Pandemic Preparedness - Covid-19
In late February I sent out a warning to my mailing list, advising people to stock up and prepare for an outbreak. Not very long after, I pulled my children out of activities, and then moved our programs online.
However the more dire scenarios I considered plausible did not come to pass and more data has emerged on transmission, fatality rates, etc.
Reporting continues to be polarized and contradictory - the purpose of this page is to help you understand how I am thinking about and understanding and managing the risk.
I welcome your feedback, corrections, sources and suggestions!
However the more dire scenarios I considered plausible did not come to pass and more data has emerged on transmission, fatality rates, etc.
Reporting continues to be polarized and contradictory - the purpose of this page is to help you understand how I am thinking about and understanding and managing the risk.
I welcome your feedback, corrections, sources and suggestions!
Death and disease are greatly diminished - 9/2 update
As far as I can tell, whatever threat covid may have posed in northern Virginia at one time - it has shrunk to near zero today, judging by the reported fatalities, which have averaged less than 1/day since the end of July. (VDH graph, viewed 9/2). This supports the idea that most populations have low susceptibility to the virus and the threshold for effective herd immunity is much lower than had been initially feared.
The New York Times recently published findings that the PCR testing is so sensitive, it may register as "positive" non-infectious, inactive cases. I've heard that PCR can have people test positive up to many weeks post-infection, which suggests that the true number of cases and fatalities attributed to the illness may be far lower than previously thought.
Even when covid was most prevalent, the risk to children was found to be less than from a seasonal flu, and research has not been able to find a significant role for children in spreading the illness to adults either. This despite the fact that childcare centers continued operating throughout the worst of the pandemic even in the hardest hit areas, and schools never closed in some affected countries like Sweden.
I spoke to the director of a camp in northern Virginia that met all summer with no masks or social distancing, inside or outside, where there were no sick kids or parents reported and no sick staff members - despite being middle-aged in many cases.
On the other hand, I know of one family where parents were sick with flu-like illness and then the 11-yr old son became sick for many weeks with significant GI symptoms in late winter, and eventually tested positive for covid.
And I know of a young adult in the area that was severely ill for about a week with covid-like symptoms in July, despite being extremely cautious about social distancing, consistent mask use etc. He tested negative to everything they looked for, and his parents never got sick, and he has recovered fully to my knowledge. None of his close contacts were known to be infected; so not sure what to make of it.
I also talked to a dog-walker a few weeks ago who said an otherwise healthy 37-yr old acquaintance just died of covid recently, in our area...
So I cannot guarantee zero risk of covid. Nor of lightning, of severe cuts, or other mishaps in our program. However, I believe that the benefits of helping young people develop confidence, leadership skills, social skills, and a relationship to nature outweigh these risks, and that close encounters with risk are necessary for us to develop effective risk-management at the personal level. And I think a strong case can be made that for most young people, the harms of enforcing covid precautions outweigh the benefits at this point.
The New York Times recently published findings that the PCR testing is so sensitive, it may register as "positive" non-infectious, inactive cases. I've heard that PCR can have people test positive up to many weeks post-infection, which suggests that the true number of cases and fatalities attributed to the illness may be far lower than previously thought.
Even when covid was most prevalent, the risk to children was found to be less than from a seasonal flu, and research has not been able to find a significant role for children in spreading the illness to adults either. This despite the fact that childcare centers continued operating throughout the worst of the pandemic even in the hardest hit areas, and schools never closed in some affected countries like Sweden.
I spoke to the director of a camp in northern Virginia that met all summer with no masks or social distancing, inside or outside, where there were no sick kids or parents reported and no sick staff members - despite being middle-aged in many cases.
On the other hand, I know of one family where parents were sick with flu-like illness and then the 11-yr old son became sick for many weeks with significant GI symptoms in late winter, and eventually tested positive for covid.
And I know of a young adult in the area that was severely ill for about a week with covid-like symptoms in July, despite being extremely cautious about social distancing, consistent mask use etc. He tested negative to everything they looked for, and his parents never got sick, and he has recovered fully to my knowledge. None of his close contacts were known to be infected; so not sure what to make of it.
