Yearly Archives: 2014

First Successful Vaccination Against “Mad Cow”-like Wasting Disease in Deer

“Gut vaccine” strategy may work for similar brain infections in humans

Researchers at NYU Langone Medical Center and elsewhere say that a vaccination they have developed to fight a brain-based, wasting syndrome among deer and other animals may hold promise on two additional fronts: Protecting U.S. livestock from contracting the disease, and preventing similar brain infections in humans.

The study, to be published in Vaccine online Dec. 21, documents a scientific milestone: The first successful vaccination of deer against chronic wasting disease (CWD), a fatal brain disorder caused by unusual infectious proteins known as prions. Prions propagate by converting otherwise healthy proteins into a disease state.

Equally important, the researchers say, this study may hold promise against human diseases suspected to be caused by prion infections, such as Creutzfeldt-Jakob disease, kuru, familial insomnia, and variably protease-sensitive prionopathy. Some studies also have associated prion-like infections with Alzheimer’s disease. “Now that we have found that preventing prion infection is possible in animals, it’s likely feasible in humans as well,” says senior study investigator and neurologist Thomas Wisniewski, MD, a professor at NYU Langone.

CWD afflicts as much as 100 percent of North America’s captive deer population, as well as large numbers of other cervids that populate the plains and forests of the Northern Hemishpere, including wild deer, elk, caribou and moose. There is growing concern among scientists that CWD could possibly spread to livestock in the same regions, especially cattle, a major life stream for the U.S. economy, in much the same manner that bovine spongiform encephalopathy, or Mad Cow Disease, another prion-based infection, spread through the United Kingdom almost two decades ago.

According to Dr. Wisniewski and his research team, if further vaccine experiments prove successful, a relatively small number of animals (as few as 10 percent) could be inoculated to induce herd immunity, in which disease transmission is essentially stopped in a much larger group.

For the study, five deer were given the vaccine; another six were given a placebo. All of the deer were exposed to prion-infected brain tissue; they also were housed together, engaging in group activities similar to those in the wild. Scientists say this kept them in constant exposure to the infectious prions. The animals receiving the vaccine were given eight boosters over 11 months until key immune antibodies were detectable in blood, saliva, and feces. The deer also were monitored daily for signs of illness, and investigators performed biopsies of the animals’ tonsils and gut tissue every three months to search for signs of CWD infection. Within two years, all of the deer given the placebo developed CWD. Four deer given the real vaccine took significantly longer to develop infection — and the fifth one continues to remain infection free.

Wisniewski and his team made the vaccine using Salmonella bacteria, which easily enters the gut, to mirror the most common mode of natural infection — ingestion of prion-contaminated food or feces. To prepare the vaccine, the team inserted a prion-like protein into the genome of an attenuated, or no longer dangerous, Salmonella bacterium. This engineered the Salmonella to induce an immune response in the gut, producing anti-prion antibodies.

“Although our anti-prion vaccine experiments have so far been successful on mice and deer, we predict that the method and concept could become a widespread technique for not only preventing, but potentially treating many prion diseases,” says lead study investigator Fernando Goni, PhD, an associate professor at NYU Langone.

Funding for the study was provided by the National Institutes of Health grants NIH NS047433, ARRA NS047433-06S1 and the Seix Dow Foundation.

In addition to Wisniewski and Goni, other NYU investigators involved in the study were Kinlung Wong, BSc; Daniel Peyser, MSc; and Jinfeng Zu, PhD. Research support was also provided by Candace Mathiason, PhD; Jeanette Hayes-Klug; Amy Nalls; Kelly Anderson; and Edward Hoover, DVM, MS, of the College of Colorado State University in Fort Collins, where the deer were kept; Lucia Yim, PhD; Veronica Estevez, MSc; and Jose A. Chabalgoity, PhD, at the University of Uruguay in Montevideo, where the vaccine was developed; and David R. Brown, MD, at the University of Bath in the United Kingdom.

For more information, go to: http://adc.med.nyu.edu/researchers/affiliated-labs/dr-thomas-wisniewski www.elsevier.com/locate/vaccine

DEC Amends New York’s Chronic Wasting Disease (CWD) Regulation in Response to Discovery of Disease in Ohio

Hunters Urged to Check CWD Information on DEC’s Website Prior to Hunting Outside of New York to Keep New York Herds Healthy

The New York State Department of Environmental Conservation (DEC) amended its Chronic Wasting Disease (CWD) regulation, effective today, to prohibit people from importing into New York certain parts of white-tailed deer, elk or moose taken in the state of Ohio, DEC Commissioner Joseph Martens announced today.

