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Three Part Question

In [NHS professionals treating patients with influenza or influenza-like illness] is the [FFP3 filtering facemask effective] at [protecting against disease transmission]?

Clinical Scenario

You are involved in close contact management with a patient with possible influenza A(H1N1) and are advised to wear personal protective equipment. This involves wearing the FFP3 filtering facemask. You wonder how effective it is at protecting the wearer.

Search Strategy

MEDLINE (1950 to June week 2 2009) and EMBASE, via OVID interface.
BSI, WHO, Department of Health, Health protection agency websites.

{[exp Respiratory Protective Devices/] OR [exp Masks/] OR [respirator.mp.] OR [ffp3.mp.] OR [filtering mask.mp.] OR [filtering face pieces.mp.]} AND {[exp Disease Transmission, Infectious/] OR [Influenza, Human/] OR [exp Disease Outbreaks/] OR [exp Communicable Disease Control/] OR [pandemic.mp.]} LIMIT to [English language and humans]
The search returned 495 papers, only three of which were relevant to the FFP3 masks used in the Manchester Royal Infirmary emergency department. One of these three papers was relevant to the question. This was a ‘UK simulation exercise’. The search was re-executed using only the term [ffp3.mp.], which returned the same 3 papers. The simulation exercise paper was excluded as it offered no information on efficacy, however its references were scrutinised for relevant material. The references offered several more papers relating to the mask but again offered no evidence.

Multiple websites were also searched for information regarding the efficacy of the FFP3 mask. This included the BSI group, World Health Organisation, Department of Health, Centre for Disease Control and Progression and Health Protection Agency websites. Although guidance on the use of the FFP3 was offered, there was no evidence or references to follow-up.

Comment(s)

There is no evidence available on the efficacy of the FFP3 respirator with regard to protection against viral particles, and therefore disease transmission. This may be due to material being classified. All guidance on personal protective equipment found on relevant websites suggests that the FFP3 be used in any scenario with aerosol generating procedures. An evidence-based guidance document was found through scrutinising references of the UK simulation exercise paper. It stated that the evidence for use of the FFP3 respirator was grade D and based on either case reports or expert opinion. Links to these sources could not be located.

Clinical Bottom Line

Despite the lack of evidence available, it is still highly recommended that the FFP3 respirator should be used in any situation with aerosol generating procedure as suggested by the global health authority.