Rabies Surveillance Identifies Potential Risk Corridors and Enables Management Evaluation

Authors

Amy J. Davis, USDA NationalWildlife Research Center,Follow
Kathleen M. Nelson, USDA National Rabies Management ProgramFollow
Jordana D. Kirby, USDA National Rabies Management ProgramFollow
Ryan M. Wallace, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and PreventionFollow
Xiaoyue Ma, Centers for Disease Control and PreventionFollow
Kim M. Pepin, USDA National Wildlife Research CenterFollow
Richard B. Chipman, USDA National Rabies Management ProgramFollow
Amy Gilbert, USDA National Wildlife Research CenterFollow

ORCID IDs

https://orcid.org/0000-0002-4962-9753

Document Type

Article

Date of this Version

10-31-2019

Citation

Viruses 2019, 11, 1006; www.mdpi.com/journal/viruses

doi:10.3390/v11111006

Comments

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license

Abstract

Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV management strategies, and identify surveillance gaps. ORV management has resulted in a decrease in RABV cases over time within vaccination zones (from occupancy (ψ) of 0.60 standard error (SE) = 0.03 in the spring of 2006 to ψ of 0.33 SE = 0.10 in the spring 2017). RABV cases also reduced in the enzootic area (from ψ of 0.60 SE = 0.03 in the spring of 2006 to ψ of 0.45 SE = 0.05 in the spring 2017). Although RABV occurrence was related to habitat type, greater impacts were associated with ORV and trap–vaccinate–release (TVR) campaigns, in addition to seasonal and yearly trends. Reductions in RABV occupancy were more pronounced in areas treated with Ontario Rabies Vaccine Bait (ONRAB) compared to RABORAL V-RG®. Our approach tracked changes in RABV occurrence across space and time, identified risk corridors for potential incursions into Canada, and highlighted surveillance gaps, while evaluating the impacts of management actions. Using this approach, we are able to provide guidance for future RABV management.