In late October, the Ohio Department of Agriculture confirmed a case of CWD in a white-tailed deer on a deer farm in Holmes County, OH – the first positive CWD case in the state. CWD has also been confirmed in captive deer on multiple farms in Pennsylvania and in the wild deer herd in that state.

Hunters who plan to hunt white-tailed deer, elk or moose in Ohio, Pennsylvania or any other state where CWD has been confirmed must remove the following parts from the animal before the carcass can be imported into New York: brain, eyes, spinal cord, tonsils, intestinal tract, spleen and retropharyngeal lymph nodes (located deep in the head, between the windpipe and base of the skull). Hunters who plan to hunt outside of New York are urged to check DEC’s website for additional information about CWD and importation restrictions. Complete information and updates on CWD are available on the Department’s website,

CWD is a highly contagious and deadly brain and central nervous system disease that affects deer, elk and moose and other members of the deer family. CWD is always fatal to deer; there are no vaccines or treatment for the disease. The agent that causes the disease is called a prion. Prions are found in the lymph nodes, brain and spinal tissues of infected animals. The prions can be shed in the urine, saliva and feces of an infected animal. Also, certain parts of a CWD infected animal remain infectious on the landscape in the soil for many years.

New York State has a tremendous white-tailed deer herd and a small, but expanding, moose population. Preventing the introduction of CWD into New York from hunter-killed carcasses is vital to protecting the health of New York’s deer and moose populations. The most effective way to protect New York’s deer and moose herds is to keep CWD infectious material out of the state, and hunters play an important role in this effort.

It is important that hunters who hunt deer, elk or moose outside of New York know the status of CWD in the state or Province where they hunt and plan accordingly. It is illegal to import a whole carcass from CWD positive states. It is also illegal to ship the entire head of a CWD-susceptible animal from a CWD positive state into New York. To comply with DEC’s CWD regulation, hunters should consider de-boning their deer, elk or moose before entering New York.

First Case of Chronic Wasting Disease Confirmed in Ohio on Private Preserve

Active steps taken to control further spread; no evidence the disease affects humans

REYNOLDSBURG, OHIO – The Ohio Department of Agriculture (ODA) and the Ohio Department of Natural Resources (ODNR) today confirmed the first positive case of Chronic Wasting Disease (CWD) in the state in a captive deer herd in Holmes County. The state continues to take quarantine action to control the further spread of the disease. There is no evidence that CWD has affected the wild deer population in the state.

The positive sample was taken from a single buck on a hunting preserve in Millersburg and tested as part of Ohio’s CWD monitoring program for captive white-tailed deer operations. The preserve had been under quarantine since April 24, 2014, and was subject to intensive monitoring and sampling protocols because of a known connection to a captive deer operation in Pennsylvania that tested positive for CWD earlier this year. The quarantine will remain enforced until the state is satisfied that disease transference can no longer occur.

“Ohio’s captive white-tail deer licensing program was enacted two years ago for the purpose of continuously monitoring the heath of the captive deer populations in the state to manage the spread of and exposure to diseases such as CWD. We have worked closely with the Pennsylvania Department of Agriculture to identify and trace back positive cases,” said State Veterinarian Dr. Tony Forshey. “We will continue to take aggressive steps to ensure that CWD does not pose a threat to the state’s wild deer population.”

The state has quarantined 43 captive deer operations in Ohio since April 15, 2014, for receiving approximately 125 deer from operations in Pennsylvania that later tested positive for CWD. Twenty-two of those quarantines were lifted after negative CWD test results were confirmed in 53 of the suspect animals from Pennsylvania. ODA will continue to enforce quarantine restrictions on 21 operations, including five hunting preserves, until the department is satisfied that the threat of disease transference has passed.

The disease is fatal in deer, elk and moose, but there is no evidence CWD can be transmitted to humans, according to the Centers for Disease Control and Prevention (CDC) and The World Health Organization. Though no human disease has been associated with CWD, the CDC recommends, as a precaution, that people or other animals do not eat any part of an animal diagnosed with or showing signs of CWD.

“We have no reason to believe that there has been transference to the state’s wild deer population,” said Scott Zody, chief of the ODNR Division of Wildlife. “With hunting season in progress, there are no CWD concerns that should prevent anyone from enjoying wild deer hunting in Ohio or from consuming meat from healthy animals.”

The ODNR Division of Wildlife is recommending that hunters continue to take standard precautions such as shooting only animals that appear healthy, wearing rubber gloves when field-dressing their deer and washing thoroughly when finished. If hunters should observe a deer that appears unhealthy, they are encouraged to contact their local wildlife office or officer.

