss the term vector. (See Teacher Background Notes)
4. Discuss relocation and expansion diffusion. (See Teacher Background Notes)
5. Discuss the two modes of diffusion, contagious and hierarchical. (See Teacher
Background Notes)
Day Two: (This may take 2 days.)
1. Divide students into groups and give the following assignment:
Have students research the following diseases. They should only look for information
that will tell them a) how the disease is contracted, b) how it should be classified,
and c) how it diffuses among the population.
The teacher may want to limit the disease list to ones with which she is familiar
or has time to research.
Some suggestions: Extensions
Aids Pneumonia
Dengue Fever
Influenza
Ebola
Alzheimer'
Cancer
Cholera
Arteriosclerosis
Sickle Cell Anemia
Bilharzia Lactose Intolerance
Tuberculosis
Malaria
Heart Disease
Yellow Fever
Seasonal Affective Disorder (SAD)
Day Three
When students have completed their research, complete the chart given below as a class.
How Disease Spreads: Classification Pattern of Diffusion
Example:
Ebolanon-vectored infectious hierarchical
Assessing Student Learning:
Have students explain why the information given for the chart is true. This may be
done either orally as the chart is completed or as a separate assessment activity.
A student response might resemble the following:
Ebola is spread by direct contact with infected people, therefore, it is a non-vectored
infectious disease. It is infectious because it is caused by a virus. Most outbreaks
of Ebola have been caused due to unsafe practices by those unfamiliar with the disease. This includes healthcare providers, family members, coroners, and veterinarians
coming into direct contact with blood, secretions, or organs of infected persons
or animals. The diffusion has been limited to locally contained outbreaks. This
suggests a hierarchical pattern of diffusion.
Lesson Title: Medical Geography-Mapping Disease-Ebola
Key Terms: Ebola, barriers to diffusion, natural reservoir, spatial diffusion, hierarchical
diffusion
Time Needed: One class period
Overview: In this lesson, students will become familiar with the type of work done by a medical
geographer. Students should have some knowledge already about how things diffuse
over space. In this lesson, students will map the diffusion of the Ebola virus.
The mapping exercise will focus on the areas of equatorial Africa that have been affected.
Information on where the disease has appeared in other parts of the world will also
be examined.
Objectives: Students will be able to:
1. Use the diffusion model to explain spatial patterns of disease.
2. Identify barriers to diffusion.
3. Ask geographic questions.
4. Define a natural reservoir.
5. Use a data set to create a thematic map.
Materials:
1. Ebola Data Sheet
2. Ebola Subtypes diagram
Preparation:
1. Teacher should read a few of the suggested books and view videos. Crucial media
includes The Coming Plague by Laurie Garrett (section on Ebola) and Outbreak, video
produced by CNN.
2. Familiarize yourself with the mapping activity.
3. Students should be introduced to concepts of diffusion and the models of diffusion
prior to this activity.
4. Students should be familiar with mapping techniques and creating categories for
a thematic map.
5. Teacher should become familiar with background information given on diffusion
and Ebola. See background history of Ebola below:
On August 26, 1976, Mabola Lokela entered the Yambuku Hospital with a fever. One
of the Belgian Sisters gave him a shot of chloroquine, believing him to have Malaria.
When Mabalo returned to the hospital on September 1st with a high grade fever, he
was sent home to rest where his wife Sophie tended him. On September 5th Mabalo again
returned to the hospital. This time he was bleeding from his nose and gums. He
vomited blood and had acute diarrhea, also permeated with blood. On September 8th
Mabalo died. On September 20th Mabalo's mother, who had prepared his body for burial, also
died from the dreadful disease that had taken her son. His wife, Sophie became terribly
ill but survived. The child she was carrying did not. Out of Mabalo's twenty-one
friends and family members who contracted the disease, eighteen died.
