Flu Tracking (Part 2/3)
Lesson 8 of 11
Objective: Students will analyze past and present influenza data to determine how epidemiologists evaluate a spread of the disease.
Today is a review day disguised as new content. (Shhh, don't tell.) Students are using the FluView Interactive to help them remember their graph interpretation and data analysis skills. Here is an overview of what students will learn today.
Yesterday, students looked at data from the last season's flu data. With that knowledge, have them rate on a scale from 1 to 10 (1 being a flu-free season, 10 being the worst flu season since 1918), how severe they believe this year's flu season will be for...
- the nation,
- the state,
- and the county in which they live.
Also, have students predict if they think influenza A or influenza B will be more prevalent for...
- the nation,
- the state,
- and the county in which they live.
Students should open the FluView Interactive National and Regional Level Outpatient Illness and Viral Surveillance by going to this link. Project the interactive and walk students through some of the basic tools. (Note: see the handout I give students that shows the different tools they can use in this interactive.)
First, direct students attention to the Season and show them the drop down menu.
Also, show them how they can change weeks during a particular season using the arrow icons. Ask them to notice what changes in the interactive as they select those tools. One of the first questions from students that will naturally arise is why the flu season starts with week 40?
(Note: I ask my students in what month of the year is week 40 [October] and then inquire what is happening at that time that might contribute to an increase in the occurrence of the flu. I make a special point to remind my students that influenza is always present the entire year, but its incidence increases during the fall and winter.)
Next, direct their attention to the National, HHS Regions, and Census Divisions and have them view the differences in the interactive using each selection. Ask students how the interactive has changed. The next natural question that arises is what are HHS Regions and Census Divisions?
(Note: I have my students select the map portion of the interactive and maximize it so I can show them what these groupings are. First, I have them select HHS regions and then maximize the map. I ask them to use the drop down HHS region menu to determine what HHS region we are. I demonstrate that HHS regions can be selected by either using the drop down menu or selecting the area on the map. Then, I ask them how they would determine what Census Region we are in and give them a minute to figure out how to do this.) Finally, ask them how to minimize the map. Give them some time to determine how to do this.
Have students switch the settings back to National. Together look at the Pie Chart WHO//NREVSS graph. Ask the students what types (strains) of influenza the CDC is monitoring. Have students consider that the location of the strains on the graph is almost always the same. If they are having trouble determining the relative amounts, they can always take the sum of all of the tests as the numbers are given in the key and then figure the percentage by dividing the number of a particular strain by the total number of positive specimens and multiplying it by 100%.
(Note: This particular graph can be especially hard for colorblind or color-deficient students to read because the red, green, and orange are right next to each other. Without singling students out, make note of who might need extra help in determining the location of certain strains.)
Next, look in the upper right corner at the Line Chart ILINet. Ask students to remember what ILI stands for from their activity from yesterday. Have students maximize the chart and view the national average. Then have them compare it to their HHS Region and their Census Division. Have them minimize the chart.
Finally, have them look at the Stacked Column Chart WHO//NREVSS in the lower right hand corner. Remind them that they looked at this particular type of chart yesterday. The first thing they should notice is that this graph has two y-axes. Have them look at both and ask under what circumstances would one axis be better to observe than another. Also, have them notice what happens when they uncheck the boxes indicating particular strains or variants. Encourage them to drag their mouse over the stacked column (bar) as it will show the specific number of positive specimens as well as the percentage of positive specimens in a pop up box. (Both of these tools are especially helpful for my colorblind/color-deficient students as the shades that CDC picks can be difficult to view.)
A Final Note: It is very important to briefly show some of the tools and features that can be found on this interactive. One could just let students figure out how to use the interactive on their own. However, I have found that giving a brief tutorial lessens students' frustrations and allows them to focus on the important questions that they need to answer about the severity of this year's flu season and what strain(s) should be considered for next year's flu vaccine.
Using the provided handout, allow students some time to individually explore this year's flu season and compare it with the 2009-10 flu season. Move about the room providing any technical support that students might need.
Here is a sample of a student's work that includes my comments. As you can see from the comments, there are some areas in graph reading where this student still needs assistance.
Next have students pair with their lab partners and look at one additional flu season of their choosing. Have them answer the questions in the following handout. Once they have interpreted the data for the additional flu season, have them look for patterns in the data by considering the following questions and the questions found on the handout.
- To which flu seasons does this year compare.
- Are there any particular strains or variants that occur more frequently?
- What factors do they need to consider to explain why a particular season is more severe than another season?
This student struggled with this assignment. Next year, I will provided a graph reading checklist to help struggling students.
Now that students have analyzed the beginning of this year's flu season, have them respond to and perhaps revise their predictions. How realistic were they? In light of what they have learned today, how would the change their predictions? Encourage them to provide specific evidence to support their claim. Have students record their responses in their lab notebook and turn them in for evaluation at the end of the hour.