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 February 9, 2004

Objectives I. To review the basics of tick ecology II. To review current issues within GIS methodology III. To review the procedures involved in producing tick threat maps IV. To review uses of tick threat maps

Introduction Why 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

Introduction Why 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

Introduction Site 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

Tick Habitat: Forested Bivouac Areas

Edge or Ecotone Effects

Tick Habitat: Wetlands

Tick Habitat:Young Woodlands & Thickets

Tick Habitat: Meadows/Old Fields

GIS Challenge Problems that stem from limitations of equipment and interpreting results: 1)Issues of Scale 2)Habitat Heterogeneity 3)Paucity of Data

Methods Geographic Information Systems

Methods Tick Collection Ticks were collected using timed-walks with tick drags

Methods Tick 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

Methods Geographic Information Systems Ticks were collected from over 136 sites during the 2nd year

Results: Tick and Habitat Data Proc 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

Results Mean Encounter Rates Nymphs and Adults –0-1 = low –2-4 = moderate –> 4 = high Larvae –0-1 = low –2-10 = moderate –> 10 = high

Results Mean 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

Results Data Analysis Linking the results from our habitat models and mean encounter rates with… Vegetation map is embedded within our orthophoto

Results: Summary Two sets of Analyses 1)Models that show distributions or associations with habitats 2)Mean encounter rates implicit within tick distribution models

Orthographic Photo

Conclusions Tick threat assessment maps are a decision-making tool for: 1)Minimizing exposure to ticks 2)IPM & reducing insecticides in the environment 3)As a guide for vegetation management to reduce tick habitat

Conclusions ( cont. ) For use by: 1)Troops before/after deployment 2)Field crews/natural resource personnel 3)Preventive medicine personnel

Vision

1)Develop set of rules for disease vectors 2)Develop predictive models 3)Develop these as components 4)Develop disease vector maps

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