Medical Device Reprocessing Association of Ontario (MDRAO) Practice Exam

What unique characteristic do prions have?

1. They are living organisms

2. They can remain infectious for years in a dried state

3. They can be easily destroyed by routine disinfection

4. They primarily affect fungal infections

The correct answer is: They can remain infectious for years in a dried state

Prions are unique infectious agents composed solely of misfolded proteins. The characteristic that distinguishes them is their ability to remain infectious over long periods, particularly when in a dried state. Unlike conventional pathogens such as bacteria or viruses, prions do not contain any nucleic acids (DNA or RNA), which makes them resistant to typical methods of inactivation. They can survive in the environment, retaining their infectious properties for years, especially when dried, making them particularly challenging to eliminate from contaminated facilities and equipment. The other characteristics mentioned in the options do not accurately describe prions. For instance, prions are not classified as living organisms because they lack the cellular structure and metabolic processes characteristic of living cells. They are not easily destroyed by routine disinfection; in fact, they require stringent and specialized decontamination protocols. Additionally, prions are specifically known for their role in neurodegenerative diseases affecting mammals, rather than having any primary effect on fungal infections. This distinct property of enduring infectiousness over time is critical to understanding prion disease management and prevention.