Coronavirus - worldwide spread and control

[Jonathan Edwards]

If testing in the UK has ramped up significantly, but the number of positive results has stayed pretty flat, that's a sign that the true number of new cases is probably falling.

But by that argument the change in testing numbers means the data are valueless so we have to assume nothing.
It merely emphasises that we have no organised strategy.
GPs do not have data on their patients. Nobody knows what these figures mean for local spread. It bears no relation to competent ongoing epidemiology. `

As I said before, in medicine we plan on the basis of the worst reasonably likely situation , not the most likely situation.

I am also puzzled by the fact that the curve really does look flat. If increases in testing were involved then there should be obvious step changes at some point or at least some odd contours.

 

[Ravn]

Our national government in Australia is pushing hard for (internal) reopening, just when we are on the brink of eliminating the damn thing.

Yeah, NZ is talking about significant reopening soon, too. The first easing from level 4 to level 3 restrictions was quite small and cautious - we're currently still in level 3 - but the next one down to level 2 will be a much bigger jump. At least the borders will stay closed. Still, makes me a bit nervous, not convinced our contact tracing ability is that great yet. Can only hope that our current community transmission truly is as low as they think it is, in which case we might just get away with it.

 

[Ravn]

This is an interesting take on the various strategies taken against corona spread, based on something the author calls 'catch rate', basically a measure of how many people in the community you have to test to find an infected case.

The Swedish state epidemiologist, Anders Tegnell, recently claimed that Denmark and Europe, with the reopening, are beginning to follow the Swedish path . But is that correct?

Developments in European countries' test activity during the reopening suggest that the majority are now working to fight or even eradicate viruses.

In the following, I will compare the corona strategy of European countries based on the test activity. Instead of looking at the number of tests per inhabitant, I want to look at the proportion of infected among those tested - the so-called 'catch rate'.
It actually says more about how aggressively a country is testing. If you have many infected per 100 tested, you probably also have a large dark figure, and so you can not be said to test particularly aggressively.
If there are only a few, the dark figure is correspondingly low, and one must assume that 'catch' most infected. The catch rate is therefore an important indicator of the country's strategy.

https://videnskab.dk/kultur-samfund/er-danmark-og-europa-ved-at-teste-sig-ud-af-corona-krisen
https://translate.google.com/transl...g-europa-ved-at-teste-sig-ud-af-corona-krisen

 

[lunarainbows]

If testing in the UK has ramped up significantly, but the number of positive results has stayed pretty flat, that's a sign that the true number of new cases is probably falling.

It may be the case, but the number of cases also clearly hasn’t fallen significantly enough to be able to actually ease lockdown, re open and do contact tracing (as an earlier guardian article said - need case numbers to be very low to do contact tracing).

Also, the figure they’re giving still isn’t the “true” figure, because testing still isn’t being done widely in the community. We have been told cases in hospitals have peaked as they have been falling in the past week, but the number of healthcare workers are increasing (From a guardian article before). We have been told care home deaths are high but care home workers and residents aren’t being properly tested. Also it’s only recently that “community testing” was even introduced, ie “frontline” health workers, and it’s been difficult for them to obtain tests as the online system wasn’t working very well.

So the number of cases may actually be rising in certain populations (care workers, care home residents, other sections of community, and that seems to be the case in the guardian article, even from the “true” figures), and we don’t have an accurate record of that. Lewis Goodall was on newsnight 2 days ago saying care homes are a real problem at the moment.

Also note that the number of tests have fallen from 122,000 down to 69,463 (on 5 May), only around 50,000 actual people tested.

Devi Sridhar was on Newsnight 2 days ago, Saying we are still not testing widely enough - that if you’re getting around 2% of all the tests you do are positives - you’re doing well. If it’s around 2-5%, you’re ok. And if it’s 8-10%, you are in real trouble, which is where the U.K. is, at 6,111 positive cases on 5 May (the number new cases that day has increased from what I said before, don’t know why?).

 

[Marco]

This is an interesting take on the various strategies taken against corona spread, based on something the author calls 'catch rate', basically a measure of how many people in the community you have to test to find an infected case.



https://videnskab.dk/kultur-samfund/er-danmark-og-europa-ved-at-teste-sig-ud-af-corona-krisen
https://translate.google.com/translate?sl=auto&tl=en&u=https://videnskab.dk/kultur-samfund/er-danmark-og-europa-ved-at-teste-sig-ud-af-corona-krisen

That's one of the most interesting and informative articles I've read to date. Thanks for posting it.

 

[lunarainbows]

China eased restrictions after a few months but it was only because they actually got cases down so much, and they had a strict lockdown with isolating of mild cases as well as more severe cases, contact tracing in place, so when lockdown opened they are able to keep on top of it - basically what we were all supposed to be doing as per the WHO but didn’t do. So we can’t even compare our timelines to China tbh. And in the places in China where cases have come back up, like Harbin, the restrictions have gone back up again.

