A novel approach to assess the probability of disease eradication from a wild-animal reservoir host

Abstract

Surveying and declaring disease freedom in wildlife is difficult because information on population size and spatial distribution is often inadequate. We describe and demonstrate a novel spatial model of wildlife disease-surveillance data for predicting the probability of freedom of bovine tuberculosis (caused by Mycobacterium bovis) in New Zealand, in which the introduced brushtail possum (Trichosurus vulpecula) is the primary wildlife reservoir. Using parameters governing home-range size, probability of capture, probability of infection and spatial relative risks of infection we employed survey data on reservoir hosts and spillover sentinels to make inference on the probability of eradication. Our analysis revealed high sensitivity of model predictions to parameter values, which demonstrated important differences in the information contained in survey data of host-reservoir and spillover-sentinel species. The modelling can increase cost efficiency by reducing the likelihood of prematurely declaring success due to insufficient control, and avoiding unnecessary costs due to excessive control and monitoring.

Epidemiological modelling for the assessment of bovine tuberculosis surveillance in the dairy farm network in Emilia-Romagna (Italy)

“…Furthermore, by taking into consideration the cost of different testing strategies, it will be possible to use our modelling approach to run cost-effectiveness analyses of different options of surveillance (Anderson et al, 2013;Cameron, 2012).…”

Interactions between four species in a complex wildlife: livestock disease community: implications for Mycobacterium bovis maintenance and transmission

“…Primarily caused in cattle by Mycobacterium bovis infection, this bacterial disease can spill over into human and wildlife populations. Wildlife reservoirs have been identified in brush-tailed possums (Trichosurus vulpecula) in New Zealand (Anderson et al 2013); badgers in the England, Wales and Ireland (O'Connor et al 2012); wild deer in the USA and Canada (Nishi et al 2006;O'Brien et al 2011); buffalo and other wildlife in South Africa (Renwick et al 2007) and European bison (Bison bonasus) and wild boar (Sus scrofa) in Europe (Naranjo et al 2008;Gortázar et al 2011;Krajewska et al 2015). In an infected animal, M. bovis can be excreted in all bodily fluids, meaning transmission is possible directly through close contact (aerosol transmission, meat or milk ingestion) or indirectly via contact with fluids or excreta in the environment (Neill et al 2001;Radostits et al 2007).…”

Comparison of ranging behaviour in a multi-species complex of free-ranging hosts of bovine tuberculosis in relation to their use as disease sentinels

“…This new approach [17,18] is based on spatially explicit modelling of TB detection probabilities, using either sentinel species, possums themselves, or possum surveillance devices. However, the home-range data available to parameterize the TB detection kernel models are suboptimal in terms of there being few data for some species (particularly pigs, deer and cattle), and with the relative differences in range size between species being confounded by the data being from different habitats.…”