DEPARTMENT OF COMPARATIVE PATHOBIOLOGY
Lisa Keefe, BS
Graduate Student in Epidemiology
Department of Comparative Pathobiology
Purdue University
“Using Harvested White-Tailed Deer (Odocoileus virginianus) And GIS Methods To
Characterize Distribution
And Habitat Parameters Of Borrelia burgdorferi And Its Vector Ixodes scapularis In Indiana”
Thursday, April 3, 2008
VPTH
112
3:30
pm
Abstract:
Keefe, Lisa, Eran Raizman,
Catherine Hill, Ching Ching Wu, Manuel Moro
Indiana
has geographic areas endemic for Ixodes
scapularis but the specific distribution of Borrelia burgdorferi, the causative agent of Lyme disease, is
unknown. The objective of this study was to characterize the distribution of B. burgdorferi and its vector I.
scapularis based on habitat parameters in order to identify habitat risk
factors for endemicity. During three consecutive years (2005-2007), ticks were
collected from 3412 hunter killed white-tailed deer at hunting check points in
46 of 92 counties. The distribution of tick infested deer was determined based
on deer kill locations identified on road atlas maps by the hunters. These
locations were digitized into an ArcGIS® database for habitat analysis. Habitat
requirements were deduced from the habitat classification within 2, 3 and 4km
buffer zones around each deer kill location. I. scapularis was found in 24 Indiana counties. Only three counties and 24
deer had ticks positive for B.
burgdorferi in northwest Indiana.
The remaining two positive ticks were found outside of this northwest corner.
These were on two deer in two separate counties ~138km south of the
concentrated area. The habitat parameters where the positive ticks were found
matched the required conditions for Lyme disease cycle perpetuation: well
drained soils, deciduous forest, edge loci between forests and cultivated
fields, and warm winters followed by dry springs. From a public health
perspective, the importance of our findings is in the construction of a map
that highlights Indiana
locations with high risk of B. burgdorferi transmission.
Key Words: Borrelia
burgdorferi, Ixodes scapularis,
GIS, White-tailed deer (Odocoileus
virginianus).