DON T CATCH THE TICK FEVER!

DON T CATCH THE TICK FEVER!

MASTER TEACHER Helen MeBane

GRADES 6-8

OVERVIEW
Students will be introduced to how an epidemiologist studies ticks on white-footed mice to learn more about Lyme disease. This disease has become an important public health problem; there were 16,000 reported cases from 1982 to 1996. Students will view the velcro-like hooks on the front legs of ticks under the microscope which enable them to attach to people s clothes easily.

ITV SERIES
Real Science: 305 Disease and Discovery

LEARNING OBJECTIVES
Students will be able to:
*describe what an epidemiologist does
*describe Lyme disease
*list the steps in making a blood smear
*list the nine health checks given to each white-footed mouse captured
*draw and label the external parts of a tick

MATERIALS
(per groups of three)
microscope with light source
slide of a dead tick
cover slip
map of Northeastern United States

(per student)
Activity Sheet Handout

VOCABULARY
epidemiologist - a disease detective who is interested in what causes human or animal illness.
Lyme disease - an infection caused by bacteria which is spread by the bite of ticks.
babesiosis - a disease caused by a malaria-like parasite.
blood smear - dyed blood cells that show the cell's structure.
serum smear - yellowish fluid which separates from a clot when the blood coagulates.
fecal sample - waste material from an animal.

PREVIEWING ACTIVITIES
Ask the students if they know of any disease(s) contracted from ticks. The teacher will then explain Lyme disease (is an infection caused by the bite of ticks infected with Borrelia burgdorferi, a corkscrew-shaped bacteria). The white-footed mouse is responsible for transmitting Lyme disease to humans in the northeastern and north-central United States. A transparency of the "Annual Reported Cases of Lyme Disease in the United States, 1982-96" shows that 16,000 people have contracted the disease. This transparency may be obtained from the website of Centers for Disease Control and Prevention. It has become an important public health problem in some regions of the United States because it has increased dramatically. Website for annual report.(http://www.cdc.gov/ncidod/diseases/lyme/lyme.htm)

FOCUS FOR VIEWING
Say, "As part of our study of insects, we will view the external parts of a tick and learn what disease(s) some infected ticks may carry." To give the students a specific responsibility while viewing the video, say, "Let s learn what an epidemiologist s job entails." As we watch this video, students will be answering the questions from the handout-Activity Sheet at the end of the lesson. Students are to record their answers as tape is viewed.

VIEWING ACTIVITIES
Begin the tape where Lydia Chan says, "But first our reporter Bridget went to Harvard University School of Public Health in Boston to talk to Dr. Sam Talfur, an epidemiologist."
Pause the tape after Dr. Talfur answers Bridget's question of "What is an epidemiologist?" Ask students what is an epidemiologist? See the Activity Sheet, this is the first question on the handout. (He/She is a disease detective who is interested in what causes human or animal illness.) Resume the tape.

Pause the tape after Dr. Talfur answers Bridget's question, "What are some diseases which deer tick carry?" Ask the students the same question. See the Activity sheet, this is the second question on the handout. (There are four diseases: lyme disease, babesiosis, deer borne fever, and deer borne encephalitis.) Resume the tape.

Pause the tape after Dr. Talfur explains the five symptoms of Lyme disease. Ask the students what are the five symptoms of Lyme disease. See the Activity sheet, this is the third question on the handout. (They are fever, chills, fatigue, muscle aches, and night sweats.) Resume the tape.

Pause the tape, after Dr. Talfur opens a white styrofoam box. Ask the students, "Does anyone know where Nantucket Island is located?" See the Activity sheet, this is the fourth question on the handout. (It is 30 miles south of Cape Cod, Massachusetts.) Teacher will hold up a map of northeastern U.S. and ask a student to locate and point out Nantucket Island to the class. Resume the tape.

Pause the tape, immediately at next scene after Dr. Talfur explains how most people get exposed to ticks. Ask the students how most people get bitten by ticks. See the Activity sheet, this is the fifth question on the handout. (By being out collecting blueberries, peaches, or plums (season) or by bird watching.) Resume the tape.

Pause the tape after Dr. Talfur demonstrates the five steps in making blood smears. See the Activity sheet, this is the sixth question on the handout. Ask the students to write five steps in making a blood smear after they have viewed the steps.
(The steps are:
1. get a little blood on a slide.
2. smear the blood to see each cell.
3. wave the slide to rapidly dry the blood on slide.
4. Put a stream of alcohol on the slide to stick the blood cells on slide.
5. Put the slide into a dye to make the cells stand out.)
Resume the tape.

Pause the tape, after Dr. Talfur puts a slide under the microscope. Ask the students what the dot is in the center of the slide. See the Activity sheet, this is the sixth question on the handout. (That is the bacteria which makes people so sick.) Resume the tape.

Pause the tape after Dr. Talfur explains the easiest way to remove a tick from your body. Ask the students, "What is the easiest way to remove a tick from your body?" See the Activity sheet, this is the eighth question on the handout. (It is to pull it straight out using a pair of tweezers.) Resume the tape.

Pause the tape after Dr. Talfur explains how mosquitoes find people. Ask the students to first explain how mosquitoes find you. See the Activity sheet, this is the ninth question on the handout. (Mosquitoes know you are around because you release carbon dioxide when you exhale.) Resume the tape.

Pause the tape, after Dr. Talfur brushed his leg on the shrub and explains how ticks find people. Ask the students, "How do ticks come in contact with you?" See the Activity sheet, this is the tenth question on the handout. (They have their two front legs out; they feel your vibrations. They have velcro-like hooks on front legs which attach to the fabric of your clothes when you brush against the shrub they are in.) Resume the tape.