I also talked to a dog-walker a few weeks ago who said an otherwise healthy 37-yr old acquaintance just died of covid recently, in our area...
So I cannot guarantee zero risk of covid. Nor of lightning, of severe cuts, or other mishaps in our program. However, I believe that the benefits of helping young people develop confidence, leadership skills, social skills, and a relationship to nature outweigh these risks, and that close encounters with risk are necessary for us to develop effective risk-management at the personal level. And I think a strong case can be made that for most young people, the harms of enforcing covid precautions outweigh the benefits at this point.
Some raw notes and sources from research into susceptibility of children, and transmission routes (Updated 6/13/2020, unless otherwise noted; dates represent when I last viewed the source)
According to NPR, data from the (largely indoor) essential worker daycare that has continued even under lockdowns, there have been no recorded clusters (NPR, 7/1)
Early in the epidemic, contact tracing found 0 infections among 43 close contacts of 10 patients under 18, vs. 8.3% (55/655) of the close contacts of adults 18+. The Dutch are allowing children under 13 to attend schools and play outside without social distancing and also teens. (rivm.nl 6/29, edsource.org 6/30)
An April 26 study from Australia looked at about 850 people that were considered exposed close contacts in schools – to 18 different infected people (half adult, half child). No teacher or staff got sick from an initial school case. Only one 2 children were found infected, possibly from the exposure. (Study) The study did not specify what kinds of precautions were being followed, if any, at those schools at the time.
The most comprehensive review to-date has been finding minimal child-child or child-adult transmission:
“Around the world, children make up a minority of confirmed cases of COVID-19, usually contributing to between 1 – 5% of total case numbers. Concerns exist that low case rates reflect selective testing of only the most unwell, however data from South Korea and subsequently Iceland which have undertaken widespread community testing, have also demonstrated significantly lower case numbers in children. This has also been seen in the Italian town of Vo, which screening 70% of its population and found 0 children <10 years positive, despite a 2.6% positive rate in the general population.”
“Notably, the China/WHO joint commission could not recall episodes during contact tracing where transmission occurred from a child to an adult. Studies of multiple family clusters have revealed children were unlikely to be the index case, in Guangzhou, China, Israel, the USA, Switzerland and internationally. Limited data on positive cases in schools have not demonstrated significant transmission. A SARS-CoV2 positive child in a cluster in the French alps did not transmit to anyone else, despite exposure to over 100 people.”
(Boast et al. 2020, accessed 6/13, here)
The Italian study that found zero children under 10 testing positive, included a number of children living in households with infected adults. (Munro and Faust 2020)
Another review found 9% of 31 household clusters attributable to a child, while citing another analysis that found zero index cases under 15, among 419 households. (source)
The Swiss authorities have argued that children play only a minor role in transmission, in part on the basis of a study that found “a particularly low expression of ACE2 in the few young pediatric samples in the analysis”
Some German research by Christian Drosten claimed to find children with viral loads similar to those in adults, although the conclusions are being challenged.
A recent study out of Hong Kong attributed 80% of transmission to superspreading, primarily in the context of dense, enclosed social gatherings (clubs, pubs, etc.). (Adam et al 2020) No reports of pediatric super spreaders. (Munro and Faust 5/5/2020)
In general, it seems risk of getting or spreading for those under 10 very low. But it seems that at least by age 15, children may be similarly infectious to adults. (Theodoratou et al. 5/6/2020 source)
Mobile toilet was found to have elevated aerosols (source)
No specific evidence of transmission by fomites, but it is assumed based on other coronaviruses. An analysis of 75k cases in China found most (78 – 85%) of transmission within families, and an absence of significant clusters elsewhere. An article examining 445 contacts of 10 cases (presumably adults). Of these contacts, only 2 became infected, and they were both household members; 5 continuously exposed household members also did not become infected. Evidence to-date shows transmission is driven by droplet – close contact. (PHOntario)
Severity is related to the initial infectious load (Geoffrey et al 4/19/2020 source)
Sensitive to heat (source)
Conclusions
Evidence seems to suggest that 70% plus of infected patients may not spread the disease to anyone, but that most of the spread is by super-spreaders in areas of densely packed, enclosed areas like clubs. Minimal evidence of kids getting or spreading the virus in public, with greatest concern being children exposed to sick family members at home.
