Detection of SARS-CoV-2 within the healthcare environment: a multicentre study conducted during the first wave of the COVID-19 outbreak in England
Moore G., Rickard H., Stevenson D., Bou PA., Pitman J., Crook A., Davies K., Spencer A., Burton C., Easterbrook L., Love HE., Summers S., Welch SR., Wand N., Thompson K-A., Pottage T., Richards KS., Dunning J., Bennett A.
AbstractUnderstanding how Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is spread within the hospital setting is essential if staff are to be adequately protected, effective infection control measures are to be implemented and nosocomial transmission is to be prevented.The presence of SARS-CoV-2 in the air and on environmental surfaces around hospitalised patients, with and without respiratory symptoms, was investigated. Environmental sampling was carried out within eight hospitals in England during the first wave of the COVID-19 outbreak. Samples were analysed using reverse transcription polymerase chain reaction (RT-PCR) and virus isolation assays.SARS-CoV-2 RNA was detected on 30 (8.9%) of 336 environmental surfaces. Ct values ranged from 28·8 to 39·1 equating to 2·2 × 105 to 59 genomic copies/swab. Concomitant bacterial counts were low, suggesting the cleaning performed by nursing and domestic staff across all eight hospitals was effective. SARS-CoV-2 RNA was detected in four of 55 air samples taken <1 m from four different patients. In all cases, the concentration of viral RNA was low and ranged from <10 to 460 genomic copies per m3 of air. Infectious virus was not recovered from any of the PCR positive samples analysed.Effective cleaning can reduce the risk of fomite (contact) transmission but some surface types may facilitate the survival, persistence and/or dispersal of SARS-CoV-2. The presence of low or undetectable concentrations of viral RNA in the air supports current guidance on the use of specific PPE ensembles for aerosol and non-aerosol generating procedures.