Spatial analysis of wildlife tuberculosis based on a serologic survey using dried blood spots, Portugal

We investigated the spatial epidemiology of bovine tuberculosis (TB) in wildlife in a multihost system. We surveyed bovine TB in Portugal by serologic analysis of elutes of dried blood spots obtained from hunted wild boar. We modeled spatial disease risk by using areal generalized linear mixed models with conditional autoregressive priors. Antibodies against Mycobaterium bovis were detected in 2.4% (95% CI 1.5%–3.8%) of 678 wild boar in 2 geographic clusters, and the predicted risk fits well with independent reports of M. bovis culture. Results show that elutes are an almost perfect substitute for serum (Cohen unweighted κ = 0.818), indicating that serologic tests coupled with dried blood spots are an effective strategy for large-scale bovine TB surveys, using wild boar as sentinel species. Results also show that bovine TB is an emerging wildlife disease and stress the need to prevent further geographic spread and prevalence increase.This study was supported by Plan Nacional (grant CGL2017-89866 from the Ministry of Economy and Competitiveness, Spain, and Fondo Europeo de Desarollo Regional) and Programa Operacional Regional do Norte (grant ON.2 O Novo Norte), Quadro de Referência Estratégico Nacional through the Fundo Europeu de Desenvolvimento Regional. N.S. was supported by PhD grant SFRH/BD/69390/2010 from Fundação para a Ciência e Tecnologia.Peer reviewe