I have been a member of an EBM list-server for more than a decade where experts of EBM discuss world health issues like the CORONA pandemic. This thread started with a UK physician/epidemiologist writing
” I was recently made aware that since April 16 or so, no new cases with COVID19 were reported in China [https://www.worldometers.info/coronavirus/country/china/]
Assuming that data are accurate, this is puzzling and I would be interested in learning possible explanations where did SARS-CoV2 go in China?
Typically, pandemic is supposed to be under control when herd immunity develops, which in case of COVID19 requires that at least 60% of population develops effective antibody response. This is unlikely to be the case. Which leaves us with the question could social distancing measures followed by the contact tracing accomplish the feat? In other words, after the curve is “crushed” using severe social distancing measures followed by testing, tracing and isolation as one reopens society, can this theoretically lead to elimination of the virus (as presumably every isolated case will recover or die without spreading the virus to uninfected people)?
We have heard all along that social distancing only buys us time until effective vaccine is developed. But, if China has already effectively controlled the virus, then vaccine may not be necessary. [A related question is what are possible mechanisms that lead to the end of pandemics]?
From New Zealand
“That’s exactly what we have done in New Zealand. We had 1 month of severe restrictions, starting 25th March, then 2 weeks of moderate restrictions and now minimal restrictions other than a closed border. During that period we rapidly increased testing and contact tracing.
We have only had 2 cases in the last 7 days, both linked to known clusters and who were already self-isolated.
Elimination is possible without a vaccine. All you have to do is keep infected people away from everyone else. It’s not rocket science, just a ton of work, and I would advise you to wear a mask.
Another chipped in saying that this article will shed some light- Seasonal and pandemic influenza: 100 years of progress, still much to learn https://www.nature.com/articles/s41385-020-0287-5
In this list we really have an open conversation as another from the US stated: “Sorry to be non-evidenced (or is that non-scientific). But, I’ve been told (“lots of people tell me”) that if something looks too good to be true, it is probably not true. This has buzzed my ‘fake meter’. I’d be interested to hear any other information about this.
I certainly think that a ultra-authoritarian government could create an ‘ultra-lockdown’ that could prevent almost all interpersonal contact for over 2 weeks, enough to kill the spread of the virus. That would probably need closed borders too.”
Came the reply from NZ, “A very non-ultra-authoritarian government (New Zealand) created an ultra-lockdown with closed borders for 4 weeks plus rapidly scaled up testing and contact tracing and voila! Elimination. Just took a bit of leadership.”
A UK expert suggested.
It is helpful to have a fake o meter.
However in this case it is simple: countries with good leaders who followed pre-existing pandemic plans have sorted Covid out with relatively minimal disruption.
Others (esp UK and US) have been, according to Richard Horton (Editor Lancet), criminally incompetent.
Conversations goes on,
‘I totally agree with you R and J. However, in my infinite ignorance I think of New Zealand as a small and very congenial country while China is HUGE and much more diverse. Also, whenever someone reports 0 (yes, ZERO) cases it just doesn’t seem correct. There must have been a few slip ups. Sorry, but this just doesn’t make sense. If it were true it would blow the “so what test” out of the water. And, we’d all want to know the details. Sorry to keep jamming on this theme.’
This is truely Global list! comes a Canadian Chinese academic.
‘The data from the link you checked below weren’t updated very well. Please look at this one at the English version: https://sa.sogou.com/new-weball/page/sgs/epidemic?type_page=VR
. The data on this website are updated everyday, at least the info for Canada is consistent with what I know from Canadian websites.
I asked my friends in China and confirmed that there are some asymptomatic patients and few symptomatic patients in China everyday. If everyone wears a mask and keep social distance, we probably really do not need vaccine for COVID-19 or any influenza. However, it’s impossible and also I don’t like this life style. So, I still look forward to the effective vaccine.’
Reply from the list: ‘Whether the cases are zero or few, the implications remain the same: it is possible to eliminate the virus by social measures only! I have never heard this before but R from NZ confirmed in one of his earlier responses that this is possible.
