Reduction of Chronic Wasting Disease Prion Seeding Activity following Digestion by Mountain Lions

Detection of prions from spiked and free-ranging carnivore feces

Chronic wasting disease (CWD) is a highly contagious, fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting wild and captive cervids. Although experimental feeding studies have demonstrated prions in feces of crows (Corvus brachyrhynchos), coyotes (Canis latrans), and cougars (Puma concolor), the role of scavengers and predators in CWD epidemiology remains poorly understood. Here we applied the real-time quaking-induced conversion (RT-QuIC) assay to detect PrPCWD in feces from cervid consumers, to advance surveillance approaches, which could be used to improve disease research and adaptive management of CWD. We assessed recovery and detection of PrPCWD by experimental spiking of PrPCWD into carnivore feces from 9 species sourced from CWD-free populations or captive facilities. We then applied this technique to detect PrPCWD from feces of predators and scavengers in free-ranging populations. Our results demonstrate that spiked PrPCWD is detectable from feces of free-ranging mammalian and avian carnivores using RT-QuIC. Results show that PrPCWD acquired in natural settings is detectable in feces from free-ranging carnivores, and that PrPCWD rates of detection in carnivore feces reflect relative prevalence estimates observed in the corresponding cervid populations. This study adapts an important diagnostic tool for CWD, allowing investigation of the epidemiology of CWD at the community-level.

Mouse models of chronic wasting disease: A review

Animal models are essential tools for investigating and understanding complex prion diseases like chronic wasting disease (CWD), an infectious prion disease of cervids (elk, deer, moose, and reindeer). Over the past several decades, numerous mouse models have been generated to aid in the advancement of CWD knowledge and comprehension. These models have facilitated the investigation of pathogenesis, transmission, and potential therapies for CWD. Findings have impacted CWD management and disease outcomes, though much remains unknown, and a cure has yet to be discovered. Studying wildlife for CWD effects is singularly difficult due to the long incubation time, subtle clinical signs at early stages, lack of convenient in-the-field live testing methods, and lack of reproducibility of a controlled laboratory setting. Mouse models in many cases is the first step to understanding the mechanisms of disease in a shortened time frame. Here, we provide a comprehensive review of studies with mouse models in CWD research. We begin by reviewing studies that examined the use of mouse models for bioassays for tissues, bodily fluids, and excreta that spread disease, then address routes of infectivity and infectious load. Next, we delve into studies of genetic factors that influence protein structure. We then move on to immune factors, possible transmission through environmental contamination, and species barriers and differing prion strains. We conclude with studies that make use of cervidized mouse models in the search for therapies for CWD.

Ojibwe Perspectives Toward Proper Wolf Stewardship and Wisconsin’s February 2021 Wolf Hunting Season

In February 2021, the Wisconsin DNR implemented a wolf season in which > 20% of the population was killed in 63 h. Wisconsin’s Ojibwe tribes had a visceral reaction to this killing. This paper provides a perspective for this reaction by reviewing the Ojibwe relationship with Ma’iingan. This relationship maintains that Ma’iingan and Ojibwe are to be considered relatives whose fates are intertwined. Ma’iingan and Ojibwe have lived parallel histories, suffering from the effects of colonization, the decimation of wolf populations and decline of tribal culture. The Ojibwe tribes ceded vast territories in treaties with the United States while retaining common use rights, including the right to hunt and fish. These rights were reaffirmed just as wolves were reestablishing themselves in Wisconsin. The tribes continue to strengthen their culture, while wolf populations continue to recover. By examining these comparative histories, it becomes apparent that “whatever happens to one happens to the other.” Unfortunately, Ma’iingan were not adjudicated during the Wisconsin treaty case, creating uncertainty over how the relationship between the Ojibwe and Ma’iingan is to be respected by the state. The tribes believe their treaty right includes protection for wolves, so that wolves can fulfill their cultural and ecological purposes. Tribes maintain that Ma’iingan should determine their own population levels, in order to provide ecological and cultural benefits. A respectful and appreciative relationship with Ma’iingan should be maintained so that the future well-being of both Ma’iingan and the Ojibwe will be assured.