CWD (chronic wasting disease) has emerged as one of the most important diseases of cervids and continues to adversely affect farmed and wild cervid populations, despite control and preventive measures. This study aims to use the current scientific understanding of CWD transmission and knowledge of farmed cervid operations to conduct a qualitative risk assessment for CWD transmission to cervid farms and, applying this risk assessment, systematically describe the CWD transmission risks experienced by CWD-positive farmed cervid operations in Minnesota and Wisconsin. A systematic review of literature related to CWD transmission informed our criteria to stratify CWD transmission risks to cervid operations into high-risk low uncertainty, moderate-risk high uncertainty, and negligible-risk low uncertainty categories. Case data from 34 CWD-positive farmed cervid operations in Minnesota and Wisconsin from 2002 to January 2019 were categorized by transmission risks exposure and evaluated for trends. The majority of case farms recorded high transmission risks (56%), which were likely sources of CWD, but many (44%) had only moderate or negligible transmission risks, including most of the herds (62%) detected since 2012. The presence of CWD-positive cervid farms with only moderate or low CWD transmission risks necessitates further investigation of these risks to inform effective control measures.
Bibliographical noteFunding Information:
Funding: This research was funded by the Minnesota Board of Animal Health, contract number 146769. The APC was funded by SJ Wells professional development fund.
Acknowledgments: The authors acknowledge the Minnesota Board of Animal Health for funding this project and the Minnesota Board of Animal Health and the Wisconsin Department of Agriculture, Trade, and Consumer Protection for providing CWD case investigation information. The authors also acknowledge the contributions of Cara Cherry for her review of early Minnesota farmed cervid CWD cases and Linda Glaser and Mackenzie Reberg for assisting in obtaining Minnesota case data and their reviews of the analysis.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Chronic wasting disease
- Risk analysis
- Transmissible spongiform encephalopathy
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't