Bacterial but no SARS-CoV-2 contamination after terminal disinfection of tertiary care intensive care units treating COVID-19 patients

Hofmaenner, Daniel A.; Wendel Garcia, Pedro David; Duvnjak, Branko; Chakrakodi, Bhavya; Maier, Julian D.; Huber, Michael; Huder, Jon; Wolfensberger, Aline; Schreiber, Peter W.; Schuepbach, Reto A.; Zinkernagel, Annelies S.; Buehler, Philipp K.; Brugger, Silvio D.

BACKGROUND: In intensive care units (ICUs) treating patients with Coronavirus disease 2019 (COVID-19) invasive ventilation poses a high risk for aerosol and droplet formation. Surface contamination of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) or bacteria can result in nosocomial transmission. METHODS: Two tertiary care COVID-19 intensive care units treating 53 patients for 870 patient days were sampled after terminal cleaning and preparation for regular use to treat non-COVID-19 patients. RESULTS: A total of 176 swabs were sampled of defined locations covering both ICUs. No SARS-CoV-2 ribonucleic acid (RNA) was detected. Gram-negative bacterial contamination was mainly linked to sinks and siphons. Skin flora was isolated from most swabbed areas and Enterococcus faecium was detected on two keyboards. CONCLUSIONS: After basic cleaning with standard disinfection measures no remaining SARS-CoV-2 RNA was detected. Bacterial contamination was low and mainly localised in sinks and siphons.