The Four Safety Dimensions for Covid-19 Prevention–Staying Safe Out There

world with covid-19

There are four simple concepts which will help you stay safe and avoid contracting Covid-19 as you begin to reenter society, and as things begin to open up.

  1. Proximity or closeness to other people outside your own household. A very safe distance is 10 feet, and adequately distance is 6 feet, and anything less than 3 feet of social distance is probably risky.
  2. How long you are in contact with those people. Studies of transmission suggest that a contact time of 30 minutes or more is risky, but in situations of close social distance anything more than five minutes may be risky. (If everyone is wearing a mask, safe contact times may be somewhat longer.)
  3. Whether the environment is confined or open, inside or outside, and if inside how large is the inside environment and is there good air circulation? Outside is almost always better than inside, and inside environments which are larger and have good air circulation are probably less risky than small and sealed environments like elevators. (Or small public restrooms.)
  4. Whether or not everyone is wearing a mask. Studies suggest that the use of masks can reduce transmission by 80 or 90%. That is why doctors and nurses always wear masks when treating sick Covid 19 patients. They also wear eye protection. The use of masks protects you from spreading coronavirus to other people, and also protects you from them spreading coronavirus.

When the more dangerous options among these four factors overlap, you are in peril.

For example, let’s say you decide to get a massage. The massage room is inside, very small, and the massage takes 90 minutes. This is a high-risk situation even if you and the masseuse are both wearing a mask. (And even higher risk if either is not wearing a mask.) You have close social distance, extended exposure, in a small and poorly circulated room, and perhaps the only safety factor is the wearing of masks.

In contrast, you go for a walk in your neighborhood. Other people are out walking but everyone respects at least a 6 foot social distance, and you do not stop to talk with people. Any contact is 6 feet away and lasts only a few seconds. This is a relatively safe situation regardless of the use of masks.

Let’s look at each factor separately.

Indoors versus outdoors

Japanese researchers looked at 110 people who had Covid-19. Only 12.5 percent passed the illness on if their only interactions with people were outdoors. But of those who interacted with people indoors, 75 percent infected other people. Out of the 22 people who met people indoors only six did not infect anyone else. But of the 88 people who met people only outdoors, 77 did not infect anyone. The reason for this appears to be that the tiny droplets that can infect you disperse very rapidly outside. So it appears that outdoor contact is not perfectly safe, but is six times safer than indoor contact.

Duration of contact

There is some interesting data from China and France in terms of likelihood of catching Covid-19 in various different indoor settings. The worst setting was the household where 13 percent of people contracted Covid-19 if someone in their household had it. The next most risky type of environment was public transport, which ranged from 2% to 12% depending on whether or not there was a super spreader event. (Super spreader events are those rare people that seem to be very efficient at spreading the virus.)

Particularly relevant was the finding that 7% of people who came into contact with an infected person in a restaurant dining environment contracted Covid-19. That’s pretty risky to avoid cooking at home! (Note that 85 coronavirus cases were linked on 6/28/20 to a SINGLE restaurant in Michigan, in a single week of operation! The restaurant had poor circulation, poor social distancing rules, and no air filters on ventilation.)

All the other indoor environments had about the same risk, 2%, and this included shared work or study spaces, schools, healthcare settings, and all other settings. The better the ventilation was the less likely transmission.

What about masks?

Masks are particularly helpful in high risk indoor situations, where they block the spread of droplets that can transmit Covid-19. Because the risk of infection is lower outdoors, especially if people are properly socially distancing, they may add very little benefit. But if you are in close contact with other people outdoors, masks may help significantly. This may be why in cities that had large Black Lives Matter demonstrations, there were relatively few outbreaks, as many of the protesters wore masks.

Large Events

Large events are particularly problematic because of super spreader individuals. Research from China and Hong Kong showed that 80% of new infections came from about 20% of people. These are called super spreaders, and we don’t really fully understand why some people are so infectious. But being in a large event such as a sporting event or concert makes it highly likely that there will be one or many super spreader individuals. Avoid these even if they reopen. (As reported on 6/28/20, Swiss authorities had to quarantine 300 people who attended a Zurich nightclub on 6/21/20 because of a super spreader individual.)

High-risk versus low risk situations

Here’s the deal with viral particles. We still don’t really know how many Covid-19 infectious viral particles it takes to get you sick. But some experts estimate that the threshold may be about a thousand particles. A cough releases 3000 droplets and a sneeze releases about 30,000 droplets. These droplets can contain 200 million viral particles, which explains why symptomatic people can spread Covid-19 indoors so easily.

