Part of the reason Chronic Wasting Disease (CWD) has proven so difficult to contain and control is its varied routes of transmission within and between cervid herds and species.
Infected animals spread it to others through direct contact. Social interactions in high density settings facilitate transfer of prions in saliva during animal-to-animal contact. Even more common is indirect transmission. Feces, urine, and carcasses of diseased animals contaminate shared environments, including soil, plants, and open water.
Now, research from Wisconsin has demonstrated there may be a vector facilitating transmission among white-tailed deer--ticks. Published in the May 2023 issue of Scientific Reports, this study describes how mutual grooming by deer may lead to incidental ingestion of blood-sucking ticks that harbor infectious prions in the blood meals they've taken from CWD infected deer.
As if what we already knew about CWD wasn't bad enough!