key: cord-0751029-i7t94oyg authors: Lomont, Alexandra; Boubaya, Marouane; Khamis, Warda; Deslandes, Antoine; Cordel, Hugues; Seytre, Delphine; Alloui, Chakib; Malaure, Célie; Bonnet, Nicolas; Carbonnelle, Etienne; Cohen, Yves; Nunes, Hilario; Bouchaud, Olivier; Zahar, Jean-Ralph; Tandjaoui-Lambiotte, Yacine title: Environmental contamination related to SARS-CoV-2 in ICU-patients date: 2020-09-18 journal: ERJ Open Res DOI: 10.1183/23120541.00595-2020 sha: 71909346edca7e7a01c96da651d9c0fd3fe048b1 doc_id: 751029 cord_uid: i7t94oyg BACKGROUND: The coronavirus disease 2019 (Covid-19) outbreak is a main concern and data are lacking concerning risk of 2019 novel coronavirus (SARS-CoV-2) environmental contamination. OBJECTIVE: To identify risk factors of SARS-CoV-2 environmental contamination in Covid-19 patients admitted to the intensive care unit (ICU). METHODS: Prospective single center 1 day study in the ICU. Four surfaces (1/ the ventilator control screen, 2/ the control buttons of syringe pump 3/ bed rails, and 4/ the computer table located at more than a meter away of the patient) were systematically swabbed at least 8 h after any cleaning process. We analysed clinical, microbiological and radiological data to identify risk factor of SARS-CoV-2 environmental contamination. RESULTS: Forty percent of ICU patients did contaminate their environment. No particular trend emerged regarding the type of surface contaminated. Modality of oxygen support (high flow nasal cannula oxygenation, invasive mechanical ventilation, standard oxygen mask) was not associated with the risk of environmental contamination. By univariate analysis lymphopenia<0.7 G·L(−1) was associated to environmental contamination. CONCLUSION: Despite small effective, our study generate surprising results. Modality of oxygen support is not associated with risk of environmental contamination. Further studies are needed. The Covid-19 pandemic currently occurring has raised several concerns and questions. One of the major issues lies in our incomplete knowledge of the mode of transmission of the virus (SARS-CoV-2) responsible of the disease Covid-19 (1, 2) . Recent studies carried out regarding the risk of environmental contamination have shown conflicting results. Some authors suggested low or no environmental (3) contamination while others suggested a higher risk (4) . These discrepancies can be largely explained by many confounding factors, some related to patients profiles (such as symptoms severity) (5) , others related to the method of investigation (such as delay between the onset of symptoms and the samples collection). Patients admitted in intensive care units (ICU) for severe respiratory involvement of the Covid-19 could be more densely infected and responsible of more environmental contamination. The respiratory support required by ICU patient could increase environmental contamination because of aerosol generating procedures (AGP) such as oxygen therapy, noninvasive ventilation (NIV), high flow nasal cannula oxygenation (HFNO) and invasive mechanical ventilation (IMV) after endotracheal intubation. These therapies are thought to generate droplets or aerosols (6, 7) and could expose to a higher risk of environmental contamination and a higher risk of transmission to healthcare workers (7, 8) . A recent editorial tempered the risk of bio-aerosol dispersion due to HFNO use in SARS-CoV-2 patients (9) leading intensivists to more questions than answers for SARS-CoV-2 environmental contamination in Covid-19 patients admitted to the ICU. Avoiding health care worker infection is a main challenge to prevent health care systems collapse in a world health crisis. As personal protective equipment (PPE) supply could be difficult for ICU staff worldwide, improving our knowledge in environmental contamination in the ICU should be a priority. The aim of this study was to assess the burden of SARS-CoV-2 environmental contamination and to evaluate the risk factors associated with in an ICU population. This prospective single center one day study was conducted in the ICU of Avicenne hospital, a French 500-bed teaching hospital. All patients admitted to the ICU with a recent (less than 48 hours) SARS-CoV-2 positive research by RT-PCR were included. ICU ward was in neutral pressure, all patients were in single room with window open and door closed. No visitor was allowed except for patient at the end of life. Staff was continuously wearing a surgical mask, glasses (or visor) and overcoat. A FFP2 mask was used in case of aerosol-generating procedures, and gloves in case of exposition to body fluid. Four critical (i.e. frequently touched) surfaces were systematically swabbed at least 8 hours after any cleaning process. Those surfaces were: 1/ the ventilator control screen, 2/ the control buttons of syringe pump 3/ bed rails, and 4/ the computer table located at more than a meter away of the patient. For each patient demographics and medical history were recorded, focusing on data expected to modify viral excretion: immunocompromised status and lymphopenia (<0.7 G/L), smoking status, presence of fever, diarrhea or cough and Angiotensin Converting Enzyme (ACE) inhibitor use. Since several molecules were thought to influence viral load, their use was collected. In our hospital during the study period (Mars-April 