A fatal neurological disorder capable of devastating deer populations may have spread to DuPage County's forest preserves.
The forest preserve district is working with the Illinois Department of Natural Resources to do additional testing for chronic wasting disease after an infected deer was found in Mallard Lake Forest Preserve near Hanover Park.
Officials said the infected animal was among 250 deer culled between November and mid-December as part of the forest preserve district's annual deer removal program. Of the culled deer, 85 were tested for chronic wasting.
District ecologist Brian Kraskiewicz said it's the first time a deer in DuPage has tested positive for the disease. The district has been doing annual testing since 2002, the same year chronic wasting first was detected in Illinois.
"We've taken more than 1,200 samples, and this is the first one that came back positive," he said.
Officials don't yet know if the infected deer came from another county or if the disease has spread to DuPage.
"We need to know whether this is an isolated occurrence or an indication that the disease might be established at a low level of prevalence in this area of the county," IDNR project manager Marty Jones said in a statement.
Another 20 deer will be culled over the next three weeks from Mallard Lake and the nearby Hawk Hollow Forest Preserve.
"They (IDNR officials) are requesting that we go back into those two preserves and remove 20 additional deer to increase the sample size," Kraskiewicz said.
All the culled deer will be picked up by the IDNR for testing. It will take several weeks to get the test results.
Kraskiewicz stressed there's no evidence that chronic wasting can be transmitted to humans. But while there's no threat to the public's health or safety, he said the disease is deadly for deer.
Chronic wasting is a progressive neurological disease that affects deer, elk and moose. It causes them to become emaciated, display abnormal behavior, lose coordination and eventually die.
Kraskiewicz said it's highly transmissible between deer.
"It's a disease we want to control," he said. "There's no treatment or cure for it. So we just want to slow it down so it doesn't spread."
Officials said the state's first case of chronic wasting was reported in 2002 in Boone County. There have since been 372 positive results found in 11 northern Illinois counties, officials said.
Kraskiewicz said DuPage's deer management program already helps control the transmission of diseases.
"Lower deer populations tend to have lower transmission of diseases," said Kraskiewicz, adding that a healthy deer population benefits the overall ecosystem.
After chronic wasting tests, healthy DuPage deer carcasses are processed and donated to food pantries. If chronic wasting is detected, the meat is incinerated.