Early in the epidemic, contact tracing found 0 infections among 43 close contacts of 10 patients under 18, vs. 8.3% (55/655) of the close contacts of adults 18+. The Dutch are allowing children under 13 to attend schools and play outside without social distancing and also teens. (rivm.nl 6/29, edsource.org 6/30)
An April 26 study from Australia looked at about 850 people that were considered exposed close contacts in schools – to 18 different infected people (half adult, half child). No teacher or staff got sick from an initial school case. Only one 2 children were found infected, possibly from the exposure. (Study) The study did not specify what kinds of precautions were being followed, if any, at those schools at the time.
The most comprehensive review to-date has been finding minimal child-child or child-adult transmission:
“Around the world, children make up a minority of confirmed cases of COVID-19, usually contributing to between 1 – 5% of total case numbers. Concerns exist that low case rates reflect selective testing of only the most unwell, however data from South Korea and subsequently Iceland which have undertaken widespread community testing, have also demonstrated significantly lower case numbers in children. This has also been seen in the Italian town of Vo, which screening 70% of its population and found 0 children <10 years positive, despite a 2.6% positive rate in the general population.”
“Notably, the China/WHO joint commission could not recall episodes during contact tracing where transmission occurred from a child to an adult. Studies of multiple family clusters have revealed children were unlikely to be the index case, in Guangzhou, China, Israel, the USA, Switzerland and internationally. Limited data on positive cases in schools have not demonstrated significant transmission. A SARS-CoV2 positive child in a cluster in the French alps did not transmit to anyone else, despite exposure to over 100 people.”
(Boast et al. 2020, accessed 6/13, here)
The Italian study that found zero children under 10 testing positive, included a number of children living in households with infected adults. (Munro and Faust 2020)
Another review found 9% of 31 household clusters attributable to a child, while citing another analysis that found zero index cases under 15, among 419 households. (source)
The Swiss authorities have argued that children play only a minor role in transmission, in part on the basis of a study that found “a particularly low expression of ACE2 in the few young pediatric samples in the analysis”
Some German research by Christian Drosten claimed to find children with viral loads similar to those in adults, although the conclusions are being challenged.
A recent study out of Hong Kong attributed 80% of transmission to superspreading, primarily in the context of dense, enclosed social gatherings (clubs, pubs, etc.). (Adam et al 2020) No reports of pediatric super spreaders. (Munro and Faust 5/5/2020)
In general, it seems risk of getting or spreading for those under 10 very low. But it seems that at least by age 15, children may be similarly infectious to adults. (Theodoratou et al. 5/6/2020 source)
Mobile toilet was found to have elevated aerosols (source)
No specific evidence of transmission by fomites, but it is assumed based on other coronaviruses. An analysis of 75k cases in China found most (78 – 85%) of transmission within families, and an absence of significant clusters elsewhere. An article examining 445 contacts of 10 cases (presumably adults). Of these contacts, only 2 became infected, and they were both household members; 5 continuously exposed household members also did not become infected. Evidence to-date shows transmission is driven by droplet – close contact. (PHOntario)
Severity is related to the initial infectious load (Geoffrey et al 4/19/2020 source)
Sensitive to heat (source)
Conclusions
Evidence seems to suggest that 70% plus of infected patients may not spread the disease to anyone, but that most of the spread is by super-spreaders in areas of densely packed, enclosed areas like clubs. Minimal evidence of kids getting or spreading the virus in public, with greatest concern being children exposed to sick family members at home.
Case Fatality Rate & Infection Fatality Rate
In my original warning, I was concerned about the possibility of hospital overwhelm and CFRs being higher than reported, also based on independent media reports about mass death in China.
The research out of China at that time showed high CFR in Wuhan, and much lower elsewhere in China. And since then, we've seen variably low or high CFRs for different hospitals and populations around the world.
