Informing disease models with temporal and spatial contact structure among GPS-collared individuals in wild populations

PLoS One. 2014 Jan 7;9(1):e84368. doi: 10.1371/journal.pone.0084368. eCollection 2014.

Abstract

Contacts between hosts are essential for transmission of many infectious agents. Understanding how contacts, and thus transmission rates, occur in space and time is critical to effectively responding to disease outbreaks in free-ranging animal populations. Contacts between animals in the wild are often difficult to observe or measure directly. Instead, one must infer contacts from metrics such as proximity in space and time. Our objective was to examine how contacts between white-tailed deer (Odocoileus virginianus) vary in space and among seasons. We used GPS movement data from 71 deer in central New York State to quantify potential direct contacts between deer and indirect overlap in space use across time and space. Daily probabilities of direct contact decreased from winter (0.05-0.14), to low levels post-parturition through summer (0.00-0.02), and increased during the rut to winter levels. The cumulative distribution for the spatial structure of direct and indirect contact probabilities around a hypothetical point of occurrence increased rapidly with distance for deer pairs separated by 1,000 m-7,000 m. Ninety-five percent of the probabilities of direct contact occurred among deer pairs within 8,500 m of one another, and 99% within 10,900 m. Probabilities of indirect contact accumulated across greater spatial extents: 95% at 11,900 m and 99% at 49,000 m. Contacts were spatially consistent across seasons, indicating that although contact rates differ seasonally, they occur proportionally across similar landscape extents. Distributions of contact probabilities across space can inform management decisions for assessing risk and allocating resources in response.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animal Diseases / epidemiology
  • Animal Diseases / transmission*
  • Animals
  • Communicable Diseases / veterinary*
  • Contact Tracing
  • Deer*
  • Female
  • Geographic Information Systems*
  • Male
  • New York / epidemiology
  • Population Surveillance
  • Seasons
  • Spatio-Temporal Analysis*

Grants and funding

Funding for this project was provided by the New York State Department of Environmental Conservation (NYSDEC) with partial support from the United States Federal Aid in Wildlife Restoration Project W-173-G. Additional support was provided by the United States Geological Survey and the McIntire-Stennis Foundation at SUNY-ESF. The NYSDEC assisted in the selection of the study areas and provided technicians to assist in deer-trapping efforts. The NYSDEC had no role in additional data collection, analysis, decision to publish, or preparation of the manuscript. All other funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.