COVID-19 genetic material has been frequently detected in hospital air during community outbreaks, even in well-ventilated areas, according to a recent study published in Respiratory Medicine. Researchers from the Kirby Institute conducted air and surface sampling in the emergency department (ED) and intensive care unit (ICU) of a large hospital in Sydney, Australia, during two COVID-19 waves between November 2023 and July 2024. Their tests revealed that 39% of aerosol samples were positive for SARS-CoV-2 RNA.
Detection rates were significantly higher in the ED compared to the ICU. In fact, 80% of the positive samples were collected from the ED, highlighting areas such as the acute-care zone and public waiting room as key hot spots for virus presence. In the ICU, positive samples were found in a staff tearoom and near a negative-pressure room housing a COVID patient.
The study identified four positive aerosol samples collected in the ED a week before the hospital announced a multi-ward outbreak, suggesting that aerosol sampling could help detect outbreaks before they grow large. Conversely, surface contamination was less frequent, with only 7% of surface samples testing positive, both from an infected ICU patient’s room.
The authors noted that during high community transmission periods, sufficient air changes in hospital ventilation systems might not be enough to safeguard staff and patients. They recommend using high-efficiency particulate air (HEPA) filtration and ensuring staff access to respiratory protection during outbreaks. They also highlighted the need for improved ventilation and strategies to protect patients in high-traffic ED waiting areas, where various infectious diseases may circulate.
