title: Systematic review of management strategies to control chronic wasting disease in wild deer populations in North America.
abstract: BACKGROUND
  Chronic wasting disease (CWD) is a contagious, fatal prion disease affecting cervids in a growing number of regions across North America. Projected deer population declines and concern about potential spread of CWD to other species warrant strategies to manage this disease. Control efforts to date have been largely unsuccessful, resulting in continuing spread and increasing prevalence. This systematic review summarizes peer-reviewed published reports describing field-applicable CWD control strategies in wild deer populations in North America using systematic review methods. Ten databases were searched for peer-reviewed literature. Following deduplication, relevance screening, full-text appraisal, subject matter expert review and qualitative data extraction, nine references were included describing four distinct management strategies.
  
  
  RESULTS
  Six of the nine studies used predictive modeling to evaluate control strategies. All six demonstrated one or more interventions to be effective but results were dependant on parameters and assumptions used in the model. Three found preferential removal of CWD infected deer to be effective in reducing CWD prevalence; one model evaluated a test and slaughter strategy, the other selective removal of infected deer by predators and the third evaluated increased harvest of the sex with highest prevalence (males). Three models evaluated non-selective harvest of deer. There were only three reports that examined primary data collected as part of observational studies. Two of these studies supported the effectiveness of intensive non-selective culling; the third study did not find a difference between areas that were subjected to culling and those that were not. Seven of the nine studies were conducted in the United States.
  
  
  CONCLUSIONS
  This review highlights the paucity of evaluated, field-applicable control strategies for CWD in wild deer populations. Knowledge gaps in the complex epidemiology of CWD and the intricacies inherent to prion diseases currently pose significant challenges to effective control of this disease in wild deer in North America.
authors.affiliation: Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, S7N 5B4, Canada. f.uehlinger@usask.ca.
authors.forename: F D
authors.initials: FD
authors.lastname: Uehlinger
authors.affiliation: Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, S7N 5B4, Canada.
authors.forename: A C
authors.initials: AC
authors.lastname: Johnston
authors.affiliation: Canadian Wildlife Health Cooperative, Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, S7N 5B4, Canada.
authors.forename: T K
authors.initials: TK
authors.lastname: Bollinger
authors.affiliation: Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, S7N 5B4, Canada.
authors.forename: C L
authors.initials: CL
authors.lastname: Waldner
mesh_terms: D000818:Animals; D003670:Deer; D019468:Disease Management; D009656:North America / Q000453:epidemiology; D010506:Periodicals as Topic; D012106:Research / Q000592:standards; D034081:Wasting Disease, Chronic / Q000453:epidemiology / Q000517:prevention & control*
keywords: Chronic wasting disease; Control; North America; Wild deer