Predicting Ixodes scapularis abundance on white-tailed deer using geographic information systems

Area of Science:

• Veterinary Entomology
• Environmental Science
• Epidemiology

Background:

• Ixodes scapularis ticks are vectors for numerous pathogens affecting wildlife and humans.
• White-tailed deer serve as hosts for immature and adult Ixodes scapularis.
• Environmental conditions significantly influence tick survival and host-seeking behavior.

Purpose of the Study:

• To investigate the relationship between environmental variables and Ixodes scapularis abundance on white-tailed deer.
• To identify key environmental factors associated with tick infestation on deer.
• To assess the utility of environmental data for predicting tick exposure risk.

Main Methods:

• Collection of 1,410 Ixodes scapularis ticks from 139 white-tailed deer in Kent County, Maryland.
• Utilizing a geographic information system to extract 41 environmental variables.
• Employing stepwise linear regression to analyze the association between tick abundance and environmental data.

Main Results:

• A significant association (R = 0.69) was found between Ixodes scapularis abundance and seven environmental variables.
• Tick abundance was negatively correlated with urban land use, wetlands, and saturated soils.
• Tick abundance was positively correlated with well-drained, sandy soils and low water tables.

Conclusions:

• Geographically referenced environmental data can be valuable for predicting tick vector exposure.
• Environmental factors like soil type and land use patterns are critical in determining tick abundance on deer.
• This research provides a framework for anticipating tick-borne disease risk in specific regions.