Pathogen detection and disease diagnosis in wildlife: challenges and opportunities

Recent decades have witnessed an increase in the demand for pathogen detection and other diagnostic approaches for wild animal populations as interest has grown in infectious diseases that occur in wildlife. This is partially as a result of human population encroachment into wildlife habitats, efforts to protect vulnerable wildlife populations and an increased commercial use of wildlife. As contact rates increase, so does the spillover risk of pathogens between wildlife, domestic animals and humans. The challenges encountered when developing and validating diagnostic tests for use in wildlife are manifold and primarily centre on issues concerning diagnostic samples and suitable test approaches. Under these constraints, it is tempting to resolve the situation by adopting diagnostic tests validated for domestic animal species. Numerous examples using this approach have been published in the literature and some are presented in this paper. The authors present scenarios highlighting advantages and disadvantages of different types of tests in wildlife and current impediments to their validation. Special attention is drawn to future perspectives with regard to the potential of novel and innovative technologies to improve detection of existing, and discovery of unknown, pathogens as well as to accelerate our understanding of infectious wildlife diseases and their diagnosis.