A few days ago, the CDC announced that all Americans should be wearing face coverings when out in public to prevent spread of COVID19. This announcement is widely recognized to mean that masks (rather than the vague “face covering”) are necessary to prevent, or slow, additional spread of the disease. This comes after weeks of the CDC and other authorities discouraging the public from obtaining and wearing masks, in a perhaps misguided effort to preserve resources for healthcare workers. These early comments emphasized the ineffectiveness of facemasks in preventing transmission of SARS-CoV-2 (the virus that causes COVID19), while at the same time championing the value of these items for healthcare workers. Many commentators and individuals at that time saw the dissonance in this paradoxical position, and many others have been quick to point out the airborne transmission potential of SARS-CoV-2.
We have known for weeks that SARS-CoV-2 could be transmitted on airborne particles, and not just through contact droplets. Keen observers will have made the connection for themselves that some type of mask is not paranoia but prudence. The announcement simply confirms what we have known for weeks, while simultaneously weakening faith in government management of the COVID19 pandemic.
The decision to discourage the American public from wearing respiratory protection seems to have been made in order to preserve capacity for healthcare workers. However, this failed to properly inform the public about the nature of their risk, and failed to account for the respiratory protection already in the hands of non-medical people or on store shelves and not in hospital stockrooms. Many businesses and workers outside of healthcare came into this pandemic with a supply of respiratory protection. Stocks of surgical masks, dust masks, N95 (and better) respirators on store shelves were bought up almost as fast as toilet paper, despite official efforts to discourage use. These items were never going to be available to hospital stocks in any circumstance, and discouraging individuals with access that didn’t impact hospital stocks was likely a mistake. The early and routine use of respiratory protection by the public could have had an impact on SARS-CoV-2 spread, and could have helped to flatten the curve even further. This would have in turn protected healthcare workers by reducing case load and exposure, or at least spreading it out enough for manufacturing to begin to catch up to the mask demand.
We can guess that it might have been so, at any rate. It is impossible to say for certain if this alternative would have created a better outcome, and now we must live with the decisions that were made. There are no truly good answers, and every decision comes with consequences.
Consider that the theme for this discussion of respiratory protection for SARS-CoV-2/COVID19. There are no good answers, and every decision comes with consequences. Welcome to 2020, a pandemic year in which we can look back at years of predictions that called for millions of face masks and respirators. Millions that were never stockpiled, never produced, and do not exist in our time of need. We have put ourselves in the position of having no good choices left.
What is Respiratory Protection?
In short, respiratory protection is any measure or device undertaken to prevent the inhalation (breathing in) of harmful materials. In particular, we are interested in face coverings which offer respiratory protection. Masks, respirators, N95s, N99, PM2.5, bandannas, face coverings, surgical masks, dust masks: What are all of these things, and what are the differences?
There are many types of masks designed to offer the wearer at least some protection from inhaled hazards in their environment. The most common are simple dust masks, which cover the nose and mouth with a thin layer of fabric or non-woven material to help filter dusts generated during cleaning, certain types of work, or manufacturing. The highest levels of protection are provided by masks called respirators, which come in several forms. Let’s run all of these down in brief.
- Dust Masks or Comfort Masks – Simple masks that provide the lowest levels of protection, filtering out only the largest of particles such as dust. Largely for increased wearer comfort in dusty environments, while affording no meaningful protection
- Surgical Masks and Procedure Masks – Loosely fitting, and allowing air to pass around the sides of the mask, surgical masks serve more as a physical barrier against large droplets, splashes, and sprays, than as any kind of filter. Surgical masks are designed to protect everyone but the wearer, by blocking exhaled particles from reaching other people are surfaces. Surgeons wear these not to protect themselves from pathogens you may carry, but to protect you from their snot dripping into your open body compartments during surgery. According to the CDC, in medical settings surgical masks are only used to prevent spread of aerosol particles from the mask’s wearer. They do not confer any protection to the wearer from particles from other people. To protect wearers from pathogens from others, N95 or better respirators must be used
- Air Purifying Respirators – Closely fitting masks which force inhaled air through a filter, to filter out the smallest of particles possible while still allowing breathing. This type of respirator is known as an Air Purifying Respirator, as it uses filtration to purify inhaled room air. The most common are N95 respirators, which filter out >95% of particles 0.3 microns or larger. Other grades, such as N99, filter out closer to >99%, while still others such as P95 filter out >95% while being oil-proof. (For a full list of respirator ratings, and more information on additional types, see Wikipedia). There are some types of air purifying respirator which fully enclose the wearer’s head in a full-face mask, providing eye protection as well. Some of these, Powered Air Purifying Respirators (PAPR) use forced air systems to draw air through filters into the enclosed head-piece
- There are additional categories of respirator called Air-Supplied Respirators, which amount to a self-contained-breathing-apparatus that provides purified air from a canister or supply, rather than drawing room air through a filter. For the purposes of this article, we are going to be discussing Air Purifying Respirators, and specifically filtering face-pieces
- There are other types of filtering face-pieces called pollution masks, which are relatively uncommon in the United States but very common in some other countries. Some of these are little more than a Comfort Mask, while others are often a washable close-fitting fabric mask, with disposable filter inserts. These masks are often marketed as PM2.5 masks, meaning they are designed to filter pollution particles 2.5 microns in size or smaller. However, the filters used for these masks are often N95 filters, designed to filter 0.3 micron particles. Not all pollution masks are N95-equal, however, and it’s important to know which masks of this type use filters, and which are true PM2.5, just fabric, or N95 or better. Many pollution masks also cannot pass fit testing, and provide ineffective filtration
- (Important note: Although many sources use the terms interchangeably, respirator and ventilator are not the same thing. A ventilator is a device used to push air into the lungs of a critically ill patient. A respirator is a filtering device that someone breathes through, to protect themselves from the finest of inhaled particles)
For our purposes, we are going to skip over respirators that fully enclose the face, and focus on respirators which cover the nose and mouth, called half-mask filtering face-piece respirators (FFR). FFR respirators can come in different forms, such as the classic N95 respirator mask intended to be disposable, and rubber half-mask face-pieces with removable filter cartridges (elastomeric respirators) designed for multiple uses. Our primary focus here is on single use filtering face-piece respirators and fabric masks that can offer filtration. Many things in this article will apply to the cartridges of elastomeric respirators as well, however.
The ideal among all of these types of masks, for protection against SARS-CoV-2, is an N95 (or better) rated filtering face-piece respirator, that properly fits the wearer. To work, the respirator must have a close, tight, fit to the face that does not allow any air to pass around the edges of the mask. All inhaled air must pass through the filter, for the filter to protect the wearer.
There are some design differences between these types of FFR’s that are worth noting. Many disposable N95 masks have a valve in the center of the mask, that allows exhaled air to directly exit the mask. This is a one-way vale that seals during inhalation. Strap design is also important, as dual-strap designs are the most effective at sealing against the wearers face. Single strap designs have more potential for improper fit.
In ideal circumstances, an N95 or better respirator should be properly fitted to the individual wearer in a process called fit testing. During the COVID19 pandemic, many users are not going to be able to receive a proper fit testing. Please see the section on respirator fitting and wear later in this article.
Respiratory protection is used to reduce the inhalation risk of harmful or infectious particles, to the individual wearing that protection. We must recognize that there are different levels of need, based on the risk of exposure to harmful particles. At this point in the game, the average person is confronted with two distinct possibilities that should provoke the use of respiratory protection. Possibility one, any person, surfaces, or air they interact with outside the home could be infected or contaminated with SARS-CoV-2. Possibility two, they are an asymptomatic carrier of (or, not yet symptomatic with) SARS-CoV-2. In the first case, the use of masks or respirators is to protect the individual from infection. In the second case, it is to protect anyone around, or who comes along behind, the wearer from infection. It is this latter case that the CDC is focusing on in their recommendation to all Americans to wear a facial covering or mask.
Moving from the realm of possible into probable, healthcare workers are faced with the greater threat of exposure to SARS-CoV-2, where many of them can fully expect to have an infected patient directly in front of them, or in close confines in their shared air, on a typical day at work. Their risk is significantly greater, because of the environment. The infected they encounter aren’t moving through a space briefly, nor are healthcare workers themselves highly transient. They are encountering infected people at a higher rate, in a more confined setting where the infected have more time to deposit viral load into the space. Along with this comes a greater likelihood of droplet transmission, as infected sneeze and cough not just into the shared space, but directly in the physical workspace of care providers.
The risk level informs what we need from respiratory protection. The average person needs little more than protection from incidental exposure in the process of going about their routine. Those dealing with the public in closer quarters on a daily basis, from retail workers to law enforcement, need more from their respiratory protection. Healthcare workers, facing the highest (almost guaranteed) risk need the highest levels of protection available. Home caregivers need a similar level of protection to healthcare workers.
Crisis Capacity Strategies for Use of Respiratory Protection
In an ideal world, we would have enough N95 (or better) available that everyone could have a sufficient supply. Obviously, that is not the case. Filtering face-piece respirators are in short supply, if available at all, and are likely to remain so for the duration. Stocks on store shelves were depleted quickly, and hospital systems have been picking up what they can from conventional and unconventional sources (while, at the same time, not taking up offers from the firearms industry to supply more equipment, including respirators).
With the pandemic having critically strained the capacity of existing stocks of respiratory protection, health authorities have been investigating optimal strategies for extending the existing reserves of N95 and other masks. Many efforts are being made to reduce the amount of masks required by reducing patient contact and infection risk through various controls, such as telemedicine use and patient cohorting. In the environments where patient contact still must happen, there are two leading respiratory protection conservation strategies currently, extended use and reuse.