2020), hydroxychloroquine was administered as a standard of care to all patients except contra-indication. The high frequency of side effects due to drug interactions made intensivist withdraw lopinavir use in the first days of the epidemic. Therefore none of the patient included in our study was treated with lopinavir. Remdezivir was not available in our hospital at the time of the study. At the time of the data collection, safety of steroid use in ICU patients infected with SARS-CoV-2 was unknown. Therefore the standard of care in our hospital was to not use steroids if SARS-CoV-2 was positive, which was the case of all patients included. Type of respiratory support (standard oxygen mask with spontaneous ventilation, HFNO, NIV and IMV), and delays supposed to impact the environmental contamination were recorded (delay between first symptoms and sampling, delay between hospital admission and sampling, delay between room admission and sampling). Risk factors of severe respiratory involvement Categorical variables were described with frequencies and percentages. Quantitative variables were described with median (interquartile range). The incidence of environmental contamination was estimated with 95% confidence interval (95%CI). The relation between contaminated and non-contaminated rooms and potential predictors was Neither delay between first symptoms and sampling, nor fever was associated with environmental contamination. In this prospective cohort study conducted in ICU patients we identified 40% environmental contamination. As several others studies (11, 12) , our results confirm the reality of SARS- (11) reported similar results on the computer mouse but no data is available about distance between computer mouse and the patients or modality of use of the computer (dedicated to healthcare workers or not). As all patients were admitted to the ICU, all had severe infection but none of the usual risk factors of viral spreading were associated with the risk of environmental contamination. Indeed, respiratory symptoms, thoracic HRCT, and threshold for ' RT-PCR positivity, were not associated with the risk of environmental contamination. More importantly and despite a low number of events, HFNO does not seem to be associated with a higher risk of contamination. As HFNO is described to be an AGP (7) Angiotensin Converting Enzyme 2 being the cell entry receptor of SARS-CoV-2 in human cells, we paid a special attention to patients with long-term prescription of ACE inhibitors. We highlighted a statistically significant association by univariate analysis between ACE inhibitors and less environmental contamination that we could not explain and needed to be confirmed by further investigation. Numerous studies were conducted during the epidemic period and showed conflicting results concerning the intensity and modality of SARS-CoV-2 environmental contamination (3, 4, (11) (12) (13) (14) (15) (16) (17) (18) . These differences can be explained by several factors. First of all some authors did not take into account the patients profiles in their studies (4, 11, 12) , neglecting the fact that viral shedding in the environment depends not only on viral load but also on the intensity of symptoms (5) , time elapsed between the first symptoms and sampling (5, 19) and different types of ventilation (7) . Also, several authors have carried out sampling under air treatment conditions that may affect the interpretation of the results (11) . Indeed, the creation of a turbulent flow (11, 20) and the negative pressure applied in some studies (4, 12) could have modified the risk of environmental contamination. Even though our unit had no air treatment and was under neutral pressure throughout the study period. One of the strengths of our study lies in taking into account different confounding factors as the clinical, radiological, therapeutic and virological one that could have explained or at least influenced the environmental contamination. Also, unlike the other studies we took the precaution to perform the sampling at least 8 hours away of any bio-cleaning to avoid false negative results. Our results suggest, without being able to demonstrate it, that environmental contamination seems to be more frequently linked to indirect contamination, much more than airborne contamination as suggested by some authors (21-25). As in other previous work, it allows us to reassure healthcare workers of the low risk associated with HFNO (9) and aerosol generating procedures (8) . This study had several limitations. At first, it is a monocentric study conducted in an ICU wards without any air treatment. Additionally, the low number of patients and events made impossible a multivariate analysis, thus our exploratory results on lymphopenia and ACE use need to be confirmed by further studies. Furthermore, presence of SARS-CoV-2 nucleic acid could be different information of infectivity of SARS-CoV-2. As we did not carry out viral culture, viability of the virus is uncertain. Most importantly this study does not analyze room air neither healthcare worker PPE samples. These data could be of most importance in order to safely avoid healthcare worker contamination. Further studies are needed to confirm our results and to assess airborne contamination. 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