African Swine Fever

At the time of writing this chapter, a global pandemic of African swine fever (ASF) is ongoing with the virus having moved from Eastern Europe, Asia, and into the Caribbean—leaving swine production in devastation along the way. Due to the global spread of African swine fever virus (ASFV), the persistence of the virus, and the increasing number of endemic countries, this disease poses an imminent threat of introduction into North America and other countries that are currently ASF free. Throughout the chapter, we reference Eurasian wild boar (Sus scrofa) which are charismatic megafauna that are native to Europe and Asia. Wild boar were introduced into numerous areas in the southeastern United States and California by early settlers and they subsequently augmented and hybridized with established feral domestic swine (Sus scrofa) to give rise to contemporary populations of feral swine, a highly invasive species that are present across much of the United States. Feral swine are referred to by various terms, including wild hogs, feral pigs, wild boar, wild swine, razorbacks, and other regional names in North America. African swine fever has never been introduced into the United States; as such, we do not discuss feral swine in specific within the chapter. However, experimental inoculations demonstrate that feral swine are acutely susceptible to ASFV and given its current rapid global movement we anticipate similar patterns of exposure, infection, and risk amongst these populations

Accelerated evolution of SARS-CoV-2 in free-ranging white-tailed deer

The zoonotic origin of the COVID-19 pandemic virus highlights the need to fill the vast gaps in our knowledge of SARS-CoV-2 ecology and evolution in non-human hosts. Here, we detected that SARS-CoV-2 was introduced from humans into white-tailed deer more than 30 times in Ohio, USA during November 2021-March 2022. Subsequently, deer-to-deer transmission persisted for 2–8 months, disseminating across hundreds of kilometers. Newly developed Bayesian phylogenetic methods quantified how SARS-CoV-2 evolution is not only three-times faster in white-tailed deer compared to the rate observed in humans but also driven by different mutational biases and selection pressures. The long-term effect of this accelerated evolutionary rate remains to be seen as no critical phenotypic changes were observed in our animal models using white-tailed deer origin viruses. Still, SARS-CoV-2 has transmitted in white-tailed deer populations for a relatively short duration, and the risk of future changes may have serious consequences for humans and livestock