COVID-19 -- Doctors explain
Posted: Wed Mar 18, 2020 9:31 am
This from a board-certified pathologist specializing in clinical microbiology. Note his conclusion: The key is to buy time.
What You Were Afraid To Ask About #Coronavirus
[Latest update: March 17th]
This is a sort-of FAQ that started as a Facebook post from a relative. I hope it serves as a quick and easy read that explains why the plan to get through the #COVID19 #coronavirus pandemic through #flattenthecurve tactics is needed.
Credentials: I am a board-certified pathologist on staff at multiple hospitals in my metro area with a specialty in clinical microbiology; among my duties, I run several clinical microbiology labs. I was trained in the Harvard hospital affiliate system.
Disclaimer: I am on parental leave; I cannot and do not speak for any of the hospitals I work at. My license is only for Alabama, and my certifications do not extend to direct patient care. Translation: I am not your personal physician, and you should call (don’t visit!) your own doctor’s office for any issues that specifically affect you.
This is as accurate as I could make it at the time I wrote it, but this is a fast moving event and humanity as a whole is learning more by the hour, so stay tuned.
1) “Coronavirus itself is not deadly.”
FALSE, BUT:
Most cases of coronavirus are not fatal, which is what I think you meant to say. In fact, all indications are that most cases are without detectable symptoms (“asymptomatic”).
This is worth repeating: MOST OF THOSE SPREADING THE VIRUS FEEL FINE.
1a) Follow-up: “What makes coronavirus so deadly?”
It’s a rapid release of fluid into the lungs from the inside, filling the airsacs and blocking oxygen from reaching the bloodstream. The technical term is ARDS: “acute respiratory distress syndrome”. (That doesn’t really explain it well, though, does it?) We know it has links to the immune system, but it’s still pretty mysterious, even when caused by things other than viruses.
2) “Coronavirus can cause pneumonia, which is also often not deadly.”
MIXED:
Pneumonia, a type of infection of the lungs, is often not deadly *when properly treated*. The entire concern around coronavirus centers on the possibility that we might not be able to treat everyone at once. More on that below.
2a) Follow-up: "My understanding is also that many are getting viral pneumonia which can only be treated supportively, as opposed to bacterial pneumonia which can be treated with antibiotics. Is that true?"
MIXED:
This is one of the key differences between coronavirus and flu: The flu does NOT directly cause the pneumonia, but coronavirus DOES. The flu simply ties up the immune system and leaves a lowered guard against bacteria trying to invade the lungs.
If the pneumonia itself is caused by ordinary bacteria, we can use ordinary antibiotics. But antibiotics only work on bacteria, not viruses.
Antiviral drugs DO work on viruses; Tamiflu is an example, as are the drugs that make HIV a chronic illness instead of a death sentence. But since this is a brand new virus, we don’t know what antivirals, if any, will work. And even if they do work, they may work like Tamiflu does, not curing the disease but merely reducing symptoms and shortening the illness.
Emergency-speed clinical trials on antivirals began this morning [March 16th] to figure out what antivirals might help. But the only way to find out is to try them and see what happens, so it will take at least weeks, probably months, to find out.
3) “Pneumonia is most likely to be deadly to at-risk populations like the elderly and immunocompromised.”
TRUE.
“Immunocompromised” are those whose immune systems are not working at the usual level of efficiency. It doesn’t mean you have no immune system, it just means that it works at a lower level, or that one or more components is missing.
“Immunocompromised” usually means a number of groups: the elderly, transplant recipients,those with chronic diseases (including but not limited to HIV), pregnant ladies, and the very young.
For reasons we do not yet understand, coronavirus seems to be mostly skipping babies and pregnant ladies -- they aren't getting infected at higher rates or with higher chances of death. Researchers are working hard on understanding this as it may help with treatments and/or vaccines. However, there is at least one case of a pregnant woman sick with coronavirus, whose baby also tested positive after birth. We will have to be very careful with those pregnant ladies who do catch the virus, and we have no idea what the effect on newborns might be.
4) “Pneumonia doesn’t have to be deadly for the at-risk hospitalizations as long as they are able to be hospitalized.”
TRUE, BUT:
The most critical need is not just hospital beds, but mechanized breathing assistance. Simple supports like extra oxygen, extra fluids, etc. will suffice for most hospitalized cases, but 5% of so will need intensive care - intubation,ventilation, and/or ECMO (“heart-lung machine”). These are the most limited resources. ICU beds make up only 10% of hospital beds.
5) “...which usually isn’t a problem as long as 1% of the population doesn’t need to be hospitalized all at once.”
TRUE, AND:
Especially true when 5% of that 1% need precious ICU equipment, much of which is already caring for others. Even 0.05% of the population is many times what we can cram into the country’s intensive care capacity.
PLUS:
Those machines are complicated. A field hospital can be slapped together in days or even hours; the Armed Forces have lots of experience at that (think “M*A*S*H for the 21st century). But those machines usually take 90 days or so to build.
