Assessment of Surface Disinfection during Hospital Aseptic Processing

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Assessment of Surface Disinfection during
Hospital Aseptic Processing

• Dr Sarah Hiom
• All Wales Specialist Pharmacist - RD
• SMPU, Cardiff Vale NHS Trust

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• Christina Lowe (Swansea NHS Trust)
• and
• Mark Oldcorne (NE Wales NHS Trust)
• Funded by WORD
• (National Assembly for Wales)

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• Transfer into controlled work zone
• ?
• High contamination risk
• ?
• Disinfection (70 alcohol)

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Spores Bacteria - adverse conditions
Fungi - natural life cycle Spores X1000
more resistant than vegetative cells Gve gt
G-ve gt Fungi gt Fungal spores gt Bacterial spores
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Validation of Aseptic Transfer

• Current methods
• Swabs/Contact plates
• Lack sensitivity
• not appropriate for assessing disinfection

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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

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• Place item in empty TPN bag
• Heat seal
• Contained unit for analysis

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• Add recovery diluent (RD)
• 0.1 peptone / Tween 80
• Agitate for 2 min

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• Extract RD bioburden
• Filter 0.45µm Field monitor

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• Add 2ml TSB to filter
• Expel excess
• Enumerate (3d at 30ºC)

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Validate new method

• Background count
• Effect of residual alcohol on recovery rates
• Determining recovery

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Recovery

• S.epidermidis stock culture 55cfu/100µl

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Benchmark Contamination Levels

• 50ml glass vial
• Stored in unit for 5 days
• Bioburden determined after each disinfection
  point during transfer to critical work zone (n ?
  5)

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Hospital 1
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Hospital 2a
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Hospital 2b
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Hospital 3
Ungloved
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Conclusion

• Novel sensitive method to assess disinfection
  transfers
• Spray wipe transfer methods significantly
  better at reducing bioburden than spray only
  procedures (Plt0.1)
• Better bioburden reduction when vial caps opened
  before alcohol spray disinfection transfers
  (Plt0.1)
• Current operational procedures showed transfer of
  up to 9 cfu/vial into critical work zones

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• Q.
• Clinical significance of bioburden levels?
• Action limits?