Transmission events occur through contacts made between susceptible and infectious individuals either the household, workplace, school or randomly in the community, with the latter depending on spatial distance between contacts.
Per-capita contacts within schools were assumed to be double those elsewhere in order to reproduce the attack rates in children observed in past influenza pandemics. With the parameterization above, approximately one third of transmission occurs in the household, one third in schools and workplaces and the remaining third in the community. These contact patterns reproduce those reported in social mixing surveys
Paper Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand
In China, human-to-human transmission of the COVID-19 virus is largely occurring in families. … Among 344 clusters involving 1308 cases (out of a total 1836 cases reported) in Guangdong Province and Sichuan Province, most clusters (78%-85%) have occurred in families … preliminary studies ongoing in Guangdong estimate the secondary attack rate in households ranges from 3-10%.
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There have been reports of COVID-19 transmission in prisons (Hubei, Shandong, and Zhejiang, China), hospitals (as above) and in a long-term living facility. The close proximity and contact among people in these settings and the potential for environmental contamination are important factors,which could amplify transmission.
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The Joint Mission learned that infected children have largely been identified through contact tracing in households of adults.
Of note,people interviewed by the Joint Mission Team could not recall episodes in which transmission occurred from a child to an adult.
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Asymptomatic infection has been reported, but the majority of the relatively rare cases who are asymptomatic on the date of identification/report went on to develop disease. The proportion of truly asymptomatic infections is unclear but appears to be relatively rare and does not appear to be a major driver of transmission
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There have been reports of COVID-19 transmission in prisons (Hubei, Shandong, and Zhejiang, China), hospitals (as above) and in a long-term living facility. The close proximity and contact among people in these settings and the potential for environmental contamination are important factors,which could amplify transmission. Transmission in these settings warrants further study.
Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)
When I say these distinguished academics are not validating or checking their model - I mean they have not checked it against this detailed data.
However, instead of concluding that their model needs a radical revision to model this new virus, they wait for more “good” data from the field that fits their paradigm and discard the data that doesn’t fit it as anomalous.
This is not “good science” but it is a natural thing for humans to do.
Such models have to be validated against the data to provide even a qualitative prediction. Until then, they are unconfirmed scientific hypotheses.
There is nothing here to contradict the conclusions of the WHO that this pandemic can be stopped.
However they still suggest that though they can do it, that we can't. So I'd like to answer a couple of their main points as readers may have the same thoughts.
These are actual points made in that BBC article, believe it or not!
Isn't this impossible to do in the West because Asians are better at following orders than Europeans?
They start this section saying
It's far too simplistic to say, as some have, that Asians are more likely to comply with government orders.
They give Hong Kong as a counterexample - and say Hong Kong do it because it was particularly hard hit by the SARS epidemic in 2003
- but that leaves you with the impression that apart from Hong Kong which has special circumstances that don't apply to us, that their statement is true.
They don’t say anything else to contradict this ethnic stereotype that some of their readers will have in the UK.
How can you enforce isolation and quarantine in a free country like the UK?
In the article they say:
Many countries in the West will find it hard to adopt such measures due to their larger populations, and greater civil liberties.
The WHO say COVID-19 patients remain infectious for a long time, through to two weeks after they feel fully recovered from the disease. The UK advise members of the public who suspect they have COVID-19 to quarantine for 7 days after symptoms onset. This advice also applies to doctors or nurses who think they may have COVID-19.
We will soon know because we will get thousands of people on ventilators. Some time the end of next week or the end of the week after we will get masses of deaths and hundreds, mabye a thousand doctors and nurses dying if it has gone wrong. We know the Singapore method works. We don't know this works.
This is why the WHO say that if someone else in your household has COVID-19 you should both wear masks, know how to use them properly and the COVID-19 patient should have a separate bathroom that only they use and they should be confined to their bedroom, with a single carer assigned to them, and that this carer takes precautions such as washing their hands thoroughly after caring for them.
The UK's advice to self isolate in households without these precautions is creating the prolonged close contact that is ideal for this disease to spread within a household.
