Facing CJD and Prion Diseases in the Lab

According to the National Institute of Health (NIH), Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, fatal brain disorder that affects about one person in every one million people per year worldwide. In the United States there are about 300 cases per year. Some of us know the ailment better as “Mad Cow disease,” but that is only one form of this illness which is not caused by a virus or bacteria. CJD is a prion disease. A prion is a protein that exists in both a normal form, which is a harmless, and in an infectious form. The infectious form of the protein takes on a different folded shape, and once these abnormal proteins appear, they aggregate or clump together. Investigators think these prion aggregates may lead to the neuron loss and other brain damage seen in CJD. However, they do not know exactly how this damage occurs.

Since laboratory professionals may deal with specimens from possible CJD patients, we need to know how to properly handle them should such a situation arise. If the Operating Room calls your labs to process a brain biopsy specimen from a patient who was suspected of having a prion disease, would you know what to do? Can your lab do that? Should your lab do that?

Prions are dangerous, but CJD cannot be transmitted through the air or through touching or most other forms of casual contact. Prion transmission can occur, however, from contact with highly-infectious specimens. Brain tissue, eye tissue, and pituitary tissue are considered high-risk specimens, and contact with these should be avoided. When asked to handle a brain biopsy, medical staff and safety experts should work out a plan. For instance, a lab tech who is trained in Category A packaging could go to the OR, dress in fully protective PPE (including a body suit, gloves, and hood), and receive the specimen in the OR and package it there. The specimen is then ready for transport to the reference laboratory. If another department asks you to handle tissue samples from a suspected CJD patient, stop everything and escalate the issue immediately. Contact your medical director, your manager, or the safety officer and await further instructions.

There are other specimen types a lab might receive from a prion patient. Blood, serum, urine, feces, and sputum are considered no-risk specimens. Prions are not found in these types of specimens, and they may be handled and processed as usual.

The last category of specimens from prion patients is known as “low-risk.” These specimens include CSF, kidney, liver, spleen, lung, lymph nodes, placenta, and olfactory epithelium tissues. Of course the most common specimen a lab would see from this group is a spinal fluid, and labs do need to make sure they do not handle it as a normal specimen.

Lab staff should be notified when a specimen is going to be sent from a prion patient, particularly when a low-risk specimen like a CSF is on the way. Procedures should be in place, and it is recommended that such specimens have special labels on them to alert those of the potential risks.

There is no record of lab employees becoming infected with prions from handling low-risk specimens, but they must still be handled with care. All testing of low-risk specimens should be performed inside a Biological Safety Cabinet (BSC). Use disposable equipment as much as possible. For example, use disposable cups for stains or reagents where possible. Perform manual testing only; do not run low-risk specimens on automated analyzers as disinfection is not easily accomplished.

While using standard bleach solutions to disinfect surfaces is recommended after processing low-risk specimens, a lab spill of such a specimen is an entirely different matter, and this is why lab specimens should have special labeling. When a low-risk specimen spills, the area should be flooded with 2N Sodium Hydroxide (NaOH) or undiluted sodium hypochlorite (bleach). Remember, never mix bleach with formaldehyde as it produces a dangerous gas, so if a pathology specimen is spilled, only use NaOH. Leave the solution on the spilled material for one hour, then rinse with water. Place the spill materials into a sharps container so that they will be incinerated. If a spill of a low-risk CJD or prion specimen occurs, contact a manager, a medical director, or the safety officer immediately.

Laboratory professionals handle infectious specimens every day which is why it is so important that we utilize Standard Precautions. Wear PPE when working in the lab and treat all specimens as if they were infectious. It’s the only way to prevent a lab-acquired infection. If you see a co-worker not wearing gloves or a lab coat and working at a lab counter or computer, use coaching to remind them that those surfaces are potentially contaminated with pathogens, and they can be deadly. We can protect ourselves from low-risk prion disease (and other pathogens) with everyday PPE. If a specimen is processed in the lab and it is found later the patient was prion-positive, you do not want to be the one who wasn’t wearing PPE when you handled the specimens. The results will be potentially disastrous for you and your family.

Remember, if you receive a phone call that a CJD or prion specimen is being sent to the lab, escalate the situation immediately. Find out if your lab is able to receive and process that type of specimen. Protect yourself, and keep your lab safe from CJD and other infectious pathogens.

-Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years experience as a certified medical technologist. Today he is the Laboratory Safety Officer for Sentara Healthcare, a system of seven hospitals and over 20 laboratories and draw sites in the Tidewater area of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.