Central Service - Issue 1/08

EDITORIAL

The End of Steam Sterilisation?

NEWS UPDATE

What’s New in Standardisation: Use of Biological Indicators
8th CSSD/Hygiene Forum. Damp Congress Centre, 27 November 2007
European Experts Discuss Innovative Approaches to Hospital Hygiene in Blackpool Scientific symposium of the European Association of Medical Device Reprocessing (EAMDR)
1st Sino-German Workshop FORUM at the Medical Lounge Berlin
Eastern European Workshop for Sterile Supply. 6 - 8. December 2007, Bydgoszcz (Poland)

MAIN ARTICLES

Z.X. Yan, L. Stitz, P. Heeg, K. Roth*, P.-S. Mauz::
Low-Temperature Inactivation of Prion Protein on Surgical Steel Surfaces with Hydrogen Peroxide Gas Plasma Sterilization
(Zentr Steril 2008; 16 (1): 31-34)

Abstract
Pathological prion proteins (prions), the agent of transmissible spongiform encephalopathy (TSE), are found not only in the central nervous system but also in extraneural tissues, and are highly resistant to most of the routine hospital sterilization procedures. Reusable surgical instruments therefore need to be regarded as a potential source of iatrogenic transmission. Syrian golden hamster scrapie model was used as a bioassay to validate reprocessing procedures of prion decontamination for surgical instruments. Brain homogenates contaminated surgical steel wires were processed with steam at high temperature, alkaline detergents, enzymatic detergent alone or/and combined with hydrogen peroxide gas plasma sterilizers (Sterrad 100S and Sterrad NX) at low temperature. Here we report that inactivation of prions at low temperature is possible even through a single step.

M. Borneff-Lipp*, A. Kaetzke, M. Dürr::
Evaluation of Low Temperature Hydrogen Peroxide Plasma (LTP) Sterilization. Results of Three Different Technologies
(Zentr Steril 2008; 16 (1): 39-42)

Abstract
Different technologies of low temperature hydrogen peroxide gas plasma (LTP) sterilizers have been marketed for more than a decade for Central Sterile Supply Departments and decentralized smaller units or mobile outpatient surgical centers as well.
The purpose of our study was to conduct microbiological efficacy in three different models of Low Temperature Hydrogen Peroxide Plasma (STERRAD) sterilizers using simulated test objects as surrogates for real instruments. Testing was in accordance with the principles of DIN EN ISO 14937 using half cycles ("overkill"). Also, flexible and rigid endoscopes were tested in order to simulate practical clinical conditions. Tests were performed by inoculating stainless steel carriers with Geobacillus stearothermophilus ATCC 7953 spores and placing the carriers into the inner lumen of the different test objects. Evaluation was done using qualitative and quantitative methods.
A Sterility Assurance Level (SAL) of 10-6 was attained in all cases tested. Thus, all 3 models were proven to fulfill the requirements. Moreover, the new technology STERRAD NX is including the advantage of being able to sterilize instruments with more difficult dimensions concerning lumens and lengths within shorter cycle times.

SHORT COMMUNICATION

B. Hosten, C. Judel, P. Blouin, B. Besnard, G. Nicolaos*, A. Fabreguettes::
Evaluation of the Corrosion of Instruments Immersed in Alkazyme®
(Zentr Steril 2008; 16 (1): 46-47)

Abstract
The objective of this study was to evaluate the corrosion of instruments immersed in Alkazyme® or in water. Used "standard" quality instruments (n=7), and new or used "surgical" quality instruments (n=8) were immersed in Alkazyme or in water. The immersion times (reiterated 3 times) were: 20 minutes, 12h, 24h, 48h, and 7 days. pH and total water hardness were measured. The level of the macroscopic and microscopic corrosion was graduated as follows: "1" - low, "2" - medium, "3" - severe. Corrosion appeared for 2 "standard" quality instruments ("1") immersed in water for 20 min; for 1 "standard" quality instrument ("1") immersed in Alkazyme for 12 H; for 2 used "surgical" quality instruments immersed in water for 20 min ("1"); for 1 used "surgical" quality instrument immersed in Alkazyme for 20 min ("1"); for 2 new "surgical" quality instruments immersed in water for 12h ("1"). There was no corrosion for new "surgical" quality instruments immersed in Alkazyme. For the Alkazyme group the total water hardness was 0 mg/L CaCO3 and the pH = 10. For the water group, the total water hardness was 15 mg/L CaCO3 and the pH=7. The differences of pH and total water hardness can explain the lower corrosion occurring when instruments were immersed in Alkazyme rather than in water.

RECOMMENDATIONS BY THE QUALITY TASK GROUP (AK »QUALITÄT«)

Verification of Completeness of Validation Protocols for WD Processes