Unless we seriously #flattenthecurve, we don’t have ninety days. Not to mention that if the hospitals do get overwhelmed, the doctors won’t have time to docare for most other problems. Elective surgeries are already being cancelled, for instance.
6) “So if you have symptoms of the virus, treat it like a cold or flu, noproblem.”
I hate to do this to you, but FALSE, and here’s why:
If the nasty thing is going to whammy you, it waits a while first.
Judging from experience in China and South Korea, symptoms appear on average after five days (big wobble on that, two to nine days depending on amount of exposure). For the first week you only feel mild symptoms.
It’s about seven days, on average, after first symptoms that the bad pneumonia phase seems to set in. So *if* you’re going to get a bad case, it *won’t* be obvious immediately. Treat it like a cold or flu BUT keep an eye on symptoms.
And that is why we have to #flattenthecurve as fast as possible. From the time your area goes into lockdown, it will likely take an average of TWELVE DAYS for the effects to show (five days average before symptoms, plus seven days average before needing the hospital bed).
The number of confirmed cases (in places not in lockdown) has been going up by a factor of 10 per week. So in twelve days there will be ABOUT 75 TIMES the number of cases. See now why we are “overreacting”?
7) “If you think you have symptoms of pneumonia, call your doctor for instructions. If you’re not in an at-risk population, then you’re likely to still just treat it at home so as not to overwhelm the hospitals.”
TRUE.
And a great lead-in from 6), because that’s what you need to look for... and *call first* because we healthcare workers really can’t keep exposing everyone to everyone else even for treatment purposes. After all, WE have to stay healthy (or at least enough of us at any one time) in order to keep the hospitals open!
8) "There is no evidence that #COVID19 is being spread by individuals with no symptoms, right?"
There is no *direct* evidence in the United States, or most of the world. This is because of our limited ability to test, not because it's false. What we *can* detect is that we can't establish "chain of infection": that is, people are getting symptomatic, test positive, and we can't figure out who they caught it from. That implies that someone not being tested is spreading virus.
That's happening a *lot*, and in a *huge* number of places -- in fact, pretty much every new place getting their first tests. The math just doesn't work unless people who don't think they're sick are spreading virus particles.
Final thought:
The key is to buy time. Time for more ICU machines to be built; time for antivirals and vaccines to be tested; time for hospital space to be built; time for extra workers to be trained. Stay home, stay safe, stay healthy everyone. Together we can make it through this!
--Allen Bryan (Tw: @awbryanjr)
What You Were Afraid To Ask About #Coronavirus
[Latest update: March 17th]
This is a sort-of FAQ that started as a Facebook post from a relative. I hope it serves as a quick and easy read that explains why the plan to get through the #COVID19 #coronavirus pandemic through #flattenthecurve tactics is needed.
Credentials: I am a board-certified pathologist on staff at multiple hospitals in my metro area with a specialty in clinical microbiology; among my duties, I run several clinical microbiology labs. I was trained in the Harvard hospital affiliate system.
Disclaimer: I am on parental leave; I cannot and do not speak for any of the hospitals I work at. My license is only for Alabama, and my certifications do not extend to direct patient care. Translation: I am not your personal physician, and you should call (don’t visit!) your own doctor’s office for any issues that specifically affect you.
This is as accurate as I could make it at the time I wrote it, but this is a fast moving event and humanity as a whole is learning more by the hour, so stay tuned.
1) “Coronavirus itself is not deadly.”
FALSE, BUT:
Most cases of coronavirus are not fatal, which is what I think you meant to say. In fact, all indications are that most cases are without detectable symptoms (“asymptomatic”).
This is worth repeating: MOST OF THOSE SPREADING THE VIRUS FEEL FINE.
1a) Follow-up: “What makes coronavirus so deadly?”
It’s a rapid release of fluid into the lungs from the inside, filling the airsacs and blocking oxygen from reaching the bloodstream. The technical term is ARDS: “acute respiratory distress syndrome”. (That doesn’t really explain it well, though, does it?) We know it has links to the immune system, but it’s still pretty mysterious, even when caused by things other than viruses.
2) “Coronavirus can cause pneumonia, which is also often not deadly.”
MIXED:
Pneumonia, a type of infection of the lungs, is often not deadly *when properly treated*. The entire concern around coronavirus centers on the possibility that we might not be able to treat everyone at once. More on that below.
2a) Follow-up: "My understanding is also that many are getting viral pneumonia which can only be treated supportively, as opposed to bacterial pneumonia which can be treated with antibiotics. Is that true?"
MIXED:
This is one of the key differences between coronavirus and flu: The flu does NOT directly cause the pneumonia, but coronavirus DOES. The flu simply ties up the immune system and leaves a lowered guard against bacteria trying to invade the lungs.
