Geographic Investigation

"The geographical sciences add at least four dimensions to the investigation of disease incidence and response:

  • Detecting patterns and anomalies in the incidence, spreading and causes of disease
  • Asking questions about disease factors related to disease outcomes
  • Creating models of disease spreading
  • Considering access to health care. (UCP, 69)"

Let's take a look at two situations that examine these four dimensions. Our first destination is the Philippines 2004, where a disease called Schistosomiasis affects millions of people around the world. Our second destination is England 1854 where a cholera outbreak killed many people.

map of philippines 

Philippines                                    England (United Kingdom)

Get your paper ready and click on the country name to the left to investigate how geography makes a difference!

Lesson 1: Philippines 2004


Schistosomiasis affects 200 million people in 74 countries, and is a major public health challenge in the Philippines. This long-lasting disease is caused by the schistosome, a parasitic worm, which causes weakness, diarrhea, and inflammation of liver and spleen. Left untreated, it can be fatal. Despite the implementation of control measures and the successful identification of its causes, the prevalence of the disease has increased due to a number of factors, including the following:

  • development of irrigation systems for crops
  • population increase
  • repeated activities that expose people to the disease


Child suffering from schistosomiasis. (Source: Department of Health, Schistosomiasis Control Program, Agusan del Sur)

Infection takes place when tiny tadpole-like worms, which live inside snail shells, are shed into water sources and penetrate the skin of humans. The worms settle and grow inside the person, making them very sick.

1. What geographic information will help us treat and prevent this disease?

  • where the infected people live
  • where the snails are located
  • where the people can get treated
  • how many people are infected
  • all of the above


We'll examine two barangays (areas like counties in the USA). 

Go to this online map:

Click the Show Contents button  to see the map layers.  Click the Show Legend button  to see the legend.

Click the right arrow next to snail study area in the Contents.  Click Zoom to layer.

Turn on  the snail colonies layer. (click the box to the left of the layer in the Contents) Zoom in and move the map around to analyze the data.

2. Where are the snails in relation to other environmental and physical features?

3. What patterns do you see?

4. Turn on the snail infection 2006 layer. (click the box in Contents) What story does this data tell about snails and infection?

Now let's examine the infection rate. Look at 2002 vs. 2004 in Bayugan and Prosperidad.

Turn off the snail study area layer and the snail colonies (uncheck the boxes). Under Bookmarks in the upper right of the map window, you can select the barangay to zoom to it or zoom like we did for the snail study area. Turn layers on and off as necessary to investigate, compare and analyze this data. Click on an area of the barangay to see additional data.

5. Look carefully at the legend.  Although the colors may be similar, there are differences in the data. Compare the infection rates in Bayugan and Prosperidad in 2002, 2004 and 2006.

6. Does one area appear to be more infected than another? Explain your answer.

Health Care:

When you're sick, you need help from professionals. If you live in Bayugan or Prosperidad then you'll need to get to a health station or hospital to get help. Investigate the Hospitals layer and barangay health stations layer.  Also examine the surroundings (roads, etc) that might impact access.  Feel free to change the basemap in your investigation.

7. What factors affect access to health care facilities?

8. Which barangay has the better access to health care? Why?

9. What advice would you give officials that run health assistance programs in these two areas of the Philippines? What geographic proof can you offer in defense of your opinion?


Lesson 2: England 1854


Cholera is an acute intestinal infection caused by ingestion of contaminated water or food. (From This disease is common even today because many people in the world face contaminated food and water sources. In our world, approximately 2000 people a year die from cholera.

1. What could cause water and food to be contaminated in a place where it generally was not already?

2. List two modern examples of events that might cause contamination.

Factors & Disease Spread:

Dr. Snow

Dr. John Snow devoted his life's work to solving the mystery of cholera. Cholera, like other diseases, is spread easily and is quite infectious. Even parts of the world today are still dealing with this disease, but thanks to Dr. Snow's work in 1854 we can prevent and treat the disease. Additionally, Dr. Snow did some cool geographic analysis, like you're doing today, to solve his problem, even in 1854! Dr. Snow noticed the disease was spreading by household at alarming rates. Approximately 575 people died before he could zero in on the cause. In his analysis he used a hash mark for each person who died from cholera in front of the building where they lived. We have red dots to show the same thing.




3. In 1854, what might a whole household ingest to cause this infection and have the same infection affect your neighbors?

Go to this online map to investigate Cholera in 1854.

Click the Show Contents button to see the map layers.  Click the Show Legend button  to see the legend.


4. Notice the colored dots that show deaths by the location.  Zoom to the street level. How was this disease spreading?

After Dr. Snow determined the water source must be the problem, he decided to investigate water pumps where people went to gather water for their homes.

5. Using the Recorded Deaths from Cholera layer that labels deaths by nearest pump, what pumps might need investigation? Why?

6. Investigate the Analysis of Closest Pump layer and the Links to Deaths layer. How does the data and examining patterns tell us which pump is the most offensive?

7. According to the map, approximately how many deaths were associated with this pump?

Interesting facts about the Broad Street Pump to consider:

  • This pump was considered a "reliable source of clean well water" extending "25 feet below the surface of the street, reaching past the ten feet of accumulated rubbish and debris that artificially elevated most of London."
  • "Many Soho residents who lived closer to other pumps – one on Rupert Street and another on Little Marlborough–opted to walk another few blocks for the refreshing taste of Broad Street's water. It was colder than the water found at the rival pumps; it had a pleasant hint of carbonation. For these reasons, the Broad Street water insinuated itself into a complex web of local drinking habits."

  • The Broad Street pump was fouled by a cesspool with deteriorating walls, a mere two feet away from the well.

9. What can we learn from this incident in London 1854?


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