Background Intensive care unit workers are at high risk of acquiring COVID-19 infection, especially when performing invasive techniques and certain procedures that generate aerosols (< 5 μm). Therefore, one of the objectives of the health systems should implement safety practices to minimize the risk of contagion among these health professionals. Monitoring environmental contamination of SARS-CoV-2 may help to determine the potential of the environment as a transmission medium in an area highly exposed to SARS-CoV-2, such as an intensive care unit. The objective of the study was to analyze the environmental contamination by SARS-CoV-2 on surfaces collected in an intensive care unit, which is dedicated exclusively to the care of patients with COVID-19 and equipped with negative pressure of – 10 Pa and an air change rate of 20 cycles per hour. Furthermore, all ICU workers were tested for COVID-19 by quantitative RT-PCR and ELISA methods. Results A total of 102 samples (72 collected with pre-moistened swabs used for collection of nasopharyngeal exudates and 30 with moistened wipes used in the environmental microbiological control of the food industry) were obtained from ventilators, monitors, perfusion pumps, bed rails, lab benches, containers of personal protective equipment, computer keyboards and mice, telephones, workers’ shoes, floor, and other areas of close contact with COVID-19 patients and healthcare professionals who cared for them. The analysis by quantitative RT-PCR showed no detection of SARS-CoV-2 genome in environmental samples collected by any of the two methods described. Furthermore, none of the 237 ICU workers was infected by the virus. Conclusions Presence of SARS-CoV-2 on the ICU surfaces could not be determined supporting that a strict cleaning protocol with sodium hypochlorite, a high air change rate, and a negative pressure in the ICU are effective in preventing environmental contamination. These facts together with the protection measures used could also explain the absence of contagion among staff inside ICUs.

中文翻译：

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对重症监护室收集的环境表面的 SARS-CoV-2 分析：保持欧内斯特·沙克尔顿的精神

背景 重症监护病房工作人员感染 COVID-19 的风险很高，尤其是在执行侵入性技术和某些会产生气溶胶（< 5 μm）的程序时。因此，卫生系统的目标之一应该是实施安全措施，以最大限度地减少这些卫生专业人员之间的传染风险。监测 SARS-CoV-2 的环境污染可能有助于确定环境在高度暴露于 SARS-CoV-2 的区域（例如重症监护病房）中作为传播媒介的潜力。该研究的目的是分析 SARS-CoV-2 在重症监护室收集的表面上的环境污染，该重症监护室专门用于护理 COVID-19 患者，并配备了 – 10 Pa 的负压和每小时换气 20 次。此外，所有 ICU 工作人员都通过定量 RT-PCR 和 ELISA 方法进行了 COVID-19 检测。结果 从呼吸机、监护仪、灌注泵、床栏、实验室共采集到 102 个样品（72 个用预湿拭子收集，用于收集鼻咽渗出液，30 个用湿巾收集用于食品工业的环境微生物控制）。长凳、个人防护设备容器、计算机键盘和鼠标、电话、工人鞋、地板以及与 COVID-19 患者和照顾他们的医疗保健专业人员密切接触的其他区域。定量 RT-PCR 分析显示，在通过上述两种方法中的任何一种收集的环境样本中，均未检测到 SARS-CoV-2 基因组。此外，237 名 ICU 工作人员均未感染该病毒。结论 无法确定 ICU 表面是否存在 SARS-CoV-2，支持在 ICU 中使用次氯酸钠、高换气率和负压的严格清洁方案可有效防止环境污染。这些事实以及所使用的保护措施也可以解释重症监护病房内工作人员之间没有传染的原因。