Zombie deer disease

What is zombie deer disease and how is it spread?

Zombie deer disease, technically known as chronic spongiform encephalopathy (CSE) or Chronic Wasting Disease (CWD), is a neurodegenerative disease that affects deer, elk, reindeer, caribou and other members of the cervid family. This disease is similar to Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy – popularly known as mad cow disease – in cattle.

CSE is caused by prions, which are abnormal forms of proteins that replicate by inducing normal proteins in the brain to take on their abnormal shape. These abnormal prions cause damage and cell death in the brain, causing neurological symptoms and death of the affected animal. There is no treatment or cure for the disease, and it is always fatal.

EEC is highly contagious among cervids and is transmitted through direct contact between animals and their fluids (saliva, feces, blood or urine), or indirectly through the environment such as, for example, through soil, water, or plants contaminated with prions, since experts point out that these can remain in the environment for a long time because they are very resistant to heat, ultraviolet radiation and disinfectants.

EEC was initially identified in Colorado and Wyoming in the 1960s and 1970s, but has since spread to the eastern United States and west to Utah and has been detected in wild or captive cervids in at least 24 states. from the USA, two Canadian provinces, South Korea and in European reindeer and moose:

• Canada: It has been found in areas of Canada, particularly in provinces such as Alberta and Saskatchewan.
• Norway: This country reported cases of EEC in wild reindeer and moose, with the first case in Europe reported in 2016.
• Finland: has also reported cases of EEC in its reindeer and moose population.
• Sweden: has detected cases of EEC in its wildlife.

Symptoms of zombie deer disease

From the moment the infection occurs until its first manifestations appear in the animal, a year can pass, and the main symptoms of zombie deer disease include:

• Weightloss.
• Changes in behavior.
• Lack of coordination.
• Tremors.
• Excessive salivation.
• Difficulty to swallow.
• Teeth grinding.
• Excessive thirst and hunger.
• Neglected or sickly appearance.
• Isolation from the rest of the group.

These symptoms can lead affected animals to look like ‘zombies’, hence the colloquial name of the disease.

Can zombie deer disease be transmitted to humans?

Until now, no cases of CSE transmission to humans have been reported. However, there is concern among some experts about the possibility that the disease could eventually cross the species barrier and affect humans, especially those who consume cervid meat.

The possibility of transmission between species exists in the case of prion pathologies, as demonstrated by Creutzfeldt-Jakob disease (CJD) in humans and ‘mad cow disease’ in cattle, which was detected for the first time in the United Kingdom. Joined in 1986 and is related to vCJD, a rare and fatal human neurodegenerative disease first described in March 1996, the development of which is closely related to exposure, probably through the consumption of meat and meat products, to the agent that caused the bovine spongiform encephalopathy.

Furthermore, the prions responsible for ‘zombie deer disease’ have the ability to infect and spread in human cells under laboratory conditions. And it has also been proven in experiments that the prion that causes CSE can infect squirrel monkeys and laboratory mice that carry human genes.

And although there is currently little evidence that EEC prions can be transmitted to humans and cause disease, researchers hypothesize that a more easily transmissible EEC prion to humans could emerge over time if sufficiently extensive human exposure occurs. Anyone who comes into direct contact with cervids, consumes venison, or is in contact with contaminated environmental materials from EEC-affected areas could be at risk of exposure.

Diagnosing prion diseases in humans is also not easy, since, unlike other pathogens that infect people, prions do not trigger an immune response from the body, so they are more difficult to detect and this would prevent rapid intervention to prevent them. the spread of the disease.

How to Prevent the Spread of Zombie Deer Disease

There is no vaccine or treatment available to combat this lethal disease, and cervids play a fundamental role in preserving their habitat, so if their population drastically decreases this would have catastrophic consequences for the environment and other animals that depend on their existence. .

The health and wildlife authorities of the affected areas have offered a series of advice to prevent possible contagion to humans, minimize its transmission among animals residing in risk areas and, above all, prevent its further spread to other regions:

• Avoid eating meat from animals that appear sick or have tested positive for CEE, and do not touch or handle sick or dead wild animals.
• Strengthen surveillance to track the spread of the disease.
• Establish biosecurity measures to prevent further transmission, such as monitoring the movement of populations of deer, elk, and other animals susceptible to infection and conducting regular testing to monitor disease prevalence.
• Avoid artificial congregation of cervids in infected or potentially infected environments.
• Promote responsible hunting practices to limit the risk of transmission as much as possible.
• Carry out new research that helps to better understand the disease transmission process, its ecological impact and the potential implications for human health.