Tuesday, May 3, 2016

Chronic Wasting Disease Confirmed in Europe for First Time

A reindeer in Norway has been diagnosed with chronic wasting disease, a deadly disease that targets cervids, earlier this month.

This is the first time the disease, which was first detected in the United States in the 1960s, has reached Europe and is also the first-ever detection of the disease in a free-ranging reindeer (Rangifer tarandus). The reindeer was from the Nordfjella population in South Norway.

Wildlife biologists don't know yet how the disease got to Norway. "That's the million dollar question," said Matthew Dunfee, the project coordinator of the Chronic Wasting Disease Alliance. "We hope to answer it in the next coming months."

Dunfee said wildlife biologists became more aware of the disease's prevalence in the U.S. in the early 2000s, but they still are unsure of how it started. Now that it has reached Norway and there's no documented transmission route, they are trying to understand how it spread to the country.

There are two possibilities regarding how this happened, according to Dunfee. One option is that an animal was illegally and surreptitiously moved from an area in the U.S. where CWD is prevalent to Norway. Another possibility is that the disease, which takes the form of mad cow disease in cows or scrapie in bovines, which has been detected in Europe, could have jumped the species barrier into the reindeer. However, Dunfee was hesitant to suggest that was the case because previous research has shown this is a difficult barrier to cross.

In the meantime, Norway must take a few steps in order to prevent the disease from spreading, Dunfee said, especially because when the disease shows up in one animal, it's likely to be in animals in the surrounding area as well. "The odds it will only be in one animal are very low," he said.

First, managers should shut down any transmission modes possible, Dunfee said. This means prohibiting the transfer of live cervids or cervid parts. Then, they will begin to sample other animals in the area to determine the prevalence of the disease. Based on these findings, the biologists will make management recommendations. "Because there's no known management technique to eradicate CWD, the name of the game is not to eradicated CWD, it is to manage it," he said.

Wildlife biologists and managers in the U.S. continue to try to manage the disease as well. While Wyoming is known as the "great control" because it chose not to take management steps for CWD, other states such as Wisconsin have implemented significant management steps and, according to Dunfee, have lower prevalence rates.

Meanwhile, Arkansas reported its first case of CWD in an elk in Newton County this past February. Wildlife managers sampled elk and deer in and around the area and found 82 animals tested positive for the disease. Management decisions will be made in Arkansas within the next year. "That's what Europe now has to deal with," Dunfee said. "The first step is to figure out how much the disease spread in local herds. Then they can start to take adequate measures."

-The Wildlife Society
http://wildlife.org