As if to reinforce its status as an unrelenting threat to North America's cervid populations, chronic wasting disease (CWD) has expanded its range for the second time in 2010. In late February, the Missouri Departments of Agriculture, Conservation and Health and Senior Services confirmed the presence of CWD in a white-tailed deer taken from a Linn County captive cervid facility, reports the Wildlife Management Institute.

The infected deer was discovered as a result of Missouri's on-going CWD surveillance program and is the state's first documented case of CWD. Missouri first drafted a CWD Contingency Plan in 2002, and has now fully implemented it in response to the disease's presence in the state. "We have protocols in place to handle these situations quickly and effectively," said Dr. Taylor Woods, State Veterinarian for the Missouri Department of Agriculture (MDA).

Despite its confinement in an 800-acre outdoor pen, the infected deer's origin is unclear. The captive cervid facility that housed the animal contains three such pens, totaling more than 3,500 acres and includes multiple cervid species. Given the size and nature of the enclosures, it is possible that the animal was born in the pen or introduced from another location. The MDA is investigating the animal's history.

Surprisingly, the MDA has mandated quarantine only on the pen in which the infected deer was housed. Temporary bans placed on the two larger pens have been lifted, and the MDA plans to sample only 10 individuals from each of those pens to ascertain if the disease has spread from the infected pen. Current research into environmental contamination from CWD indicates that the disease agents, prions, persist indefinitely in the soil and can become more infectious when bound to various soil minerals.

While the MDA holds exclusive authority to manage CWD inside the fence, it is the Missouri Department of Conservation (MDC) that will be responsible for detecting and managing the disease if it jumps to wild deer. Currently, the MDC is preparing to cull 150 deer within a five-mile radius of the captive cervid facility. Later in the year, this intensive management area may be extended another five miles. Additionally, the MDC will initiate a hunter-harvested deer sampling program in the area to evaluate further CWD's status outside of the infected enclosure. To date, the MDC has sampled more than 24,000 wild white-tailed deer since 2002 and none proved positive for CWD.

For current CWD news, updates and regulations, visit the Chronic Wasting Disease Alliance website or the MDC website. (mcd)