Extended use is the prolonged wearing of one properly fitted N95 or other filtering face-piece. This means wearing the same mask over a shift, through multiple patient contacts, either without removing it until the end of your shift (or of your outing from your home) or with careful doffing and re-donning procedures (which are iffy, and repeated doffing and donning of the same FFR has been shown to cause fit issues). Whereas in conventional use, a new N95 would be worn for each patient contact, crisis shortages make that untenable, as supplies would be quickly exhausted. Extended use, the wearing without removal, of N95s and similar relieves some of the pressure on the stock of masks.
Reuse is the decontamination and return to service of N95 and similar masks after they’ve been worn. This has been proposed and evaluated in the past for pandemic scenarios, with COVID19 bringing new focus on solutions to allow it. Reuse following disinfection can be done up to 20 times with some of the available decon methods (discussed in the section below), and may go even further than extended use alone to preserve stocks.
Reuse without extended use will rapidly deplete masks, at least in the short term, as individual masks may be used at a faster rate than they can be decontaminated. Extended use without reuse decontamination removes one mask per user per shift, depleting the inventory until it can be restocked. Many institutions seem to have opted for a combination of these solutions, mandating extended use and then cycling each mask through decontamination. Although we have heard reports from several individuals that their institution can’t support even this, and is pushing extended use out across multiple shifts without decontamination in between.
Many healthcare workers, first responders, and others who are regularly risking exposure to COVID19 are wearing a cloth mask over their filtering face-piece during extended use, to prevent the worst of heavy contamination from affecting their mask. For those who have the least resources, the final crisis capacity strategy is the use of homemade masks from fabric or other ad-hoc materials.
If you have the choice, N95 or better should be your first choice no matter your risk profile. We aren’t here to say that anyone should risk their own well being by sacrificing their N95s (though if you are hoarding, you’re an asshole). If you have N95’s and have chosen to donate them, we absolutely support you and laud your decision. However, if able to choose, no one should feel bad for choosing the best option. This is especially true for people at the highest risk of serious infection, even if they aren’t healthcare workers.
For most of us who didn’t come into this well stocked, or who are running out of stock, our options are narrowing to fabric face masks, primarily DIY efforts. That is also becoming the situation for many healthcare workers. Many hospitals have been reduced to reusing N95 respirators to extend their stocks, or because their stocks are already depleted. Various hospitals, researchers, and companies are rushing to develop methods for decontaminating used respirators, to keep the limited stock functional as long as possible. Many decon methods are extremely damaging, and nearly all of them cause at least some degradation. N95s and the like were never meant to be reused. The best systems we have come up with so far can only get about 20 uses out of them, and they decrease efficiency with every cycle. When those respirators, never intended for reuse, finally become too degraded, what replaces them? DIY fabric face masks.
Fabric and DIY Masks
Starting in mid-March, hospital systems and other official groups began calling for donations of fabric masks from their communities, for use in keeping with the CDC’s guidelines for shortages of masks, where untested and homemade masks are the very last tier. Deaconness Health was the first we observed, putting out not just the call but a pattern and instructions for making a simple surgical mask style fabric mask. Many individuals had already begun making masks, or talking about it at least, due to already evident shortages.
Around the same time, a study started being spread around social media that suggests that cloth masks cannot provide protection from infectious particles, and may in fact increase infection risk. While the data is worth considering, especially the findings about how moisture effects filtration efficacy of cloth, it is also important to note, the study is terribly designed. It never even asks (or answers) what kind of cloth they’re talking about, and speaks as if all cloth (or means of constructing a cloth mask) are the same for dry filtration. Further, the study was funded by 3M, perhaps the largest manufacturer of N95 respirators and other types of masks. Now, we love 3M and do business with them regularly, but the conflict of interest disclosure for this study has 3M all over it. This is, in the trades, what they call “a clue”.
Now, nothing other than a properly fitted and properly used respirator is going to offer truly good levels of protection. However, as the COVID19 situation deepens, that has become less of an option not just for individuals, but for many healthcare workers as well. We are still under 1,000,000 cases in the US, and many systems are already completely out of proper respirators, and turning not just to commercial surgical and fabric masks, but calling for donations of homemade fabric masks as well. This situation has been long predicted by epidemiologists and others who study epidemics and viral diseases.
The study linked above is not the only work done to evaluate the efficacy of cloth masks, or homemade masks. These papers should be looked at together, and balanced against one another. One 2013 study evaluated homemade masks, primarily from the view of preventing patients from spreading influenza during a pandemic. This study evaluated different materials, and then a single mask design made of one material. The materials evaluation is particularly useful information. Their results on the fit of different materials are particularly interesting: Vacuum cleaner bags are too stiff to form good face masks (though that doesn’t negate potential for making filter inserts from them), while more comfortable materials such as double layers of tea towel displayed similarly high levels of filtration efficiency. They chose a homemade surgical mask style, rectangular, design for their test masks, constructed of t-shirt fabric. This may have been a poor choice, as this design is one of the worst fitting among several we have tried recently (see more details further down this post), The study concluded “An improvised face mask should be viewed as the last possible alternative if a supply of commercial face masks is not available, irrespective of the disease against which it may be required for protection. Improvised homemade face masks may be used to help protect those who could potentially, for example, be at occupational risk from close or frequent contact with symptomatic patients. However, these masks would provide the wearers little protection from microorganisms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.” Again, this is based on a potentially poor mask design, but it reinforces the notion that, no matter how effective, homemade masks are a last resort.
That 2013 study references a 2008 study from the Netherlands, that also evaluates homemade masks against professional masks. The principal finding of this study was “All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected.” Again using an influenza pandemic as the example, this group researched homemade masks from tea towels against both surgical masks and N95 type filtering face-piece mask. Particularly interesting in this study, is that they researched the performance of the masks both in short duration wear and several hours of wear. They concluded “It is also clear that home-made masks such as teacloths may still confer a significant degree of protection, albeit less strong than surgical masks or FFP2 masks. Home made masks however would not suffer from limited supplies, and would not need additional resources to provide at large scale”, while also noting that “Home made masks, and to a lesser degree surgical masks, are unlikely to confer much protection against transmission of small particles like droplet nuclei”, but that the reduction in transmission afforded could be critical none the less.
A 2010 study examining different materials that could be used in cloth masks, found as much as 60% protection but also as little as 10%, depending on material and particle sizes. They noted that “fabric materials tested in our study might also be expected to provide marginal levels of respiratory protection for 20–1000 nm aerosols (droplet nuclei). Fabric materials may provide respiratory protection levels (i.e. total inward leakage) similar to the levels obtained using some surgical masks […] Thus, the use of improvised fabric materials may be of some value compared to no protection at all when respirators are not available. Moreover, fabric materials would not suffer from limited supplies unlike respirators and surgical masks for emergency protection”. It’s important to read the whole paper, as “some value” is, without a doubt, less value than a proper respirator. The authors say, “The use of fabric materials may provide only minimal levels of respiratory protection to a wearer against virus-size submicron aerosol particles (e.g. droplet nuclei). This is partly because fabric materials show only marginal filtration performance against virus-size particles when sealed around the edges. Face seal leakage will further decrease the respiratory protection offered by fabric materials.” This issue of leakage, as created by a poor fit, is important, as many improvised/homemade mask designs are not tight fitting to the face. It’s also worth considering that this paper relies on tests done with single layers of fabric.
The importance of proper fit, and potential value of multiple-layers (and different types of fabrics) is highlighted in this review from the International Journal of Infection Control which looks at several different papers (including those above) and provides both historical analysis of cloth mask usage, and suggestions on what approaches work best, as well as pointing out areas for further research. In looking at the available data, the authors of this paper have this to say “Three factors were highlighted in these studies in regards to the filtration capacity of a cloth mask: 1) closeness of the gauze/cloth threads; 2) number of gauze/cloth layers and 3) type of gauze/cloth. Generally, the filtration capacity improved when the number of threads increased in the gauze and the mesh become finer compared to course [sic] gauze with lower thread counts. Similarly, the number of layers was found to be directly proportional to the filtration capacity in most of the laboratory studies. In these studies, the filtration effectiveness significantly improved with increasing the number of layers in the mask. Certain types of cloth provides better protection than other; e.g. fine muslin (loosely-woven cotton fabric) was better than the gauze, gauze padded with cotton were better than simple gauze or paper masks and towels were more effective than other fabrics. Cloths masks were generally found to be effective against large particles (>4 um), however some evidence exists against small particles as well. Presence of moisture, distance traveled by the droplets and the design of mask were some other factors affecting the filtration capacity. In summary, the filtration capacity of wet masks has been reported as being lower compared to dry masks. The distance traveled by the droplets is associated with the filtration capacity and filtration capacity is generally decreased by decreasing distance”. These suggestions could be used as the beginnings of a guideline for producing homemade masks for in extremis use, recognizing their inherent shortcomings: Tightly woven fabrics, multiple layers, and thicker/denser fabrics. This also points out that moisture saturation, as from exhaling, can compromise the already limited efficacy of the masks, suggesting that masks should be rotated often for clean, dry, ones.
While woven fabrics are more accessible to most home-sewers, there is evidence that non-woven fabrics are more ideal for creating masks. Non-wovens are used in the production of filtering face-pieces and other filtering materials such as sterilization wrap and HEPA filters, and have a great ability to capture viral particles than woven materials. Non-wovens are also often hydrophobic, meaning they resist saturation with moisture which could transport viral particles across the barrier.
