Environmental contamination in a COVID-19 intensive care unit (ICU) - what is the risk?

BACKGROUND: The risk of environmental contamination by SARS-CoV-2 in the intensive care unit (ICU) is unclear We aimed to evaluate the extent of environmental contamination in the ICU and correlate this with patient and disease factors, including the impact of different ventilatory modalities METHODS: Observational study where surface environmental samples collected from ICU patient rooms and common areas were tested by SARS-CoV-2 PCR, with select samples from the common area tested on cell culture Clinical data were collected and correlated to presence of environmental contamination Results were compared to historical data from a previous study in general wards (GW) RESULTS: 200 samples from 20 patient rooms, and 75 samples from common areas and the staff pantry, were tested 14 rooms had at least one site contaminated, with an overall contamination rate of 14% (28 of 200 samples) Environmental contamination was not associated with day of illness, ventilatory mode, aerosol generating procedures, or viral load There was lower frequency of environmental contamination in ICU compared to GW rooms Eight samples from the common area were positive, though all were negative on cell culture CONCLUSION: Environmental contamination in the ICU is lower compared to the GW Use of mechanical ventilation or high-flow nasal oxygen was not associated with greater surface contamination, supporting their use and safety from an infection control perspective Transmission risk via environmental surfaces in the ICUs is likely to be low Nonetheless, infection control practices should be strictly reinforced, and transmission risk via droplet or airborne spread remains