Sara Chodosh: Chronic Wasting Disease and Humans

Popular Science:

CWD appears limited to deer, moose, and elk. But University of Minnesota researchers warned local lawmakers this week that we should be taking action now to prevent the potential spread to humans. Michael Osterholm, director of the university’s Center for Infectious Disease Research and Prevention, testified that “It is my best professional judgment based on my public health experience and the risk of BSE transmission to humans in the 1980s and 1990s and my extensive review and evaluation of laboratory research studies … that it is probable that human cases of CWD associated with the consumption of contaminated meat will be documented in the years ahead. It is possible that number of human cases will be substantial and will not be isolated events,” according to the Pioneer Press.

Osterholm would know; he’s seen this kind of thing before. For a long time, experts thought another prion disease, bovine spongiform encephalopathy, better known as mad cow disease, couldn’t infect humans. Then they discovered that it actually was possible (though extremely rare) for humans who ate infected meat or came into contact with infected tissue to contract a variant of the human prion disease Creutzfeldt-Jakob. Osterholm was one of the experts who sat on British review panels at the time of the mad cow disease scare, and predicted the prions could make the leap into humans.

Carl Zimmer: A Plague Killing Deer and Elk

New York Times:

Dr. Zabel and his colleagues are developing plans to burn plots of National Park Service land in Arkansas and Colorado. If the experiments turn out as the researchers hope, they will spare some elk and deer a gruesome death.

Across a growing swath of North America, these animals are dying from a mysterious disorder called chronic wasting disease. It’s caused not by a virus or bacterium, but a deformed protein called a prion.

When ingested, prions force normal proteins in the animal’s body to become deformed as well. Over the course of months, prions can gradually wreck the animal’s nervous system, ultimately killing it.

This year is the 50th anniversary of the discovery of chronic wasting disease. In the September issue of Microbiology and Molecular Biology Reviews, Dr. Zabel, an immunologist at Colorado State University, and his former graduate student Aimee Ortega survey what scientists have learned about the slow-spreading plague.

It makes for ominous reading. “There’s a lot that we still don’t know and don’t understand about the disease,” Dr. Zabel said in an interview. Once chronic wasting disease gets a foothold, it can spread relentlessly. It’s now documented in 24 states, and continues to expand into new ranges. In some herds, as many as half of the animals carry prions.