- Explore chronic wasting disease
Know CWD [exit DNR] General information about CWD in Wisconsin including common misconceptions.
- Contact information
- For information on CWD, contact:
- Timothy Marien
CWD wildlife biologist
Bureau of Wildlife Management
Prevalence & surveillance
Prevalence is the proportion or percentage of a population that tests positive for a disease. Chronic wasting disease (CWD) prevalence is influenced by the sex and age of the deer and geographic location. CWD prevalence tends to be higher in males than in females and higher in adults than yearlings.
CWD prevalence in Wisconsin
There appears to be two central areas of CWD infection in Wisconsin. One is centered in western Dane and eastern Iowa counties. The other is located in northern Illinois and extends into southeastern Wisconsin. Analyses of the geographic distribution of disease show that the disease is not evenly distributed throughout the affected area. Disease prevalence is much higher near the centers of each infection and declines with increasing distance from the center as would be expected with this introduced disease which is now endemic in southern Wisconsin.
CWD prevalence has also changed over time. Since 2002, CWD prevalence within our western monitoring area has shown an overall increasing trend in all sex and age classes. During the past 13 years, the trend in prevalence in adult males has risen from 8-10 percent to over 25 percent and in adult females from about 3-4 percent to more than 10 percent. During that same time, the prevalence trend in yearling males has increased from about 2 percent to about 8 percent and in yearling females from roughly 2 percent to about 7 percent.
Surveillance and result maps
CWD sampling areas
In 2015 the department will continue CWD surveillance in several areas throughout the state. Hunter service testing will be provided, free of charge, for adult deer in other areas of the state.
CWD positives by section
Number of cumulative CWD positives of wild white-tailed deer by PLSS Section. Updated 11/05/2015.
Cumulative CWD positives
Locations of cumulative CWD positives of wild white-tailed deer in Wisconsin and Illinois. Updated 9/30/2015.
Prevalence of CWD by township
Prevalence of CWD by PLSS Township. Prevalence is the percentage of yearling and adult male and female deer that tested positive for CWD. Results from deer sampled 2010-2013.
Interactive CWD mapping application
A CWD results mapping application is available for users to explore CWD results in all areas of the state as well as create maps. This application shows harvest locations of all deer tested for CWD including the positive test results.
CWD prevalence trends
Trends in CWD prevalence have been estimated for a number of study areas in southern Wisconsin. These areas included in the map were selected based on the geographic distribution of disease and the number of deer that have been tested.
The points on the map include prevalence graphs. The graphs for these study area show estimates of trend curves for yearling and adult males (blue) and females (yellow) during 2002-2014. These annual monitoring data are important for Wisconsin's understanding of CWD distribution and prevalence.
The geographic information shown on these maps has been obtained from various sources, and are of varying age, reliability and resolution. These maps are not intended to be used for navigation, nor are these maps an authoritative source of information about legal land ownership or public access. Users of these maps should confirm the ownership of land through other means in order to avoid trespassing. No warranty, expressed or implied, is made regarding accuracy, applicability for a particular use, completeness, or legality of the information depicted on this map.
Area includes townships 5-6 N and ranges 2-3 E.
Area includes townships 4-5 N and ranges 4-5 E.
Area includes townships 5-6 N and ranges 6-7 E.
Southeast Monitoring Area
Area includes townships 1-4 N and ranges 13-16 E.
Southwest Monitoring Area
Area includes townships 7-8 N and ranges 5-6 E plus portions of surrounding townships to the east, west and south.
Area includes townships 7-8 N and ranges 3-4 E.
Area includes townships 7-8 N and ranges 1-2 E.
Area includes townships 9-10 N and ranges 1-2 E.
Area includes townships 9-10 N and ranges 3-4 E.
Area includes townships 10-12 N and ranges 6-8 E.