Doctors have telling people in some parts of the country to use/make masks with a pocket for inserting a filter to be cut from HEPA-filter vacuum bags (as described in the 2013 study linked). Some doctors are even making their own. Other mask designs call for the use of PM2.5 filters commonly used in pollution masks. Yet others simply use dual layers of fabric, as suggested by the available data.
Recent innovations, that appear to have started at the University of Florida, have suggested using a product called Sterilization Wrap to make masks from. This is a nonwoven synthetic fabric that is used to wrap instruments and other reusable medical equipment prior to sterilization, which stays on both through and after the sterilization process. It stays on because in layers it serves as a barrier against pathogens, keeping the instruments within sterile. There is reason to believe that, when properly used, it will function as a better filter material than cotton or any of the suggested fabrics for making homemade protective masks. UF doctors have told the media that filtration provided by “steriwrap” equals that of N99 mask material. There is a paucity of data on steriwrap material for use in masks, but it is a well known barrier for preventing contamination of sterile instruments.
Sterilization wrap is a synthetic non-woven material, typically either identified as SMS or SMMS standing for Spunbond-Meltblown-Spunboud or Spunbond-Meltblown-Meltblown-Spunbond. Spunbond fabric is created by fibers of polypropylene being spun and dispersed into a web by directed airstreams and then thermobonded. This creates a strong, but soft and flexible, fabric. Meltblown fabric is created by forcing molten thermoplastic through a die containing multiple tiny holes, as it is blown by heated air, to create a nonwoven web of extremely fine self-bonded fibers. Meltblown is fairly delicate. SMS or SMMS fabrics are a layered fabric, with Spunbond on the exterior and one or two layers of Meltblown on the interior. This creates a soft, breathable, moisture repellent fabric that has excellent filtering properties. Excellent enough to be used to wrap sterile instruments, and keep them that way. Excellent enough that the anesthesiologist at UF who has spearheaded the creation of masks from sterilization wrap has said that two layers of SMS/SMMS fabric is equal to N99 respirator material. This is the most promising ad hoc mask material we are aware of, that is readily accessible.
There are many designs for homemade face masks. In recent days many patterns have been made available from different sources. Some are good, some are terrible, and none are perfect. We have been experimenting with homemade mask designs, with the help of a seamstress, and have found that all of the designs we’ve looked at needed some tweaking.
Some designs fit better than others. Classic surgical mask style rectangular patterns have been the least successful, with poor fit, more slip, and less comfort than face contouring designs. Pleated surgical mask designs are somewhat better, as they expand to offer more appropriate coverage and contour to the face. Contoured designs work better overall. Many patterns needed to be adjusted to give full coverage to adult wearers. The design must extend over the nose, and underneath the edge of the wearers chin, and fit tightly along the entire edge, to offer protection.
Commercially produced masks and respirators often have a nose-piece, a flexible aluminum strip that can be bent to hold the mask in place over the nose. Most DIY designs lack this element, and provide no measure for achieving the same fit without it. Consequently, most DIY designs gap around the sides of the nose, ruining the efficacy of the mask. This must be dealt with, and a flexible nose-piece of some kind integrated into the design. Some sources have proposed using copper wire, which is narrow and may not fit as well or be as adjustable as a flat malleable nose-piece. We had our best success using tin ties (commonly found on coffee bags, to close them after folding the top down) cut to length and sewn inside the edge of the mask across the nose.
The means for holding the mask to the face have required refinement as well. Elastic ear-loop designs made with flat elastic have proven uncomfortable, or unstable, for extended periods, often popping off the ears. Using 2mm hair-ties proved more effective for both comfort and retention than sewn loops of flat elastic.
For prolonged wear, however, any ear loop design is going to cause discomfort and possibly injury to the ears. An “ear saver” can be made that attaches from the back of one ear loop to the other, distributing force across the back of the head instead of the ears, without changing the mask fit. Several designs for these have been proposed, including 3d printed adjustable designs. We expirimented with using simple ties of soft shoe-lace material, which worked, and with making a simple formed Kydex (thermo-formed plastic) piece consisting of a narrow (1/2” or so) strip of Kydex with each end curled over into a hook. The Kydex piece worked best of the two.
Single strap (elastic or tie) designs do not fit the face as well as dual strap designs. A dual strap design that crosses behind the head, with the upper left strap connecting at the lower right and vice versa,proved very stable, but the most difficult to don and doff safely. Dual straps that route straight are the best fit, for the easiest/safest handling.
As we have gone through the process of refining this, another issue has also emerged: An elastic shortage. Stores are sold out, online retailers are back-ordered, as homemade masks have begun to be churned out en masse. Using hair ties has partially relieved this issue, for now, but those are getting more difficult to purchase as well. Moving to a design using upper and lower ties of bias tape, strong ribbon, or similar material would resolve the issues presented by this shortage. These have the advantage of being easiest to fit to individual users, but as they are not providing the same active tension as elastic they requiring more careful donning.
There is no good substitute for proven N95 (or better) face-piece respirators. All of the “solutions” proposed to combat this crisis are the lesser of multiple evils, but are absolutely not an ideal and shouldn’t be anyone’s first choice where a choice exists. This has to be absolutely understood, but it doesn’t change the circumstance we find ourselves in where these homemade (or industry made) fabric mask alternatives are the best of bad choices, the only thing left.
However, some mask designs are worse than others. There are many DIY patterns being offered right now by sewing blogs, healthcare organizations, employers, etc., and there are many homemade and small business made masks being offered for sale right now, very suddenly. What most of these have in common is that they aren’t going to protect you. Many of them are made with single layers of material, or are made with the wrong kinds of material. Many of them are poor designs which do not create a tight seal against the face, but instead leave gaps around the nose, on the cheeks, or around the chin. While folks should be applauded for trying to help, many of these DIY’ers and small businesses aren’t helping – They’re selling false confidence. While these simplest, thinnest, worst fitting of masks might help an infected person from spreading the SARS-CoV-2 virus, even that is in doubt when thin single layers, and large gaps around the side, can allowed expelled particles to escape. If you endeavor to make your own mask, or you go to purchase already made masks from someone, please be aware of these kind of shortcomings, and of the intended use, and make appropriate selections.
Based on the available data, these are our internal recommendations for DIY face-pieces with at least some filtration capability:
- Find or make masks (plural) that are made of multiple layers of recommended fabrics, ideally sterilization wrap (at least two layers). Or, find/make masks (plural) that can use filter inserts and stock up on those inserts either by purchasing or making them (from sterilization wrap or HEPA bags)
- Ensure that the masks are a contouring design, which has dual straps or ties, and a flexible (moldable) nose-piece, to get the closest fit possible
- Wear the mask properly, at all times
- Do not touch the mask while wearing it
- Take precations handling the mask, especially when doffing it after wear, to avoid touching the outside. Doff the mask by handling only the elastics or ties
- Wash your hands before removing your mask
- Rotate masks throughout extended periods of wear (this is why multiple masks is recommended) to prevent saturation of any one. Especially with woven fabrics, a wet mask is not a filtering mask. Two – four hours seems to be the limit for woven fabrics, before materials are saturated. Remove the worn, contaminated, mask safely, and then throw away any filter insert (if they are’t being reused), and move the mask to a closed container to be washed/deconed
- Wash your hands after doffing and storing a used mask, and before donning a clean mask
- Store clean masks in a container which provides a barrier against transmission. Store dirty masks in a separate container which also provides a barrier
And, to be thorough, here is what we recommend against:
- Single layer masks of any material
- Masks without any filtering capability
- Masks that do not provide a tight seal to the face
- Masks made from bandannas, shemaghs, scarves, etc. that confer no protection to the wearer
- Single strap/elastic masks
- Touching the front of your mask
- Scratching underneath your mask
- Wearing your mask below your nose, or above your chin
- Rewearing un-decontaminated masks
Decontamination of Commercial and DIY Filtering Face-Pieces
As the COVID19 crisis has deepened, reuse of masks has emerged as an obvious answer to shortages, but once you get past wearing (and not removing) one mask all day, they can only be reused further if they can be decontaminated. This has received some study in the past, with an eye toward pandemic preparedness, but is getting far more attention now.
Different methods have been proposed, and are being adopted by healthcare systems and various end-users, as possible. The overall goal of these methods is not to sterilize the masks, but to decontaminate them of SARS-CoV-2 virus and reduce the infection risk, while maintaining their structural integrity to preserve proper fit. True sterilization may be achieved by some methods, but not all, and it is not the goal of crisis capacity decontamination strategies.
The CDC is now providing rough guidelines for decontamination processes that hospitals can consider, as well as on what to avoid doing. The CDC guidelines give the most credit to systems that aren’t going to be available to many individuals, and might even be a struggle for some hospitals, such as ultraviolet germicidal irradiation and vaporous hydrogen peroxide.
Ultraviolet Decontamination – Ultraviolet Germicidal Irradiation (UVGI) is widely used in many healthcare settings already, and low level UV sterilizers are available for water and common electronic devices, but presents challenges for use with filtering face-pieces. Firstly, for the resource limited users (those likely to be dependent upon ad hoc solutions), the common UV water and device sterilizers are likely not powerful enough to decontaminate a SARS-CoV-2 contaminated FFR, as none of them produce a dose as high as the lowest sterilization doses. Another issue is that not all FFRs studied were fully decontaminated by UV, particularly the elastics. The next issue is that UV causes some degradation of both N95+ filter material, and of the elastics. This degradation is not significant enough to rule out this method in settings where it can be done, as the degradation is largely low per cycle. Current thinking is that no more than 20 cycles of UV decon should be performed before a mask is finally disposed of. Hospitals that already have this resource have begun using it, and providing guidelines for doing so. For resource limited and home users, this isn’t the most accessible technology, thoughthere are ways.
