Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK.
Sterile Services Department, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK.
J Hosp Infect. 2021 Apr;110:15-25. doi: 10.1016/j.jhin.2021.01.005. Epub 2021 Jan 19.
Sensitive, direct protein-detection methods are now recommended for the inspection of reprocessed reusable surgical instruments in England to reduce the risk of prion transmission.
To implement an established, highly sensitive method to quantify proteinaceous residues on reprocessed instruments in a Sterile Services Department (SSD) and evaluate its potential impact on service provision.
We introduced highly sensitive epifluorescence (EDIC/EF) microscopy in a large SSD. Over three years, we periodically tested two models of washer disinfector using stainless-steel tokens spiked with mouse brain homogenate or Browne test soil for comparison. We also obtained data and feedback from staff who had been using EDIC/EF to examine almost 3000 reprocessed instruments.
All reprocessed test surfaces harboured residual contamination (up to 258.4 ng from 1-μg spikes). Proximity between surfaces affected decontamination efficacy and allowed cross-contamination. Up to 50 ng de novo proteinaceous contamination was deposited on control surfaces after a single automated washer disinfector (AWD) cycle. The test soil behaved differently than real tissue contamination. SSD staff observed proteinaceous residues on most reprocessed instruments using EDIC/EF, which can detect far smaller amounts than the currently accepted national threshold of 5 μg per side.
Implementing recent national guidelines to address the prions concern proved an eye-opener. Microscopic levels of proteins remain on many reprocessed instruments. The impact most of these residues, potentially including prions, may have on subsequent patients after sterilization remains debatable. Improving surveillance capability in SSDs can support decision making and raise the standards of surgical instruments reprocessing.
为降低朊病毒传播风险，目前英国建议采用敏感、直接的蛋白质检测方法对再处理可重复使用的手术器械进行检查。
在无菌服务部门（Sterile Services Department，SSD）实施一种已建立的、高度敏感的方法来定量检测再处理器械上的蛋白质残留，并评估其对服务提供的潜在影响。
我们在一个大型 SSD 中引入了高度敏感的荧光显微镜（EDIC/EF）。在三年的时间里，我们定期使用不锈钢代币对两种型号的清洗消毒器进行测试，代币上沾有鼠脑匀浆或 Browne 测试土，用于比较。我们还从使用 EDIC/EF 检查近 3000 件再处理器械的工作人员那里获得了数据和反馈。
所有再处理的测试表面都残留有污染（从 1-μg 污染的 258.4ng）。表面之间的接近程度会影响去污效果，并允许交叉污染。在单个自动清洗消毒器（AWD）循环后，控制表面上会沉积多达 50ng 的新蛋白质污染。测试土的行为与实际组织污染不同。SSD 工作人员使用 EDIC/EF 在大多数再处理器械上观察到蛋白质残留，这种方法可以检测到远小于目前国家 5μg/侧接受阈值的残留量。
实施解决朊病毒问题的最新国家指南令人大开眼界。许多再处理器械上仍残留有蛋白质。这些残留物中的大多数，包括朊病毒，在消毒后对随后的患者可能产生的影响仍存在争议。提高 SSD 中的监测能力可以支持决策制定并提高手术器械再处理的标准。
