Evaluation of Bait Station Density for Oral Rabies Vaccination of Raccoons in Urban and Rural Habitats in Florida.

Betsy S Haley,Brian Bjorklund,Robert Edwin Hartin,Timothy P Algeo,Anthony G Duffiney,Richard B Chipman,Ashlee Martin,Dennis Slate,Kathleen M Nelson

doi:10.3390/tropicalmed2030041

Abstract

Efforts to eliminate the raccoon variant of the rabies virus (raccoon rabies) in the eastern United States by USDA, APHIS, Wildlife Services and cooperators have included the distribution of oral rabies vaccine baits from polyvinyl chloride (PVC) bait stations in west-central Florida from 2009 to 2015. Achieving sufficient vaccine bait uptake among urban raccoons is problematic, given limitations on aerial and vehicle-based bait distribution for safety and other reasons. One or three bait stations/km2 were deployed across four 9-km2 sites within rural and urban sites in Pasco and Pinellas Counties, Florida. Based on tetracycline biomarker analysis, bait uptake was only significantly different among the urban (Pinellas County) high and low bait station densities in 2012 (p = 0.0133). Significant differences in RVNA were found between the two bait station densities for both urban 2011 and 2012 samples (p = 0.0054 and p = 0.0031). Landscape differences in terms of urban structure and human population density may modify raccoon travel routes and behavior enough for these differences to emerge in highly urbanized Pinellas County, but not in rural Pasco County. The results suggest that, in urban settings, bait stations deployed at densities of >1/km2 are likely to achieve higher seroprevalence as an index of population immunity critical to successful raccoon rabies control.

Highlights

Rabies kills approximately 59,000 humans annually, and impacts on human and animal health result in a significant economic burden [1]
In the U.S, Oral rabies vaccination (ORV) is currently aimed at the elimination and prevention of new epizootics of canine rabies in coyotes (Canis latrans) [9,10], the elimination of rabies in gray fox (Urocyon cinereoargenteus) in Texas [11] and the containment and elimination of the raccoon (Procyon lotor) variant of the rabies virus in the eastern U.S [3]
Raccoon rabies has spread rapidly in the abundant raccoon populations of eastern North America; the virus has not moved west of the Appalachian Mountain Range. Using this range as a natural barrier, USDA, APHIS, Wildlife Services (WS), National Rabies Management Program (NRMP) has implemented a large-scale ORV program to prevent the westward spread of raccoon rabies [3]

Summary

Introduction

Rabies kills approximately 59,000 humans annually, and impacts on human and animal health result in a significant economic burden [1]. Raccoon rabies has spread rapidly in the abundant raccoon populations of eastern North America; the virus has not moved west of the Appalachian Mountain Range. Using this range as a natural barrier, USDA, APHIS, Wildlife Services (WS), National Rabies Management Program (NRMP) has implemented a large-scale ORV program to prevent the westward spread of raccoon rabies [3]. WS NRMP is conducting cooperative ORV operations to continue preventing the spread of raccoon rabies into the mid-western U.S and eastern Canada (Phase I), and has begun work towards its elimination from the eastern U.S (Phase II) [3], much of which is highly urbanized

Methods

Results

Conclusion