Transfer Disinfection Validation Sarah Hiom Cardiff and Vale NHS Trust

Aseptic Preparation Isolator Technology

 High contamination risk  Disinfection (70% alcohol) Transfer into controlled work zone

Validation of Disinfection Transfer Current methods Current methods Swabs/Contact plates Lack sensitivity Lack sensitivity Not appropriate for assessing disinfection

Aim 1. To develop and validate an accurate in house disinfection assessment method 2. To use this method to benchmark contamination levels and compare disinfection transfer procedures in pilot sites across Wales

Method

Validate new method Background count Background count Effect of residual alcohol on recovery rates Effect of residual alcohol on recovery rates Determining % recovery Determining % recovery

% Recovery S.epidermidis stock culture = 55cfu/100μl Contact Plate ~ 40% Swab~ 20%

Sampling Concept

Benchmark Contamination Levels 50ml glass vial 50ml glass vial Batch (6) stored in unit for 5 days Batch (6) stored in unit for 5 days Bioburden determined after each disinfection point during transfer to critical work zone (n  5) Bioburden determined after each disinfection point during transfer to critical work zone (n  5)

Pilot conclusions Novel sensitive method to assess disinfection transfers Novel sensitive method to assess disinfection transfers Spray & wipe transfer methods significantly better at reducing bioburden than spray only procedures (P<0.1) Spray & wipe transfer methods significantly better at reducing bioburden than spray only procedures (P<0.1) Better bioburden reduction when vial caps opened before alcohol spray disinfection transfers (P<0.1) Better bioburden reduction when vial caps opened before alcohol spray disinfection transfers (P<0.1) Operational procedures showed transfer of up to 9 cfu/vial into critical work zones Operational procedures showed transfer of up to 9 cfu/vial into critical work zones

Action limits?

Bioburden (cfu/item)

Action Limits “…for transfer disinfection procedures to pass this validation test, results are expected to demonstrate no greater than two colony forming units from each item sampled within the critical work zone. ” SteriVal : Technical Information Sheet 3.3