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Vaccination strategies for managing brucellosis in Yellowstone bison
John J. Treanor a,∗ , Joseph S. Johnson b , Rick L. Wallen a , Sara Cilles c , Philip H. Crowley c , John J. Cox b , David S. Maehr b , P.J. White a , Glenn E. Plumb a
National ParkService, Yellowstone National Park, WY 82190, United States Department of Forestry, University of Kentucky, Lexington, KY 40506, United States c Department of Biology, University of Kentucky, Lexington, KY 40506, United States
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Concerns over migratory bison (Bison bison) at Yellowstone National Park transmitting brucellosis (Brucella abortus) to cattleherds on adjacent lands led to proposals for bison vaccination. We developed an individual-based model to evaluate how brucellosis infection might respond under alternate vaccination strategies, including: (1) vaccination of female calves and yearlings captured at the park boundary when bison move outside the primary conservation area; (2) combining boundary vaccination with the remote deliveryof vaccine to female calves and yearlings distributed throughout the park; and (3) vaccinating all female bison (including adults) during boundary capture and throughout the park using remote delivery of vaccine. Simulations suggested Alternative 3 would be most effective, with brucellosis seroprevalence decreasing by 66% (from 0.47 to 0.16) over a 30-year period resulting from 29% of thepopulation receiving protection through vaccination. Under this alternative, bison would receive multiple vaccinations that extend the duration of vaccine protection and defend against recurring infection in latently infected animals. The initial decrease in population seroprevalence will likely be slow due to high initial seroprevalence (40–60%), long-lived antibodies, and the culling of some vaccinatedbison that were subsequently exposed to ﬁeld strain Brucella and reacted positively on serologic tests. Vaccination is unlikely to eradicate B. abortus from Yellowstone bison, but could be an effective tool for reducing the level of infection. Our approach and ﬁndings have applicability world-wide for managers dealing with intractable wildlife diseases that cross wildlife–livestock andwildlife–human interfaces and affect public health or economic well-being. Published by Elsevier Ltd.
Article history: Received 18 March 2010 Accepted 19 March 2010 Available online 1 April 2010 Keywords: Bison Brucellosis Disease Model Vaccination Yellowstone
1. Introduction The discovery of new infectious agents and diseases transmissible to humans has raised concerns regarding free-ranging wildlife asa source of emerging human pathogens [1,2]. Humans are often indirectly exposed to wildlife pathogens through infected livestock. The crowding and mixing of wildlife with domestic livestock can increase disease prevalence and transmission potential [3,4] thereby, increasing exposure to humans. Disease transmission risk from wildlife to domestic animals and humans traditionally has resulted incontrol strategies that negatively impact wildlife populations. Traditional test-and-slaughter programs have been effective for managing diseased livestock but these practices may not be realistic or socially acceptable for wildlife [5,6]. An approach to wildlife disease management is needed that addresses both public health concerns and long-term wildlife conservation. Vaccination is commonly usedfor disease control in veterinary medicine
∗ Corresponding author. Tel.: +1 307 344 2505; fax: +1 307 344 2211. E-mail address: john firstname.lastname@example.org (J.J. Treanor). 0264-410X/$ – see front matter. Published by Elsevier Ltd. doi:10.1016/j.vaccine.2010.03.055
and wildlife vaccination may offer a promising solution . The success of a vaccination program is inﬂuenced by vaccine efﬁcacy and...