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Part 3 of the R0 thread continued:
Ammar is right when he says suppression measures are a way to lower R.
Here’s where he is wrong
Ammar is right when he says suppression measures are a way to lower R.
Here’s where he is wrong
Pushing R below 1 with use of social distancing will need to continue till a vaccine is available. Measures will need to be in place for as long as virus is circulating or a treatment is developed. https://twitter.com/AmmarRashidT/status/1267476157873688579?s=20
Suppression strategies cannot prevent the epidemic. They allow governments to buy vital time until a vaccine or treatment becomes available. Lockdowns are only a way of delaying the epidemic till that can happen.
Source: The Science of Social Distancing https://asm.org/Articles/2020/April/The-Science-of-Social-Distancing
Source: The Science of Social Distancing https://asm.org/Articles/2020/April/The-Science-of-Social-Distancing
Does forcing R0 below 1 mean containment is achieved?
No, it means the virus’s spread has been paused, not contained.
Once controls are eased, the pandemic will re-emerge. Cases will bounce back up as restrictions are lifted.
No, it means the virus’s spread has been paused, not contained.
Once controls are eased, the pandemic will re-emerge. Cases will bounce back up as restrictions are lifted.
Germany was among the many countries to have brought R below 1 only to see cases rise when restrictions were eased.
How long will it take?
The simple answer is, nobody knows.
So when Ammar says number of cases will go down if restrictions are in place for “long enough," he is downplaying scope of the kind of lockdown he is suggesting.
The simple answer is, nobody knows.
So when Ammar says number of cases will go down if restrictions are in place for “long enough," he is downplaying scope of the kind of lockdown he is suggesting.
Here’s an example from Italy and South Korea to help you understand
Source: https://www.nytimes.com/2020/04/23/world/europe/coronavirus-R0-explainer.html
Source: https://www.nytimes.com/2020/04/23/world/europe/coronavirus-R0-explainer.html
Months of periodic lockdowns will be needed to control transmission
Govts will be on alert about a possibile second wave. Countries with intense travel links with China will remain vigilant until concerns about further outbreaks are over. This is particularly worrying for Pak.
Govts will be on alert about a possibile second wave. Countries with intense travel links with China will remain vigilant until concerns about further outbreaks are over. This is particularly worrying for Pak.
Despite its exemplary success at controlling epidemic at the start, South Korea already had measures in place to reimpose lockdowns for when cases resurged.
Before we move onto India, let me just say... Data from India is not reliable. Much has been written about India downplaying extent of their COVID19 crisis by releasing incomplete and biased data to justify policy decisions. https://www.huffingtonpost.in/entry/india-coronavirus-cases-response-data-crisis_in_5ec49658c5b6956f4169fb4f
But since Ammar mentions India... Here’s the reality
India is a unique example since it tried to follow China by trying to opt for a Wuhan-style lockdown.
The govt argued this was necessary to ‘flatten the curve’.
India is a unique example since it tried to follow China by trying to opt for a Wuhan-style lockdown.
The govt argued this was necessary to ‘flatten the curve’.
As Ammar notes, India has reported a steady decline in R value since end of March, claiming to have pushed it down to 1.22 from 4. https://twitter.com/AmmarRashidT/status/1267487551478251520?s=20
But the evidence it offers to back this claim is entirely unconvincing.
Nobody knows what if any model was used to arrive at these numbers. No such research or study has been made public.
Indian govt claimed a study by Indian Council of Medical Research (ICMR) had concluded-
Nobody knows what if any model was used to arrive at these numbers. No such research or study has been made public.
Indian govt claimed a study by Indian Council of Medical Research (ICMR) had concluded-
that without lockdown, cases would have crossed 820,000 by Apr 15 (when the numbers stood at 10,000).
To the bafflement of scientists and sections of Indian press, ICMR claimed no such study existed. https://scroll.in/article/959005/covid-19-ministry-claim-india-would-hit-8-20-lakh-cases-by-april-15-without-lockdown-is-questioned
To the bafflement of scientists and sections of Indian press, ICMR claimed no such study existed. https://scroll.in/article/959005/covid-19-ministry-claim-india-would-hit-8-20-lakh-cases-by-april-15-without-lockdown-is-questioned
Indian govt also declared premature success of effectiveness of its harsh measures https://ca.reuters.com/article/topNews/idCAKCN21R0XE
https://ca.reuters.com/article/topNews/idCAKCN21R0XE
They claimed there would be zero new COVID19 cases in India by May 16.