The 1976 outbreak of Ebola in the area of Yambuku, Zaire claimed two-hundred eighty
lives. Thirty-eight others survived the horrible disease. Ebola survivors face
liver, kidney, neurological, and sometimes psychological damage.
Activities:
1. Hand out the Ebola Data sheet and have students make a chart that has the year,
number of cases, and the locations of the outbreaks.
2. Mapping Exercise. Have students use the information from their charts to create
categories. The categories will show the number of cases of Ebola found in each
city using graduated circles. Label each city and draw the appropriate sized circle.
For cities with outbreaks in different years, write the year for that outbreak near the
circle. Circles may overlap. You may want to use different colors for different
cities to make the map easier to read.
3. Analyze the map by asking the following questions:
a) Where are most cases found? b) What do you notice about these locations? (they
are all clustered together in separate locations) c) Do the patterns suggest contagious
or hierarchical patterns of diffusion? (hierarchical) d) Do there seem to be any barriers to diffusion? (Discuss this term) e) What are other observations you
can make or questions you can ask by studying the map? (Lead students to make geographic
observations and ask geographic questions-the why of where)
4. Show students the Ebola Subtypes diagram. Explain that although all subtypes
exhibit the same or similar symptoms, the genetic makeup of the subtypes differs.
However, the subtype found at a location is genetically the same over time.
Also, point out that the natural reservoir (discuss this term) of the Ebola virus
is unknown. Although the "Reston" subtype in the United States via the Philippines
was traced to monkeys and the "Tai" subtype was transmitted to humans from chimpanzees
in Cote d'Ivoire, scientists do not believe that monkeys are the source since they also
succumb to the disease. It is interesting to note that transmission from monkey
to person and person to person does not always cause death. However, transmission
by needles and contaminated syringes has caused death every time.
5. Conclude the lesson. Summarize with students what they know to this point. (What
is it?, Where is it?, How is it spread?) Review key terms. Discuss how medical
professionals might be able to use this geographic information. (Predict where it
may show up in the future, look for relationships of people's practices at the times of
the occurrences, etc.)
Extension:
Have students research each country and its cases of Ebola. They should gather information
that will lead to questions such as: Were entire villages wiped out? Are people
still living there? What might be the barriers to diffusion?
Performance Assessment Activity
Background
When epidemics strike, several groups may be called to lend assistance. The groups
include the World Health Organization, the Centers for Disease Control, and other
health organizations around the world. Medical geographers can be of invaluable
assistance to the medical professional. The job of the medical geographer is to look for reasons
that a disease occurs at a location. The MG observes relationships between the disease
and the environment. He will also determine if there are any cultural practices that contribute to the appearance and spread of the disease. The MG must ask geographic
questions (such as where did it begin? Why here? Where did it spread?) and make geographic
observations. Finally, he will map his observations to answer questions, make observations, and ask more questions. The skills of the MG can help determine cause,
reveal the source, and contain the spread of disease.
Task
There has been an outbreak of an infectious disease somewhere in the world. As part
of a UN medical team, your task is to determine how the disease spreads, to what
extent it has affected the population, and the type of disease with which you are
dealing. You must research information on the disease. Your final product will be an oral report
with visuals. The visuals will be a map or series of maps that show the affected
areas, the diffusion of the disease and its origin. Other visuals may be used to
enhance the presentation. The report should provide background information of the disease,
explain the origin (or propose a possible origin) and explain the maps and visuals.
Procedure
1. Read the Checklist for Creating a Thematic Map and the Checklist for making an
Oral Presentation with Visuals.
2. Review Models of Diffusion.
3. Choose an infectious disease that has caused an epidemic or pandemic. (Any time
period may be used).
4. Research the disease.
5. Gather data on the location and diffusion of the disease. Organize the data into
a chart.
