Clinical Microbiology and Virology, University College London Hospitals NHS Foundation Trust, London, UK.
BMC Infect Dis. 2012 Aug 3;12:174. doi: 10.1186/1471-2334-12-174.
The near-patient environment is often heavily contaminated, yet the decontamination of near-patient surfaces and equipment is often poor. The Nanoclave Cabinet produces large amounts of ultraviolet-C (UV-C) radiation (53 W/m2) and is designed to rapidly disinfect individual items of clinical equipment. Controlled laboratory studies were conducted to assess its ability to eradicate a range of potential pathogens including Clostridium difficile spores and Adenovirus from different types of surface.
Each test surface was inoculated with known levels of vegetative bacteria (10(6) cfu/cm(2)), C. difficile spores (10(2)-10(6) cfu/cm(2)) or Adenovirus (10(9) viral genomes), placed in the Nanoclave Cabinet and exposed for up to 6 minutes to the UV-C light source. Survival of bacterial contaminants was determined via conventional cultivation techniques. Degradation of viral DNA was determined via PCR. Results were compared to the number of colonies or level of DNA recovered from non-exposed control surfaces. Experiments were repeated to incorporate organic soils and to compare the efficacy of the Nanoclave Cabinet to that of antimicrobial wipes.
After exposing 8 common non-critical patient care items to two 30-second UV-C irradiation cycles, bacterial numbers on 40 of 51 target sites were consistently reduced to below detectable levels (≥ 4.7 log10 reduction). Bacterial load was reduced but still persisted on other sites. Objects that proved difficult to disinfect using the Nanoclave Cabinet (e.g. blood pressure cuff) were also difficult to disinfect using antimicrobial wipes. The efficacy of the Nanoclave Cabinet was not affected by the presence of organic soils. Clostridium difficile spores were more resistant to UV-C irradiation than vegetative bacteria. However, two 60-second irradiation cycles were sufficient to reduce the number of surface-associated spores from 10(3) cfu/cm(2) to below detectable levels. A 3 log10 reduction in detectable Adenovirus DNA was achieved within 3 minutes; after 6 minutes, viral DNA was undetectable.
The results of this study suggest that the Nanoclave Cabinet can provide rapid and effective disinfection of some patient-related equipment. However, laboratory studies do not necessarily replicate 'in-use' conditions and further tests are required to assess the usability, acceptability and relative performance of the Nanoclave Cabinet when used in situ.
近患者环境通常受到严重污染，但近患者表面和设备的去污往往很差。纳米消毒器柜产生大量的紫外线-C（UV-C）辐射（53 W/m2），旨在快速消毒各种临床设备。进行了受控的实验室研究，以评估其消除包括艰难梭菌孢子和腺病毒在内的各种潜在病原体的能力，这些病原体来自不同类型的表面。
每个测试表面都接种了已知数量的活菌（10（6）cfu/cm（2））、艰难梭菌孢子（10（2）-10（6）cfu/cm（2））或腺病毒（10（9）病毒基因组），将它们放置在纳米消毒器柜中，并在 UV-C 光源下暴露长达 6 分钟。通过常规培养技术确定细菌污染物的存活情况。通过 PCR 确定病毒 DNA 的降解情况。结果与未暴露的对照表面上回收的菌落数量或 DNA 水平进行比较。实验重复进行，以纳入有机土壤，并比较纳米消毒器柜的功效与抗菌擦拭巾的功效。
将 8 种常见的非关键患者护理物品暴露于两个 30 秒的 UV-C 照射周期后，51 个目标部位中有 40 个部位的细菌数量始终减少到低于检测水平（≥4.7 log10 减少）。尽管细菌负荷在其他部位仍然存在，但数量有所减少。使用纳米消毒器柜难以消毒的物品（例如血压袖带）也难以使用抗菌擦拭巾消毒。纳米消毒器柜的功效不受有机土壤的影响。艰难梭菌孢子比活菌对 UV-C 照射更具抵抗力。然而，两个 60 秒的照射周期足以将表面相关孢子的数量从 10（3）cfu/cm（2）减少到低于检测水平。在 3 分钟内可实现对可检测腺病毒 DNA 的 3 对数减少；6 分钟后，病毒 DNA 无法检测到。
本研究结果表明，纳米消毒器柜可快速有效消毒一些与患者相关的设备。然而，实验室研究并不一定能复制“使用中”的条件，需要进一步测试以评估纳米消毒器柜在现场使用时的可用性、可接受性和相对性能。