On May 16, India saw the highest spike in number of cases by then.
Apparently, the claim was made from mere extrapolation from data shown in a chart. https://www.indiatoday.in/news-analysis/story/health-ministry-covid19-pandemic-case-prediction-graph-1678917-2020-05-17
On May 16, India saw the highest spike in number of cases by then.
Apparently, the claim was made from mere extrapolation from data shown in a chart. https://www.indiatoday.in/news-analysis/story/health-ministry-covid19-pandemic-case-prediction-graph-1678917-2020-05-17
Apart from a couple charts, few other details have been revealed about these projections; the scientific rationale or methodology has not been made public, nobody knows where these numbers have come from.
Its pointless to talk about data from India. But effects of India’s lockdown are on display for the world to see
https://qz.com/india/1837337/data-show-indias-coronavirus-lockdown-may-not-be-working/*
https://qz.com/india/1837337/data-show-indias-coronavirus-lockdown-may-not-be-working/*
Despite more than 2 months of grinding lockdown, India’s cases are rising staggeringly and disease is far from being contained.
India recently recorded 4th highest number of COVID19 cases globally with more than 370000 cases. Actual number could be higher https://timesofindia.indiatimes.com/india/india-brazil-growth-rate-fastest-among-the-worst-hit-countries/articleshow/76277293.cms
India recently recorded 4th highest number of COVID19 cases globally with more than 370000 cases. Actual number could be higher https://timesofindia.indiatimes.com/india/india-brazil-growth-rate-fastest-among-the-worst-hit-countries/articleshow/76277293.cms
The move crippled 75% of the Indian economy. It caused massive supply chain disruptions, and internally displace millions of people. https://www.business-standard.com/article/economy-policy/with-75-economy-under-lockdown-analysts-see-sharp-fall-in-gdp-120032600231_1.html
Instead of focussing on strengthening healthcare capacity, Indian government has been forced to target its efforts at setting up relief camps for the millions caught in the lockdown fiasco.
This has lead to a debate in Indian press about whether lockdowns are actually counterproductive.
But anyway, limited published works have studied the impact of lockdown on COVID19 spread in India, so lets move on.
But anyway, limited published works have studied the impact of lockdown on COVID19 spread in India, so lets move on.
Strict social distancing is useful when it is inexpensive and can delay the epidemic. Aim of this strategy is to contain the virus till a cure emerges.
The COVID19 Response Team at Imperial has suggested that sustaining routine social distancing depends on low daily case -
The COVID19 Response Team at Imperial has suggested that sustaining routine social distancing depends on low daily case -
numbers, very low incidence of isolated cases, & more than 80% new cases being detected in people who are already in self isolation.
Scientists believes this may be too difficult for some countries now anyway as COVID19 has become pandemic.
https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2020-05-29-COVID19-Report-25.pdf
Scientists believes this may be too difficult for some countries now anyway as COVID19 has become pandemic.
https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2020-05-29-COVID19-Report-25.pdf
Although a worthy goal — and wealthy countries like China, South Korea, Singapore or New Zealand that can aim for it, should — this approach may be impossible to replicate in developing nations. https://twitter.com/AmmarRashidT/status/1267495013539291136?s=20
Superpowers such as Britain & US opted out of this strategy.
No European country has put in place the full measures China was able to use, even though some can afford to.
No European country has put in place the full measures China was able to use, even though some can afford to.
Some studies suggest benefits of social distancing are small for highly transmissible diseases like COVID19.
Due to factors like high pop density, high rates of contact & mobility, super-spreading events are likely in countries like Pak which will need for even broader measures.
Due to factors like high pop density, high rates of contact & mobility, super-spreading events are likely in countries like Pak which will need for even broader measures.
Sustaining strict lockdown over several months may not be feasible for many countries, socially and economically.
Besides, strong measures have lead to lockdown fatigue in many countries.
Besides, strong measures have lead to lockdown fatigue in many countries.
Govts are fearful that people’s psyche will change over time if policies remain unchanged, which could have a counter effect in driving up infection numbers. https://www.bloomberg.com/opinion/articles/2020-03-19/coronavirus-behavior-fatigue-threatens-second-wave
But periodic lockdowns will be necessary. They provide crucial time to increase healthcare capacity.