Hydrogen Peroxide Vapor – This method has also been recommended by the CDC as an effective means of decontaminating FFRs. In this process, vaporized hydrogen peroxide is circulated in a closed container at levels between 140 and 1400 parts-per-million (75ppm is considered dangerous to humans), for the necessary length of time to destroy a given pathogen. The h2o2 is then pulled from the chamber and broken down into component water and oxygen by a catalytic converter. This is an intensive process, requiring specialized equipment, but evidence supports its use where possible. Some hospitals are already equipped for this process and research non-profit Battelle has received emergency authorization from the FDA to produce and deliver their own vaporous hydrogen peroxide system, something Battelle has worked on for several years. These systems are going to be delivered to several states, but realistically will not be able to be produced in enough numbers to serve every institution.
Other methods of decontamination that have been suggested, which might have more meaning for resource limited and home users, are microwave steam, steam, boiling, and both moist and dry heat.
Microwave Steam – Microwave generated steam has been proposed as a method of deconing filtering face-pieces. Much like steaming some vegetables in the microwave this method is simple, requiring only a microwave and a container for water that allows steam to escape directly onto the mask. Microwave generated steam has proven successful in studies but, it does not come without risks of damage to the mask. In at least one study, microwave generated steam caused damage to FFRs. Another study, using microwave steam bags was more successful, and reported no significant change to filtration performance.
Even if effective, this method will only work with FFRs which do not have any metal components, such as nose-pieces or elastic attachments. This rules out its use for many designs, especially the homemade designs we have proposed.
Warm Moist Heat – This method uses heat and intermediate humidity to inactivate the virus. As discussed in this paper from N95 Decon, viruses have been shown to more readily deactivate at intermediate humidity values than at either high humidity or low. The decon concept is simple, the masks to be deconed are “baked” at a temperature high enough to inactivate the SARS-CoV-2 virus but low enough to not damage masks (65-80C, roughly 150-175F), along with a moisture source that provides humidity and evaporation. It is suggested that a 30 minute soak at those temperatures, with intermediate humidity (50-80%), is sufficient to inactivate the SARS-CoV-2 virus. The low end of the temperature range is enough to deactivate the SARs-CoV-2 virus and the high end is the limit most N95’s can tolerate. The CDC’s guidelines recommend 15-30 minutes at 60C with 80% relative humidity, based on successful inactivation of H1N1 virus. Other sources have suggested a design for a chamber to provide warm moist heat, which consists of an enclosed box, partially filled with water, with a rack to hold the masks to be decontaminated above the waterline.
Steam – Actual steaming has also been considered. The previously cited work by Dr. Tsai at the University of Tennessee says that steam decontamination of masks at 125-degrees C for three minutes has an unnoticeable effect on the electrostatic charge of N95-type masks. InstantPot brand pressure cookers have been getting a lot of attention recently for this use, with support for the idea that they are a superior improvised method to other types of steam pressure cooker. However, studies done have pointed out that the temperatures used maycause other physical damage to N95 masks. 3M recommends against steam for decontaminating N95 masks, due to damage caused by the temperatures. Temperature used may be key, as a study from the Netherlands suggests that slightly lower steam temperatures did not reduce effectiveness of the masks used. However, aStanford review of decontamination methods found that even if initial damage wasn’t found, more than five steam cycles degraded the mask too much.
Oven/Dry Heat Decontamination – This has been suggested for various filtering face-pieces, as a means to decon them for reuse. Many hospitals are setting up large scale dry heat decontamination systems (i.e. ovens) to decon a days worth of used N95’s at once. It has been suggested that this is a viable means for home decontamination as well, though concerns have also been raised.
One study evaluated using a rice cooker, without water, to provide dry heat decontamination. They found that no decrease in filter performance arose from the cycle they used. For this method, heat should be within the same ranges previously discussed for warm moist heat, between 60 and 80 degrees Celsius. Higher heats will damage masks and decrease filtration provided.
To decontaminate an N95 or mask of SARS-CoV-2 you need to soak it at around 160-degrees Fahrenheit for 30 minutes (158F, or 70C, destroys SARS-CoV-2 virions) and the soak time lets the heat reach deeper parts of the material). This is slightly detrimental to the face-piece, although the degradation per soak has been determined to be low when done properly. Cumulatively, this 1-2% degradation will add up, however. The number being tossed around for this decontamination processes (as with some others) is that it allows for up to 20 uses of a single mask, before it is unacceptably degraded. For DIY masks, this point may be reached sooner, or later, depending on the materials used, and we don’t have good data to say either way. We can probably safely assume that masks made from non-woven fabrics like sterilization wrap will have similar properties to N95’s in this regard.
In the oven, masks should be suspended with a heat safe clip, so that they are not resting against any metal components or racks of the oven. Direct contact with the metal can cause distortion of the materials as heat is concentrated in the area of contact. Free hanging allows heat to evenly soak into the mask at the set temperature.
There is a concern about oven decontamination at home spreading infection, and health authorities are telling people not to decon masks or N95’s at home. This is largely an attempt at covering their ass in case of misuse of their recommendations leading to infection, but there may be a legitimate concern hidden within. Handling contaminated masks in the home may spread the infectious particles if great care is not taken, just from handling and contact. Further, many home ovens have a fan, that can aerosolize material (viral particles) from the surface of the mask, and push them out of the oven before they are “killed”.
We have found a few potential solutions to this problem. One, is to use a toaster oven that has no fan (particularly if you can set that up in a garage, closed off from the home, or even outside your home). The second solution is to fabricate a simple bag from sterilization wrap, into which masks can be dropped, without contacting the outside of the bag. The top of the bag is then rolled and clipped closed with a heat resistant clip. This can be done before ever bringing a contaminated mask into your home. That package can then be inserted into the oven, suspended or elevated on a low-heat-transfer rack such as hardwood, and soaked at the 160-175 temperature range for 30 minutes without risk of anything getting out of the bag. This creates a package that can be left intact until the next time you need your mask, and will prevent any other contamination from reducing efficacy of your mask as well.
The other hitch to home decon in the oven is that many home ovens won’t go as low as 160. Many won’t go under 200, and some will only go to 170. Many toaster ovens, however, will go as low as 160, or 170, and they aren’t terribly expensive (and can commonly be found in thrift stores for just a few bucks). Using a toaster oven also facilitates creating a “mask decon area” that’s not in the living space of your home. If you are using an oven that won’t go lower than 200, use of a bag as described above and cracking the door of the oven can get you into a temperature range appropriate for decontamination, but low enough to not accelerate degradation of your mask.
Heat based methods offer a lot of potential for small-scale and home users. We encourage you to read the cited (linked) sources thoroughly, run your own searches, and devise optimal strategies from the available data for your needs and FFRs. Useful meta-analyses of this subject are being done, evaluating multiple studies and their results at once, and will be beneficial for time constrained research.
Disinfectant Chemicals – Although many disinfectants are effective against SARS-CoV-2 on surfaces, that does not mean that they will work on masks. Simply wiping the surface of any mask with a disinfectant will do nothing to penetrate between fibers and inactivate virus particles trapped within. A mask would have to be soaked with a liquid disinfectant to achieve proper penetration. This is a problem, as many disinfectants can seriously damage the masks materials.
Hydrogen peroxide can inactivate SARS-CoV-2 in very low concentrations (<1%) and has been shown to be fairly safe for using to disinfect N95 masks, though one study noted corrosion of steel staples on some masks.
Bleach has been found to damage masks, rendering them unusable or unsafe to use, as well as creating concerns about inhalation dangers for wearers of the bleached masks. Alcohol destroys the electrostatic charge of N95 (and similar) mask materials, and reduces the filtration ability to far below safe levels. Soapy water was also found to damage N95 type materials.
Washing with Soap and Water – Air filtration company Smart Air performed testing by washing N95 masks with soap and water, and found that this damaged the material, reducing filtration efficiency by 21%. Homemade masks of cotton cloths can be washed in this method, as long as you are gentle, without risking damaging their limited filtration abilities (so long as they are dry again when worn). Similarly, fabric masks that take a filter insert can also be washed with soap and water, or in a washing machine, safely – The filter insert cannot be, however.
Time – Where possible, simply letting the mask sit in an isolated, dry, environment for 72+ hours is likely sufficient to inact,ive any SARS-CoV-2 contamination. Although fabrics, and non-wovens such as N95 and steriwrap materials, have not been specifically tested, SARS-CoV-2 survives the longest on plastic and stainless steel, remaining viable on those surfaces for around 72 hours. Allowing the mask to decontaminate in a safe place, where spread of infectious particles from the mask is unlikely/actively prevented, is unlikely to cause degradation of the mask, preserving it for further reuse, and also conserves supplies/resources used for other methods of decon.
Lower temperatures can increase virus survival, as can relative humidity below 20% and over 80%, so the ideal environment for time decontamination would be warm and of moderate humidity. Direct exposure to sunlight may also be beneficial to inactivation of the virus on masks, as SARS-CoV-2 has displayed UV sensitivity, and solar ultraviolet has been proposed as a factor in inactivation of other UV sensitive viruses.