In contrast a single breath releases about 50 to 100 droplets, which fall to the ground quite quickly. Although we don’t know the exact data it’s reasonable to assume that a person breathing may release 30 viral particles per minute. Speaking may change that to 300 per minute. So, this tells you that it would take perhaps 40 minutes of someone breathing near you, or about five minutes of someone speaking with you face-to-face in order to risk infection, assuming it takes 1000 viral particles to contract coronavirus.

This is important because it tells you that if you walk by someone outside or even inside in a grocery store, your risk is low. But let’s say you see a friend of yours in the grocery store, and you spend 15 minutes talking with them. That’s pretty high risk especially if you are face-to-face and not wearing a mask.

Where have most infections occurred?

  • Prisons
  • Long-term care facilities
  • Meatpacking plants
  • Business networking and conferences such as the Biogen conference in Boston in late February
  • With more relevance to most of us, weddings, funerals, birthday parties, family get-togethers,  which make up about 10% of the early super spreading events

Most of us aren’t in prison, we don’t live in a nursing home, we don’t work in a meatpacking plant. But many people have lately been tempted to go to parties which are clearly a high risk situation.

Finally, don’t forget to wash your hands or use alcohol gel. Don’t touch your face which includes your eyes, ears, nose, or mouth. When you get home wash thoroughly, and you may want to even jump in the shower and wash your hair, as some studies in medical settings have found that hair is particularly good at holding viral particles.

Here’s a good way to think about risk. It comes from advice about sexual health. If you have sex with someone, you are being exposed not just to them but to all their prior sexual partners. In a similar way, let’s say you get together with her friend who is not part of your household. You’re not only being exposed to them, but to every person they have had contact with in the last 14 days or so. The clerk in the store who didn’t wear a mask and stepped close to them, the UPS guy who knocked on the door and asked a question from 2 feet away, all the friends that they have had contact with, the people they live with, and all the people that those people have had contact with. As you can see one of the reasons coronavirus spreads so much is that the larger our social networks are the more risk there is.

Finally, be aware that many coronavirus infections are asymptomatic meaning that the people who have coronavirus are neither coughing or sneezing. Some studies suggest that as many as half of the cases are asymptomatic. This means you can’t depend on people knowing that they might be sick. The Center for Disease Control released data on June 26, 2020 that suggests that the real number of coronavirus infections is perhaps 10 times what has been reported. As of today, there are about 2.5 million cases reported in the United States, which means we may have had 25 million cases! That is 7.5% of the US population. This sounds like a lot, but it also means that 92.5% of the United States population is still in danger of contracting the coronavirus.

And that is why I’ve been practicing virtually since early March, and will continue to do so until there is either an effective treatment or a vaccine for the coronavirus. Be safe out there, and ask yourself about each activity if it is worth the risk not only to yourself, but also to all the people you might come into contact with including older parents and grandparents. We are all in this together, and even the young and healthy can transmit coronavirus if they get sick. Yes, we all miss going to restaurants, movie theaters, bars, parties, concerts, and sporting events. But it’s not permanent. I suspect that within the next six months will have much more effective treatments, and within 12 months we will have a vaccine which will let us get back to normal.

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Dr. Andrew Gottlieb is a clinical psychologist in Palo Alto, California. His practice serves the greater Silicon Valley area, including the towns of San Jose, Cupertino, Santa Clara, Sunnyvale, Mountain View, Los Altos, Menlo Park, San Carlos, Redwood City, Belmont, and San Mateo. Dr. Gottlieb specializes in treating anxiety, depression, relationship problems, OCD, and other difficulties using evidence-based Cognitive Behavioral Therapy (CBT). CBT is a modern no-drug therapy approach that is targeted, skill-based, and proven effective by many research studies. Visit his website at CambridgeTherapy.com or watch Dr. Gottlieb on YouTube. He can be reached by phone at (650) 324-2666 and email at: Dr. Gottlieb Email.

Transcript of Dr. David Price video, “Empowering and protecting your family during the Covid-19 pandemic”

I’ll be publishing a number of articles on Covid-19 over the next few weeks, but today I wanted to put up my edited transcript of a video that has gone viral over the last few days. It’s a video call with  Dr. David Price of the Weill Cornell Medical Center in New York City. Dr. Price is a Fellow in Pulmonary Medicine and Critical Care, who works primarily with Covid-19 patients, so has had a good deal of experience treating this new illness.

