It's tick time again! Recognizing black-legged (deer ticks) and measuring the spread of Lyme disease Actual sizes: These guys below (Ixodes scapularis) spread Lyme and other tick born diseases. Ixodes scapularis (Blacklegged ticks or Deer ticks) 1. Can you recognize when a tick is a deer tick? Please explain. 2. Which of the above tick stages do expect are the usual transmitters of Lyme disease? Why? Nymphs are the usual transmitters of Lyme because they are so small and are often not noticed right away. We wanted you to recognize these critters, so we found pictures that had been blown up so that you could notice some of their characteristics. Enlarged sizes: 3. How much do you guess that the images were blown up? How did you figure this out? TickEncounter Resource Center
4. What do you notice about these tick images that will help you recognize a deer tick? We wondered if the number of reported cases of Lyme disease was growing larger, staying the same, or getting smaller. Below is the data that we found. Confirmed cases of Lyme disease by locality 21-215 Year 21 22 23 24 25 26 27 28 29 21 211 212 213 214 215 U.S. 17,29 23,763 21,273 19,84 23,35 19,931 27,444 28,921 29,959 22,561 24,364 22,14 27,23 25,359 28,453 Total 5. How do you think that the number of confirmed cases has changed over the years? 6. We also made a bar chart of the data. Can you refine your answer to question #5 from looking at our bar chart? Please explain. 35, Number of con/irmed cases in U.S. 1991-215 Number of cases 3, 25, 2, 15, 1, 5, Years We did research and found that Lyme disease was first diagnosed in 1975. It was first recognized in Lyme, Connecticut... hence it s name. We thought it might also be interesting to study how the incidence of Lyme disease had changed in individual states. We chose to look closely at Connecticut. We used the CDC (Center for Disease Control and Prevention) data below and created a graph of the incidence of Lyme disease in Connecticut. Incidence of Lyme disease in Connecticut 22 23 24 25 26 27 28 29 21 211 212 213 214 215 Connecticut 4,631 1,43 1,348 1,81 1,788 3,58 2,738 2,751 1,964 2,4 1,653 2,111 1,719 1,873
Confirmed cases 5, 4,5 4, 3,5 3, 2,5 2, 1,5 1, 5 Incidence of Lyme disease in Connecticut year 7. Describe any trend that you see and try to list any factors that you think might be contributing to this trend. 8. What do you notice about the prevalence of Lyme disease? What can you conclude?
There are probably some significant developments in the diagnosis, prevention understanding, and treatment of Lyme disease that have affected how its prevalence has changed. Here are a few that we found. A vaccine was created in 1998 but then pulled off the market four years later when there were too many suits alleging that the vaccine caused the disease. GlaxoSmithKline (the company that produced the vaccine) believes that the vaccine only had 78% efficacy and that the vaccine had just not protected the people who had the vaccine and still got Lyme disease. There is evidence that Global warming is causing the ticks to survive in longitudes that are further north and had previously been too cold for the ticks to survive. Ticks are found in rural areas. In the South of the United States ticks feed on lizards but the lizards also eat the ticks. The lizards are called a dead-end host because ingesting the ticks does not pass along the Lyme bacteria to the lizard. 9. With Excel or by hand, create a growth chart for your state with the numbers given at the end of this activity. 