COVID-19 Protection: A Summary of Important Findings

How a simple ABCD method can reduce your risk of infection.

Posted Mar 23, 2020

To protect ourselves from coronavirus (COVID-19) infection, my husband and I are doing all the things public health officials have recently recommended such as staying away from public places as much as possible, practicing rigorous hand hygiene, disinfecting surfaces, maintaining social distance and so forth.

But as I continue to read new research on coronavirus transmission, such as a March 17 article in the prestigious New England Journal of Medicine by Van Doremalen et al. on how long coronavirus survives in the air and on surfaces, I realize that my family and friends aren’t doing nearly enough to prevent infection.

In particular, hot-off-the-press research by Van Doremalen and others paints an ominous picture of ways coronavirus can spread that aren’t getting much play in the mainstream media.

Here’s a summary of the new findings, which you may have heard, along with the implications of those findings, which you likely have not heard, and some recommendations for what additional steps you can take to reduce the odds of infection.

The findings 

  • COVID-19 can live and retain its infectious potency on hard surfaces such as plastic and metal up to three days (past studies on similar viruses show that the interval can be as long as nine days)
  • The virus survives in a viable state on cardboard up to 24 hours
  • The virus can stay suspended in the air (in aerosol form) up to three hours
  • COVID-19 seems to be spread mostly within small clusters of co-workers, friends and family

The implications

Some of the implications of this new research are obvious: Touching door handles (especially in public places), shopping cart handles, gas pump handles, elevator buttons, cross walk buttons, or any hard surface that is touched by many people, is perilous.

When you touch these highly trafficked surfaces, the virus gets on your hands, which can then be transmitted to your respiratory pathways when you touch your mouth, nose or eyes (which people do on average 23 times an hour involuntarily).

Less obvious are the perils of touching surfaces that may not have been handled by many people but are still possible sources of infection if anyone else had ever touched or sneezed/coughed/breathed upon them. Here’s a partial list (future research might indicate some of these items are not problematic, but, to be safe now, I'm erring on the side of caution):

  • Cardboard packages you receive at home
  • Wrapping material of objects in those packages
  • Objects themselves in those packages
  • Shopping bags handled by baggers or others
  • Plastic food containers
  • Scoops and tongs for bulk items in grocery stores
  • Anything you purchase anywhere, including produce, that could have been touched, breathed/sneezed/coughed upon by someone else
  • Paper receipts handed back to you
  • Mail you receive
  • Your credit/debit card and ID handed back to you after a purchase
  • Pens (e.g. in banks) that you use to sign a form or slip or electronic styluses
  • Fur of pets (that you might be tempted to pet when you meet a friendly pooch on a walk)
  • Paper currency and coins

I know… this list includes items you touch even when you are doing all the things public health officials have been telling you to do, and it would be natural, after reading the list, to say, “Geez, that’s ridiculous: Can’t I ever touch anything?”

The answer to that question is that you can touch common things necessary to your survival if you practice what I call the ABCD’s.

How to decrease your chances of infection

  • A: Awareness of everything you touch, including your face
  • B: Barriers placed between your hands and objects you touch
  • C: Cover your mouth and nose in very high-risk areas such as hospitals, clinics and in drug pick-up lines at the pharmacy
  • D: Dispose, Disinfect and Distance

Awareness: This is the hardest thing to do regularly because so much of what we touch is automatic and involuntary. My husband and I have had success though, simply imagining that our hands are on fire, which keeps us from touching common objects (which we might set ablaze, in our imaginations) or our faces.

Barriers: The simplest protection is to hold a paper towel or tissue when you touch anything that another person has touched, breather/sneezed/coughed upon, unless at least nine days have elapsed since the item was in contact with another person. Gloves will work too, but those can be hard to get and are inconvenient for some.

Cover: Because the virus can hang in the air for up to three hours, wear a face mask if you have to visit an area that is high-risk, such as a clinic, hospital or waiting line for drug pick-up.

Dispose, disinfect, distance: Dispose of the barrier (paper towel, tissue or glove) you place between yourself and objects you touched, or your mask, immediately after use. Disinfect your hands by using a hand sanitizer (you can also wash your hands with soap and water for 20 seconds). For hard, nonporous surfaces you can also use disinfectant sprays or wipes. In your house, if you don't live alone, frequently disinfect high touch surfaces such as refrigerator door handles, faucets, toilet handles, doorknobs, TV remotes, keyboards of computers, mobile devices, game controllers, light switches, dishwasher controls, microwave handle and controls, oven handles and controls, and phones. Keep a distance of at least six feet from other people.

Perhaps the hardest and harshest of the “D’s” is distancing yourself from family and loved ones during the epidemic. It’s hard, harsh and seemingly impractical, I know, but the fact that COVID-19 seems to spread most among small clusters of family, friends and co-workers means that the people you care about the most pose the greatest risk to you (and vice versa). 

So, a close friend of ours who is a health care worker is now staying at a hotel to avoid infecting his wife should he contract the disease.

Because of what Dr. Eric Haseltine in a recent post calls our “normalcy bias,” you might be thinking at this point that it’s unrealistic and unnecessary to practice fanatical hygiene as I’ve suggested, impossible to avoid people you live with and that “enough is enough.”

And, you could be right. But the virus is indifferent to our habits, convenience and social needs, so although you may be right that what I’ve suggested is impractical, you could be dead right.


N van Doremalen, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. The New England Journal of Medicine. DOI: 10.1056/NEJMc2004973 (2020).

G. Kampfa, et al Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents, March 2020Volume The Journal of Hospital Infection, 104, Issue 3, Pages 246–251