Forum Navigation
You need to log in to create posts and topics.

Mask use in public and re-use of PPE - CDC

Briefly:

  • The CDC is now supporting widespread mask use by the public
  • China and other east Asian health authorities have been recommending this for many years.
  • The US CDC also gives guidance on decontamination and reuse of masks, including leaving them for five days before reuse, and cites studies show coronavirus extinction on cardboard in 48 hours (5 days providing a margin of error).
  • Some evidence that surgical masks are as good as N95s in preventing SARS  and influenza transmission, when worn in public.
  • Also evidence for non-medical use, and when there is no alternative, that homemade masks might help, including cloth masks (which can be washed in hot soapy water and reused).

In more detail:

CDC policy on mask use

There has been a significant shift in American CDC policy to increased wearing of masks by medical frontline staff and the public, in line with Chinese and east Asian practice.

Our MoH is following the WHO position; its guidance is here.

Many of our facilities’ staff now wear masks for each consultation.

See forum posts:

Masks reduced transmission of SARS by 70% – Cochrane analysis

Evidence for aerosol transmission of coronaviridae (new)

Reuse of PPE

The CDC has released a statement on reusing masks in case supplies run low, which may be useful for facilities that wish to prepare for a mask shortage.

The United States is at a different stage of the pandemic, and emphasises that reuse is not the usual ‘standard of care’.

Key points:

  • “ultraviolet germicidal irradiation, vaporous hydrogen peroxide, and moist heat showed the most promise as potential methods to decontaminate FFRs (filtering facepiece respirators).”
  • Strategies for FFR extended use and reuse (without decontamination of the respirator) are currently available from CDC’s National Institute for Occupational Safety and Health (NIOSH)
  • It references a paper on SARS-COV-2 survival in the environment on different materials,  where the figure for near-extinction on cardboard is given as two days.
  • It suggests healthcare workers store their masks in a breathable paper bag at the end of each shift and re-use after five days.

The FDA has approved a specific ‘Battelle’ system for hydrogen peroxide decontamination of masks.

Homemade masks

A Cambridge study finds homemade masks vary in effectiveness depending on material but are better than nothing:

“The median-fit factor of the homemade masks was one-half that of the surgical masks. Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask. Our findings suggest that a homemade mask should only be considered as a last resort to prevent droplet transmission from infected individuals, but it would be better than no protection.”

 

Thanks for breaking down this useful information .

There is such a mass of information flooding to us and Urgent Care emails and forum have been a great source to reinforce the NEED for PPE for all contact .

 

BMJ  article 9/4/20 reviews the literature and conclude people should wear masks when they go out in public during this pandemic.

"In conclusion, in the face of a pandemic the search for perfect evidence may be the enemy of good policy. As with parachutes for jumping out of aeroplanes,38 it is time to act without waiting for randomised controlled trial evidence.39"

Closer reading of the BMJ article and the information put out by the CDC on mask use indicates that there is NO evidence to support mask use in public but the lack of evidence AND the 'low risk' may be worth doing (this is mostly interpreting anecdotal evidence from SE Asia's relative success (that may need air quotes now too) given the low 'side effects' (and possible shortage faced by frontline workers). The real purpose of a face mask is to limit spread by a sick person (or hopefully asymptomatic carriers).

In hospital, the current recommendation is for work in the COVID hot-zones is facemask only instead of N95 respirators when doing potentially aerosolising procedures. This is not really recommended by the CDC either that state using a facemask is better than nothing if N95 respirators are not available. The smart use of limited resources is our best option and there will have to be a degree of common sense in the use of PPE.

I think it is very important to understand that PPE is only as good as our standards around its use. Donning and doffing must be done in a way as to not contaminate ourselves or anyone else. More importantly, physical distancing, not touching our eyes or face, and excellent hand hygiene are our best bets!!

Maintaining the hygiene of the face mask is important.

This may not be something the general public understands fully.

The face mask must not be touched byt the hand until it is being removed and replaced.

I use a general surgical mask with microporetape applied to stop glassess fogging it is changed in my break, if I have one, or if there has been a high risk consultation.