(And, given huge differences in geography and the population size between China and NZ, this also implies that density is not an issue, which has been a key force causing a huge number of deaths in NYC and Northern Italy).
R and colleagues: are you aware of any historical precedents that a pandemic was controlled by social/public health measures only (and in such a short period of time)? Any references to this effect would be welcome.
An Oxford university EBM expert has this to say….
‘You are correct that 0 is unlikely, thanks for making that important point. It assumes perfect testing etc.
I think we need to look at the claim about 0 tests more charitably (while pointing out that it is based on strong assumptions).
This is because there is a range of countries who have got close enough to 0 for the virus to be manageable enough to open up the economy. These include Taiwan (beside PR China more densely populated than anyone who has not been there can imagine), NZ (sparsely populated, got it late) and others.
The countries where it is a s*+t show, and where they are making decisions between lives lost due to virus and lives lost due to economic disaster are those that did not Follow pre-existing pandemic plans (many were published a long time ago: https://www.who.int/influenza/preparedness/pandemic/en/
This is a key point because we need to follow the same plans now and for the next one.
A very interesting email from UK…
“This is a key point because we need to follow the same plans now and for the next one.”
The key point is: Who is “we”.
In many parts of the world a lockdown that would effectively stop an epidemic is (a) impossible; (b) made more impossible by their country’s poor leadership, corrupt governance, limited public services; and (c) aggravates food insecurity and other humanitarian crisis.
Life is a lot more complicated than simply blaming poor leadership or ineffective lock downs.’
‘Cannot agree more about the need to follow well-tested procedures, particularly when it comes to such serious public health threats as in case of COVID19. However, even when these rules are abolished, people still have to make their decisions. In such cases, they often resort to heuristics such as the one we described in this article [https://www.medrxiv.org/content/10.1101/2020.05.14.20093633v1
] when in the wake of reluctance of federal government in the US to assume leadership, the governors of individual states were left to make their own decisions how to deal with the corona-virus. The results show that the governors’ make predictable decisions according to the Weber-Fechner law of psychophysics.’
Then comes an Indian
Great point. The incompetent, corrupt governments and leaders may have created a new crises (hinge, malnourishment, death) while not dissolving the original crises. Die of Corona or die of malnutrition and hunger. Take your pick is the slogan for some of these countries. India’s youthful and old migrant laborer are literally walking hundred of miles, hungry and broken to reach their home destinations as they have no employment!.
Hope we study both of these Public Health Crises along with COVID 19 when time is opportune in an evidence based fashion as what is the ‘cost of these interventions’ and the outcomes. And by the way, to me both are 2 legged animal made!’
And at this point I could not resist writing an email about my country Sri Lanka
Practicing EBM as a family physician (with a strong informatics background) to the best of my ability, sometimes more than once thinking that I should go back to eminence-based medicine – still hanging on 🙂
Basics epidemiology and logical thinking still works.
What seems to work In Sri Lanka
- Social distancing with face-masks
- Meticulous case finding and quarantine measure implemented by the frontline preventative workers of the MoH with the government intelligence agencies
- The leadership that valued human lives over propping up an ailing economies advised by epidemiologists (this was against huge pressure from the industry and also curative health experts that wanted TESTS, TESTS and TESTS and increasing ICU beds and ventilators)
- The cases we get now are really cluster related and almost no community spread has been reported
So watch out where the CORONA virus goes in Sri Lanka?
- Sri Lanka with 22 million people is one of the few democracies in Asia with a parliamentary system.
- Corruption is sky-high irrespective of who governs. Currently because the parliament has been dissolved pending the new elections we are really doing good minimising the corruption and spending on CORONA.
- However with less than 3.2 of GDP spent on healthcare, every citizen is guaranteed healthcare from a upper respiratory tract infection to a coronary bypass from public hospitals.
- No one dies of hunger (we had one child death due to malnutrition that was the key news story even in COVID time just 4 weeks ago)
I haven’t still seen a reply….and the conversation will continue….
Have a pleasant Sunday with your families and do not let the CORONA interfere with your life.
See you soon