Whatever decontamination strategy works for your needs, you must maintain strict procedures for performing it. Until the mask is decontaminated, it remains a transmission risk and must be treated as such. So must any containers used for storing the contaminated mask. Similarly, poor handling or careless procedures for decontamination can damage the mask, and render it ineffective. Too many decontamination cycles can also damage your mask. Institute a set of procedures for identification and separation of clean and dirty masks, and for the handling, decontamination, and return to service of worn masks. Label masks clearly, and use tally marks to track the number of decontamination cycles.
Masks that have visible damage must be immediately thrown away, as they will not serve their purpose. Masks that have been heavily soiled by blood or other deposits of bodily fluids, mucus, etc. should also be immediately disposed of, as decontamination methods may not penetrate heavy soiling to fully inactivate SARS-CoV-2 or other pathogens.
Proper Wear and Storage of Commercial and DIY Filtering Face-Pieces
Filtering face-pieces cannot work, will not protect you or anyone else, if they are not worn properly. As all of this has been going on, we’ve all seen people doing ridiculous things with their PPE, but many of you could be guilty as well. Let’s go over this and make sure we’re all getting it right.
To begin with, masks must actually cover the parts of your face used to breathe. This means your mouth, and your nose. Don’t be one of these chuckleheads walking around with your mask below your nose because “it’s more comfortable.” That’s not how this works, that’s not how any of this works. They must also actually seal tightly. To do this, they must go over the chin, and fit tightly over the nose and across the cheeks. This means that you can’t have anything on your face that gets in the way of this seal. Beards are right out. Piercings that might interfere as well. Care must be taken with long hair to make sure you don’t entrap hair under the edge of the mask, violating the seal to your face. Yes, guys, this means you’re gonna have to shave if you’re serious about this.
In professional environments, N95 and better respirators are fitted to each wearer. Yes, even those disposable N95’s are supposed to be fit tested. By regulations, workers requiring filtering face-pieces need to be fit tested for the appropriate respirator annually. This process involves using an enclosed hood worn over the head, into which a scented or flavored substance is aerosolized. If the mask fits properly, the subject will not be able to detect the aerosolized substance (often saccharine or banana oil). Every different model of respirator, even from the same manufacturer, requires separate fit testing.
In resource limited situations, from austere environments to crisis posture, this type of testing may be difficult to perform in adequate numbers. Ad hoc, improvised, or homemade filtering face-pieces present a further challenge to this, as designs can have a wide variation and tolerances from handmade mask to handmade mask can vary widely. If possible, and the provided masks are consistent enough in manufacture, fit testing should be performed. Realistically, we can anticipate that it’s not going to be possible in great numbers.
However, it will remain critical that you individually seal check each mask that you wear. Visually inspect each mask before wearing it, to ensure that it is free of damage, holes, etc. When putting on the mask, ensure that the flexible nose-piece is properly adjusted for a tight fit, and that the mask is seated correctly on the face. The edges of the mask should feel tight all around. With the mask in place and secured, press your hands over the mask enough to block airflow without deforming it, and exhale fully. The mask should expand briefly, before allowing air to escape. Similarly, inhale fully. The mask should contract against the face, rather than pull air in around the edges. You shouldn’t feel air moving past the edges of the mask.
Once the mask is in place and seal checked, leave it alone. Don’t reach under it to scratch, don’t pull at it to adjust it, don’t touch it. Touching it spreads contamination hands-to-mask or mask-to-hands. Reaching under it violates the seal of the mask, spreading contamination inside and defeating the purpose of the mask. And all of these actions risk breaking the seal and moving it out of position. If you must adjust your mask, do so in isolation from others, do not reach under the mask, attempt to avoid directly touching the surface, touching the elastics/ties instead to pull/adjust, and wash your hands thoroughly before and after.
Donning your mask:
- Wash your hands before handling, or donning, and clear mask
- If using an N95 (or better), or other filtering face-piece with dual elastic straps, cup the front of the clean mask in the palm of your hand and place over your nose and mouth. With your other hand, pull the lower elastic over your head and into place below your ears. Repeat this with the upper strap, placing it above the ears towards the crown of your head
- If using a mask with dual ear loops, grasp the mask by the loops, place the mask over the nose and mouth, and place the loops over each ear. If using an “ear saver” or other comfort device, hook one end of the device into one ear loop, hold it in place, and then extend the other to loop over the opposite end
- If using a mask with ties, grasp by the upper ties, place the mask over the nose and mouth and secure first the upper ties (to prevent the mask from flopping) and then the lower
- Use your hands to adjust the mask, ensuring that it covers underneath the chin and over the nose, and that it isn’t folded under anywhere
- Adjust the flexible nose-piece to fit tightly across the bridge of the nose
Masks should be removed when you are done wearing them, or when it is time to switch to another mask. When it is time to take your mask off, you have to be extremely cautious. The surface of the mask, during wear, may have collected infectious particles. If you touch the surface, and then touch your face incidentally during the removal process, you’ve just defeated the entire purpose of wearing the mask. You must avoid cross-contamination of this nature during doffing (removal) of the mask.
Here are the proper steps for removing your mask:
- Wash your hands prior to removing your mask, to remove any viral particles from your hands
- Reach behind your head or ears, and grasp the elastics, ties, or clip securing your mask, and unfasten them or stretch and lift them off over the top of the head
- If using a mask with ties or elastics that go around the head, untie the lower tie or stretch and lift the lower elastic over the head first, and then remove the upper
- Do not remove the upper first, and allow the front of the mask to flop down onto your chest/neck
- Using the elastics/ties only, pull the mask forward off your face, and away from your face
Avoid shaking, snapping, or violently moving your mask through the air, as this may aerosolize particles
- Handling it only by the elastics/ties place the mask into a paper bag, steriwrap bag, or other container, and roll the top or close the container
- Wash your hands thoroughly once more, to remove any viral particles picked up from handling the mask
- Remove a clean mask from storage, and place it on the face, secure it, and perform a seal check while you have clean hands
Clean masks should be stored in a clean, dry, container that prevents dust, debris, or any pathogens from getting on them. Even unworn, masks exposed to the environment can pick up pollutants or infectious material, compromising their effectiveness or safety. If you have constructed bags of steriwrap, as described earlier, you can simply leave your masks in these awaiting use. Masks should not be stored in containers that trap moisture, however. This can degrade mask performance, and in the case of worn masks can preserve pathogens and increase the risk of their spread.
Masks Alone Aren’t Enough
Respiratory protection by itself is not enough to protect you from infection, from anything. If you are not practicing proper hand hygiene, and not using other forms of PPE when necessary, your mask by itself isn’t much protection. If you are in regular close contact with COVID19 patients, whether in a healthcare setting or caring for a family member recovering at home, you should (in addition to gloves and respirator) be wearing a face-shield when in contact with them. Face shields, or goggles that fully seal to the face, protect you from particles expelled by coughing or sneezing, which can get into the eyes.
This is strictly a review of available literature, and none of the preceding is medical advice. Do not take any actions without the direction of your personal physician, workplace medical director, or other healthcare authority.
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This is an overview of the current Coronavirus pandemic, affecting the United States and the rest of the world.
Upfront, I want to be very clear that this is not a situation that merits panic or extreme anxiety. I also want to be very clear that this is a serious situation, and needs to be taken seriously. The purpose of this post is to increase understanding of Coronavirus, what it is doing and going to do, separated from any rumor or agendas, and to use that to make suggestions about courses of action over the days and months ahead. From my background, I am concerned about this pandemic – Not strictly for the disease and its potential effects, but from the second and third order effects this will have on infrastructure, supply chains, the economy, and the healthcare systems of afflicted countries.
For background; I have been a frontline medical provider as an EMT and medical tech intermittently since 2004. I was on a Pre-Med track at New Mexico Tech from 2006-2009. I am a virology and epidemiology nerd, and have been reading about these topics for fun for over twenty years. I am well read, and have no-little education in relevant subjects – I am not an expert. What follows will not be my opinion on the Coronavirus, but facts and information with appropriate citation. This is an effort to break down the “need to know”, using my education and experience to cut through the heaps of misinformation, conjecture, falsehoods, and rumor that surround this pandemic.
My opinion will come in the later sections of this post – I will share my opinions on what we should all be doing about this situation, and what my experience leads me to expect from the coming weeks and months. Take what is useful, and discard the rest.
Much of this will be useful to international readers, but my focus in writing this was primarily on the United States. International friends, I hope you don’t ignore what’s useful here because of that, and that you can pull your own resources to examine your local situation with this as a starting point.
Two more notes before we began:
First, pay close attention to links in this article. This is heavily cited, and some sentences will contain multiple links. I have spent the past several days reading over 500 studies, papers, articles, dashboards, situation reports, twitter threads etc. etc., and condensing them down to the most important and relevant for this article (with many of the rest being diverted to the above Twitter feed). If you want to know more, or verify for yourself, then follow the links.
Second, this is not medical advice. Consult with a physician before taking any actions that could impact your health. TANSTAAFL, YMMV, and IANAD.
What is Corona Virus?
Corona Virus, COVID19, Wuhan Virus, the names by which this viral infection has become known are numerous, sometimes confusing, (and sometimes even racist). We will be using two names for accuracy: COVID19 (Coronavirus Disease 2019) is the disease caused by the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) virus. In different sources you will hear others such as nCoV 2019, Novel Corona Virus 2019, CoV19, which are not inaccurate. For simplicity sake we’re going to stick to SARS-CoV2 to refer to the virus, and COVID19 to refer to the disease, in general.