If the pneumonia itself is caused by ordinary bacteria, we can use ordinary antibiotics. But antibiotics only work on bacteria, not viruses.
Antiviral drugs DO work on viruses; Tamiflu is an example, as are the drugs that make HIV a chronic illness instead of a death sentence. But since this is a brand new virus, we don’t know what antivirals, if any, will work. And even if they do work, they may work like Tamiflu does, not curing the disease but merely reducing symptoms and shortening the illness.
Emergency-speed clinical trials on antivirals began this morning [March 16th] to figure out what antivirals might help. But the only way to find out is to try them and see what happens, so it will take at least weeks, probably months, to find out.
3) “Pneumonia is most likely to be deadly to at-risk populations like the elderly and immunocompromised.”
TRUE.
“Immunocompromised” are those whose immune systems are not working at the usual level of efficiency. It doesn’t mean you have no immune system, it just means that it works at a lower level, or that one or more components is missing.
“Immunocompromised” usually means a number of groups: the elderly, transplant recipients,those with chronic diseases (including but not limited to HIV), pregnant ladies, and the very young.
For reasons we do not yet understand, coronavirus seems to be mostly skipping babies and pregnant ladies -- they aren't getting infected at higher rates or with higher chances of death. Researchers are working hard on understanding this as it may help with treatments and/or vaccines. However, there is at least one case of a pregnant woman sick with coronavirus, whose baby also tested positive after birth. We will have to be very careful with those pregnant ladies who do catch the virus, and we have no idea what the effect on newborns might be.
4) “Pneumonia doesn’t have to be deadly for the at-risk hospitalizations as long as they are able to be hospitalized.”
TRUE, BUT:
The most critical need is not just hospital beds, but mechanized breathing assistance. Simple supports like extra oxygen, extra fluids, etc. will suffice for most hospitalized cases, but 5% of so will need intensive care - intubation,ventilation, and/or ECMO (“heart-lung machine”). These are the most limited resources. ICU beds make up only 10% of hospital beds.
5) “...which usually isn’t a problem as long as 1% of the population doesn’t need to be hospitalized all at once.”
TRUE, AND:
Especially true when 5% of that 1% need precious ICU equipment, much of which is already caring for others. Even 0.05% of the population is many times what we can cram into the country’s intensive care capacity.
PLUS:
Those machines are complicated. A field hospital can be slapped together in days or even hours; the Armed Forces have lots of experience at that (think “M*A*S*H for the 21st century). But those machines usually take 90 days or so to build.
Unless we seriously #flattenthecurve, we don’t have ninety days. Not to mention that if the hospitals do get overwhelmed, the doctors won’t have time to docare for most other problems. Elective surgeries are already being cancelled, for instance.
6) “So if you have symptoms of the virus, treat it like a cold or flu, noproblem.”
I hate to do this to you, but FALSE, and here’s why:
If the nasty thing is going to whammy you, it waits a while first.
Judging from experience in China and South Korea, symptoms appear on average after five days (big wobble on that, two to nine days depending on amount of exposure). For the first week you only feel mild symptoms.
It’s about seven days, on average, after first symptoms that the bad pneumonia phase seems to set in. So *if* you’re going to get a bad case, it *won’t* be obvious immediately. Treat it like a cold or flu BUT keep an eye on symptoms.
And that is why we have to #flattenthecurve as fast as possible. From the time your area goes into lockdown, it will likely take an average of TWELVE DAYS for the effects to show (five days average before symptoms, plus seven days average before needing the hospital bed).
The number of confirmed cases (in places not in lockdown) has been going up by a factor of 10 per week. So in twelve days there will be ABOUT 75 TIMES the number of cases. See now why we are “overreacting”?
7) “If you think you have symptoms of pneumonia, call your doctor for instructions. If you’re not in an at-risk population, then you’re likely to still just treat it at home so as not to overwhelm the hospitals.”
TRUE.
And a great lead-in from 6), because that’s what you need to look for... and *call first* because we healthcare workers really can’t keep exposing everyone to everyone else even for treatment purposes. After all, WE have to stay healthy (or at least enough of us at any one time) in order to keep the hospitals open!
8) "There is no evidence that #COVID19 is being spread by individuals with no symptoms, right?"
There is no *direct* evidence in the United States, or most of the world. This is because of our limited ability to test, not because it's false. What we *can* detect is that we can't establish "chain of infection": that is, people are getting symptomatic, test positive, and we can't figure out who they caught it from. That implies that someone not being tested is spreading virus.
That's happening a *lot*, and in a *huge* number of places -- in fact, pretty much every new place getting their first tests. The math just doesn't work unless people who don't think they're sick are spreading virus particles.
Final thought:
The key is to buy time. Time for more ICU machines to be built; time for antivirals and vaccines to be tested; time for hospital space to be built; time for extra workers to be trained. Stay home, stay safe, stay healthy everyone. Together we can make it through this!
--Allen Bryan (Tw: @awbryanjr)