What is it that the U.K., USA, hope to achieve? It’s clear in the number of new cases coming in every day that we still have a lot of new cases, and we don’t even have proper contact tracing to trace thousands of new cases every day! Many thousands are still coming in from abroad without quarantine. We are still not testing people in the community - like you and me - unless you happen to be a “frontline workers”. There are still big issues with PPE. Things will get worse the more you ease at this point. Yet they’re starting anyway with a phased plan to get things back to normal.

What do they expect to happen then? For cases to fall? Or what? I don’t get how short sighted some countries are being and why they seem to have put a time limit on lockdown or restrictions, regardless of what is actually going on, on the ground. And to make matters worse, not to use that time to build up proper community based structures for testing and tracing or monitoring.

 

[lunarainbows]

And not forgetting that it is certain sections of society who are disproportionately affected, and who will be affected further when lockdown is eased.

 

[FMMM1]

But by that argument the change in testing numbers means the data are valueless so we have to assume nothing.
It merely emphasises that we have no organised strategy.
GPs do not have data on their patients. Nobody knows what these figures mean for local spread. It bears no relation to competent ongoing epidemiology. `

As I said before, in medicine we plan on the basis of the worst reasonably likely situation , not the most likely situation.

I am also puzzled by the fact that the curve really does look flat. If increases in testing were involved then there should be obvious step changes at some point or at least some odd contours.

If we had testing of everyone who was symptomatic; plus contact tracing for all confirmed/suspected cases (e.g. symptomatic but not positive on 1st test) then presumably we would have a strategy --- roughly North Korea's (successful) approach. It seems relatively simple e.g. even if you cannot diagnose using (PCR - virus) test then diagnose via symptoms. It looks like a logistics problem and others have highlighted that the army are good at that sort of thing. Meanwhile the UK falls further behind other countries --- New Zealand, Australia, Germany ---.

 

[Wonko]

The UK has the NHS, which is devolved in countries which are not England.

It is possibly a matter of curiosity as to why the death rate as a proportion of tested infected hospital cases would appear to be roughly double in England (2% roughly) than in the rest of the UK (1% roughly).

It would appear that the NHS in England is losing twice as many CV-19 patients as the NHS in other parts in the UK, despite assurances that at no point has it been 'over run' and that it has spare capacity in the order of 40% ATM (I can't give a quote, it was in the briefing last week or so)

So, the NHS may be 'the best health service in the world, envied by all' (paraphrasing), but it seems this may not be so if you're in England, and have Covid-19.

https://coronavirus.data.gov.uk/#countries

If you're 'planning' to catch it it might be an idea to do so somewhere that is not in England.

 

[Adrian]

There is a paper describing patients who have been hospitalized in the UK with Cov-19

https://www.medrxiv.org/content/10.1101/2020.04.23.20076042v1.full.pdf

5Structured abstract

Objective–To characterize the clinical features of patients withsevere COVID-19in the UK.
Design–Prospective observational cohort study with rapid data gathering and near real-time analysis, using a pre-approved questionnaire adopted by the WHO.Setting–166 UK hospitals between 6thFebruary and 18thApril 2020. Participants-16,749 people with COVID-19.

Interventions–No interventions were performed, but with consent samples were taken for research purposes. Many participants were co-enrolled in other interventional studies and clinical trials.

Results-The median age was 72years [IQR57, 82; range 0, 104], the median duration of symptoms before admission was 4days[IQR 1,8]and the median duration of hospital stay was 7days [IQR 4,12]. The commonest comorbidities were chronic cardiac disease (29%), uncomplicated diabetes (19%), non-asthmatic chronic pulmonary disease (19%) and asthma (14%); 47% had no documented reported comorbidity.Increased age and comorbidities including obesity were associated with a higher probability of mortality. Distinct clusters of symptoms were found: 1. respiratory (cough, sputum, sore throat, runny nose, ear pain, wheeze, and chest pain); 2. systemic(myalgia, joint pain andfatigue); 3. enteric (abdominal pain, vomiting and diarrhoea). Overall, 49% of patients were discharged alive, 33% have died and 17% continued to receive care at date of reporting.17%required admission to High Dependency or Intensive Care Units; of these, 31% were discharged alive, 45% died and 24% continued to receive care at the reporting date. Of those receiving mechanical ventilation, 20% were discharged alive, 53% died and 27% remained in hospital.

Conclusions–We present the largest detailed description of COVID-19 in Europe, demonstrating the importance of pandemic preparedness and the need to maintain readiness to launch research studies in response to outbreaks

 

[Arnie Pye]

I'm completely out of touch. I find it hard to take things in these days and my memory sucks when it comes to new information.

Can anyone give me a link which answers the following questions?

What are the tests being touted by the UK government? Are they :

Tests for evidence of past infection with covid-19?
Tests for current infection?
Tests for antibodies?

How reliable are the tests? Chances of false positive? Chances of false negative?

 

[Robert 1973]

Another Covd-19 article by Dr Hammond, which seems to be a little muddled. On the one hand he says he will “never understand” why we stopped testing, tracing and isolating (ie suppression strategy) and then he says we are now stuck with “staged herd immunity” (ie mitigation strategy). But we’re not stuck with it. We still have a choice. And most independent scientists seem to support suppression until a vaccine and/or effective treatments can be developed. If Dr Hammond thinks mitigation was a mistake before, why does he seem to think we have no choice but to pursue it now?

