Thank You, Masked Man: Can disposable surgical masks protect us from airborne diseases?

Communicable Diseases 234 views

The latest research indicates that disposable paper “surgical masks” are better barriers to exhaling than inhaling airborne diseases. N95 respirators protect better.

Thank You, Masked Man: Can disposable surgical masks protect us from airborne diseases?

We were settling down to write a post about the worrying new resurgence of scarlet fever—which we will, probably next post—when the Wait-a-Minute deity tapped us on the shoulder. The Wait-a-Minute deity’s evil twin, the Spare-a-Minute deity, had told us the scarlet fever post would be simple. We could use search-and-replace on our last Communicable Diseases post.

But the Wait-a-Minute god (hereinafter, WAM) stilled our hand and asked, Why would you want to frighten your nice readers again without telling them something they could use? We were sitting on a train when WAM came calling, and what we noticed, besides all the foreheads that used to be faces, was the number of people wearing face masks.

Having just gone through the turnstile of another World AIDS Day, we recalled of the day, before GRID turned into AIDS, when people—both the medical types and the deeply worried well—suited up as if for a moon walk to enter the AIDS ward. It seems so quaint now, but safe contact was a concern well before safe sex became one.

But public consciousness was raised.

Then we remembered the SARS epidemic, during which we were living (and commuting) in Asia. Of grim necessity, the public went literally white-faced, commonly enough that the fashion-conscious were looking to color treatments and finer paper stocks for their lower-face masks.

But then the Public-Health Police weighed in with their killjoy message: Knock yourself out with the decorations, but if you think those flimsy, disposable masks are protecting you, you’re just zoomin’ yourselves.

So ensued a discussion of what an effective face mask would be (not look like). Absent much clarity on the matter, say nothing of the power of resurgent vanity, lower faces re-appeared (before vanishing again into ubiquitous foreheads, but that’s about a different kind of contagion).

Before we proceed with the latest reliable information about face masks, let us take a moment to thank the persistent mask-wearers. If you’re going out into public with a nasty flu, we really do appreciate your consideration. And if you adhere to the Jain faith, we respect your choice not to kill living things by inhaling them. We all should be so pro-life.

"360 feedback helped me get promoted."

Michelle (not her real name) manages a team in Bangkok. She'd been unsuccessful at promotion in to senior management of her organisation. 360 feedback helped her learn that her peers and subordinates were concerned about angry outbursts and panic when under stress. You can imagine how much courage it took to face up to this. But Jane achieved her dream: she was promoted to senior management.

Learn More

So, as we say these days, What’s good?

What follows is not a caveat emptor. It’s closer to a “user beware,” that is, a reminder that buying a book is not the same as reading it.

Facial-respiratory protection, it turns out, is a lot like condom use. It only works when it’s “worn” every time—and anytime it’s called for. Guess what? People get tired of wearing face masks, too.

And it’s not just a vanity issue, though it most certainly is that as well. There’s also the fact that people wearing any kind of face masks, effectively showing only their eyes, are scary to others—others on either side of the disease exchange.

Again, as with condoms, for the most part people don’t like wearing face masks. They’re hot and mildly suffocating in the best of environments. They return your own breath to you unsparingly. And they get in the literal way of a whole host of things we do like to do, eating and drinking at the top of that pyramid.

We sound this note because the American Institutional Hygiene Association (AIHA) gets right to it on its web page about “Respiratory Protection for Reducing Disease Transmission.” It discusses the two main forms of protection, the disposable surgical (or facial) mask (SM) and the N95 filtering facepiece respirators (FFR).

By definition, to be called an N95 respirator, the face mask “when subjected to careful testing, the respirator blocks at least 95% of very small (0.3 micron) test particles,” according to the U.S. Food and Drug Administration.

The AIHA webpage specifies the qualifiers about protection tha go beyond the integrity of the gear, to wit (verbatim):

  • Proper fit is Critical for protection.
  • N95 FFRs can only protect when worn.
  • Respirators alone will not prevent disease transmission

Re SMs, the AIHA is similarly blunt: 1) “SMs are not designed to reduce the inhalation of small airborne particles that may contain infectious organisms. 2) Do not expect a SM to protect you from inhaling infectious organisms.”

For the uninitiated, the FFR is “designed and tested to filter small particles from the air. This can reduce the number of infectious particles you inhale and might reduce your chance of infection.” But that takes us back to the qualifiers above.