Pause the tape after Dr. Talfur explains how he estimates how many ticks there are in an area. Ask the students, "How does Dr. Talfur determine the number of ticks in an area?" See the Activity sheet, this is the eleventh question on the handout. (He counts the number of ticks he finds on the mice and then multiples that by the number of mice he usually finds in an acre of land.) Resume the tape.

Pause the tape after Dr. Talfur explains the nine health checks on each mouse he has captured. Ask the students to list the nine health checks he does on each mouse he has captured. See the Activity sheet, this is the twelfth question on the handout. He:
1. checks for an ear tag or if it is a newly captured mouse, it is given an ear tag
2. weighs them
3. determines their sexes
4. determines if they are reproducing or breeding
5. counts the number of ticks on their bodies
6. does a blood smear
7. does a serum smear
8. does a filter paper sample
9. does a fecal sample.
Resume the tape.

Pause the tape after Dr. Talfur counts the number of ticks the mouse has which he is holding. Ask the students, "List the four areas ticks attach to on a white-footed mouse." See the Activity sheet, this is the thirteenth question on the handout. (Ticks are usually found on outer ears, around the eyes, face, and under the chin.) Resume the tape.

Pause the tape, after Dr. Talfur cuts the tip of the mouse s tail. Ask the students, "How does Dr. Talfur get the mouse s blood sample?" See the Activity sheet, this is the fourteenth question on the handout. (He cuts the tip of the tail off and smears it on a slide the same as he did with the human blood smear.) Resume the tape.

Stop and eject the tape after the young man suggests you read, Rats, Lice, and History by Hans Zinsser.

POST-VIEWING ACTIVITIES
Explain, "Now that you understand what an epidemiologist does and what lyme disease is, let s view the slides of dead ticks under the microscope draw a replica and label their external parts."

Give the students a copy of the "Reported Cases of Lyme Disease, United States, 1982-1996" from the internet and have them develop five questions from viewing this chart to exchange with other students in the class. Students transfer this bar graph to a pie graph information. Students estimate how many ticks there would be in an acre of land if there were ten white-footed mice captured with 10 to 15 ticks on each mouse.

ACTION PLAN
Students write a letter to an epidemiologist and invites him/her to the classroom. Ask him/her questions: Which chemicals work the best for controlling ticks? Is there an effective vaccine against Lyme disease? Are there any effects of a mother s infection on a developing fetus?

Students may visit an epidemiology lab at our local hospital.

Have students visit the following sites that have more information on lyme disease:
http://www.delphi.com/child/lyme.html
http://altavista.com/cgi-bin/query?pg=q&what=web&kl=XX&q=LYME+DISEASE

EXTENSION
Science
Students may visit the Center for Disease Control website at:
http://www.cdc.gov for further information: for example, the life cycle of Lyme disease ticks or to determine what precautions (if any) a person may take to avoid being bitten by a tick. Students may write the National Center for Infectious Diseases, Division of Vector-Borne Infectious Diseases, Atlanta, Georgia 30333 for more information.

Students develop their own brochure of diseases. For example, the students would first fold a white paper in half. On front cover, the students would draw a person with the disease, under the drawing would be title of the disease, and if the disease is a bacteria or virus. On inside cover on left side, a brief description of disease and a list of symptoms. On inside cover on right side, a brief description on how the disease is spread and its treatment . On back side, a brief description of its prevention and at the bottom the name of the student.

Caroline Biological Sappy Company
2700 York Road
Burlington, NC 27215
1-800-334-5551
or FAX 1-800-222-7112

Art
Create a 3-D model of a tick using any materials the students wishes to use.

Language Arts
Read Rats, Lice, and History by Hans Zinsser use as a reference book.

Social Studies
Determine, by using a U. S. map, the geographic distribution of Lyme disease and locate the areas of the highest incidence.

ACTIVITY SHEET

I. Questions: (Answer these to the best of your ability.)
1. What is an epidemiologist?

2. What are some diseases which deer tick carry?

3. List five symptoms of Lyme Disease.

4. Where is Nantucket Island?

5. How do most people get exposed to ticks?

6. List five steps in making a blood smear.

7. What is the small, purple dot in the center of the slide under the microscope?

8. What is the easiest way to remove a tick from your body?

9. How do mosquitoes find you?

10. How do ticks come in contact with you out in the brush?

11. How does Dr. Talfur determine the number of ticks in an area?

12. List nine health checks Dr. Talfur does on each mouse he has captured.

13. List the four areas ticks attach to on a white-footed mouse.

14. How does Dr. Talfur get the mouse s blood sample?

II. Draw and label the external parts of a tick. (Use the back side of this paper if you wish.)

Helen Mebane, 1997 NTTI Teacher of the Year, teaches seventh grade life science at Memorial Middle School in Kingsville, Tx. She is part of a Regional Collaborative for Excellence in Science Teaching funded by an Eisenhower Science Professional Development grant. This mentor program enables elementary teachers to do hands-on science activities with a middle school science teacher. Helen initiated the Future Brahmas Investigating Science program with all the first graders from Harrel Elementary School. Her commitment to increasing science awareness is demonstrated through her sponsorship of the science club, conducting the South Texas Engineers in Math and Science for middle school students, conducting science workshops for Region 2 teachers, and co-sponsoring the Odyssey of the Mind. Helen is also a key leader for the National Science Teachers Association. She is an active member Society for the Advancement of Chicanos and Native Americans in Science and is part of a team which is writing a culturally relevant manual. Helen holds a B.S. in Biology and Chemistry from Texas A&M University-Kingsville with a gifted/talented certification.

Updated: April 01, 2008