Sea Mammals Vulnerable To Prion Disease
There is a deadly prion epidemic expanding around the globe. The epidemic consists of a family of fatal neurodegenerative diseases that are unstoppable among humans and a variety of other mammals, including sea mammals. We know them as mad cow disease, chronic wasting disease, scrapie, Creutzfeldt-Jakob disease and Alzheimer’s disease. The diseases are virtually identical in pathology and progression. There are no cures. They are fatal. They all are transmissible. The nightmare is spreading further every day.
Alzheimer’s disease is already killing 44 million people around the world today. The numbers are expected to triple by the middle of the century. Canada has declared that chronic wasting disease is unstoppable among deer and elk populations. We have no idea how prevalent the problem is among livestock because of token testing.
Prion disease has been found in dolphins. All mammals are likely vulnerable to TSE.
Prion disease is prion disease–also known as transmissible spongiform encephalopathy (TSE). It’s unstoppable. The common denominator among impacted species is a deadly protein called a prion (pree-ON). The bad news is that the disease is in the oceans and the pathogen will migrate, mutate and multiply in that environment just as it does on land. It’s likely responsible for many of the dolphins and whales around the world that are beaching themselves in an attempt to speak to human civilization about the toxins that we are dumping into the oceans. In fact, sewage dumped into the ocean is contributing to the prion problem in the oceans (I will elaborate in another post).
Prion protein (PrP) has attracted lots of scientific research. It’s even earned a Nobel Prize for Dr. Stanley Prusiner at the University of California San Francisco. President Obama presented Prusiner with the National Medal of Science in 2010 to underscore the importance of this pioneering work with prions.
Dolphins, of course, are ocean mammals. Marino (2004) and Herman et al. (2002) showed that the bottlenose dolphins possess an Encephalization Quotient (EQ) ranging from 4 to 5, which is tantalizingly close to human levels and higher than any other animals (in other words, they are susceptible to prion disease).
It is interesting that the bottle-nosed dolphin has special capacity of short-term and long-term memory for visual, auditory and multimodal information and abstract concepts. The dolphins are capable of understanding semantics and syntax, and even can understand symbolic references to objects that are absent. All of these evidences may suggest that the dolphin brain is still very much like a mystery and well worth carrying out deep exploration (Herman et al., 2001).
The recent discovery of prion disease (PD) case in a free-ranging bottlenose dolphin (Tursiops truncatus) prompted us to carry out an extensive search for the disease-associated isoform (PrPSc) of the cellular prion protein (PrPC) in the brain and in a range of lymphoid tissues from 23 striped dolphins (Stenella coeruleoalba), 5 bottlenose dolphins and 2 Risso s dolphins (Grampus griseus) found stranded between 2007 and 2012 along the Italian coastline.
Three striped dolphins and one bottlenose dolphin showed microscopic lesions of encephalitis, with no evidence of spongiform brain lesions being detected in any of the 30 free-ranging cetaceans investigated herein. Nevertheless, we could still observe a prominent PrPC immunoreactivity in the brain as well as in lymphoid tissues from these dolphins. Although immunohistochemical and Western blot investigations yielded negative results for PrPSc deposition in all tissues from the dolphins under study, the reported occurrence of a spontaneous PD case in a wild dolphin is an intriguing issue and a matter of concern for both prion biology and intra/inter-species transmissibility, as well as for cetacean conservation medicine.
Once Japanese officials understand the importance of this discovery, they might lose their taste for killing dolphins. The country is very sensitive to the threats of mad cow disease and dolphins are getting the same disease from contaminants in the oceans. Mad whales also are a real possibility. We all need to demand testing of beached whales and dolphins and demand an end to the killing of these magnificent creatures in the sea.
Prions are associated with an entire family of neurological disorders that are killing people, wildlife and livestock around the world.
These deadly diseases are known as Transmissible Spongiform Encephalopathy (TSE). The operative word is “transmissible.” TSEs include Alzheimer’s disease, Creutzfeldt-Jakob disease, Parkinson’s disease, Huntington’s disease, scrapie, chronic wasting disease and mad cow disease. Victims permanently contaminate the world around them with their bodily fluids. Once contaminated with prions, items cannot be sterilized.