1. Headline
  1. Headline
SCHMIDT KRUEGER
Andy Manis  /  AP file
Mark Schmidt, left, and Steve Krueger, both with the Wisconsin Department of Natural Resources, load deer carcasses in Black Earth, Wis., during a 2002 effort to monitor chronic wasting disease.
By Jon Bonné
msnbc.com
updated 9/21/2004 9:44:40 AM ET 2004-09-21T13:44:40

Mad cow disease, chronic wasting disease and similar ailments are all thought to be caused by misshapen forms of special proteins known as prions. In the case of chronic wasting, research shows infection can occur even by proximity to sick deer.

So how do you safely dispose of stricken animals?

It isn't as simple as burying their carcasses, or even incinerating them.

Prions are simply proteins, not living organisms, and they can survive almost anything, even hundreds of degrees of heat. Placing infected tissue in a landfill simply removes it, but scientists worry that the prions can leach through soil and groundwater, and spread.

Incineration is possible, but it isn't as easy as burning the carcass in a fire. Temperatures of more than 1,100 degrees Fahrenheit — sometimes up to 1,800 degrees — are required to effectively neutralize prions. Unlike most bacteria, regular cooking won't help at all.

"Disposal issues are tough," says Barbara Powers, director of Colorado State University's Veterinary Diagnostic Laboratory.

Even many of sterilization techniques used in hospitals, such as autoclaving, are not necessarily effective — though some may be when infected material is dipped in sodium hydroxide, or lye and heated well above the boiling point of water.

A combination of heat — about 275 degrees Fahrenheit — and bursts of unimaginably high pressure — over 100,000 psi — showed promise in reducing prion infectivity, at least in processed meats like hot dogs, in research published last year.

And a similar method has become the default process for getting rid of infected animals. Large vat-like machines known as alkaline hydrolysis tissue digesters, one of which Powers' lab operates, can essentially dissolve entire carcasses.

Infected material is placed in a solution of potassium hydroxide — also known as caustic potash — for at least six hours, at 300 degrees Fahrenheit and 60 psi, about four times ambient air pressure.

All remains at the end is a sterile brown, syrupy liquid that can be hauled away to compost.

"It's like a big steam cooker," Powers says. "That'll take care of the prions."

© 2013 msnbc.com Reprints

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

More on TODAY.com

  1. Courtesy of Steve Mason

    Parents plead forgiveness for late daughter's $200K student-loan debt

    7/31/2014 7:10:12 PM +00:00 2014-07-31T19:10:12
  1. Special hospital unit in Georgia prepares for Ebola patient

    Emory University Hospital in Atlanta said it is preparing an isolation unit to receive a patient with Ebola disease "within the next several days."

    7/31/2014 9:52:34 PM +00:00 2014-07-31T21:52:34
  1. Kerry and UN announce 72-hour cease-fire in Gaza

    There was no immediate comment from Hamas or Israeli forces, but the United Nations representative in Jerusalem received promises that all parties have agreed to the cease-fire, according to a joint statement from the U.N. and State Department.

    7/31/2014 9:55:08 PM +00:00 2014-07-31T21:55:08
  1. Courtesy of Tyler Doss

    Watch therapy dog help boy move arm again after brain surgeries

    7/31/2014 8:45:48 PM +00:00 2014-07-31T20:45:48