The CFR is calculated as the number of deaths out of the number of detected cases in a population - it is skewed by the amount of testing being done. So if a hospital only tests people with very severe symptoms, for example, there will be a low number of confirmed cases and relatively high number of deaths, giving a high CFR as an artifact of testing. Estimates for the CFR have ranged from 0.06% in Singapore to about 19% in France (source).
The IFR is the number of people that die out of all those that are infected, IFR estimates have been ranging from about 0.03% (Iceland, lower) to as high as 1.0%.
Why such drastic variation?
In all data-sets, we see that old age and underlying conditions raise the chance of dying from this. Also, the initial exposure level is important to disease severity, so various socio-cultural factors would affect the spread and severity of outcomes.
More on this below.
The research out of China at that time showed high CFR in Wuhan, and much lower elsewhere in China. And since then, we've seen variably low or high CFRs for different hospitals and populations around the world.
The CFR is calculated as the number of deaths out of the number of detected cases in a population - it is skewed by the amount of testing being done. So if a hospital only tests people with very severe symptoms, for example, there will be a low number of confirmed cases and relatively high number of deaths, giving a high CFR as an artifact of testing. Estimates for the CFR have ranged from 0.06% in Singapore to about 19% in France (source).
The IFR is the number of people that die out of all those that are infected, IFR estimates have been ranging from about 0.03% (Iceland, lower) to as high as 1.0%.
Why such drastic variation?
In all data-sets, we see that old age and underlying conditions raise the chance of dying from this. Also, the initial exposure level is important to disease severity, so various socio-cultural factors would affect the spread and severity of outcomes.
Transmission
At the beginning of the outbreak my conception of transmission was somewhat binary - that any exposure to virus, even trace, is equally likely to generate a severe or mild infection. Hearing of aerosol transmission and reported doubling times (how long it takes for reported cases to double within a population) as low as 3.5 days in multiple countries, led me to fear that trace airborne exposure could be a non-negligible risk for many people.
My understanding now is much more nuanced, and I am no longer that worried about trace exposure. Some sources for my reasoning include here and here.
Most exposure these days is trace level, and sub-infectious. One inhales some viral particles, but none of them land on the right cells, or cell receptors, and no infection occurs.
The next level of exposure would be the minimal infectious dose. One is exposed to enough viral particles that at least one, or a few, land on the needed cell receptors and are able to infect and replicate.
In this instance, a typical individual will mount an immune response that suppresses the infection before the virus is able: to replicate widely; to do much damage; to trigger much inflammation; or to cause visible symptoms. It's like the police responding to robbery - fairly easy to contain without much social disruption. Such cases should also be less contagious.
At the opposite extreme, there is the person who was standing for an hour some 2 feet from a highly infectious individual on the metro to work. This person inhales a large amount of the virus, which begins simultaneously replicating and growing exponentially in many cells, outpacing the immune response. This is like a surprise invasion of a massive army, and may overwhelm even the immune system of a healthy, younger person.
Furthermore, individual susceptibility will determine what constitutes sub-infectious, low or high infectious dosage for a given person. And of course, we should assume a broad spectrum of intermediate exposure levels and courses of illness, depending on how these specific variables interact.
This is my updated mental of how transmission occurs. I am sure the reality is much more complicated, but I think it is a useful model.
Masks and social distancing
For a long time now, authorities have counseled the public to stay 6' apart, and have variously either discouraged, encouraged or mandated mask use, depending on the day and the jurisdiction.
My understanding is that infective dose is a function of exposure and susceptibility. Exposure is how many viable particles of virus one inhales, which is a function of the viable virus concentration in the air and the number of breaths taken. Susceptibility depends on one's immune status and the prevalence of the specific cell receptors the virus must encounter.
Accordingly, in the confines of a bus, office, bar or an airplane, 6' or even 20' may not be enough distance for unprotected people to remain uninfected if together for some time, as the concentration may steadily increase from the exhalations of an individual who is at the highly contagious stage of infection, and the exposure time may be considerable. In these situations, it would seem that a mask may well offer an advantage, by reducing exposure.