6. Create the map(s). See Steps for Creating a Thematic Map below.
7. Write the report.
8. Create additional visuals.
9. Have a peer check your work.
Checklist for Writing an Oral Report
_____ Report has a clear beginning, middle, and end.
_____ There is a clear thesis.
_____ The report poses geographic questions.
_____The report makes geographic observations.
Checklist for Map or Visual
_____ The map includes all the essential elements.
_____ Map or visual is neat, clear, and easy to view from a distance.
_____ Map/Visual uses color or shading to enhance the map.
_____ Theme of map is obvious at first glance.
Steps for Creating a Thematic Map
1. Choose a base map appropriate for your theme.
2. Collect the data.
3. Choose symbols, colors, or shading that will be easy to read and have meaning on
the map.
4. Choose reasonable category breaks for the data.
Evaluation:
Maps, discussion and performance based assessment tools.
Bibliography
Brown, Lester R. State of the World : 1997. New York: W. W. Norton &
Company, 1997.
Carnes, Mark, C, and Garraty, John, A. Mapping America's Past : A
Historical Atlas. New York: Henry Hot and Company, 1996.
Cliff, Andrew, D. and Haggett, Peter. Atlas of Disease Distributions:
Analytic Approaches to Epidemiological Data. Towbridge, Wiltshire:
Great Britain, 1988.
Crichton, Michael. The Andromeda Strain. New York: Dell Publishing,
1969.
Crosby, Alfred, W. America's Forgotten Pandemic: The Influenza of 1918.
Cambridge, Mass. : Harvard University Press, 1989.
Crosby, Alfred, W. Germs, Seeds & Animals: Studies in Ecological History.
New York: M.E. Sharpe, 1994.
de Blij, H.J. Human Geography: Culture, Society, and Space. New York:
John Wiley & Sons, Inc., 1996.
Diamond, Jared. Guns, Germs, and Steel. New York: W. W. Norton &
Company, 1997.
Doyle, Rodger. Atlas of Contemporary America
. New York: Facts on File, 1994.
Espenshade, Edward B. Jr (Editor). Goode's World Atlas. New York: Rand McNally &
Company, 1995.
Fisher, J. The Plague Makers. New York: Simon & Schuster, 1994.
Garrett, Laurie. The Coming Plague : Newly Emerging Diseases In A World
Out of Balance. New York: Farrar, Strauss and Giroux, 1994.
Gersmehl, Phil. Why Not Here? Teaching Geography to a New Standard.
Minneapolis: University of Minnesota, 1996.
Gould, Stephen, J. Bully for Brontosaurus. New York: Penguin Books, 1992.
Hanson, Susan (Editor). 10 Geographic Ideas That Changed the World.
New Jersey, New Brunswick: Rutgers University Press, 1997.
Johnston, R.J. Geography and Geographers : Anglo-American Human
Geography Since 1945. New York: Hodder & Son, 1991.
Kennedy, Paul. Preparing for The Twenty-First Century. New York:
Random House, 1993.
Krieg, Joann P. Epidemics In the Modern World. New York: Twayne
Publishers, 1992.
Martin, Geoffrey J. and James, Preston, E. All Possible Worlds: A History
of Geographical Ideas. New York: John Wiley & Sons, 1993.
McNeill, William H. Plagues and Peoples. New York: Doubleday, 1976.
Morris, Scott, E. Using and Understanding Maps: Population of the World.
New York: Chelsea House Publishers, 1993.
Preston, Richard. The Hot Zone. New York: Dell Publishing Group, 1994.
Pyle, Russell, Roy. The Diffusion of Influenza : Patterns and Paradigms. New Jersey,
Totowa : Rowman & Littlefield, Adams & Company, 1986.
Ryan, Frank. The Forgotten Plague. Boston: Little, Brown and Company, 1993.
Ryan, Frank. Virus X : Tracking The New Killer Plagues Out of The Present and Into
The Future. New York: Little, Brown, 1997.
Wilson, Edmund, O. The Diversity of Life. New York: Penguin, 1993.
Resources:
ModelsOfDiffusion.JPG
Typical.JPG
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