The opinions expressed are his opinions, and some medical professionals disagree with some of his points particularly about the potential for transmission from speaking. In general, though, I found this interesting and useful. The complete transcript of his entire 57 minute talk is at this link:  Edited Transcript of Dr. David Price video, “Empowering and protecting your family during the Covid-19 pandemic”

Here’s the link to the original talk: https://vimeo.com/399733860 

Title: Empowering and protecting your family during the Covid-19 pandemic

Edited transcript. (Edited for clarity, headings, underlines and boldface are mine.)

surgical mask

I’m going to post a few excerpts from his talk here, and you can find the entire transcript here: Edited Transcript of Dr. David Price video, “Empowering and protecting your family during the Covid-19 pandemic”

My job is to decide which patients need ventilators and once patients are put on ventilators how long they have to stay on them. The treatment of these patients and so my whole long-winded point is that I’m kind of in a unique position to comment on what’s going on.

And what I mean by empowering is to learn about this disease. I know you guys have a lot of questions. We will get to as many of these questions as we can. But the main reason I want to have this call is that I don’t want you guys to be scared. We’re three months into this in the medical world and we understand this disease. So I’m going to go through ways to protect your family and then what to do if and when someone gets Covid-19 and how we can protect our circle.

What is Covid-19?

And so when the common questions I get is what is this disease look like? Commonly people have fever and cough and they have a sore throat. And then the virus goes to their entire body and what we have found is that the most likely place that this will affect is your lungs.

And so people will commonly have a cough but for about 80% of people, you just don’t feel good. You have a mild cough maybe have a little headache. The disease lasts from what we’re seeing between five to seven to fourteen days. Some people who have a mild disease by about day five are starting to feel better. People who aren’t feeling better usually start to get short of breath around day three to five and then start to feel better around that seven-day mark.

The first kind of big topic we’re gonna talk about and I think the reason I wanted to have this call is how to protect your family.  I think we’ve learned a lot and I want to kind of share all the stuff that I’ve learned so far with you guys. So I think the first thing is how do you get Covid-19. I  think that this is really important and we really learned a lot over the last couple weeks to months about how you get this disease.

The overarching theme is sustained contact with someone who has this disease, of which the vast majority is people with fever and aches. Or with someone who is about to get the disease. So someone in the next two days who’s going to develop symptoms of this disease. The way that you get this is the transmission of the virus almost exclusively from your hands to your face. From your hands to your face and into your eyes, into your nose or into your mouth.

How to Stay Safe by Keeping Your Hands Clean and Germ-Free

So the first step which I think is incredibly clear is to become a hand cleaning fanatic. Know where your hands are and know that they’re clean and sterile at all times.

So very simply for what this means for me in the city is that I walk around with hand sanitizer like Purell. So I walk around with Purell and so every when I leave my apartment everything that I see that I’m going to touch I make sure that I Purell first.

So when I leave my apartment door and I go to the elevator, it’s okay that I touch it with my hand, but then I Purell. When I go downstairs and I open the door it’s okay to touch the door. You can open it with your elbow, but if you touch the door then I make sure to Purell.

The second thing is you have to start psychologically working on the connection between your hands and your face.

You don’t realize that you move your hand, you know, you scratch your nose and so the virus has taken advantage of this and the reason why people get this disease is that you have sustained contact with someone. So someone at a party has this and you shake their hand.

And then you touch your face. It’s that simple. That is how you get this disease. So what does that mean? I think there are two practical things that you can do. One is just to start to be aware of when you touch your face. Atul Gawande is a Harvard trained surgeon who is very famous, has a recommendation for people to just start wearing masks. The idea here is not that the mask is going to prevent you from getting Covid because as I said, it’s not a disease that you are getting from the air. The reason to put on a mask is that you just stop touching your face.

And so what I would recommend is now when you’re leaving your house is to wear a mask. And I think those two things combined are incredibly powerful and will prevent the transmission of the disease in your family in ninety-nine percent of cases. Know that your hands are clean and sterile, and don’t touch your face.

Four important points (the Rules):

  1. Always know where your hands are and have hand sanitizer. When you touch stuff that’s outside your home, just make sure that you’re washing your hands.
  2. Start to learn how to not touch your face. A really good way to do that is to start wearing a mask when you’re out and if you want to practice,  wear a mask in your home.
  3.  You don’t need an N95 mask or a medical mask. Any mask will do because this is not preventing the disease. This is training you not to touch your face.
  4. And the fourth thing is just to stay away from people. Stay 6 feet away from people.

So I think this when you understand those four rules the next thing I think is so important becomes true.

You don’t have to be scared of the outside world. No, you don’t have to be scared of your neighbor.

