Transforming Disease Vector Management Through the Development of User Friendly Applications

1. Transforming Disease Vector Management Through the Development of User Friendly Applications CDR Kenneth J. Stein, Ph.D.,MSC, USNR OIC FH FT Dix Det 05 steinkj@earthlink.net February 9, 2004

2. Objectives • To review the basics of tick ecology • To review current issues within GIS methodology • To review the procedures involved in producing tick threat maps • To review uses of tick threat maps

3. IntroductionWhy ticks? • Recent increases in the number of diseases transmitted by ticks • Lyme Disease, Rocky Mountain Spotted Fever, Ehrlichiosis, and Babesiosis • Newly emerging diseases throughout the World; e.g., West Nile Virus

4. IntroductionWhy ticks?(cont.) • Developed for personnel on Federal Lands; e.g., Military, National Parks, etc. • Personnel could reduce exposure to ticks if they could predict where ticks were located • Preventive measures for various tick species exist—compliance is poor

5. IntroductionSite Location • Fort Pickett is a 45,000 acre Virginia National Guard training area • It consists of mixed hardwood forests, mostly oaks and loblolly pines • Fort Pickett holds a variety of other habitats: riverine and wetlands, meadows and thickets • Large number of personnel who train annually, > 10,000 in summer

6. Tick Habitat: Forested Bivouac Areas

7. Edge or Ecotone Effects

8. Tick Habitat: Wetlands

9. Tick Habitat:Young Woodlands & Thickets

10. Tick Habitat: Meadows/Old Fields

11. GIS Challenge • Problems that stem from limitations of equipment and interpreting results: • Issues of Scale • Habitat Heterogeneity • Paucity of Data

12. MethodsGeographic Information Systems

13. MethodsTick Collection Ticks were collected using timed-walks with tick drags

14. MethodsTick Collection • 1st yr. 18 sites and visited each site 10 times = 180 collections • Baseline data • Presence/Absence models • Tentative density predictions • 2nd yr. 136 unique site visits • 350 minutes in each of 7 habitat/edge categories

17. MethodsGeographic Information Systems Ticks were collected from over 136 sites during the 2nd year

18. Results: Tick and Habitat DataProc GENMOD - SAS • 2 variables • Nymphs and Adults: Forest and Edge • Larvae: No relationships, primary aspects • 4 variables • Nymphs and Adults: Forest and Edge • Larvae: Disturbed and Maturing

19. ResultsMean Encounter Rates • Nymphs and Adults • 0-1 = low • 2-4 = moderate • > 4 = high • Larvae • 0-1 = low • 2-10 = moderate • > 10 = high

20. ResultsMean Encounter Rates • 1st yr. • Adults = 78% • Nymphs = 90% • Larvae = 98% • 2nd yr. • Adults = 78%; P=0.001 • Nymphs = 95%; P=0.001 • Larvae = 98%; P=0.037

21. ResultsData Analysis • Linking the results from our habitat models and mean encounter rates with… • Vegetation map is embedded within our orthophoto

22. Results: SummaryTwo sets of Analyses • Models that show distributions or associations with habitats • Mean encounter rates implicit within tick distribution models

23. Orthographic Photo

26. Conclusions • Tick threat assessment maps are a decision-making tool for: • Minimizing exposure to ticks • IPM & reducing insecticides in the environment • As a guide for vegetation management to reduce tick habitat

27. Conclusions(cont.) • For use by: • Troops before/after deployment • Field crews/natural resource personnel • Preventive medicine personnel

28. Vision

29. Vision • Develop set of rules for disease vectors • Develop predictive models • Develop these as components • Develop disease vector maps

30. Acknowledgments • LTC Cannon, LTC Johnson, Karl Neidhardt, Ben Pagac, Melissa Miller, and Alexandra Spring, CHPPM • Scott Klopfer, Conservation Management Institute • Virginia Department of Military Affairs, Fort Pickett, VA • Clara M. Stein