It’s a “slow-moving” disaster in North America, scientists say, warning that the epidemic wreaking havoc in the deer population may jump to humans, as it happened with the so called Mad Cow Disease in the ’90s.
They call it the “Zombie Deer Disease”, or CWD (Chronic Wasting Disease) and it’s not a pretty thing. Animals attacked by the disease become lethargic, they drool and lose weight, they stumble around and look emaciated. Just like BSE (bovine spongiform encephalopaty, or mad cow disease) CWD it is caused by prions: abnormal, transmissible pathogenic agents, and just like BSE it is a neurological disease attacking the hosts’ brains and nervous systems.
Cases have been growing across North America, mainly noticed by hunters who spotted deers acting strangely. But last October the first case was certified in a dead animal in Yellowstone National Park, north-west Wyoming, the US most famous nature reserve.
CWD is spreading across all the cervid family: not just deers but elk, moose, caribou and reindeer. There is no treatment and no vaccine. The US Centers for Disease Control strongly recommend that hunted prey be tested for the disease and that meat from cervids that appear ill should not be eaten.
Twenty years ago, Mad Cow Disease was stumped by culling hundred of thousands of animals and by banning the addition of animal by-products to bovine food (resulting in contaminated beef). The EU also resorted to banning all British beef for ten years -from 1996 to 2006 – because the disease had been particularly rampant in the UK. The human variant CJD (Creutzfeld Jacob Disease), with an incubation period of decades, as of 2020 had killed 178 people in the UK and 50 in the rest of the world.
Mad Cow Disese was transmitted to humans by eating beef contaminated with it (particularly the brain, spinal cord and digestive tract, and thus all offals).
The same may become true of Zombie Deer Disease. The consumption of deer and other members of the cervid family is low in Europe but noticeably higher in the United States, where the hunting season is under way. Moreover, once an environment is infected, the pathogen agent is extremely hard to eradicate: it can persist for years in dirt or on surfaces, and it resists to disinfectants, radiation and fire. The disease could also jump from deer, elk and moose to other mammals, including livestock.
