The COVID-19 outbreak has rapidly progressed worldwide finding the health system, scientists and society unprepared to face a little-known, fast spreading, and extremely deadly virus. Italy is one of the countries hardest hit by the pandemic, resulting in healthcare facilities bearing heavy burdens and severe restrictive measures. Despite efforts to clarify the virus transmission, especially in indoor scenarios, several aspects of SARS-CoV-2 spread are still rudimentary. This study evaluated the contamination of the air and surfaces by SARS-CoV-2 RNA in the COVID-19 isolation ward of a hospital in Milan, Italy. A total of 42 air and surface samples were collected inside five different zones of the ward including contaminated (COVID-19 patients' area), semi-contaminated (undressing room), and clean areas. SARS-CoV-2 RNA detection was performed using real time reverse transcription polymerase chain reaction. Overall, 24.3% of swab samples were positive, but none of these were collected in the clean area. Thus, the positivity rate was higher in contaminated (35.0%) and semi-contaminated (50.0%) areas than in clean areas (0.0%; P<0.05). The most contaminated surfaces were hand sanitizer dispensers (100.0%), medical equipment (50.0%), medical equipment touch screens (50.0%), shelves for medical equipment (40.0%), bedrails (33.3%), and door handles (25.0%). All the air samples collected from the contaminated area, namely the intensive care unit and corridor, were positive while viral RNA was not detected in either semi-contaminated or clean areas. These results showed that environmental contamination did not involve clean areas, but the results also support the need for strict disinfection, hand hygiene and protective measures for healthcare workers as well as the need for airborne isolation precautions.

COVID-19 疫情在全球范围内迅速蔓延，发现卫生系统、科学家和社会没有准备好面对一种鲜为人知、传播迅速且极其致命的病毒。意大利是受疫情影响最严重的国家之一，医疗机构负担沉重，限制措施严厉。尽管努力澄清病毒传播，特别是在室内场景中，但 SARS-CoV-2 传播的几个方面仍处于初级阶段。本研究评估了意大利米兰一家医院 COVID-19 隔离病房中 SARS-CoV-2 RNA 对空气和表面的污染。在病房的五个不同区域内共采集了 42 个空气和表面样本，包括污染区（COVID-19 患者区）、半污染区（更衣室）和清洁区。使用实时逆转录聚合酶链反应进行 SARS-CoV-2 RNA 检测。总体而言，24.3% 的拭子样本呈阳性，但这些样本均未在清洁区域收集。因此，污染区（35.0%）和半污染区（50.0%）的阳性率高于清洁区（0.0%；P <0.05）。污染最严重的表面是洗手液分配器（100.0%）、医疗设备（50.0%）、医疗设备触摸屏（50.0%）、医疗设备架子（40.0%）、床栏（33.3%）和门把手（25.0%） ）。从受污染区域（即重症监护室和走廊）采集的所有空气样本均呈阳性，而在半污染区域或清洁区域均未检测到病毒 RNA。这些结果表明，环境污染不涉及清洁区域，但结果也支持对医护人员进行严格消毒、手部卫生和防护措施的必要性，以及空气隔离预防措施的必要性。