Emerging and endemic infections in wildlife: epidemiology, ecology and management in a changing world

The importance of gaining a greater understanding of the infectious diseases of wild animal populations and the impact of emerging and re-emerging pathogens has never been more sharply in focus than in the current post-COVID-19 world. The zoonotic origin of the pandemic [1], its links with damaging human impacts on nature [2] and increasing public interests in these links [3] provide both an urgent need and a timely opportunity to engage more deeply in the topic of this Special Issue. Pathogens of wildlife populations that spill over to humans (zoonoses) and domesticated animals account for a significant proportion of the most pressing emerging, reemerging and endemic diseases impacting human and veterinary health globally [4]. Although perhaps obvious that new diseases in humans are most likely to come from animals, especially wildlife, the risk of emergence is higher where the reporting effort is low [5], while effective diagnosis is key to discovering spillover events. Apart from the appearance of new diseases from wildlife, the presence and spillback of antimicrobial and antiparasitic resistance in wildlife populations are an additional source of concern. Reliance on antimicrobials in human medicine and food production has led to the widespread dissemination of resistant genes into the environment [6], and the place of wild animals in the fate of this ‘resistome’, including the potential to combine resistant genes into emerging pathogens, is highly uncertain [7].
It is essential that we place greater emphasis on identifying pathogens within wildlife populations, engaging in active and passive surveillance, gaining a greater understanding of the ecology and epidemiology of the disease and developing early detection and warning systems and appropriate control approaches from local to international scales. Such monitoring and control efforts will benefit from being integrated into a broader One Health strategy, where the health of the wildlife populations themselves, as well as the health of the broader ecosystem, is considered. This Special Issue assembles contributions relating to the identification, monitoring, ecology and control of emerging and endemic wildlife diseases. The range of pathogens is broad, spanning bacterial (Mycobacterium tuberculosis complex, Coxiella sp., tularemia), viral (herpes, rabies, rabbit hemorrhagic disease) and parasitological (Echinococcus and other helminths, toxoplasmosis) pathogens of wildlife hosts. These pathogens carry known risks to veterinary and human population health and circulate in wildlife populations from the Arctic to the tropics. All are subject to global change, including climatic, environmental and societal factors, and the papers in this Special Issue specifically consider how these factors influence the epidemiology of such infections and challenges around their detection and control.