Environmental Contamination With SARS-CoV-2 in a Hospital Setting.

Background The coronavirus disease 2019 (COVID-19) pandemic is a global concern and has changed the way we practice medicine in acute hospital settings. This is particularly true with regard to patient triage, patient risk assessment, use of personal protective equipment, and environmental disinfection. Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily through inhalation of respiratory droplets generated through talking, coughing, or sneezing. There is, however, a potential risk that respiratory droplets settling on inanimate surfaces and objects in the hospital environment could provide a reservoir for nosocomial infections in patients and pose a healthcare risk to medical staff. Indeed, there have been previous reports of healthcare-associated outbreaks in hospitals. Several authors have argued that the risk of transmission via fomites may be insignificant. It is, however, not clear what proportion of SARS-CoV-2 infections are attributable to direct contact with fomites; a few reports have indicated possible transmission via this route. Environmental contamination with SARS-CoV-2 in healthcare institutions has been shown to vary according to the function or service provided by a unit or department. Information that identifies hospital areas that have a propensity for higher environmental burden may improve the practice of infection control and environmental cleaning and decontamination in healthcare institutions. This study aimed to investigate environmental SARS-CoV-2 contamination in the clinical areas of patients with COVID-19 infection. Methodology We conducted a cross-sectional study performing swabbing of frequently touched surfaces, equipment, and ventilation ducts in five specific clinical areas of Peterborough City Hospital which is part of the North West Anglia NHS Foundation Trust. The five clinical areas that were chosen for swabbing were the Emergency Department (ED), Intensive Care Unit (ICU), Isolation Ward, Respiratory Ward, and a Gastroenterology Ward that was serving as a receiving ward at the height of the second COVID-19 infection wave in the United Kingdom. Surfaces to be swabbed were divided into the patient zone, doctor zone, and nursing zone. Swabs from the chosen surfaces were collected on two consecutive days. A total of 158 surface swabs were collected during the second wave of the COVID-19 pandemic. SARS-CoV-2 RNA was detected by reverse transcription polymerase chain reaction. Results The most contaminated clinical areas were the three receiving wards where 12% (11/96) of the swabs were positive. Inside the patient rooms, these surfaces included bed rails and controls, bedside tables, television screens, remote control units, and the room ventilation system. Outside the patient room, these surfaces included mobile computers and computer desk surfaces in the doctors' offices. All swabs taken from the ED and ICU were found to be negative. Conclusions Our study confirms the potential infection risks posed by environmental contamination with the SARS-CoV-2 virus. This highlights the importance of adequate environmental cleaning for proper infection control and prevention in healthcare settings.

Kumar S ，Bukhari I ，Afzal Z ，Tucker S ，Lucas-Evans R ，Dayala A ，Mlangeni D ... -  《Cureus》

Monitoring COVID-19 Transmission Risks by Quantitative Real-Time PCR Tracing of Droplets in Hospital and Living Environments.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination occurs through droplets and biological fluids released in the surroundings from patients or asymptomatic carriers. Surfaces and objects contaminated by saliva or nose secretions represent a risk for indirect transmission of coronavirus disease 2019 (COVID-19). We assayed surfaces from hospital and living spaces to identify the presence of viral RNA and the spread of fomites in the environment. Anthropic contamination by droplets and biological fluids was monitored by detecting the microbiota signature using multiplex quantitative real-time PCR (qPCR) on selected species and massive sequencing on 16S amplicons. A total of 92 samples (flocked swabs) were collected from critical areas during the pandemic, including indoor (three hospitals and three public buildings) and outdoor surfaces exposed to anthropic contamination (handles and handrails, playgrounds). Traces of biological fluids were frequently detected in spaces open to the public and on objects that are touched with the hands (>80%). However, viral RNA was not detected in hospital wards or other indoor and outdoor surfaces either in the air system of a COVID hospital but only in the surroundings of an infected patient, in consistent association with droplet traces and fomites. Handled objects accumulated the highest level of multiple contaminations by saliva, nose secretions, and fecal traces, further supporting the priority role of handwashing in prevention. In conclusion, anthropic contamination by droplets and biological fluids is widespread in spaces open to the public and can be traced by qPCR. Monitoring fomites can support evaluation of indirect transmission risks for coronavirus or other flu-like viruses in the environment.IMPORTANCE Several studies have evaluated the presence of SARS-CoV-2 in the environment. Saliva and nasopharyngeal droplets can land on objects and surfaces, creating fomites. A suitable indicator would allow the detection of droplets or biofluids carrying the virus. Therefore, we searched for viral RNA and droplets and fomites on at risk surfaces. We monitored by qPCR or next generation sequencing (NGS) droplets through their microbiota. Although the study was performed during the pandemic, SARS-CoV-2 was not significantly found on surfaces, with the only exception of environmental areas near infectious patients. Conversely, anthropic contamination was frequent, suggesting a role for biofluids as putative markers of indirect transmission and risk assessment. Moreover, all SARS-CoV-2-contaminated surfaces showed droplets' microbiota. Fomite monitoring by qPCR may have an impact on public health strategies, supporting prevention of indirect transmission similarly to what is done for other communicable diseases (e.g., influenza and influenza-like infections).

