Environmental detection of SARS-CoV-2 in hospital rooms in different wards of a university hospital.

Background: Transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can occur through direct, indirect, or close contact with infected people. However, the extent of environmental contamination is unknown. The nature of the relation between patients' symptoms and SARS-CoV-2 environmental shedding remains unclear. The aim of this study was to assess the relationship between patient coronavirus disease 2019 (COVID-19) status and environmental contamination.

Methods: Between May and November 2020, environmental swabs were taken before and after room disinfection at day 7 after symptom onset in a cohort of patients clinically or biologically diagnosed with COVID-19. Twelve surfaces per room were collected in 13 rooms. Sample analysis was performed by reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 detection [SARS-CoV-2 R-Gene (biomérieux, Marcy l'Etoile, France)]. Clinical data (day of illness, symptoms, RT-PCR results) was collected from the clinical software.

Results: Five medical units were included in the study. Of 156 samples collected in 13 rooms, five rooms (38.5%) presented 11 SARS-CoV-2-positive samples. These positive samples were detected on eight different surfaces. There was no association between detection of SARS-CoV-2 and patient age (P=1) or patient symptoms (P=0.3).

Conclusion: Viral shedding during COVID-19 appears to be unrelated to the presence of symptoms, patient age, and low-value cycle threshold of patient's test. This study supports the evidence for the environmental shedding of SARS-CoV-2 until at least 7 days after symptom onset. It emphasizes the need for strict compliance with contact precautions, hand hygiene, the correct use of personal protective equipment and room disinfection for the routine care of patients with COVID-19.