So what do you do if you get sick? Quarantining Tips

If you develop a fever and you are otherwise fine, then isolate yourself from your family. So what does that mean? it’s just simply about the same rules about hands and touching your faces, you don’t want sustained contact with the person who’s sick to the point where you’re going to be able to pick this up off of surfaces or off their person and then touch your face. So what people are recommending is that if you’re able,  have the person in a separate room.

If you’re able, have the person who’s sick have their own bathroom. If the person has to come out and interact with people in the family, this is a perfect indication for one medical mask and the reason is you want to put the mask on the person who is sick. And so if in our apartment if I was sick and I had to come out and interact with my family before I would leave the bedroom, I would wash my hands, I would put on a mask, and then I would sit down and eat food at the table and then after that when I was done I would eat the food, I put it in the sink and make sure that anything I touched which is a very simple area on the table, is just washed and then I’ll go back to my room. The point is to not have sustained contact with someone in your home who has this disease. You’re gonna want to take care of them, you’re gonna want to be in and out of there, checking their temperature. Don’t do it!

Who should go to the hospital?

If you’re feeling short of breath come to the hospital. That is the rule that is the clearest thing.

It’s not “I have a fever.”  It’s not “I think I have Covid-19”. It’s not “I can’t stop having these body aches.” It’s “I feel short of breath when I get up to go to the bathroom.”

Those are people that should come to the hospital and be evaluated. At Cornell right now what we’re doing is a lot of the people that come to the emergency room, we’re sending home to live out the four or five days of their disease so that they can feel better. We say “oh you look completely fine,  go home.”

But we’re also seeing is that people who feel short of breath who come to the hospital some of them go on to the floor and just are short of breath for five to six, or seven days and then they go home. So of the entire population of people who get Covid-19 about 10% need to go to the hospital because they get short of breath.

Of the 10% who are coming to the hospital about one to three percent of those are requiring admission to the ICU and should be put on the ventilator. So what happens when people get put on ventilators? The vast majority of people, the overwhelming majority of people come off the ventilator and they usually come off the ventilator seven to ten days later, but I think the important thing for you guys to know is going to the hospital is not a death sentence. It’s a safe place for you to be. Go to the hospital when you’re short of breath. Don’t go to the hospital because you have Covid-19.

We are wondering being in a city as it really safe to go on a run or walk taking in the social distancing measures? 

Amazing question. Yes, please. If you’re in a city, you can go outside just follow the rules. When you go outside Purell your hands. When you’re going to press the elevator button, Purell your hands. When you touch the door Purell your hands, don’t touch your face. When you’re out walking in the city and don’t come within three to six feet of people. But say hello smile no one is giving each other this disease by walking through a city. If there’s a bike path you can walk on it, the only caveat is just don’t get sloppy don’t you know the problem with telling people they can do things is that everyone just assumes their old lifestyle. That is not what I’m saying, I’m saying it’s safe in New York City,  in Philadelphia to go on a walk,  just follow the rules.

If you become sick how long should you wait before you go to the doctor or hospital?

So I think we loosely addressed it, but I’ll directly address it. Which is,  don’t go to the doctor, don’t go to the hospital. The only rule for going to the hospital is if you’re short of breath.

What is amazing now is the during the Covid-19 outbreak is the use of telehealth and so by far if you feel sick and you are a little nervous or contact your health care provider by telehealth, and they will tell you that you have nothing or that you have Covid-19 and you should stay home. So do not go to the doctor do not go to the hospital.

I would encourage you to use telemedicine which is completely rampant right now because we have a ton of doctors who are at home and we’ll take your call over the internet.

If you are unaware you have the virus during the incubation period, can you infect other people?

Yes, I think that the answer is yes, and so this comes from the cruise ship data. I think there was a concern, a big concern about the asymptomatic spread,  meaning people who never have symptoms of the disease spreading it to people who then get the disease. What we know from the cruise ship data is that that asymptomatic spread it turns out that most of the people who received the virus from someone else, the person who they received the virus from becomes symptomatic in one to two days.

So it’s likely that people who get this disease are shedding the disease one to two days before they have fever So what does that mean practically? It means that if you develop Covid-19 and have a fever, know who the people are in your life that you interacted with over the prior two to three days and let them know.  Because then they can do they can follow the rules they can isolate themselves in their house, they can create a separate bathroom and then after two to three to four days if they’re not feeling symptoms, they’re probably not going to have Covid disease. So the simple answer to your question that is yes,  people transmit this disease but I do not believe that there’s this whole group of people out there who are giving this disease to everyone, and they themselves are truly asymptomatic, and they never develop symptoms. Most will get sick a few days later.