Piana A ，Colucci ME ，Valeriani F ，Marcolongo A ，Sotgiu G ，Pasquarella C ，Margarucci LM ，Petrucca A ，Gianfranceschi G ，Babudieri S ，Vitali P ，D'Ermo G ，Bizzarro A ，De Maio F ，Vitali M ，Azara A ，Romano F ，Simmaco M ，Romano Spica V ... -  《mSphere》

Role of hospital environmental surfaces in the transmission of the severe acute respiratory syndrome - Coronavirus-2.

Severe acute respiratory syndrome - Coronavirus-2 (SARS-CoV-2) is mainly transmitted via respiratory secretions through coughing, sneezing, or contact with contaminated surfaces. This virus can be present in feces and many body fluids. The study aimed to screen the hospital environment as a potential source for SARS-CoV-2 transmission and identify the hospital zones with the highest contamination levels. Swabs were collected from different sites in the hospital before and after routine cleaning/disinfection, transported in vials containing 1-3 mL of viral transport medium, and stored at -80 ℃ as soon as possible until the time of testing. The real-time reverse-transcription PCR (rRT-PCR) system targeting RNA-dependent RNA polymerase and E genes was used to detect the SARS-CoV-2 RNA. Moderate environmental contamination by SARS-CoV-2 RNA was detected by rRT-PCR before routine cleaning/disinfection (52% of the swabs were positive). The hospital surfaces with the highest contamination levels were elevators' buttons, sinks and faucets' handles at the waiting rooms, patient's room and bathroom, call buttons and telephones in the patient's room, toilet bowl surface, the doorknob and light switches at the X-ray room, and the computer keyboard at the staffroom. All the swabs collected after routine cleaning/disinfection were negative for SARS-CoV-2 RNA by rRT-PCR. The hospital environment is a high-risk area that can be contaminated by SARS-CoV-2 through contact, respiratory, and maybe fecal shedding of the virus. To limit this fatal virus transmission, strict adherence to proper hand hygiene with frequent optimal decontamination of hospital environmental surfaces is essential.

El-Masry EA ，Taha AE 《Journal of Infection in Developing Countries》

SARS-CoV-2 RNA contamination on surfaces of a COVID-19 ward in a hospital of Northern Italy: what risk of transmission?

D'accolti M ，Soffritti I ，Passaro A ，Zuliani G ，Antonioli P ，Mazzacane S ，Manfredini R ，Caselli E ... -  《-》

Surfaces and equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the emergency department at a university hospital.

Environmental contamination by patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through respiratory droplets suggests that surfaces and equipment could be a medium of transmission. We aimed to assess the surface and equipment contamination by SARS-COV-2 of an emergency department (ED) during the coronavirus infectious disease-2019 (COVID-19) outbreak. We performed multiple samples from different sites in ED patients care and non-patient care areas with sterile premoistened swabs and used real-time reverse transcriptase polymerase chain reaction (RT-PCR) to detect the presence of SARS-CoV-2 ribonucleic acid (RNA). We also sampled the personal protective equipment (PPE) from health care workers (HCWs). Among the 192 total samples, 10 (5.2%) were positive. In patient care areas, 5/46 (10.9%) of the surfaces directly in contact with COVID-19 patients revealed the presence of SARS-CoV-2 RNA, and 4/56 (7.1%) of the surfaces that were not directly in contact with COVID-19 patients were positive. SARS-CoV-2 RNA was present only in the patients' examination and monitoring rooms. Before decontamination SARS-CoV-2 RNA was present on the saturation clip, the scuff for blood pressure measurement, the stretcher, the plastic screens between patients and the floor. After decontamination, SARS-CoV-2 RNA remained on the scuff, the stretcher and the trolleys. All samples from non-patient care areas or staff working rooms were negative. Only one sample from the PPE of the HCWs was positive. Our findings suggest that surfaces and equipment contamination by SARS-CoV-2 RNA in an ED during the COVID-19 outbreak is low and concerns exclusively patients' examination and monitoring rooms, preserving non-patient care areas.

Peyrony O ，Ellouze S ，Fontaine JP ，Thegat-Le Cam M ，Salmona M ，Feghoul L ，Mahjoub N ，Mercier-Delarue S ，Gabassi A ，Delaugerre C ，Le Goff J ，Saint-Louis CORE (COvid REsearch) group ... -  《-》