Objective of such measures is to delay duration of epidemic & ‘flatten’ the peak. This spreads cases over a longer time and relieves pressure on hospitals https://wwwnc.cdc.gov/eid/article/26/5/19-0995_article
Objective of such measures is to delay duration of epidemic & ‘flatten’ the peak. This spreads cases over a longer time and relieves pressure on hospitals https://wwwnc.cdc.gov/eid/article/26/5/19-0995_article
“If hospitals are overwhelmed with COVID19 cases, countries can't move ahead with lifting lockdown. But if they’re coping, it may be enough for some to reopen economies and let businesses start to stagger back.”
https://www.politico.com/news/2020/04/25/hospital-coronavirus-lockdown-207611
https://www.politico.com/news/2020/04/25/hospital-coronavirus-lockdown-207611
For eg. UK announced its lockdown by end of March. Cases peaked in mid-April when 3000 COVID19 patients were being seen every day.
This number is down to 500 now, while field hospitals are hibernating.
They will re-open when cases increase.
This number is down to 500 now, while field hospitals are hibernating.
They will re-open when cases increase.
Ignore Ammar’s attempt at misleading, and Asad Umer’s statement doesn't seem too unreasonable. https://twitter.com/AmmarRashidT/status/1267493732397584390?s=20
https://twitter.com/AmmarRashidT/status/1267493732397584390?s=20
Govts will not be aimed at simply forcing R0 below 1, but managing it within acceptable levels.
This will allow epidemic to proceed at a controlled rate, ensuring demand on healthcare system is kept under capacity, while looking for sustained and constant fall in death rates.
This will allow epidemic to proceed at a controlled rate, ensuring demand on healthcare system is kept under capacity, while looking for sustained and constant fall in death rates.
In such a scheme, lockdown can be lifted and reimposed in response to fluctuations in R.
Because remember, winter is coming. This will mean by winter, we may escape overwhelming the healthcare system when the outbreak is expected to get worse.
Because remember, winter is coming. This will mean by winter, we may escape overwhelming the healthcare system when the outbreak is expected to get worse.
This graph shared by @AmmarRashidT is not based on actual research.
It’s made using a basic data analysis software for purpose of the Science Wire .in
Besides, it shows Rt and not R0 like Ammar misunderstood https://twitter.com/AmmarRashidT/status/1267486771190865923?s=20
It’s made using a basic data analysis software for purpose of the Science Wire .in
Besides, it shows Rt and not R0 like Ammar misunderstood
https://twitter.com/AmmarRashidT/status/1267486771190865923?s=20
But these independent data analysts and modellers are tracking how Rt estimates have changed over time in regions of Pakistan.
Rt value for Pakistan is consistently close to 1, even though it climbed up temporarily during the Eid holiday period.
these independent data analysts and modellers are tracking how Rt estimates have changed over time in regions of Pakistan.Rt value for Pakistan is consistently close to 1, even though it climbed up temporarily during the Eid holiday period.
While I cant account for the accuracy or precision of this model, I'll leave the link for the website for you to explore and make up your own mind about whether you think the epidemic in Pakistan is proceeding at a controlled rate.
Source for projections: https://co.vid19.pk
Source for projections: https://co.vid19.pk
Experts believe best way to minimise loss of lives during initial stages is to protect vulnerable people & those at risk of severe infection.
This could ultimately reduce the death rates, as in the coming years infection rates will be reduced & a treatment may become available.
This could ultimately reduce the death rates, as in the coming years infection rates will be reduced & a treatment may become available.
So, to conclude.
Lockdowns will need to be in place till there is a vaccine. They buy time for governments.
R below 1 does not mean cases will stay low or the virus is contained. https://twitter.com/AmmarRashidT/status/1267498308903239680?s=20
Lockdowns will need to be in place till there is a vaccine. They buy time for governments.
R below 1 does not mean cases will stay low or the virus is contained. https://twitter.com/AmmarRashidT/status/1267498308903239680?s=20
However, whatever measures a country chooses to fight COVID19 must occur in conjunction with testing and contact tracing. Low testing is considered reason behind India’s rise in cases, and Mexico’s high death toll. As we stand now, testing in Pakistan is abysmally low.
But scientists believe social distancing along with aggressive TTQ, only works if implemented early in the pandemic.
Health experts caution clusters will be difficult to manage in countries with more widespread transmission.
Health experts caution clusters will be difficult to manage in countries with more widespread transmission.
Innovative strategies will be needed to tackle this crisis. But whatever strategy our resident twitter public health expert seems to think will work on paper, may already be too late for a country like Pakistan. https://twitter.com/AmmarRashidT/status/1267500600092176389?s=20
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