On the larger matter of whether face masks are useful, the AIHA is more encouraging (verbatim):

“Infectious diseases such as influenza (the flu) can be spread by several methods, including:

  • Airborne droplets or sprays
  • Hand to mouth/nose/eye contact
  • Direct surface contact
  • Combinations of these methods

Because recent evidence suggests that inhalation of microscopic airborne particles may also transmit some diseases, it has been suggested that masks might reduce disease transmission.” [Emphasis ours]

The University of New South Wales News from September 13 of this year cites new research to bolster its similarly blunt claim: “The longstanding belief that a surgical mask provides adequate protection against infections spread by droplets has been turned upside down.”

The study, published in the online journal Influenza and Other Respiratory Viruses, was summarized by its principal author, Raina McIntyre, UNSW Professor of Infectious Disease Epidemiology, as follows:

“We showed that even for infections spread by droplets, respirators protect better....

“This turns upside down the long-held beliefs on infection control. It suggests that transmission of infection cannot be neatly classified as large droplets versus airborne particles.

“Probably infections we believe to be spread by large droplets also have some airborne transmission.”

"I don't wait so long speak out loud now."

Arjun always felt undervalued and ignored - at school, in his family, at work. He knew he was smart but felt largely unacknowledged by others. MBTI coaching helped him identify how a preference for introversion and intuitive reflection might be contributing. He tested new skills in himself, more extraversion, thinking and sensing skills that helped him stay in the moment and confidently speak his truth out loud.

Learn More

The Old In-Out

The Infectious Diseases Society of America (IDSA) makes the important distinction between preventing disease 1) transmission and 2) acquisition. In its study of the comparative efficacy of surgical masks and N95 FFRs worn by health care workers (HCW), it explained that:

  • “Surgical masks are designed to trap respiratory secretions (including bacteria and viruses) expelled by the wearer and prevent disease transmission to others. Surgical masks are not designed to prevent inhalation of airborne particles, and their ability to protect HCWs from disease acquisition varies.”
  • “N95 masks (termed respirators in the United States) are designed to reduce an individual's exposure to airborne contaminants, including infectious viral or bacterial particles. Although N95 masks are designed to primarily protect the wearer from infection, they presumably also prevent transmission if fitted correctly on a patient at high risk of transmitting a virus.”

It also made clear the greater effectiveness of the FFR. Interestingly, it also noted that “[S]ome HCWs find the more expensive N95 masks difficult to tolerate.”

What should someone who is not a health-care worker do, or wear?

No one’s saying “don’t bother” with the disposable paper surgical mask. It’s at the least a courtesy to others when you’re sick.

The FDA makes a recommendation that accords with that of other agencies’:

“If worn properly, a facemask is meant to help block large-particle droplets, splashes, sprays or splatter that may contain germs (viruses and bacteria), keeping it from reaching your mouth and nose. Facemasks may also help reduce exposure of your saliva and respiratory secretions to others.

“While a facemask may be effective in blocking splashes and large-particle droplets, a facemask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes or certain medical procedures. Facemasks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the facemask and your face.

“Facemasks are not intended to be used more than once. If your mask is damaged or soiled, or if breathing through the mask becomes difficult, you should remove the facemask, discard it safely, and replace it with a new one. To safely discard your mask, place it in a plastic bag and put it in the trash. Wash your hands after handling the used mask.” [Emphasis ours]

The FDA also makes recommendations about kinds of N95 respirators appropriate for the public. It adds, however, “The Centers for Disease Control and Prevention (CDC) does not generally recommend facemasks and respirators for use in home or community settings. However, they may be appropriate for persons at increased risk of severe illness from influenza or other respiratory diseases.”

Another consideration is price. Prices for N95 respirators in USD vary from $18-30 per disposable mask.

The FDA recommendation that most mirrors ours is: Check with your doctor

Sources/Reading:

https://www.aiha.org/about-ih/Pages/Respiratory-Protection-For-Reducing-Disease-Transmission.aspx

https://med.unsw.edu.au/news/unsw-research-questions-efficacy-face-masks

http://onlinelibrary.wiley.com/doi/10.1111/j.1750-2659.2011.00237.x/full

https://www.dhs.wisconsin.gov/ic/ppe.htm

https://academic.oup.com/cid/article/49/2/275/405108

Specifically about N95 respirators:

https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/GeneralHospitalDevicesandSupplies/PersonalProtectiveEquipment/ucm055977.htm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4868605/

https://www.health.ny.gov/publications/2805/index.htm

 

HIV - A Survival Guide

HIV - A Survival Guide

Download this FREE Survival Guide! Learn the basics for successful living with HIV. The guide will help you if you've just been diagnosed or living with HIV for a long time.

Download
0 Comments