Since 2002, the state has conducted surveillance throughout Ohio for the disease. State and federal officials will continue this regular sampling and testing throughout the hunting season to continue to monitor the health of the state’s wild deer population. Tissue samples from 753 deer killed on Ohio’s roads were collected from September 2013 through March 2014 and were tested for CWD. An additional 88 hunter-harvested mature white-tailed deer and nine deer displaying symptoms consistent with CWD were tested as well and were all negative.

In response to this positive finding, the ODNR Division of Wildlife will increase sampling efforts in the wild deer population within six miles of the hunting preserve from which the CWD-positive deer came as well as near the other captive operations that are under quarantine. Those samples will include high-risk animals such as those killed on roads or exhibiting neurological symptoms as well as hunter-harvested deer in the area.

CWD, first discovered in captive mule deer in Colorado in 1967, attacks the brains of infected deer, elk and moose, producing small lesions that eventually result in death. It is transmitted by direct animal-to-animal contact through saliva, feces and urine. Signs of the disease include weight loss, excessive salivation, increased drinking and urination, and abnormal behavior like stumbling, trembling and depression. Infected deer and elk may also allow unusually close approach by humans or natural predators. The disease is fatal in deer, and there is no known treatment or vaccine.

Test Results from Captive Deer Herd With Chronic Wasting Disease Released

79.8 percent of the deer tested positive for the disease

DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD). The owners of the quarantined herd have entered into a fence maintenance agreement with the Iowa Department of Agriculture and Land Stewardship, which requires the owners to maintain the 8’ foot perimeter fence around the herd premises for five years after the depopulation was complete and the premises had been cleaned and disinfected

CWD is a progressive, fatal, degenerative neurological disease of farmed and free-ranging deer, elk, and moose. There is no known treatment or vaccine for CWD. CWD is not a disease that affects humans.

On July 18, 2012, USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Lab in Ames, IA confirmed that a male white tail deer harvested from a hunting preserve in southeast IA was positive for CWD. An investigation revealed that this animal had just been introduced into the hunting preserve from the above-referenced captive deer herd in north-central Iowa.

The captive deer herd was immediately quarantined to prevent the spread of CWD. The herd has remained in quarantine until its depopulation on August 25 to 27, 2014.

The Iowa Department of Agriculture and Land Stewardship participated in a joint operation to depopulate the infected herd with USDA Veterinary Services, which was the lead agency, and USDA Wildlife Services.

Federal indemnity funding became available in 2014. USDA APHIS appraised the captive deer herd of 376 animals at that time, which was before depopulation and testing, at $1,354,250. At that time a herd plan was developed with the owners and officials from USDA and the Iowa Department of Agriculture and Land Stewardship.

Once the depopulation was complete and the premises had been cleaned and disinfected, indemnity of $917,100.00 from the USDA has been or will be paid to the owners as compensation for the 356 captive deer depopulated.

The Iowa Department of Agriculture and Land Stewardship operates a voluntary CWD program for farms that sell live animals. Currently 145 Iowa farms participate in the voluntary program. The above-referenced captive deer facility left the voluntary CWD program prior to the discovery of the disease as they had stopped selling live animals. All deer harvested in a hunting preserve must be tested for CWD.

Study Finds Elk May be able to Adapt to Chronic Wasting Disease

CHEYENNE – A ten-year study conducted by the University of Wyoming and the Wyoming Game and Fish Department suggests that the effects of chronic wasting disease (CWD) on elk populations may not be as devastating as once believed.

Research has shown that genes play a role in elk susceptibility to CWD. Some elk have genes that prolong the time between exposure to the CWD prion, the infectious agent of CWD, and the onset of the disease. These genes become dominant over many decades, greatly reducing the impact of CWD on the population. Elk with these genes live longer even when heavily exposed to CWD and therefore have more opportunity to reproduce than elk with other genes.

Some people have feared that winter feedgrounds for elk would concentrate the disease resulting in much higher incidence of CWD.

“This study model essentially represents the worst-case scenario that would face feedground elk,” said Dr. Terry Kreeger, retired state wildlife veterinarian for the Wyoming Game and Fish Department. “We predict a genetic shift over several decades favoring genes that prolong the incubation time of CWD resulting in elk populations that are able to persist in the face of the disease.”

Scott Edberg, Deputy Chief of the Wyoming Game and Fish Wildlife Division states, “It helps to know that based on this research, if CWD should become established on feedgrounds, we won’t see a devastating effect on populations as many have feared. This research also looked at how hunting would affect populations, and it appears, Game and Fish would still need to have hunting seasons to manage elk populations even if faced with CWD on feedgrounds.”

The full study was published in an issue of Ecospohere, an online, open-access, peer-reviewed scientific publication of the Ecological Society of America and can be accessed at www.esajournals.org