Lyme Disease and West Nile Virus Risk Assessment Aberdeen Proving Ground, Edgewood Area Thomas M. Kollars, Jr., PhD Entomological Sciences Program, CHPPM

Lyme Disease Risk Model 1. Study conducted June 2001 through April Sites – 10 areas, 3 habitats –Wooded – Ecotone – Field 3. Environmental Variables –Elevation (min, max, mean) –Habitat Type –Tree Density –Canopy Cover –Shrub –Herbaceous –Monocot –Fern

Regression Analysis of adult I. scapularis and Habitat Variables

Based upon shrub density as correlated with adult Ixodes scapularis using regression model When mean of 200 sample points are used/10m intersect R sqr. =0.87 F (1, 18)=120 P<0.001

Lyme Disease Risk Assessment Edgewood Area from adult Black-legged Ticks >1 Tick >.5 and < 1 Tick <.5 Tick

Accuracy of Lyme Disease Risk Model based on shrub density Model tested in March/April sites 2m 2 dragged 1= 25 shrubs

Mpb Matapex silt loam 2%-5% slope, mean 0.57 Roa Romney and Elkton soils, cratered, mean 0.32 Ud Udorthents, loamy, 0 to 10 % Slopes, mean 0.12 BeBBeltville silt loam, 2 to 5 % slopes, mean 0.23 MUMattapex-Udorthents-Urban, 0 to 2 % slope, mean 0.00 BeABeltville silt loam, 0 to 2 % slopes, mean 1.00 OtOthello silt loam, mean 0.0 Comparison of adult I. scapularis among soil types using ANOVA and LSD (where > 6 samples were taken)

Risk assessment of adult I. scapularis based on soil type at Edgewood area (APG) (p<0.05) 1 tick per 4m 2 1 tick per 9m 2 1 tick per 17m 2

Risk Assessment Map of Aberdeen Proving Ground based upon extrapolated adult Black-legged Tick and Soil Classification 1 tick per 4m 2 1 tick per 9m 2 1 tick per 17m 2

West Nile Risk Assessment 10 study areas, 3 habitats each 2001 June 0330 –0730 identify bird species July through October - Landing counts Model using Sugeno and Takagi Fuzzy Reasoning

West Nile Virus Risk Assessment

Mosquito Feeding and Flight Behavior

West Nile Virus Potential At Edgewood based upon Sugeno and Takagi Fuzzy Reasoning Bird Risk =  (fuzzy (wnv antibody x flock)) = BR Mosquito Risk =  (fuzzy (ornithophilic x homophilic)) = MR  1 = BR 1 (BR O )  MR 1 (MR O ) min {High (BR O ), High (MR O )} = 0.75  2 = BR 2 (BR O )  MR 2 (MR O ) = min {Moderate (BR O ), Moderate (MR O )} = 0.5 High WNVP  1 = High (BR O ) + High (MR O ) = = 3.65 Moderate WNVP  2 = Moderate (BR O ) + Moderate (MR O ) = = 2.77 Control Measures Should Be Implemented When WNVP =  0 =  1  1 +  2  2 /  1 +  2 = 4.12 / 1.25 = 3.3

De-fuzzified WNV Risk at each Site

IPM Mosquito Control Continuous Surveillance Periodic Surveillance West Nile Risk Assessment Edgewood Area Using Fuzzy Logic Model

Continuing Surveillance Tick-borne Disease surveillance –Continue to refine adult black-legged tick prediction –Identify variables associated with immature tick populations –Identify variables associated with other tick species –Test infection rates of ticks by PCR –Expand and test model at other installations Arbo-virus / West Nile Virus Surveillance –Continue to identify bird and mosquito species –Test infection rates in mosquitoes by PCR –Expand surveillance to other installations