SARS-CoV-2 is a member of a large group of viruses, named Coronaviruses for the crown or corona appearance of the virions (the individual virus particle). Coronaviruses are a common group of viruses, first identified in the 1960’s, that affect birds and mammals. Coronaviruses are not rare, being responsible for some types of common cold and existing worldwide in various forms both benign and severe in humans. Coronaviruses have caused global health scares before, including the 2003 SARS outbreak, and MERS.
SARS-CoV-2 is a novel (that means new) strain of Betacoronavirus, from group B. It is a positive-sense single-stranded RNA virus, which causes Coronavirus Disease 2019. COVID19 first emerged as an outbreak of viral pneumonia in Wuhan, China, in December of 2019. The outbreak was traced to a novel strain of coronavirus dubbed SARS-CoV-2. SARS-CoV-2 causes respiratory illness, which ranges from mild to severe-life-threatening.
Since emerging in China, COVID19 has spread globally, infecting (as of 18 March 2020) more than 214,894 people. There have been 8,732 deaths, and more than 83,000 recoveries. (From https://jsapi.dev/covid19-dashboard/ , accessed 18 March, 1530MDT). On 11 March 2020 the World Health Organization declared COVID19 to be a pandemic.
Where Did It Come From?
Virologists have identified Horseshoe Bats as being the primary natural reservoir for related coronaviruses, and suspect that SARS-CoV-2 originated within bat populations. However, there is evidence that an intermediate reservoir, likely pangolins, was involved in the jump to humans.
Where that jump occurred is not known precisely, but early suspicions that it originated in the Wuhan Seafood Market have been disproved, as earlier cases with no association with the market have been identified. The earliest known case of COVID19 is from November 17th, 2019, but the origin of that infection has not yet been identified.
The information we have on the genetics and origins of SAR-CoV-2 tells us that it is not any kind of bioengineered virus. This is a naturally occurring virus, that came about most likely due to a “recombination event” between strains of Coronavirus in bat and pangolin hosts .
What Are the Symptoms:
SARS-CoV-2 causes COVID19. Symptoms of COVID19 can range from mild to extremely severe.
Common Symptoms are:
• Dry Cough
Some may have:
• Nasal Congestion
• Runny Nose
• Sore Throat
• The above, plus Difficulty Breathing
Mild cases present not unlike the common cold, with symptoms of mild fever, dry coughing, and tiredness, with sore throat, nasal congestion, headache, and muscle pain possible. No worse symptoms are typically present in mild cases.
Moderate cases present with a moderate pneumonia, respiratory symptoms including cough, shortness of breath (which can present as rapid, shallow, breathing in children), without any signs of more severe pneumonia.
More severe COVID19 cases display a worsened pneumonia, often with a fever associated with severe shortness of breath, worsening respiratory illness, rapid breathing, and decreased blood oxygen levels. Severe cases can progress to Acute Respiratory Distress Syndrome (ARDS), where inflammation in the lungs creates fluid buildup that severely impedes the transfer of oxygen between the lungs and blood. ARDS can lead to sepsis, respiratory failure, septic shock, multi-organ failure, and then death.
How Is It Transmitted:
SARS-CoV-2 is transmitted from human-to-human, meaning an infected person can pass the infection on to someone else. The basic reproduction number of SARS-CoV-2 has been estimated as between 2.2 and 3.9 , meaning that each infected person could transmit the virus to between two and four people.
The virus is spread primarily by respiratory droplets from coughing, but can also be transmitted as an aerosol (particularly in continued exposure or confined space). The virus can also potentially survive in aerosols for up to three hours.
In the primary transmission route, droplets containing the virus are expelled, and can land in the noses or mouths of people nearby, or be inhaled. Infectious particles can also land on or be transferred to surfaces where they are picked up by others, who then transmit the virus to themselves by touching their face or other bodily opening.
SARS-CoV-2 can survive for at least several days on surfaces, and can be spread by that route as well.
The incubation time of the virus, the time it takes for an infected person to show symptoms, is estimated to range between 5 and 14 days. There is some evidence to suggest that pre-symptomatic people can still spread the infection as well as some evidence that asymptomatic people can also spread it. Viral shedding, virus particles leaving the body to potentially infect others, lasts an average of 20 days, but has been documented to last up to 37 days.
Who Is At Risk:
Everyone is at risk of infection from SARS-CoV-2.
However, certain parts of the population are at greater risk of having severe symptoms than others. The highest risk factors for severe COVID19 are being older, or having preexisting health conditions such as high blood pressure, diabetes, heart disease, lung disease, cancer (or history of cancer), diabetes, or obesity. Children are at low risk of serious illness with COVID19, although they can be infected. Symptoms in children are typically mild, resembling the common cold. Pregnant women may be more susceptible to infection than others, due to physiological changes associated with pregnancy. The risk to the unborn child, however, appears low.
How Serious Is It:
COVID19 is not the black death, it is more severe than the flu. The global situation, due to the pandemic, is not great. Potentially, it could be very bad. It could also be not that bad. It depends on what people do, from here.
The case fatality rate (the percentage of cases that will result in death) is difficult to accurately predict during an active epidemic or pandemic, with lots of moving pieces and potential impacts and consequences if wrong. Current estimates for the CFR of COVID19 run as high as 3.9%, with the WHO saying 3.4%.
It is important to remember that the fatality of COVID19 depends highly on your age, health, and geographic location, and that the percentage of people dying is largely clustered within the highest risk factors although there are severe cases occurring outside of the highest risk population.
The current percentage of deaths, among known cases, is around 4% globally (although this is not a perfectly accurate number, as unknown cases are a certainty. Certain countries are faring better, or worse, than this. Italy, for example, currently has an almost 8% fatality rate, while South Korea has a less than 1% fatality rate. Differences in these numbers are to be expected from region to region in an ongoing situation like this, where different response efforts are mounted in each region or nation.
Currently (1530 MDT 18 March) in the US we have just over 8990 identified cases of COVID19, with 150 deaths, for a current fatality rate of around 1.6%. However, these numbers can be safely assumed to be inaccurate, perhaps to a large degree, because the US is woefully behind on testing for COVID19 (As of 18 March 2020, the US has tested less than 60,000 people). When considering US infection rates, or trajectory, Italy may be a particularly pertinent example, as the US infection trajectory appears to be very similar to Italy, just running about a week behind, as charted by multiple sources.
Italy is in crisis, with hospitals overwhelmed by COVID19 cases, and although there are differences between Italy and the US in health system resources per capita, the Italian model provides concern for the outlook in the US.
The disease trajectory is very important to look at, because it gives us an entry to the concept of “flattening the curve”. To flatten the curve means to slow the spread of infection, thereby spreading the number of new infections out over a longer period of time. Experts have been saying that containment of COVID19 may be impossible, since late February. The disease is here, the SARS-CoV-2 virus is spreading, and we can’t stop the spread. How fast it spreads is what will make the final difference. If COVID19 spreads rapidly, the US healthcare system will quickly be overtaxed, as Italy’s has been, as cases exceed capacity. We are probably going to exceed capacity anyway, but the longer we can delay any infection, the less we’ll do that.
Estimates suggest that 5% of infected will need critical care in hospital , which means ICU beds and ventilators. There are an estimated 68,000 ventilators in the US healthcare system, with slightly less than 9,000 in the Strategic National Stockpile. There are around 68,000 ICU beds available in the US. Typical occupancy of ICU beds has been measured as between 57% and 82%, with between 20% and 38% of beds being patients requiring mechanical ventilation. That is the norm in the US, without a virulent disease outbreak.
What does this mean for COVID2019? One report predicts the following “If the infection curve is not flattened and the pandemic is concentrated in a 6-month period, that would leave a capacity gap of 1,373,248 inpatient beds (274 percent potentially available capacity) and 295,350 ICU beds (508 percent potentially available capacity). If the curve of transmission is flattened to 12 months, then the needed inpatient and ICU beds would be reduced to 137 percent and 254 percent of current capacity. However, if hospitals can indeed reduce current bed occupancy by 50 percent and flatten the transmission curve to 18 months, then the capacity needed would be reduced to 89 percent of inpatient and 166 percent of ICU beds. If the infection rate is only 20 percent (low end of current estimates), we would largely be able to meet the needs for inpatient care if we flatten the curve to 12 months.”
This is why what seems to many to be drastic measures are being taken to slow the spread of the SARS-CoV-2 virus. Epidemiologic controls such as social distancing, cancellation of events and gatherings, school closures , and encouraging self quarantine are enacted to flatten the disease trajectory, and spread the rate of infection out across a longer timeline in which resources can be better preserved and renewed. While many are screaming that it is unreasonable that they can’t go to concerts, or to see a movie, and that travel restrictions are in place, these measures could make the difference between life and death not just for COVID19 patients, but for those patients that occupy up to 82% of the ICU beds in the United States under normal conditions.
What To Do?
The first and most important thing to talk about, when we ask what should we do about all of this, is to encourage following the given guidelines for reduction of spreading SARS-CoV-2. National and global health agencies aren’t lying to you about the importance of hand washing, covering your cough, and in general not being a nasty bastard, or about the importance of maintaining social distance from other people.
Even if we are healthy, and do not fall into any of the higher risk factors (age, comorbidities, etc), we are at risk of spreading SARS-CoV-2 infection to those who are more vulnerable. That risk is only heightened if we ignore the guidelines being put out. Each of us has a role to play in flattening the curve, and trying to preserve the integrity of the healthcare system. In short, if you ignore these guidelines because you personally aren’t at risk, you’re putting others at increased risk, and that makes you an asshole. So, how can we do our part, and not be assholes, and minimize our own chances of infection along the way?
