A recent study published in Respiratory Medicine found that COVID-19 genetic material was frequently present in hospital air during community outbreaks, even in well-ventilated areas.
Researchers from the Kirby Institute conducted air and surface sampling in the emergency department (ED) and intensive care unit (ICU) of a large Sydney hospital during two COVID-19 waves between November 2023 and July 2024. They discovered that 39% of aerosol samples tested positive for the virus.
The ED had a significantly higher detection rate than the ICU. Of the positive samples, 80% were from the ED and 20% from the ICU.
In the ED, the acute-care area, public waiting room, and a walkway were key hotspots. In the ICU, positive samples were found in a staff tearoom and near a COVID patient’s room.
The researchers noted that the higher detection rate in the ED suggests it poses a greater risk than the ICU, especially in areas like the waiting room and acute-care area.
Significantly, four positive samples were taken in the ED before the hospital declared an outbreak on November 8, showing the potential of using aerosol sampling for early outbreak detection.
Surface contamination was less common, with only two of 28 samples testing positive, both from a COVID patient’s room.
The study highlights that despite good ventilation, more than one-third of aerosol samples contained viral RNA, suggesting ventilation alone may not protect staff and patients during high community transmission periods.
The authors emphasise the need for high-efficiency particulate air (HEPA) filtration and respiratory protection for staff, particularly in busy areas like emergency departments. They suggest portable air purifiers and better ventilation maintenance could help reduce transmission risks.