5, Incidence of Lyme disease in your state 4,5 4, Confirmed cases 3,5 3, 2,5 2, 1,5 1, 5 year The CDC has some recommendations to help you prevent tick bites. Avoid wooded or bushy areas with high grass and leaf litter. Walk in the center of trails. Use repellents that contain 2% or more DEET Bathe or shower as soon as possible after coming indoors (preferably within two hours) to wash off and more easily find ticks that are crawling on you. Conduct a full-body tick check upon return from tick-infested areas. Examine gear and pets. Ticks can ride into the home on clothing and pets. 1. Given where your community is and how often you are involved in outdoor activities, what do you expect are your odds of contracting Lyme disease? State 22 23 24 25 26 27 28 29 21 211 212 213 214 215 Alabama 11 8 6 3 11 13 6 3 1 9 13 11 28 14 Alaska 3 3 3 4 3 1 6 7 7 9 4 14 5 1 Arizona 4 4 13 1 1 2 2 3 2 8 7 22 14 8 Arkansas 3 1 California 97 86 48 95 85 75 74 117 126 79 61 9 54 83 Colorado 1 2 1
Connecticut 4,631 1,43 1,348 1,81 1,788 3,58 2,738 2,751 1,964 2,4 1,652 2,111 1,719 1,873 Delaware 194 212 339 646 482 715 772 984 656 767 57 4 341 334 DC 25 14 16 1 62 116 71 53 34 N N 33 35 78 Florida 79 43 46 47 34 3 72 77 56 78 67 87 85 116 Georgia 2 1 12 6 8 11 35 4 1 32 31 8 4 8 Hawaii Idaho 4 3 6 2 7 9 5 4 6 3 14 8 3 Illinois 47 71 87 127 11 149 18 136 135 194 24 337 233 287 Indiana 21 25 32 33 26 55 42 61 62 81 64 11 1 12 Iowa 42 58 49 89 97 123 85 77 68 72 92 153 11 13 Kansas 7 4 3 3 4 8 16 18 7 11 9 18 12 11 Kentucky 25 17 15 5 7 6 5 1 5 3 8 17 11 12 Louisiana 5 7 2 3 1 2 3 2 1 3 2 Maine 219 175 225 247 338 529 78 791 559 81 885 1,127 1,169 993 Maryland 738 691 891 1,235 1,248 2,576 1,746 1,466 1,163 938 1,113 81 957 1,249 Massachusetts 1,87 1,532 1,532 2,336 1,432 2,988 3,96 4,19 2,38 1,81 3,396 3,816 3,646 2,922 Michigan 26 12 27 62 55 51 76 81 76 89 8 114 93 125 Minnesota 867 474 1,23 917 914 1,238 1,46 1,63 1,293 1,185 911 1,431 896 1,174 Mississippi 12 21 3 1 1 3 1 2 4 Missouri 41 7 25 15 5 1 6 3 4 5 1 1 7 2 Montana 1 4 6 3 3 9 6 16 5 2 Nebraska 6 2 2 2 11 7 8 4 7 7 5 7 6 5 Nevada 2 3 1 3 4 15 9 1 2 3 1 11 4 5 New Hampshire 261 19 226 265 617 896 1,211 996 83 887 1,2 1,324 622 436 New Jersey 2,349 2,887 2,698 3,363 2,432 3,134 3,214 4,598 3,32 3,398 2,732 2,785 2,589 3,932 New Mexico 1 1 1 3 3 5 4 1 3 2 1 New York 5,535 5,399 5,1 5,565 4,46 4,165 5,741 4,134 2,385 3,118 2,44 3,512 2,853 3,252 North Carolina 137 156 122 49 31 53 16 21 21 18 27 39 27 38 North Dakota 1 3 7 12 8 1 21 22 1 12 2 15 Ohio 82 66 5 58 43 33 4 51 21 36 49 74 94 112 Oklahoma 3 1 1 2 2 1 1 Oregon 12 16 11 3 7 6 18 12 7 9 5 12 3 3 Pennsylvania 3,989 5,73 3,985 4,287 3,242 3,994 3,818 4,95 3,298 4,739 4,146 4,981 6,47 7,351 Rhode Island 852 736 249 39 38 177 186 15 115 111 133 444 57 564 South Carolina 26 18 22 15 2 31 14 25 19 24 35 33 2 13 South Dakota 2 1 1 2 1 3 1 1 2 4 3 2 5 Tennessee 28 2 2 8 15 31 7 1 6 5 2 11 7 6 Texas 139 85 98 69 29 87 15 88 55 28 33 48 2 18 Utah 5 2 1 2 5 7 3 6 3 6 2 1 5 3 Vermont 37 43 5 54 15 138 33 323 271 476 386 674 442 491 Virginia 259 195 216 274 357 959 886 698 911 756 85 925 976 1,12 Washington 11 7 14 13 8 12 22 15 12 17 13 11 8 17 West Virginia 26 31 38 61 28 84 12 143 128 17 82 116 112 243 Wisconsin 1,9 74 1,144 1,459 1,466 1,814 1,493 1,952 2,55 2,48 1,368 1,447 991 1,39 Wyoming 2 2 4 3 1 3 1 1 1 3 1 2 U.S. TOTAL 23,763 21,273 19,84 23,35 19,931 27,444 28,921 29,959 22,561 24,364 22,14 27,23 25,359 28,453 Sources: http://www.cdc.gov/lyme/stats/chartstables/casesbyyear.html http://research.msu.edu/tags/lyme-disease-spread http://en.wikipedia.org/wiki/lyme_disease http://www.tickencounter.org/tick_identification/deer_tick http://www.aldf.com/deer-tick-ecology/ Brought to you by Yummymath.com