Open the windows to curb Covid spread: Experts
Opening windows and ventilating spaces ought to be at the heart of efforts to avoid the spread of Covid-19, a group of professionals said Thursday, arguing that confusion over airborne transmission meant this simple measure had been overlooked.
Mounting evidence convinced many places to look at mask-wearing suggestions and health authorities have for months said that crowded, badly ventilated indoor spaces certainly are a particular risk.
The virus is most probably to spread through inhalation at close range rather than through contact with surfaces or at long range, said respiratory experts said in a commentary published in the BMJ medical journal.
But despite this, the role of aerosol transmission gets "only a cursory mention in a few infection control guidelines."
"People are more likely to be infected in a room with windows that can not be opened or lacking any ventilation system," they said.
The authors, including Julian Tang from the University of Leicester and Linsey Marr from Virginia Tech, said part of the situation has been a insufficient clarity in this is of terms such as for example "droplet" and "airborne" when describing transmission.
"Essentially, if you can inhale particles - irrespective of their size or name - you are sucking in aerosols," they said.
"Although this may happen at long range, it really is more likely when near someone, as the aerosols between two people are a lot more concentrated at short range, rather like being near someone who's smoking."
At the beginning of the pandemic, health authorities, including the World Health Organization (WHO), discounted the opportunity that simply breathing could send infectious micro-droplets in to the air.
But they did a U-turn as authorities piled on pressure and evidence mounted.
The BMJ commentary said precautions like wearing masks, keeping one's distance and reducing crowding in indoor spaces would all help curb viral spread, whether it had been through inhaled particles or direct contact with surfaces.
But it stressed a crucial difference was "the need for added focus on ventilation because the tiniest suspended particles can remain airborne all night, and these constitute an essential route of transmission."
In March, the WHO released a guidance document encouraging better ventilation in buildings.
It said that while "knowledge gaps" remain, transmission of the virus that triggers Covid-19 is specially effective in crowded, confined indoor spaces where there is poor or no ventilation. --AFP