Hand Washing: Wash your hands! Hand washing with soap and water is the most effective way to not just remove, but kill, virus on your hands. Soap kills SARS-CoV-2 very effectively. Hands should be washed regularly, whenever you return home, before, during, and after meal prep, before eating, before and after caring for the sick or injured, after going to the bathroom (before as well, if in public facilities. You don’t want SARS-CoV-2 on your business, right?), after sneezing, coughing, or blowing your nose. This is kindergarten advice, but we teach it early because it’s fundamental and you need to be on board fully.
- Wet hands with clean running water
- Lather with soap, rubbing your hands together, between your fingers and under your fingernails
- Scrub for at least 20 seconds
- Rinse well under clean running water
- Dry using a clean towel.
Hand sanitizer should be used when soap and water aren’t available, but hand sanitizer will never be as effective as soap and water. Hand sanitizer must be at least 60% alcohol.
- Apply gel to one palm
- Rub gel over all surfaces of the hands and fingers, until it dries (at least 20 seconds)
Do NOT apply rubbing alcohol or household cleaners to your skin. These products can cause tissue damage, creating openings in the skin making you more susceptible to infection instead of less. DO use moisturizing lotion on your hands, to prevent them drying out from frequent washing. Dry skin can crack, and again create a pathway for infection. Keep your hands in good shape, and the skin well conditioned.
Avoid Touching Your Face: Your eyes, mouth, and nose are primary routes by which viruses can enter your body. Picking up pathogens on your hands, and then touching your face, is a known transmission route for almost every viral infection (and bacterial). People touch their face, without thinking about it, as much as 23 times an hour and every time you do, you’re potentially infecting yourself if your hands have picked up a pathogen. Work to break this habit.
Practice Respiratory Hygiene: Cover your mouth when you cough or sneeze, ideally with a tissue. You aren’t preschoolers, and shouldn’t need to be told this. If you are ill, wearing a face mask that blocks droplet spread from coughs and sneezes is more effective and hygienic than coughing into your elbow, and certainly more so than into your hand. Wash your hands after coughing or sneezing.
Clean and Disinfect Regularly Touched Surfaces: Those pathogens you can pick up on your hands? You redistribute them to anything you touch, and the more you touch it, the more likely it is. Others can also deposit nastiness on commonly touched surfaces for you to pick up. Regularly clean and disinfect surfaces and objects that get touched regularly, from tables and counters to computer keyboards and mice to doorknobs and steering wheels. You should also use disinfecting wipes or gel on public door and cart handles, prior to touching them, and then still wash your hands afterwards.
Wash Your Phone: That’s right, your phone. There are few objects we touch as often in our daily lives, in this modern world, as our phones. If anything in your possession is likely to be a literal hive of scum and villainy, it is your phone. Many modern phones are water resistant enough to wash, but if in doubt, give them a thorough wipe down with 70% alcohol wipes, or Clorox wipes. https://www.cnet.com/how-to/help-keep-coronavirus-off-your-phone-how-to-effectively-clean-and-disinfect-your-device/ Take the case off, and wash it with soap and water. This should be done about as often as you wash your hands.
Disinfect Items You Carry in Public: Your keys, every-day-carry gear, and the rest of the stuff you regularly take into public and touch also need the same treatment.
Keep Your Distance: When you have to be out in public, keep your distance from other people. Droplets from coughs and sneezes can travel more than six feet https://www.sciencefocus.com/the-human-body/how-far-do-germs-travel-when-we-cough/ . Proximity to infected individuals is the primary source of SARS-CoV-2 transmission, and you don’t know who may or may not be infectious (or if you are, even). Keep your distance.
Don’t Shake Hands: You may have impeccable hand washing habits, but not everyone else does. Politely decline to shake hands, and find other ways to greet people that require minimal-to-no contact.
Work From Home if Possible: Many of you reading this already have been given orders to work from home. Do it. It’s an adjustment if you’re not used to it, but you can do it (I transitioned to full-time work-at-home dad last fall, and it’s been a wild ride, but I did it). If you don’t want to get sick, avoid sick people. Since you don’t know who the sick people are, that means avoid people as much as possible. Text your most introverted friend, they’ve been doing this for years and will walk you through it.
If you absolutely have to go in to work, maintain health and hygiene practices in the workplace (your workplace should be doing this, but if it falls on you, it falls on you, do it).
Avoid Crowds and Large Gatherings: Follow the advice given by the CDC, WHO, and other health-concerned alphabet soups, and don’t go where there are lots of people. The more people you are around, the more likely you are to be exposed to SARS-CoV-2. Now is not the time to go to large church services, or to gather all your friends, neighbors, and their brothers-in-law for a BBQ.
Avoid the Doctor, Urgent Care, and Emergency Room Unless Absolutely Necessary: This is a fine line. If you need medical care, you need it and should not avoid it. However, now is not the time to go to the ER because you’ve got a tummy ache, and if you have the skills, support, or network to avoid having to go in for minor or routine things, you should. Healthcare facilities will be where COVID19 patients are, both known and unknown. If you want an exposure, one of the best ways to do it will be to sit in an Urgent Care or Emergency Department for a few hours. Don’t be stupid and avoid getting treatment when you really need it, but make good decisions about when you can take care of issues at home, too.
These things are important for all of us. They are especially important for people who are at elevated risk, due to age or comorbidities. I have told my family members who are over 60, and in other risk categories, to take these steps seriously and extremely.
These steps are also critically important for any of us who have care providers roles in our networks and families, or have close contact with elderly or at risk friends and family.
When to Wear a Mask and Gloves:
Now, if you want. Especially if you’re at increased risk (or in contact with someone who is), and have to be out among other people.
Masks and gloves and other barrier precautions do not eliminate the need to wash your hands and maintain other hygiene and distancing protocols. Read that again. Your hands (and face) should be clean and disinfected prior to putting on mask and gloves. Your gloved hands should never touch your face. Your hands need to be washed as soon as you take the gloves off.
Not all masks are equal, and it is important to know the differences. The simple facemask, or surgical mask, does nothing to protect the wearer from inhalation of particles or virus-bearing droplets. These masks do, however, protect others from droplets the wearer expels. N95 respirators, when properly fitted, do protect the wearer from inhaled particles and can help prevent infection. If you are sick, wear a simple face mask. If you are worried about getting sick, trying to prevent infection, immune-compromised, or all of the above, wear an N95 respirator.
Wash your hands and face before putting on any kind of mask. Cover mouth and nose with the mask, making sure there are no gaps. Avoid touching the mask while using it, and if you do, wash your hands. Replace the mask with a new one as soon as it is damp, and do not re-use single use masks. When removing, do not touch the front of the mask, remove it from behind and throw it away immediately in a closed trashcan. Wash your hands immediately after removal.
Avoid reuse of masks. This may be difficult, due to shortages. If reuse or multiple-uses of masks has to be performed, it is important to follow the guidelines closely.
What If I’m Sick?
The most common COVID19 symptoms, and the mildest form of the disease, are fairly indistinguishable from the common cold by observation. For many infected, that’s all that will happen to them as the virus runs its course. But, what do we do if it gets worse, or we’re at risk?
The difference between mild or moderate and severe symptoms is respiratory function. As symptoms worsen, respiratory function decreases. This decreased respiratory function, as discussed in the symptoms section, is what leads to severe complications or death as it worsens. The condition of anyone who is sick with COVID19-like symptoms needs to be closely monitored, particularly their breathing.
The CDC has the following advice for those who are sick:
- Stay Home except to get medical care. Don’t leave, don’t visit public areas. Stay in touch with your doctor, without visiting their office unnecessarily. Avoid public transportation, ride sharing, or taxis.
- Practice home isolation: Separate yourself from others in your home as much as possible. Dedicate a specific sick room, away from others, and use a separate bathroom if possible. Limit contact with pets and animals, as well as other people, as it’s possible they could spread infection to other household members.
- Call before visiting your doctor. If you have routine appointments, notify your doctor that you are sick before coming in, and follow their directions.
- Wear a facemask if you are sick. If you are experiencing difficulty breathing, or otherwise unable to wear a facemask, everyone in contact with you should wear an N95 mask.
- Practice respiratory and personal hygiene. Cover your cough, wash your hands, throw your tissues and other trash in a dedicated lined trashcan. Wash your hands often, not just after coughing, sneezing, or touching your face.
- Avoid sharing personal or household items. Do not share dishes, utensils, towels, or bedding with others. Wash these items thoroughly with soap and water after use.
- Clean all regularly touched surfaces every day (multiple times a day would be better) in your “sick room”, and anything you touch if you have to go out of that room. Phones, remote controls, counters, tables, doorknobs, bathroom fixtures, toilets, tablets, bedside tables, etc. are all candidates for regular cleaning and disinfecting. Caregivers should wear masks, gloves, and wait as long as possible after the infected person has used the bathroom, when cleaning for them.
- Monitor your symptoms. If your symptoms worsen, particularly if shortness of breath or difficulty breathing develops, seek medical attention. Call before going in to your doctors, the emergency room, or urgent care, and follow their directions. Wear a facemask if you have to visit medical facilities, and maintain at least 6-feet of social distance from others.
- Do not discontinue home isolation (except to seek medical attention) until the following conditions are met: You have had no fever for 72 hours without the use of medicine, other symptoms have improved, AND at least 7 days have passed since your first symptoms. All three conditions must be met. Alternatively, you can leave home isolation after meeting the first two conditions if you have received testing for COVID19 and been tested negative twice, 24 hours apart.
