Scientists are concerned about the possibility of it reaching humans – Executive Summary

In the forests and grasslands of the United States, a silent phenomenon has become alarming: Chronic wasting disease (CWD), known as “zombie deer disease,” is spreading, raising concerns among scientists and the general public.

This neurological disease, characterized by a myriad of symptoms – such as drooling, lethargy, stumbling, and empty eyes – has already been detected in more than 800 deer and elk specimens in the US state of Wyoming alone, highlighting the urgency and scale of the problem. “The problem of the disease,” noted the “Conversation” portal.

According to Samuel J. Branco, senior professor of genetic immunology at Nottingham Trent University, and Philip P. Wilson, a One Health professor at the same university, says the crux of the problem lies in a strange culprit: prions.

Prions are misfolded proteins and can also cause normal brain proteins to misfold, causing neurodegeneration: this feature makes prion diseases particularly worrisome, because they are highly resilient and can persist in the environment for years. Extreme temperature.

The spread of CWD poses potential environmental and human health risks: Although there is no conclusive evidence that CWD can directly infect humans, the possibility remains a point of concern.

Prion diseases, such as Creutzfeldt-Jakob disease in humans, or “mad cow disease,” have shown that they can cross the species barrier — with devastating consequences. For example, an outbreak of mad cow disease in Britain led to the slaughter of millions of cattle and led to the deaths of 178 people.

Although there are no confirmed cases of CWD in humans, concerns remain due to several factors: First, studies have shown that the prions responsible for CWD can infect and spread within human cells under laboratory conditions, raising the specter of possible spillover.

Second, humans are already inadvertently exposed to potentially infected animals through hunting: humans consumed between 7,000 and 15,000 CWD-infected animals annually in 2017, with projections indicating an annual increase of 20%. In other words, in areas with high prevalence, such as Wisconsin, thousands of people may have unwittingly consumed infected deer meat.

But the inherent difficulties in detecting and diagnosing prion diseases in humans also complicate the problem: unlike traditional infectious agents, prions do not elicit an immune response, making them difficult to detect through conventional means, which represents a major obstacle to early intervention and containment. efforts.

The ability of CWD to affect human health is not limited to direct transmission. Environmental persistence means that humans can also be exposed through indirect routes, such as contaminated soil, water and other environmental sources. Given their resilience and ability to persist in the environment for long periods, the long-term consequences for human health remain uncertain but merit serious consideration.

Another problem arises: The spread of CWD poses significant economic and environmental risks: Deer hunting is a popular recreational activity in certain areas of the United States, but it is also a vital source of livelihood in many communities.

Is it an American problem? No, Europe is suffering too

In 2016, the first cases were diagnosed in Europe, more specifically in wild deer in Norway – reinforcing the recognized potential for the disease to spread beyond the current variant and highlighting the need for international cooperation in disease surveillance and control.