Coronavirus: Upgrading masks dramatically cuts infection, study finds

Upgrading face masks in hospitals dramatically lowers the incidence of Covid-19 infections among health workers, a study has found.

Prior to December, staff on coronavirus wards at Addenbrooke’s Hospital wore fluid resistant surgical masks (FRSMs), before these were upgraded to filtering face piece 3 (FFP3) respirators.

The decision was taken after data showed that these medics were 47 times more likely to contract the disease than their peers.

After the change, the transmission rate among staff on Covid-19 wards fell significantly, meaning it was equivalent to the level of cases seen in other parts of the hospital.

Dr Chris Illingworth, an academic involved in the research, said: “Before the face masks were upgraded, the majority of infections among healthcare workers on the Covid-19 wards were likely due to direct exposure to patients with Covid-19.

“Once FFP3 respirators were introduced, the number of cases attributed to exposure on Covid-19 wards dropped dramatically - in fact, our model suggests that FFP3 respirators may have cut ward-based infection to zero.”

The government recommends that FFP3 respirators should be used by staff performing aerosol-generating procedures such as intubation on coronavirus patients.

Matt Butler, consultant physician at Addenbrookes Hospital, told The Independent: “Addenbrookes Hospital upgraded to tighter fitting face masks called FFP3 respirators in December 2020 and examined the impact this had on staff infection rates.

“We found that prior to the change staff were at a 47 fold excess risk if they were face to face with Covid-19 patients compared to unexposed NHS staff. This risk was entirely eliminated by the use of the higher quality FFP3 respirators. This meant that even though the masks had only been in place for three weeks on only five wards, between six to fourteen staff members were prevented from becoming infected.”

He added: “If we scaled up this effect across the NHS it will mean thousands of healthcare workers will be prevented from becoming infected especially in light of the Delta variant and its associated escape from vaccine induced immunity.”

He added the researchers were now calling for an immediate change to infection prevention control guidance across the NHS with all staff allowed to use FFP3 respirators.

Updated guidance now means NHS trusts are obliged to look at the coronavirus risk facing their staff and provide FFP3 respirators where necessary.

Dr Michael Weekes, who works at the medicine department at Cambridge University, said now was the time to reassess the PPE given to frontline health professionals.

He added: “Upgrading the equipment so that FFP3 masks are offered to all healthcare workers caring for patients with Covid-19 could reduce the number of infections, keep more hospital staff safe and remove some of the burden on already stretched healthcare services caused by absence of key staff due to illness.

“Vaccination is clearly also an absolute priority for anyone who hasn’t yet taken up their offer.”

The Royal College of Nursing (RCN) wants to see better respiratory protective equipment given to health workers.

Rose Gallagher, the RCN’s lead for infection prevention and control, said: “We are still seeing cases of Covid-19, even from some who have been vaccinated, and it is vital staff are fully protected and there are no attempts to restrict or ease off on measures to further reduce the risk of infection.”

Although the research from Addenbrooke’s has yet to be peer-reviewed, authors said they were releasing it early due to its potential importance.

Additional reporting from PA