J Hosp Infect. 2020 Aug 20:S0195-6701(20)30401-1. doi: 10.1016/j.jhin.2020.08.014. Online ahead of print.
BACKGROUND: Identifying the extent of environmental contamination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for infection control and prevention. The extent of environmental contamination has not been fully investigated in the context of severe coronavirus disease (COVID-19) patients.
AIM: To investigate environmental SARS-CoV-2 contamination in the isolation rooms of severe COVID-19 patients requiring mechanical ventilation or high-flow oxygen therapy.
METHODS: We collected environmental swab samples and air samples from the isolation rooms of three COVID-19 patients with severe pneumonia. Patient 1 and Patient 2 received mechanical ventilation with a closed suction system, while Patient 3 received high-flow oxygen therapy and noninvasive ventilation. Real-time reverse transcription polymerase chain reaction (rRT-PCR) was used to detect SARS-CoV-2; viral cultures were performed for samples not negative on rRT-PCR.
FINDINGS: Of the 48 swab samples collected in the rooms of Patient 1 and Patient 2, only samples from the outside surfaces of the endotracheal tubes tested positive for SARS-CoV-2 by rRT-PCR. However, in Patient 3's room, 13 of the 28 environmental samples (fomites, fixed structures, and ventilation exit on the ceiling) showed positive results. Air samples were negative for SARS-CoV-2. Viable viruses were identified on the surface of the endotracheal tube of Patient 1 and seven sites in Patient 3's room.
CONCLUSION: Environmental contamination of SARS-CoV-2 can be a route of viral transmission. However, it might be minimized when patients receive mechanical ventilation with a closed suction system. These findings can provide evidence for guidelines for the safe use of personal protective equipment.