Modeling vaccination and targeted removal of white‐tailed deer in Michigan for bovine tuberculosis control

Abstract

White-tailed deer (Odocoileus virginianus) in Michigan, USA, is one of the few species in the world considered a maintenance host for bovine tuberculosis (TB). Prevalence of TB over the past decade has remained steady in Deer Management Unit (DMU) 452 and new control strategies are needed to further reduce prevalence or eradicate the disease. There is little public support for large-scale culling of deer in Michigan, and vaccination is being considered as a potential management tool. Our goal was to evaluate the use of vaccination and/or targeted removal via live-trapping as TB control measures and how changes in vaccine parameters affect prevalence reduction. We used a spatially explicit stochastic individual-based model of TB dynamics in white-tailed deer to evaluate 39 management scenarios for their ability to 1) reach a 95% probability of eradication, and 2) lower TB prevalence over 30 years. We found continuation of current management would not result in a detectable prevalence reduction, nor would treatment of a ''hot-spot'' of infection within DMU 452. Application frequency played a larger role in prevalence reduction than vaccine efficacy, guaranteed immunity period, or half-life. Vaccination (alone or with targeted removal) applied annually throughout DMU 452 was necessary for a detectable reduction in prevalence. Projected costs for application over DMU 452 would exceed US$1.5 million annually. Vaccination will be costly and require long-term commitment, but the economic losses associated with allowing TB to persist in Michigan could outweigh vaccination costs. ß 2012 The Wildlife Society.

Covariation between the physiological and behavioral components of pathogen transmission: host heterogeneity determines epidemic outcomes

“…Across the three different mechanisms, negative covariation decreased maximum prevalence, increased time to reach maximum prevalence, and dampened the rate at which the disease spread through the population relative to all other types of covariation. Universally, differences between types of covariation were strongest for theoretical pathogens with lower transmission efficiency, which suggests that such heterogeneity may be most important for less infectious, more chronic diseases in wildlife such as bovine tuberculosis (Cosgrove et al 2012). This finding is consistent with studies using empirically informed networks that have found dynamic interactions to be more important at lower transmissibility (Chen et al 2014, Springer et al 2017.…”

Open questions and recent advances in the control of a multi‐host infectious disease: animal tuberculosis

“…A combined field feasibility and modelling study of a live‐trap/test/cull or vaccinate approach suggested that 30 years of application in DMU 452 would cost ∼US$50 million and carry only a 34% probability of bovine TB eradication from white‐tailed deer (Cosgrove et al. 2012a, b). Consequently, mass distribution of oral baits is likely to be necessary.…”

Mycobacterium bovis (bovine tuberculosis) infection in North American wildlife: current status and opportunities for mitigation of risks of further infection in wildlife populations

“…Recent epidemiological models suggest that once M. bovis is introduced, the probability of becoming established in a wildlife population is at least 10% [104]. Furthermore, once established M. bovis can be fiscally impossible to eradicate, recent analysis found that to achieve eradication in Michigan would cost at least US $1.5 million annually over the next 30 years [105]. As a result identification and rapid response when M. bovis is transmitted from livestock to wildlife has proven the most successful tool for preventing establishment of M. bovis in wildlife [33].…”