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Overview:
Students have probably heard about parasite-borne diseases, but they might not know the specifics of how these diseases are spread and how disease rates can be reduced. In this lesson, they will research some parasite-borne diseases and report on how parasites infect their hosts and how people are trying to reduce infection rates.
Connections to the Curriculum:
Geography, life science
Connections to the National Geography Standards:
Standard 3: "How to analyze the spatial organization of people, places, and environments on Earth's surface"
Standard 18: "How to apply geography to interpret the present and plan for the future"
Time:
Three to four hours
Materials Required:
- Computer with Internet access
- Blank Xpeditions outline maps of the world, one for each group of students
- Writing and drawing materials, including poster board for presentations
Objectives:
Students will
- explore National Geographic's Parasites Web site and define the word "parasite";
- discuss what they know about the role of parasites in transmitting disease;
- research and answer questions about parasite-borne diseases;
- discuss actions being taken to reduce or eradicate parasite-borne disease around the world; and
- prepare reports to the governments of countries that have specific parasite-borne diseases, describing the role of the parasites in the disease and explaining what might be done to reduce or eradicate the disease.
Geographic Skills:
Acquiring Geographic Information
Analyzing Geographic Information
S u g g e s t e d P r o c e d u r e
Opening:
Have students go to the National Geographic Parasites Web site and click through the Life Cycle on the first page. Ask them to define the word "parasite" based on what they have learned about the parasite on this page (the cystacanth worm). Then have them verify the word's meaning by looking up the definition in a dictionary.
Ask students to describe what they already know about the role of parasites in transmitting disease. What diseases in this country and other parts of the world are spread by parasites? What actions can be taken to reduce the risk from these parasites?
Development:
Divide the class into seven groups, and assign each group to one of these parasite-transmitted diseases: malaria, Lyme borreliosis (Lyme disease), African trypanosomiasis ("sleeping sickness"), giardiasis, onchocerciasis ("river blindness"), schistosomiasis, and American trypanosomiasis (Chagas' disease). If you have a very large class, you might want to assign two groups to each disease to keep group size down.
Have groups visit the following Web sites to find out about their assigned diseases. As they go through the sites, they should answer the questions below.
Centers for Disease Control and Prevention
Google (search for specific diseases)
Ohio State University: Parasite Images
World Health Organization: Infectious Diseases
Questions:
- Where does this disease occur? (Each group should use a blank outline map of the world to show the distribution of the disease throughout the world.)
- Which parasite spreads this disease?
- How is the disease transmitted?
- What actions are being taken to eradicate this disease?
Closing:
As a class, discuss the things that are being done to reduce or eradicate parasite-born diseases around the world, based on what students have learned in their research.
Suggested Student Assessment:
Have each group pretend it has been hired by the government of a country that has a high rate of the disease it has studied. The government has asked the group to prepare a report that explains how the parasites can be reduced in order to lower disease rates. Have each group prepare an oral and visual presentations (e.g., posters and charts) that discusses its recommendations, taking information from the Web sites students have visited and the questions they have answered.
Some good things to include in the presentations would be information on how controlling insect or mammal populations can help reduce parasite transmission to humans; measures people can take to avoid parasites and the insects or other animals that carry them; and things people can do to reduce disease transmission from one person to another.
Extending the Lesson:
Have students find out whether Lyme disease or giardiasis can be contracted in their area. Then have them choose one of these diseases, even if it's not a big problem in their area. Have them report on the measures health officials are taking, if any, to reduce the occurrence of the parasite and the steps individuals can take to minimize their risk if they decide to participate in outdoor activities such as camping or hiking.
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