Assessing Human Behavioral Risk Factors for Tick-Borne Diseases
1. METHODS FOR ASSESSMENT OF DEMOGRAPHIC AND HUMAN
BEHAVIORAL RISK FACTORS FOR TICK-BORNE DISEASE
TRANSMISSION
Celia Grace Murnock, Sarah Davis, Meagan Clark, Kaitlyn Bower, Timothy Lamendola, Randy Singh, Jiayi Ma, Natalie DeLeon, Amy
Radcliff, Sarah Hempstead, Michael A. Little and Ralph M. Garruto
Laboratory of Biomedical Anthropology and Neurosciences, Department of Anthropology, Binghamton University, SUNY, Binghamton
NY 13902.
Introduction
Lyme disease and other tick-borne diseases (TBDs) are a major public health concern in the
Northeastern US. Though a great deal of research has been conducted on the ecology of the
infectious agents and tick vectors, as well as on the clinical manifestations of the disease, one area
that has not received much attention to date has been the potential impact that human behaviors
have on the risk of infection. While most outdoor enthusiasts in areas of the US where TBDs are
endemic have been made aware of the risk of contact and infection while hiking, camping, or
hunting, very few people think about that same risk while they are walking through a city
playground or across a college campus. This project seeks to explore the human behavioral risk
factors for contact with potentially infected ticks within a high foot traffic built environment, using
the Binghamton University campus as a natural experimental model. In order to accomplish this
we have developed a detailed method for surveying campus walkways and as well as gathering
high-resolution data on foot traffic patterns and specific human behaviors.
Methods
Walkway Surveys
Four separate but adjoining residential areas on the Binghamton University campus were chosen for initial
observation based on population, microecology and proximity to tick habitat- College-in-the-Woods (CIW),
Hillside (HS), Susquehanna (SQ) and Mountainview (MV). Within each of these areas, all high-foot traffic
walkways adjacent to areas likely to contain ticks were identified and assigned unique numbers so that data
collected could be systematically tracked. Preliminary data including walkway length, type of ground cover
and proximity of trash receptacles, benches, picnic tables or other features were collected for each walkway
and entered into a spreadsheet to be used as a reference guide throughout the remainder of the data collection
process. A standardized observation point , defined by GPS coordinates, was also chosen for each walkway in
order ensure a consistent and effective vantage point.
Preliminary Results
35 hours of demographic (overall foot traffic) observation were conducted at the College-in-the-Woods
residential area between mid October and early November 2012, with a total of 6,040 individuals observed.
Of these individuals, 7.2% (436 individuals) were wearing clothing or footwear that exposed skin, such as
open shoes/sandals or shorts/capris. Furthermore, 8.6 % (521 individuals) walked onto or otherwise had
contact with ground cover that was not concrete or asphalt. A small number of individuals (0.78%, 47
individuals) exhibited potential risk related to both attire and activity. It is worth noting that these
observations were conducted in late fall when temperatures in Binghamton rarely exceeded 55°F.
Discussion
These preliminary results suggest that level of skin exposure may be a significant risk factor for contact with
ticks within the built environment. The numbers of individuals wearing attire which exposes the skin of the upper
and lower limbs is expected to increase significantly with warmer weather, as is the frequency of activities such as
sitting or lying on or near the ground, leaning against trees and feeding animals. Current data is already being
used in conjunction with tick ecological data as well as pathogen data for the agents of Lyme disease (Borrelia
burgdorferi), anaplasmosis (Anaplasma phagocytophilum) and human monocytic ehrlochiosis (Ehrlichia chaffeensis)
in order to mathematically model risk of transmission for a given individual. It is expected that the results of this
model will yield insight into public health prevention and intervention protocols for tick-borne diseases within
the built environment.
Future Directions
Demographic and behavioral data collection in two of the four residential area on campus is already
underway, and observations at the remaining two sites will be conducted throughout 2013. Ideally, data will
be gathered from the same sites during spring, summer, and early fall to examine potential seasonal variation.
This ambitious plan will allow for a high resolution analysis of the demographic and behavioral patterns on the
campus and their relationship to vector ecology. This same premise can further be extrapolated for use in public
parks and other green spaces within an urban or suburban environment.
Maps of College-in-the-Woods (CIW) with
walkways highlighted. Image: Google
Maps/Post-editing by K. Bower
Observation Forms
For each of these walkways observations will be collected on two
standard forms designed to be used in conjunction with one another.
The first, a demographic overview form, is intended to record the total
number of individuals using a given walkway during a specific time.
It is broken down by gender as well as level of skin exposure (full
body coverage vs. exposure of the lower limb including feet and
ankles, upper limb and/or trunk) and general behavioral category
(walking on asphalt vs. any other activity or contact with any non-
asphalt ground cover). This form allows us to get a clear picture of
the foot traffic dynamics on a given walkway, and more broadly
within a residential area. The second form will capture potential risk
behaviors in much greater detail, with categories for activities such as
leaning or sitting against trees or rocks, sitting or lying on the ground.
Skin exposure is recorded on this form in greater detail, with separate areas for noting different areas of
exposure. Like the demographic overview, this form is also broken down by gender. Both forms also include
space for recording weather conditions, food litter, and animal activity in the general area of the walkway being
observed as well as space to confirm the features (trash cans, dumpsters, benches or picnic tables) noted in the
original survey.
Data Collection Protocol
Each observation lasts one half hour and is conducted within an 11 hour window (8 am-7pm) 7 days per week, with
a goal of covering all hours for every day of the week. Both observations will be completed simultaneously by a
team of two researchers, ensuring that the specific behavioral data will truly correlate with the demographic data.
All collected data is subsequently entered into an Excel spreadsheet so that total numbers of individuals could be
calculated along with the prevalence of skin exposure and different activities along and around the walkways.
Completed observations are tracked using a separate Excel spreadsheet as well as a paper sign-up log for real-time
updates.
Detailed Behavioral Data Collection Sheet ,
developed 2012
Sources:
1.Lyme disease the Centers for Disease Control and Prevention website retrieved from http://www.cdc.gov/lyme on 4/12/13
2.“College in the Woods, Binghamton University” Map.Google Maps. Google, March 2013
3.Carroll, J. F., & Kramer, M. (2001). Different activities and footwear influence exposure to host-seeking nymphs of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae). Journal of medical
entomology, 38(4), 596-600.
4. Highest risk for Lyme disease starts now. 2011. Hunterdon County Health Department, Hunterdon NJ. Retrieved from http://www.co.hunterdon.nj.us/health/notices/2011/lymedisease.htm on
April 14, 2013.
This work is supported by the Undergraduate Awards for Research and Creative Work and the Jean-Pierre Mileur Faculty Development Fund of Harpur College and by an Eckler Mini Grant from the
Binghamton Foundation.
Deer ticks, the vector of
Lyme and several other
tick-borne diseases, can
be easy to miss. Photo:
Hunterdon Co., NY
Health Department
R. Singh collects observations
outside of the community center in
College –in-the-Woods. Photo: A.
Radcliff
R. Singh and J. Ma measure a
walkway in College-in-the-Woods.
Photo: A. Radcliff
Walking in leaf litter while wearing flip-
flops exposes an individual to higher risk
of contact with ticks. Photo: A. Radcliff
Though this individual is walking on
asphalt, her open-backed shoes present a
risk related to skin exposure. Photo: A.
Radcliff