Mapping the Spread of HIV/AIDS
Diseases have haunted the human race throughout history. With the continued expansion of the world’s population, international travel and global trade, diseases are able to spread more rapidly now than ever before. Since its origination in the 1930s, HIV has reached every coun¬try in the world and killed 30 million people. It is estimated that another 34 million people currently are living and struggling with HIV/AIDS.
This certainly is not the first disease calamity to strike humans. The Spanish Flu pandemic of 1918–19 resulted in the death of an estimated 50 million people, either directly from the disease or from its complications. Before that, yellow fever, small pox and the black plague ravaged populations around the world. Another old killer, malaria, still plays a deadly role in many nations.
Disease detectives, called epidemiologists, help us to understand and defeat these awful illnesses. Epidemiologists study factors that affect the health of populations. Their work is a colossal investigation being conducted in remote natural settings and high-tech laboratories around the world. Epidemiologists collect data to identify outbreaks of old and new diseases, analyze samples, make computer projections, and evaluate possible cures and strategies. Their goal is to identify the cause of disease and determine what to do about it.
The following classroom activity places students in the role of disease detectives, as they investigate trends in HIV infection worldwide. Students will discover that many countries with high HIV infection rates have low levels of per capita income and education, two characteristics often linked with disease. For example, malnutrition and insufficient protection against parasites, often found in economically deprived nations and communities, can limit the immune system’s ability to fight off infections. Under these circumstances, individuals are more susceptible to infection by HIV and other pathogens (disease causing organisms). HIV/AIDS treatments are expensive, and are less available in economically disadvantaged countries. Poor children have an increased likelihood of contracting HIV/AIDS from an infected mother during pregnancy or while nursing, because HIV treatments to reduce the chances of HIV transmission are expensive and may not be an option, or even available.
HIV/AIDS also depletes household resources and income. Medical care is expensive and family members who care for the sick may not be able to work. Children may be left to fend for themselves or even become orphaned. And poverty sometimes leads people to participate in risky activities that increase their chances of being exposed to disease. Sustainable economic development, improved standards of living, and better education are essential to combating the global HIV/AIDS pandemic.
Ask students, Does anyone know what “CSI” stands for? [crime scene investigation] Have any of you watched one of the different CSI programs on television? How do the investigators on these programs gather information? Mention that students will apply problem-solving strategies and scientific techniques like those used on CSI to collect clues and explain a mystery. Discuss the topic of mapping a crime scene and help students understand how the mapping process informs investigators. Ask, What does a crime scene map tell the investigators? [It helps them determine the sequence of events.]
Divide the class into 10 HIV/AIDS mapping teams. Provide each team with one of the ten “Adult HIV/ AIDS Prevalence Rate, by Country” tables. If you have fewer than ten teams, give some groups two tables or divide the remaining countries among all teams.
Explain that each table lists 16 or 17 different countries for which HIV/AIDS data are available (data are not available for all countries). The number to the right of each country name is the percentage of the adult population in that country living with HIV/AIDS. (For this activity, an “adult” is defined as a person aged 15 to 49.) The data were collected from The World Factbook produced by the U.S. Central Intelligence Agency. They are from the year 2009. The percentage of infected adults in each country was calculated by dividing the total adult population by the number of adults living with HIV/ AIDS, whether or not they exhibited AIDS symptoms.
Create a color legend for the map, or assign one or more students to create the legend. The table below provides suggested percentage ranges to be represented by each color of map pin or adhesive dot. However, you may adjust the legend on your class map to match the colors available.
0.1% – <0.5% Blue
0.5% – <1% Green
1% – <5% Yellow
5% – <15% Orange
15% – <26% Red
*< = less than
Have each student team locate its assigned countries on the world map. Then, have students place an appropriately-colored pin or dot in the center of each country to represent the percentage of adults in that country who are living with HIV/AIDS. Some countries may be difficult to locate. A world atlas or access to geography websites will be helpful.
When all teams have plotted their countries, have them use the questions on the student page to analyze the total map display.
Lead a class discussion of the results. Ask, Do you see any trends? Where is HIV/AIDS most prevalent? [central and southern Africa.] Which country has the highest percentage of adults living with HIV/AIDS? [Swaziland: 26.1%.] What are the numbers worldwide? [34 million people are living with HIV/AIDS.]
Note: Though CDC estimates have changed over time, the numbers used on the student sheets remain useful for this lesson.
Keywords: disease | epidemiology | hiv/aids | immune response | immune system | infection | viral assembly | virion | virus | viruses | hiv
- Vogt, G., and Moreno, N. (2012) The Science of HIV/AIDS Teacher’s Guide. Baylor College of Medicine: Houston. ISBN: 978-1-888997-62-0
- Photo © Punchstock. Licensed for use.
Your slide tray is being processed.
Funded by the following grant(s)
Grant Number: 5R25RR018605