In an outdoor environment, we would expect that viral concentrations decrease exponentially with time and distance from exhalation, such that maintaining a distance of 6' without a mask may be safer than a distance of 15' with masks on a bus.
My understanding now is much more nuanced, and I am no longer that worried about trace exposure. Some sources for my reasoning include here and here.
Most exposure these days is trace level, and sub-infectious. One inhales some viral particles, but none of them land on the right cells, or cell receptors, and no infection occurs.
The next level of exposure would be the minimal infectious dose. One is exposed to enough viral particles that at least one, or a few, land on the needed cell receptors and are able to infect and replicate.
In this instance, a typical individual will mount an immune response that suppresses the infection before the virus is able: to replicate widely; to do much damage; to trigger much inflammation; or to cause visible symptoms. It's like the police responding to robbery - fairly easy to contain without much social disruption. Such cases should also be less contagious.
At the opposite extreme, there is the person who was standing for an hour some 2 feet from a highly infectious individual on the metro to work. This person inhales a large amount of the virus, which begins simultaneously replicating and growing exponentially in many cells, outpacing the immune response. This is like a surprise invasion of a massive army, and may overwhelm even the immune system of a healthy, younger person.
Furthermore, individual susceptibility will determine what constitutes sub-infectious, low or high infectious dosage for a given person. And of course, we should assume a broad spectrum of intermediate exposure levels and courses of illness, depending on how these specific variables interact.
This is my updated mental of how transmission occurs. I am sure the reality is much more complicated, but I think it is a useful model.
Masks and social distancing
For a long time now, authorities have counseled the public to stay 6' apart, and have variously either discouraged, encouraged or mandated mask use, depending on the day and the jurisdiction.
My understanding is that infective dose is a function of exposure and susceptibility. Exposure is how many viable particles of virus one inhales, which is a function of the viable virus concentration in the air and the number of breaths taken. Susceptibility depends on one's immune status and the prevalence of the specific cell receptors the virus must encounter.
Accordingly, in the confines of a bus, office, bar or an airplane, 6' or even 20' may not be enough distance for unprotected people to remain uninfected if together for some time, as the concentration may steadily increase from the exhalations of an individual who is at the highly contagious stage of infection, and the exposure time may be considerable. In these situations, it would seem that a mask may well offer an advantage, by reducing exposure.
In an outdoor environment, we would expect that viral concentrations decrease exponentially with time and distance from exhalation, such that maintaining a distance of 6' without a mask may be safer than a distance of 15' with masks on a bus.
Amplification at home
While my model is mostly optimistic with regards to lower severity and transmission of illness with following standard precautions, it also points to the possibility of elevated risk posed within households should someone become infected.
If a family member does become infected, and have even a moderate course of the illness, other family members may be at risk of a relatively high initial infectious dose and a more serious course of illness.
The big challenge here is pre-symptomatic transmission.
The worst cases that children have are generally from adult household members, although it is also common for children not to become infected from contacts in the home.
If a family member does become infected, and have even a moderate course of the illness, other family members may be at risk of a relatively high initial infectious dose and a more serious course of illness.
The big challenge here is pre-symptomatic transmission.
The worst cases that children have are generally from adult household members, although it is also common for children not to become infected from contacts in the home.
Reducing susceptibility
In addition, this model underscores the vital importance of cultivating strong immunity. The following strategies all have scientific support.
Sleep - maintain a stable, regular, adecquate sleep cycle
Vitamin D - supplement daily with a moderate dose
Exercise - regular, vigorous exercise
Phytoncides - spending time in forested areas; this was shown to help in Japan - but I don't know to what extent these effects depend on the presence of specific tree species.
Managing weight and other risk factors - The measures above also fit well with a program to reduce weight and improve overall physical fitness, reducing known risk factors.
Stress reduction - All of the above measures should also help reduce stress, which can significantly lowers immunity.
Sleep - maintain a stable, regular, adecquate sleep cycle
Vitamin D - supplement daily with a moderate dose
Exercise - regular, vigorous exercise
Phytoncides - spending time in forested areas; this was shown to help in Japan - but I don't know to what extent these effects depend on the presence of specific tree species.