If you are a family member, roommate, intimate partner, or caregiver to someone who is sick, you need to monitor yourself for symptoms as well, while taking precautions to prevent infection. Help the patient to maintain their isolation, and do not share items, bedding, dishes, etc. with them. Stay out of their “sick room” as much as possible (no, it’s not weird to skype in the same house, do it) and wear personal protective equipment (gloves, N95, goggles) when you have to enter.
If you are responsible for monitoring their health for them, as in the case of an elderly family member, keep a close eye on their symptoms and be prepared to call their doctor if symptoms worsen, particularly their breathing. We need to observe them for increased/increasing respiratory effort: An increase in the number of breaths per minute; cyanosis (turning blue in the nail beds, lips, etc), grunting or other sounds of effort when breathing, nose flaring, retracting (when the area between the ribs and in the neck sinks in when a person attempts to inhale), and other signs of increased effort like wheezing, sweating, etc. These symptoms should be your trigger point for contacting their doctor.
What to Prepare?
A lot of people have been caught behind the power curve on this. Not everyone has the financial ability to lay in multiple layers of preparations for unexpected events. Not everyone anticipated this emergency, and their preparations are weak in key areas. Some people are just now realizing the need for emergency and disaster preparedness and are playing catch up. None of this is helped by the panic run on stores and the national supply chain for items both ludicrous and essential, like toilet paper and meat.
If you are already well prepared for this event, good for you. You’ve done well. Give yourself a pat on the back, and then get back to taking care of yourself and your family, keeping them out of the doctors office unless necessary. Use your security as an opportunity to be a good ambassador for your lifestyle, be it prepping, gun owning, whatever it is that may be essential in this emergency.
If you haven’t prepared well, and are scrambling, please know you have my sympathy and understanding, and don’t give up. There is still time to get things you need, and to take advantage of resupply of essentials. As I am writing this, I am hearing reports from my personal network (which spans all of the US, and several other countries) of store shelves being replenished with items that went out of stock last week, and I am still finding many essentials online with careful searching.
As you try to stock up on, or improve your stocks, of various items consider unconventional sources. The great toilet paper debacle provides an excellent example: Big box stores and grocers quickly ran out of toilet paper as people panic bought, while office supply, home and hardware stores, restaurant supply, and medical supply business continued to hold stock. Many still do. Similarly, many people have been having trouble finding their regular groceries at the usual stores, while ethnic markets and smaller community grocers have things still in stock. Many of us do not shop at ethnic markets or “funny” grocery stores, because we’ve bought into the monoculture ideology of brand-recognition and not eating “strange” food. This situation presents a really good opportunity for you to get over that kind of nonsense.
As we evaluate our preparedness, we need to consider what the future holds. We are not tasked just with being prepared for the COVID19 outbreak and its health effects, but also with preparing for the second and third order effects of the pandemic.
The economy is taking a massive hit already from the COVID19 pandemic. As more people stay home, either to maintain social distancing or because they’ve fallen ill, this will only get worse. Fewer consumers will be spending money, and staffing will be a problem for businesses. Once again, the toilet paper stupidity provides us with a perfect example as manufacturers, normally running 24/7 to meet regular demand, are hit by the double hammer of a spike in demand and a reduced production capacity. This is happening with almost everything. It is reasonable to expect ongoing shortages of good, and increased disruption to our supply chains. If you are not currently prepared to weather these events, it is not to late to begin, but you need to begin now. A reasonable goal would be to have, and maintain, at least a months worth of supplies on hand. Everything you need, from groceries to household products to medications. If you can bring your stocks up even higher, do so. Talk to your provider about changing any prescriptions that aren’t to a 90-days supply. Begin adding additional supplies now, and building a stockpile of the things you need most. Doing this while you can, to any extent, will soften the impacts of quarantines, lockdowns, illness, job loss, and the rest of what we can look forward to.
Preparedness is not just stuff, however, but behavior. Your behavior, actions and lifestyle, are going to have more to do with whether or not you become infected with SARS-CoV-2 (and when you do) and with your success or failure in the other aspects of this crisis.
Personally speaking, I have largely isolated my immediate family. We are staying home, and continuing life largely as normal. We are obeying all handwashing and hygiene protocols discussed in this article, and doing so strictly (this has meant making a game out of it for the kids as we do it more often and more strictly enforced, while also explaining to them why it’s important especially right now). We are doing everything we can to maintain our health, and keep our immune systems robust, including good amounts of sleep, eating well, exercising, and continuing use of both Vitamin D, and Elderberrywhile also avoiding snakeoil.
Ourhousehold posture is good, with preexisting habits of cleanliness and doubling down on keeping things clean, and neat. We have identified a “sick room” for isolation of anyone symptomatic, and talked over the fundamentals of a care plan. We have made an effort to get to know our neighbors (pre-dating this crisis) and have reaffirmed those connections in recent days. Most of our closest family, friends, and neighbors have gotten some version of this article, as a conversation, in recent days.
We have discussed within the household, and those closest to us, various plans for further isolation and pulling back to a more remote location if the situation devolves more aggressively, and gone through checks on equipment and contacts necessary for this.
I pulled a large number of medical supplies from my caches, to organize and stage them so that I can run my home as a clinic for my family and closest friends to keep them from having to risk COVID19 exposure over minor issues (or even major ones, if they are within my scope).
Even though we came into this better prepared than many, we have begun adding a few things to our supplies, as possible, to ensure our ability to do two things: Stay at home for 2-weeks per infected individual, without having to go anywhere for anything and risk spread; and to weather the coming supply chain shortages as they happen without insufficiency.
We are keeping an eye on restocking for masks, ammunition, and medical supplies to let others know, or to secure additional numbers for distribution to friends and family. At the same time, we are not adding unnecessarily just because it’s available, and thus denying others the ability to prepare.
My instructions to my elderly father and his wife are to stay home (they have 18+ months worth of supplies, and live remotely), avoid the doctors office, and pretend they’re young again without the risk of contributing to the upcoming baby-boom, and if they get sick to contact their doctor as soon as either of them displays any increased shortness of breath/difficulty breathing.
What Comes Next?
The epidemic continues to evolve. Most of what we have currently are models, predictions, of what might happen, and what could make things better or worse. Everyone is feeling the stress of these large unknowns, and the more tangible effects of shortages and beginning disruptions. More affecting than the COVID19 illness itself, and already evident, may be this strain on society at large as services, venues, businesses, and normal routines are disrupted by this epidemic. As noted above, the economy is already suffering , and supply chains are disrupted. Services we all rely on are also disrupted, as various governmental offices close and police departments begin scaling back response to all but the most dire calls.
Modeling potentials tells us that, no matter how successful various measures are, COVID19 and its impacts are going to last, at the very least, months. COVID19 will continue to spread. The situation will get worse, from what it is today. Models suggest that saturation of healthcare resources will begin within the next couple of weeks. If people continue to violate social distancing and quarantine orders, it will get much worse much faster.
Spread mitigation efforts (social distancing, event cancellation, etc) are likely to turn to more severe suppression efforts, such as lockdowns, local travel restrictions (even street closures), and forced distancing with people restricted to their homes. Many places are already discussing these measures, and it would be reasonable to expect them in the coming days to weeks. The downside to this is that the more successful severe measures are at suppressing infection, the less herd immunity is developed in communities. With decreased herd immunity, lifting any restrictions without a vaccine available will mean a renewed spike in infection rates. This may cycle going forward until vaccine production is successful and stockpiles exist to inoculate the population.
Predictions for how long this epidemic will go on vary from weeks to months or longer, with many predictions extending past a year, and the earlier l linked paper on modeling predicting this continuing through 2021.
Testing for COVID19 is improving in the US, with various efforts underway to provide new tests , increase access, and speed up processing, but it is still not at the capacity it needs to be. We will get there, but until we do, the only safe assumption is that anyone is infected, and to act accordingly (while simultaneously acting as if we are not infected, and want to prevent it).
Work is underway to develop a COVID19 vaccine, but it remains at least 12-18 months away. This is the nature of vaccine production, and there isn’t much that can be done to change it. What we can do is everything detailed above, to ensure that more people make it to that point and that the pressure on health infrastructure isn’t increased to the breaking point (which will slow vaccine research and production even more). Even as the situation improves, the strain on the healthcare system will remain increased as people recovering from COVID19 suffer lasting effects, and from minor issues that couldn’t be treated and blossomed into larger issues. Individuals who put in the work (either ongoing, or starting now) to improve and maintain their own health will fare better in this new paradigm, than those who do not. We are learning more every day about how to successfully treat COVID19. The world health community is racing to meet the challenges of this epidemic, and finding success. But we aren’t there yet, and we have a long way to go.
We’re going to stop here for now. I will probably follow this post up with a second post entirely focused on COVID19 mythbusting. Although this post contains most of the necessary information to disprove all the common nonsense going around, it will probably be helpful to put together a “listicle” that goes over them one at a time and debunks them. That’s coming, but I am going to take a break. This post has taken almost a week of work, regularly staying up till 3AM to research and write.
This is a serious epidemic, and needs to be taken seriously. The Las Vegas casinos don’t close for nothing, and their choices are entirely built on extremely solid math. They chose to forgo billions of dollars of business and close, due to COVID19. If that doesn’t shape your concern about this, then nothing will.
I have established a Twitter feed solely focused on sharing information on COVID19/SARS-CoV-2 at Twitter.com/ControlMeasures – This is a rapidly changing situation, with new information almost constantly being generated, if you want to take a deeper dive, look at that feed over the coming days.