Prion Contamination Threatens Public Health
After 22 years of caution, the FDA recently determined that defending the nation’s blood supply against prion disease is no longer necessary. Instead, we will now safeguard blood banks based on the honor system. In the age of bioterrorism, what’s wrong with this picture?
Thanks to the infinite wisdom of the FDA and other health agencies around the world, global prion policies for blood banks changed overnight. Thanks to the honor system, people once deemed at a higher risk of exposure to prion disease are no longer banned from donating blood. How did the U.S., Australia and the United Kingdom all reach the same conclusion at once?
Neurodegenerative disease is the fastest-growing cause of death in the world. Most forms are highly infectious. As such, protecting the blood supply and medical facilities from prion contamination is virtually impossible. Removing the few policies designed to safeguard public health is negligent at best. This policy shift comes years after the United States took prions off the list of select agents, which meant that they were extremely dangerous and highly regulated. Today, policies regulating deadly prions are virtually non-existent anywhere in the world. The prion pandemic will continue to escalate.
After the outbreak of mad cow disease in the United Kingdom, the US Food and Drug Administration (FDA) imposed a ban on blood donations from anyone who spent more than six months in Britain from 1980 to 1997 because of the possible exposure to Creutzfeldt-Jakob disease (CJD).
Unfortunately, CJD is just the tip of the iceberg. Alzheimer’s disease, Parkinson’s disease and ALS also are forms of prion disease. Who is warning these families and caregivers about the dangers of prion contamination? What is preventing people battling these diseases from donating blood and organs?
CJD is an infectious, incurable disease. It has been transmitted from infected humans to patients through the transplantation of the covering of the brain, use of contaminated brain electrodes, and injection of growth hormones derived from human pituitary glands. It has been transmitted through dental procedures.
There is evidence that CJD can be transmitted from donors to patients through blood transfusions. In fact, CJD and other prion diseases are readily transmitted through bodily fluids and tissue—including skin. There is no test at present that can detect blood that is infected with CJD, and no method that can completely remove abnormal prion proteins from blood. The blood transfusion and transplant services ask anyone with an increased risk of any type of CJD not to donate blood, tissues or organs.
In 1987, FDA issued its first recommendations to blood establishments for deferral of individuals who received human cadaveric pituitary growth hormone injections to reduce the possible risk of prion transmission through blood and blood products. In 1999, FDA issued the first recommendations for CJD and vCJD. FDA held several Transmissible Spongiform Encephalopathies Advisory Committee (TSEAC) meetings between 1995 and 2015 to review scientific evidence. In 2016, FDA terminated TSEAC, but the prion threat isn’t going away.
Blood transfusion can be a highly efficient route of transmission for prion diseases, and show that RBCs, platelets and fresh plasma from infected individuals are all potentially infectious.
Evidence from a small number of case reports involving patients and laboratory animal studies that vCJD can be transmitted through transfusion–even if the donor shows no signs of the disease. It also has been transmitted through organ transplants, infected dental instruments and infected surgical instruments. Prion contamination is extremely difficult, if not impossible, to sterilize. After several lawsuits, hospitals now discard contaminated medical instruments to eliminate the risks of prion transmission and the associated liability. Dentists should follow that example.
Across the animal kingdom, this epidemic is called prion disease. In cattle, prion disease is commonly called mad cow disease, but the clinical term for the disease is bovine spongiform encephalopathy—BSE. BSE is a form of transmissible spongiform encephalopathy (TSE). The operative word is “transmissible.”
According to the prion hypothesis, vCJD and BSE are caused by proteinaceous infectious particles— prions. Prion disease also includes Alzheimer’s disease, Parkinson’s disease, ALS, chronic wasting disease and more. It impacts most, if not all, mammals including deer, elk, reindeer, moose, whales, dolphins, camels, elephants, mink, sheep and cattle.
There is no test for vCJD in humans that could be used to screen blood and organ donors. Organ and blood donation programs must take special precautions to keep vCJD out of circulation.