Managing weight and other risk factors - The measures above also fit well with a program to reduce weight and improve overall physical fitness, reducing known risk factors.
Stress reduction - All of the above measures should also help reduce stress, which can significantly lowers immunity.
Early treatment with anti-malarials?
In the same way that leading media outlets and authority figures vigorously downplayed the threat of Covid-19 and discouraged the use of masks at the time when such measures could have greatly limited major outbreaks, now the same outlets and authorities are waging a similar campaign against the use of hydroxychloroquine (HCQ), and are also not discussing evidence about the use of ivermectin.
While I don't believe the science is definitive either way about the efficacy (although there is some supportive evidence) for these drugs, the narrative that HCQ being dangerous is contradicted by a very long and safe track record according to the WHO's own pre-Covid-19 documentation, despite the current hype to the contrary.
According to its proponents, for HCQ to work well, it should be taken (preferably with Zn+), before symptoms begin or at the first suspicion of illness, so that it can reduce the replication and spread of the virus. Thus, in India for example, HCQ is being taken prophylacticly by police and medical workers on a large scale. According to a recent report about half of 10,000 cops have been taking it, and half have not been. Among those taking it, there have only been mild infections and no deaths, in the other group, 9 have died.
A recent article somehow passed peer-review into the Lancet, was used by the WHO to justify discontinuing other trials, and by the media to further deprecate the drug, was retracted for using fraudulent data.
A recent VA study being cited at times to show HCQ mortality, is one where the HCQ was given without zinc, preferentially to more severely ill patients, and the drug was administered long after the time when it would have been expected to provide benefit. Not surprisingly, the drug did not help, and more people taking it died, as they were sicker to begin with.
In India HCQ is being offered for general use in slums where social distancing is impossible, and for asymptomatic family members of people confirmed or suspected of having Covid-19. India currently is reporting 3 deaths per million population vs. almost 300 for the US, despite it's very dense, low-income population and over 2 million tests having been administered. I take those numbers with considerable salt, but it seems worth investigating.
A recently published randomized controlled trial that showed ineffectiveness did not administer the drug early enough to definitively show the effectiveness or lack thereof for HCQ. Chris Martenson has been reporting very on this controversy for a while, see a recent discussion here.
While I don't believe the science is definitive either way about the efficacy (although there is some supportive evidence) for these drugs, the narrative that HCQ being dangerous is contradicted by a very long and safe track record according to the WHO's own pre-Covid-19 documentation, despite the current hype to the contrary.
According to its proponents, for HCQ to work well, it should be taken (preferably with Zn+), before symptoms begin or at the first suspicion of illness, so that it can reduce the replication and spread of the virus. Thus, in India for example, HCQ is being taken prophylacticly by police and medical workers on a large scale. According to a recent report about half of 10,000 cops have been taking it, and half have not been. Among those taking it, there have only been mild infections and no deaths, in the other group, 9 have died.
A recent article somehow passed peer-review into the Lancet, was used by the WHO to justify discontinuing other trials, and by the media to further deprecate the drug, was retracted for using fraudulent data.
A recent VA study being cited at times to show HCQ mortality, is one where the HCQ was given without zinc, preferentially to more severely ill patients, and the drug was administered long after the time when it would have been expected to provide benefit. Not surprisingly, the drug did not help, and more people taking it died, as they were sicker to begin with.
In India HCQ is being offered for general use in slums where social distancing is impossible, and for asymptomatic family members of people confirmed or suspected of having Covid-19. India currently is reporting 3 deaths per million population vs. almost 300 for the US, despite it's very dense, low-income population and over 2 million tests having been administered. I take those numbers with considerable salt, but it seems worth investigating.
A recently published randomized controlled trial that showed ineffectiveness did not administer the drug early enough to definitively show the effectiveness or lack thereof for HCQ. Chris Martenson has been reporting very on this controversy for a while, see a recent discussion here.
Concluding thoughts
As I stated up-front, there is still considerable uncertainty, and I wish I had the time to just keep digging. But for now, the evidence I'm seeing is that the virus can be very severe, but more containable than initially thought, and at a minimum not deadly for the vast majority of people under 50 or so.
