ECJ EUROPEAN Cleaning Journal

Fifty per cent of air samples taken from hospital hallways and more than 20 per cent from bathrooms revealed high levels of coronavirus in a series of studies.

Researchers analysed the results of 24 studies from eight countries between January 1 and October 27 2020. Air samples from ICU rooms were found to be more than twice as likely to be positive for genetic material of the virus, while more than 23 per cent of samples taken from toilets and/or bathrooms tested positive for viral RNA.

Researchers say the high incidence of positive tests in the washrooms could be due to the small size of the rooms coupled with poor ventilation and the presence of viral material in stool samples. "Toilet flushing may lead to the aerosolisation of RNA in small and non-ventilated toilets or bathrooms," wrote the authors.

Around 12 per cent of staff areas including meeting and dining rooms proved positive for the virus. According to the authors, this is consistent with the possible cross-transmission of Covid-19 among healthcare professionals during breaks in small rooms when face masks are frequently removed.

It was unclear from the studies whether the virus levels present in hospital environments would be sufficiently viable to infect people. "However, high viral loads found in toilets and bathrooms, staff areas and public hallways argue for a careful consideration of these areas for the prevention of Covid-19 transmission," wrote the authors.

The team, from Central Hospital at the University of Nantes, in France, says the high concentration of the virus plus the fact people were being cramped together in poorly-ventilated rooms could explain why frontline healthcare workers frequently contract the virus despite wearing personal protective equipment.