Are people becoming immune after they recover?

Yes, people are absolutely becoming immune. The stories you’re hearing about people having rebound symptoms is usually the fact that they just haven’t fully resolved the disease. So let me say that more clearly so we know that from a day or two before you have the disease until about 14 days into the disease that you’re spreading the disease to the environment.

 

Full Transcript Here: Edited Transcript of Dr. David Price video, “Empowering and protecting your family during the Covid-19 pandemic”

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Dr. Andrew Gottlieb is a clinical psychologist in Palo Alto, California. His practice serves the greater Silicon Valley area, including the towns of San Jose, Cupertino, Santa Clara, Sunnyvale, Mountain View, Los Altos, Menlo Park, San Carlos, Redwood City, Belmont, and San Mateo. Dr. Gottlieb specializes in treating anxiety, depression, relationship problems, OCD, and other difficulties using evidence-based Cognitive Behavioral Therapy (CBT). CBT is a modern no-drug therapy approach that is targeted, skill-based, and proven effective by many research studies. Visit his website at CambridgeTherapy.com or watch Dr. Gottlieb on YouTube. He can be reached by phone at (650) 324-2666 and email at: Dr. Gottlieb Email.

Why You Shouldn’t Believe Everything You Read in the Newspapers about Medical Studies

One of my favorite journals is called PLOS ONE.  This is a journal which supports open access. That means anyone can access any article in this Journal without paying a fee. Medical studies published in this journal are accessible to anyone.

Most of you probably don’t realize but when you see a medical study quoted in a newspaper article, you can’t actually access the original study on the Internet without paying a hefty fee, usually $20-$40! If you have access to a medical library then you may be able to access the article but for most people the original articles are off-limits without paying large fees.

Plos.org is an organization that supports open access publication of scientific articles.

That’s why I admire them.

Back to my main story. A recent study in PLOS ONE looked at how often medical research results are replicated, meaning does a second or third similar study show the same results.

The researchers in this study looked at 4723 studies that were included in 306 meta-analysis articles. (A meta-analysis is a study where you combine the results of many other research studies in order to get an overview of findings.)   The researchers divided the studies into lifestyle related studies which looked at things like drinking coffee or smoking cigarettes and non-lifestyle studies such as genetic markers for Alzheimer’s. There were 639 lifestyle studies and 4084 non-lifestyle studies.

The question is of the studies that were picked up by newspapers, how many of them were replicated by subsequent studies?  The answer is only about half of the studies held up when tested again in another study. The other thing that was interesting in this article was that when studies failed to replicate, newspapers never reported that failure. Interesting examples included studies that linked a specific gene to depression, schizophrenia, or autism. None of these studies replicated successfully, which you think would be big news and would be reported by many newspapers, but the truth is that not a single newspaper article reported these failures to replicate.

This shows that newspapers don’t have much genuine interest in good science reporting. Good science reporting always involves being skeptical of new and different results, as well as following up on attempts to replicate those results.

So, what does this mean about science results reported in popular media? What it probably means is that if the finding is new and exciting and different, you probably should be highly skeptical of it being true. And the more esoteric the finding is (such as genetic markers) the more skeptical you should be.

For instance, a recent study that was funded by drug companies looked at whether the statin class of medications have side effects or whether these side effects are just a placebo effect. I’ll write more extensively about this study later, but the study’s findings–that only when people knew they were taking statins did they experience side effects– should probably be viewed very skeptically since many other studies have shown side effects from statins and many clinical reports have confirmed the side effects. (And of course any study that is funded by the manufacturer of a drug should be viewed highly skeptically.)

The bottom line is this: finding the truth is hard, and science is no shortcut. Only findings that have been repeated and replicated in numerous studies should be believed.

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Dr. Andrew Gottlieb is a clinical psychologist in Palo Alto, California. His practice serves the greater Silicon Valley area, including the towns of San Jose, Cupertino, Santa Clara, Sunnyvale, Mountain View, Los Altos, Menlo Park, San Carlos, Redwood City, Belmont, and San Mateo. Dr. Gottlieb specializes in treating anxiety, depression, relationship problems, OCD, and other difficulties using evidence-based Cognitive Behavioral Therapy (CBT). CBT is a modern no-drug therapy approach that is targeted, skill-based, and proven effective by many research studies. Visit his website at CambridgeTherapy.com or watch Dr. Gottlieb on YouTube. He can be reached by phone at (650) 324-2666 and email at: Dr. Gottlieb Email.