WHO recommends masks indoors if ventilation poor

The World Health Organization yesterday recommended wearing facemasks when indoors with other people, if the ventilation has been deemed inadequate, in an update to its Covid-19 guidance on masks. 

The new recommendations apply in areas of known or suspected cluster or community transmission of the new coronavirus.

"WHO advises that the general public should wear a non-medical mask in indoor (eg shops, shared workplaces, schools) or outdoor settings where physical distancing of at least one metre cannot be maintained," the new guidance says.

"If indoors, unless ventilation has been assessed to be adequate, WHO advises that the general public should wear a non-medical mask, regardless of whether physical distancing of at least one metre can be maintained."

The UN health agency also urged people not to wear masks during vigorous physical activity, and not to use masks with valves, saying they bypassed the filtration function of the facemask.

In its fourth update on mask guidance during the pandemic -- the last was in August -- the WHO called for wider use in healthcare settings, especially in areas plagued by infection clusters or community transmission.

In such cases, the WHO recommended "universal masking for all persons (staff, patients, visitors, service providers and others) within the health facility (including primary, secondary and tertiary care levels; outpatient care; and long-term care facilities)"

It also called for the wearing of masks by inpatients when physical distancing of at least one metre cannot be maintained or when patients were outside of their care areas.