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Contact networks can be analyzed to assess the potential for disease spread throughout the network. The lack of Canadian facility-level equine contact data makes the characterization of the equine contact structure difficult. Therefore, the purpose of this study was to use empirical contact data to characterize and compare equine network characteristics between equine facilities in Ontario. Contact pattern data from 4 equine facilities were collected using radio-frequency identification tags. The collected data were used to form 7 static contact networks (1 for each study day) for each facility. The assumption of homogenous mixing, where each individual in a population has an equal probability of coming in contact, was assessed for each network, since homogenous mixing is often used to describe mixing patterns in disease transmission models. At the facility level, neither the day-long static networks, nor a combined, week-long network were representative of homogenous mixing. The Jaccard Similarity Index indicated that 11-62% of the contacts were repeated throughout the study period. A network generated with survey-based data enabled the prediction of 8.7-79.6% of the contacts that were recorded with the RFID tags. With respect to the node centrality, the normalized node degree ranged from 0.0 to 0.96, with a mean of 0.31. The node strength ranged from 0 to 1 with a mean of 0.38. For both the node degree and node strength, a node's centrality score relative to the other nodes' centrality scores tended to be consistent throughout the study week. A significant (p < 0.05), weak positive correlation existed between the node degree and strength (0.41 < r < 0.54). The normalized betweenness centrality ranged from 0.00 to 1.00, with a mean of 0.11. Lastly, an exponential random graph model was used to quantify the relationship between the distance between the horses' stalls and edge formation. The distance parameter was not significant for all of the facilities. To conclude, the non-homogenous nature of the contact patterns, coupled with the large range of the centrality measures indicate the importance of using empirical data to understand processes such as disease spread potential within equine populations. Although the collection of a full set of data is optimal, the study results suggest an ability to infer contact networks using observational data in situations where little-to-no data exist. This study serves as a starting point for the characterization of equine contact networks in Ontario., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Contact networks can be used to assess disease spread potential within a population. However, the data required to generate the networks can be challenging to collect. One method of collecting this type of data is by using radio-frequency identification (RFID) tags. The OpenBeacon RFID system generally consists of tags and readers. Communicating tags should be within 10m of the readers, which are powered by an external power source. The readers are challenging to implement in agricultural settings due to the lack of a power source and the large area needed to be covered. Methods: OpenBeacon firmware was modified to use the tag’s onboard flash memory for data storage. The tags were deployed within an equine facility for a 7-day period. Tags were attached to the horses’ halters, worn by facility staff, and placed in strategic locations around the facility to monitor which participants had contact with the specified locations during the study period. When the tags came within 2m of each other, they recorded the contact event participant IDs, and start and end times. At the end of the study period, the data were downloaded to a computer and analyzed using network analysis methods. Results: The resulting networks were plausible given the facility schedule as described in a survey completed by the facility manager. Furthermore, changes in the daily facility operations as described in the survey were reflected in the tag-collected data. In terms of the battery life, 88% of batteries maintained a charge for at least 6 days. Lastly, no consistent trends were evident in the horses’ centrality metrics. Discussion: This study demonstrates the utility of RFID tags for the collection of equine contact data. Future work should include the collection of contact data from multiple equine facilities to better characterize equine disease spread potential in Ontario. [ABSTRACT FROM AUTHOR]