Rapid and sensitive determination of residual prion infectivity from prion decontaminated surfaces

Introduction: Prion disease transmission has been linked to prion contaminated instruments within laboratory and medical settings. The development of a method to assess the contamination state of relevant surfaces would aid in the development of prion surveillance protocols.

Objectives: To develop a surveillance technique that could be used on clinical and laboratory surfaces to assess the prion contamination status.

Methods: An environmental swabbing technique was applied to select surfaces. Surfaces were contaminated with HY TME and disinfected for 10 minutes with various disinfectants. For select surfaces, swab extracts were examined for residual infectivity with RT-QuIC and bioassay. Finally, stainless steel wires were contaminated and analyzed with RT-QuIC to assess potential remaining surface infectivity following disinfection.

Results/Discussion: Bleach treatment of HY TME contaminated glass surfaces resulted in a failure to detect RT-QuIC seeding activity and infectivity associated with bioassay from surface swab extracts, while H₂O and 70% ethanol were ineffective disinfectants. The RT-QuIC assessment of HY TME contaminated stainless steel wires treated with bleach failed to exhibit seeding activity from the surface.

Conclusion: The described swabbing methodology coupled with RT-QuIC can be used to both recover prions from surfaces and determine disinfection efficacy. The RT-QuIC analysis and bioassay of the same swab extracts congruent. The disinfected surface swab analysis is an indicator of surface disinfection, as evidenced by the comparable results of surface swab extracts and stainless-steel wires. Overall, this method can be implemented in both laboratory and clinical settings to survey for prion contamination.

Funding: CJD Foundation