Oral rabies vaccination in north america: opportunities, complexities, and challenges.

Dennis Slate,Michael Niezgoda,Kathleen M Nelson,Timothy P Algeo,Dennis Donovan,Jesse D Blanton,Richard B Chipman,Charles E Rupprecht,Jeffrey M Bethony

doi:10.1371/journal.pntd.0000549

Abstract

Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV). Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, and research in border areas among Canada, Mexico, and the US. Advances in enhanced surveillance have facilitated sampling of greater scope and intensity near ORV zones for improved rabies management decision-making in real time. The value of enhanced surveillance as a complement to public health surveillance was best illustrated in Ohio during 2007, where 19 rabies cases were detected that were critical for the formulation of focused contingency actions for controlling rabies in this strategically key area. Diverse complexities and challenges are commonplace when applying ORV to control rabies in wild meso-carnivores. Nevertheless, intervention has resulted in notable successes, including the elimination of an arctic fox (Vulpes lagopus) rabies virus variant in most of southern Ontario, Canada, with ancillary benefits of elimination extending into Quebec and the northeastern US. Progress continues with ORV toward preventing the spread and working toward elimination of a unique variant of gray fox (Urocyon cinereoargenteus) rabies in west central Texas. Elimination of rabies in coyotes (Canis latrans) through ORV contributed to the US being declared free of canine rabies in 2007. Raccoon (Procyon lotor) rabies control continues to present the greatest challenges among meso-carnivore rabies reservoirs, yet to date intervention has prevented this variant from gaining a broad geographic foothold beyond ORV zones designed to prevent its spread from the eastern US. Progress continues toward the development and testing of new bait-vaccine combinations that increase the chance for improved delivery and performance in the diverse meso-carnivore rabies reservoir complex in the US.

Highlights

Oral rabies vaccination (ORV) represents a socially acceptable methodology that may be applied on a broad geographic scale to manage the disease in specific terrestrial wildlife reservoirs, as well as in free-ranging or feral dog (Canis familiaris) populations, where parenteral vaccination is impractical
Success in geographically confining or reducing terrestrial rabies virus diversity should facilitate an enhanced focus on the public and animal health dilemma associated with rabies in bats in the US and elsewhere in North America
The virus currently persists in isolated foci in southwestern Ontario as a result of spill-over into skunks (Mephitis mephitis) [6] and the lack of an effective oral vaccine-bait formulation for use in skunks [7]

Summary

Introduction

Oral rabies vaccination (ORV) represents a socially acceptable methodology that may be applied on a broad geographic scale to manage the disease in specific terrestrial wildlife reservoirs, as well as in free-ranging or feral dog (Canis familiaris) populations, where parenteral vaccination is impractical. The integration of ORV into conventional prevention and control strategies signifies a paradigm shift toward the achievement of effective rabies control in terrestrial wild Carnivora and feral dog reservoirs. A major underlying impetus for the integration of ORV into conventional prevention and control beginning in the 1990s was the potential for accrued public health benefits of preventing continued spread of raccoon rabies within the eastern US [17] where much of the country’s human population resides [18]. This paper draws largely from specific examples of contemporary wildlife rabies control programs in North America to illustrate key ecological, biological, logistical, and environmental complexities and challenges, and the initiatives taken to achieve success

Methods

Findings

Summary