Inactivation of prions in daily medical practice

The danger of transmission of non conventional agents such as prions constitutes a risk that is difficult to evaluate as the actual understanding of the infectious mechanism is minimal. The efficacy of each procedure is evaluated via submitting infectious particles mixed with cellular products to inactivating treatments, and then by inoculating animals with fractions of the preparation. With these protocols, some ineffective treatments can be identified (for example, soaking in aldehyde), and three reference treatments are recommended by the WHO: soaking in 1 N sodium hydroxide (1 h, 20 °C), soaking in 12.5% bleach (1 h, 20 °C) and steam sterilization in autoclave (134 °C–138 °C, 18 min). Universal precautions of asepsis and hygiene must be applied, especially in anatomo-pathological laboratories and for the re-use of medical devices in neurosurgery or in ophthalmology