Researchers at Cambridge University have found that the quality of face masks worn by healthcare workers can dramatically reduce their chances of contracting Covid-19.

The research has not yet been peer-reviewed, but has been released early due to the “urgent need to share information relating to the pandemic,” says the university.

The researchers found that high-grade protective facemasks, such as filtering face piece 3 (FFP3) respirators, provide up to 100% protection against direct, ward-based Covid-19 infection.

In another study, researchers from the University of Cambridge found that surgical face masks provided little protection from the virus. This is because they fit loosely on the face and do not protect the wearer from smaller airborne particles, known as aerosols. However, they do protect you against larger droplets.

Because FFP3 facemasks are tightly fitted and are specifically designed to filter out aerosols, they provide a much higher level of protection. For this reason, professional bodies have been campaigning for the government to provide all healthcare workers with these highly protective facemasks.

Until recently, guidance recommended that healthcare workers on Covid wards use surgical facemasks 

Until recently, UK Infection Protection Control guidance recommended that healthcare workers caring for patients with Covid-19 should use fluid resistant surgical masks type IIR (FRSMs) as respiratory protective equipment. Healthcare workers were only advised to use FPP3 masks if aerosol-generating procedures were being carried out (for example, inserting a breathing tube into the patient’s windpipe).

The guidance has recently been updated to oblige NHS organisations to assess the risk that Covid-19 poses to staff and provide FFP3 respirators where appropriate. However, some professional bodies, such as the BMA, want all NHS Trusts to provide their staff with FPP3 masks whenever they are dealing with a Covid-19 patient.

The BMA particularly want protection for staff working on ‘red’ Covid wards, after the study found that staff on these wards faced a risk that was 47 times higher than those on ‘green’ or non-Covid wards, despite the fact that staff were carrying out all the relevant infection control measures.

Once the researchers swapped staff’s surgical facemasks for FPP3 respirators, they found that the incidence of infection on Covid and non-Covid wards was similar; whereas previously, cases were far higher on Covid-19 wards.

The results suggest that almost all cases among healthcare workers on non-Covid-19 wards were caused by community-acquired infection, whereas cases among healthcare workers on Covid-19 wards were caused by both community-acquired infection and direct, ward-based infection from patients with Covid-19 – but that these direct infections were effectively mitigated by the use of FFP3 respirators.

"The new health secretary has an opportunity to do the right thing here"

Dr Devender Khurana, BMA regional Council Chair for the East of England, is among those campaigning for better PPE. He said: “For some time now it’s been fairly widely accepted that FFP3 masks should be given to all NHS staff who treat patients with Covid-19 or in areas where they are exposed to airborne particles from a patient.

“Much like Addenbrooke’s hospital in Cambridge, some NHS Trusts are already providing FPP3 masks and sufficient occupational protection to all relevant staff. This is despite the fact that Public Health England guidance still doesn’t recommend wearing FFP3 masks outside of areas where there is the highest risk of infection.”

“Considering the risk here it’s imperative that there is now clear guidance from Government which ensures that all Covid-19 facing NHS staff have sufficient occupational protection. We ask all Trusts to learn from this evidence and provide FPP3 masks to be worn by all relevant staff when dealing with Covid-19 patients. The new health secretary, Sajid Javid, has an opportunity to do the right thing here so we’d urge him to take this issue seriously and act on the evidence available to us in order to avoid even more healthcare workers being needlessly exposed to Covid-19.”