So the UK measures are focused on reducing community spread, which is a minor component of COVID-19. They increase spread in the household, which for the fictional disease is already 100% so it makes no difference. But for the real world disease that is 10% or less. Given this background it is not clear they are slowing down the disease. These measures may increase the spread. The last thing we want to do is to increase the spread of COVID-19.
This is too urgent to let slide.
Let's call for a debate, with utmost urgency, on the scientific evidence basis of the UK's policy. It should be public too, so that we can all follow the discussion and hear the arguments on both sides of the debate.
I am calling for a debate, with utmost urgency, on the scientific evidence basis of the UK's policy. It should be public too, so that we can all follow the discussion and hear the arguments on both sides of the debate.
This debate should include invited experts from the WHO, such as Dr Bruce Aylward who spent 9 days in China including a day and a half in Wuhan along
It should include Invited experts from the WHO, such as Dr Bruce Aylward and Dr Maria van Kerkove, both of whom spent 9 days studying the situation in China including a day and a half in Wuhan while preparing the Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19).
his debate should include invited experts from the WHO, such as Dr Bruce Aylward who spent 9 days in China including a day and a half in Wuhan along
It should include Invited experts from the WHO, such as Dr Bruce Aylward and Dr Maria van Kerkove, both of whom spent 9 days studying the situation in China including a day and a half in Wuhan while preparing the Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19).
This is too urgent to let slide.
Vox has a useful article that summarizes some of what we know about fatality rates and the numbers that are admitted to hospital and intensive care.
Many more of the doctors and nurses will be sick than die. When doctors and nurses become sick, these are people that were able to save your life.
Some nurses would return from retirement to help fight the outbreak and those would be most at risk. The health minister Matt Hnacock tweeted that he is delighted that 4000 nurses and 500 doctors have signed up to return to the NHS to fight COVID-19 in the first 48 hours.
NEWS: Delighted that 4,000 nurses and 500 doctors have signed up to return to the NHS in the first 48 hours of our call. Brilliant support in our national effort tackling
Of course it is great that they are doing this, but they need to be adequately protected.
If the virus spreads through the health care system until we get herd immunity at 50%, then 13.5 in 1000 of those will die. Many will surely be over 70 and 48 in 1000 of those over 70 will die if they are not adequately protected.
Many more of the doctors and nurses will be sick than die. When doctors and nurses become sick, these are people that were able to save your life.
Vox has a useful article that summarizes some of what we know about fatality rates and the numbers that are admitted to hospital and intensive care.
If we go by the figures from Spain then out of 2916 confirmed cases in the range 60 - 69, then 1230 required hospitalization and 132 needed intensive care, and 63 died. The ones that die for the most part need intensive care until they die. So that is 132+63 need intensive care.
Converting that to numbers per 1000 then out of 1000 of those infected in this age range 60 - 69, then 422 will need hospitalization, 67 need intensive care, and of those, 22 die
Now the ones that need hospitalization of course are also taking up the time of other nurses and health workers. If they need ventilators then that means 2 or 3 nurses looking after them 24/7. Even if they work 12 hour shifts (normally it's 8 hours) then that's 4 nurses minimum for each one in intensive care, so that's 268 health workers out of those 1000 taken up caring for the ones in intensive care.
So of 1000 health workers in the age range 60 - 69 that get infected, 690 nurses will be taken out of action because they are sick, or they are caring for the ones who got sick. If half get sick that means out of every 1000, 345 will be taken out of action because of sickness.
At age range 70 - 79 it is of course worse. Again by the Spanish figures, out of 3132 cases, 1678 were hospitalized. Of those, 165 in intensive care + 164 died (nearly all died in intensive care in this age range).
Now it is 536 out of 1000 that are hospitalized, 105 need intensive care and of those, 53 die. Those 105 need 420 health workers to look after them in intensive care. So now we have 956 out of 1000 who are infected at this age range are taken out of action either because they are sick or because they are caring for those who are sick.
If about half get infected then it's 500 of them taken out of action.
We have 100 ventilators needed for every 1000 volunteers at this age range.
This of course also is adding to the stress on the system by increasing the need for intensive care beds - an extra 50 beds for every 1000 health care workers age over 70 and an extra 30 intensive care beds for every 1000 over 70.