The Wisconsin Department of Natural Resources says one in four male adult deer has CWD in those areas. The DNR says the prevalence rate of about 25 percent is based on 2013 test results in a management zone where the disease was first discovered more than a decade ago.
The Journal Sentinel reports a year ago, the prevalence rate in the zone west of Madison was about 20 percent in adult male deer. The DNR says year-to-year comparisons are difficult because the annual sampling isn't necessarily the same.
But conservation officials say the trend is clear. The rate of infection is rising and it's higher in male adult deer.