Civil, Geological and Mining Engineering Department, Polytechnique Montréal, Montreal, Canada.
Civil, Geological and Mining Engineering Department, Polytechnique Montréal, Montreal, Canada.
J Hosp Infect. 2023 Nov;141:9-16. doi: 10.1016/j.jhin.2023.08.007. Epub 2023 Aug 19.
Ice machines in healthcare facilities have been suspected and even linked to outbreaks and pseudo-outbreaks. Guidelines exist for maintenance of these devices but there is no clear independent infection control standard, and little is known about their microbial contamination.
To evaluate the microbial contamination, amplification, and presence of opportunistic pathogens in ice-water machines in a healthcare facility.
Concentrations of general microbial indicators (heterotrophic plate counts (HPC), total and intact cells), faecal indicators (enterococci) and opportunistic pathogens (Pseudomonas aeruginosa, non-tuberculous mycobacteria (NTM), Candida spp.) were measured in 36 ice-water machines on patient wards of a 772-bed hospital. Profile sampling was performed on five ice-water machines and adjacent faucets to identify sites of microbial proliferation.
Candida spp. were found in half of ice-water samples while enterococci and P. aeruginosa were present in six and 11 drain inlets respectively. NTM were measured in all ice-water samples and 35 out of 36 biofilms. Pre-filters and ice machines are sites for additional amplification: NTM densities were on average 1.3 log higher in water of ice machine flushed 5 min compared to flushed adjacent tap water.
Ice machine design needs to be adapted to reduce microbial proliferation. The absence of correlation between HPC densities (current microbial indicators) and NTM concentrations suggests a need for cleaning efficiency indicators better correlated with opportunistic pathogens. Cleaning and disinfection guidelines of ice machines in healthcare facilities need to be improved, especially when ice is given to the most vulnerable patients, and NTM may be an efficiency indicator.
医疗机构中的制冰机已被怀疑甚至与暴发和类暴发有关。这些设备的维护有指南，但没有明确的独立感染控制标准，对其微生物污染也知之甚少。
评估医疗机构制冰-水机中的微生物污染、扩增和机会性病原体的存在情况。
在一家拥有 772 张病床的医院的患者病房的 36 台制冰-水机中，测量了一般微生物指标（异养平板计数（HPC）、总细胞和完整细胞）、粪便指标（肠球菌）和机会性病原体（铜绿假单胞菌、非结核分枝杆菌（NTM）、假丝酵母属）的浓度。对 5 台制冰-水机和相邻水龙头进行了剖面采样，以确定微生物增殖的部位。
半数制冰-水样本中发现了假丝酵母属，6 个排水口中有 11 个含有肠球菌，而 P. aeruginosa 在 11 个排水口中有 11 个存在。所有的制冰-水样本和 36 个生物膜样本中都检测到了 NTM。预滤器和制冰机是进一步扩增的部位：与冲洗相邻的水龙头相比，冲洗制冰机 5 分钟后的水的 NTM 密度平均高出 1.3 个对数。
需要对制冰机设计进行改进以减少微生物的增殖。HPC 密度（当前的微生物指标）与 NTM 浓度之间缺乏相关性表明，需要使用与机会性病原体更好相关的清洁效率指标。需要改进医疗机构制冰机的清洁和消毒指南，特别是在给最脆弱的患者提供冰时，NTM 可能是一个效率指标。