 

[lunarainbows]

I'm completely out of touch. I find it hard to take things in these days and my memory sucks when it comes to new information.

Can anyone give me a link which answers the following questions?

What are the tests being touted by the UK government? Are they :

Tests for evidence of past infection with covid-19?
Tests for current infection?
Tests for antibodies?

How reliable are the tests? Chances of false positive? Chances of false negative?

Govt have been talking about PCR (current infection) and antibody tests (supposed to measure if you’ve had past infection).

Antibody tests aren’t yet available on the nhs in the U.K. because they’re not certified yet for use. (I notice some private labs are selling them though).the world health organisation has warned that positive antibody tests don’t necessarily mean that someone is immune - we don’t know how long they’re immune for, there may be false positives and false negatives. The New York Times has a few good articles on antibody testing: https://www.nytimes.com/article/antibody-test-coronavirus.html

the 100,000 a day figure and the “ramping up” testing target is (so far) only about the PCR tests, as the antibody tests aren’t being used yet - this is testing to see if you have current infections. That’s what people are being tested for now on the NHS and in mobile centres.

 

[Esther12]

It may be the case, but the number of cases also clearly hasn’t fallen significantly enough to be able to actually ease lockdown, re open and do contact tracing (as an earlier guardian article said - need case numbers to be very low to do contact tracing).

Also, the figure they’re giving still isn’t the “true” figure, because testing still isn’t being done widely in the community.

Absolutely. I'd assume the true number of new cases is still much higher than the reported figure. I'm not defending government policies or testing!

But by that argument the change in testing numbers means the data are valueless so we have to assume nothing.

Pretty worthless, yeah. I thought that's what people have been assuming about the 'new cases' data, and that's why there's much more interest in deaths (which also has it's own problems).

I am also puzzled by the fact that the curve really does look flat. If increases in testing were involved then there should be obvious step changes at some point or at least some odd contours.

There has been a big increase in testing, so doesn't the steady number of positive results indicate that either i) the increase in testing means a higher proportion of declining new cases are getting positive results or ii) the number of new cases is stable, and we were so effectively identifying who should be tested that the increase in testing is just being wasted on people who don't have the virus? The latter seems pretty unlikely.

 

[Arnie Pye]

Thanks for that information @lunarainbows

 

[JaneL]

Revealed: the secret report that gave ministers warning of care home coronavirus crisis

The government has kept the Exercise Cygnus report secret since it was first circulated in Whitehall three years ago, and has resisted growing calls for more transparency, which culminated in the announcement of a legal case to force ministers to release the findings. However a copy was leaked to the Guardian, which is publishing the document in the public interest.

The report, marked “Official – Sensitive”, is being published in full, although names and email addresses of government officials have been redacted.

https://www.theguardian.com/world/2...sters-warning-of-care-home-coronavirus-crisis

 

[Anna H]

Oense om karantän: ”Viss spridning är acceptabel
https://www.svd.se/oense-om-karantan-viss-spridning-ar-acceptabel

"Disagree on quarantine: "Some dissemination is acceptable"

WHO wants you to stay home for two weeks after being sick. The Public Health Authority states that it is enough for two days. According to Anders Tegnell, the difference is partly due to the FHM accepting that the virus spreads.

The DN has reported that the Public Health Agency and the World Health Organization have different advice on when to leave their home after they have stopped showing symptoms of covid-19.

On its website WHO writes that anyone experiencing symptoms should stay at home for at least two weeks even if they "feel healthy". In an email to SvD, WHO's press department writes that they recommend that anyone who has been confirmed with the virus stay at home for another two weeks after they have stopped having symptoms.
At the same time, the Public Health Agency states on its website that it is enough for two days without symptoms.

But according to Anders Tegnell, state epidemiologist at the Public Health Authority, it is about "apples and pears". The recommendations of the Public Health Authority are addressed to the general public, ie to all Swedes who feel sick and not just to those who have been confirmed with covid-19.

In addition, the WHO in its advice assumes that one should be completely contagious, which is not the case for the Public Health Authority, according to Tegnell.

- We talk about when you've been home, had symptoms and felt sick. WHO talks about those who were diagnosed with covid-19. WHO also wants zero risk of spreading, says Anders Tegnell to SvD.

"Some dissemination in society may be acceptable. It is not possible to have zero spread."

In the DN article, the virologist Lennart Svensson, at Linköping University, criticizes the recommendations of the Public Health Authority because he believes that it is not guaranteed infection-free after two days.

Anders Tegnell, however, believes that there is no problem, and that the Public Health Authority accepts that the virus is spreading.

Don't you want zero risk?

- Some dissemination in society may be acceptable. It is not possible to have zero spread.

As for those who have been confirmed with covid-19 in Sweden, Anders Tegnell says that the Public Health Authority should review common guidelines for hospitals about when covid patients can be discharged. According to him, different hospitals make different. In some places, patients are discharged shortly after they stop showing symptoms, without being tested. Elsewhere, they are more rigorous in their routines for when corona patients are allowed to leave the hospital.

WHO's guidelines are that those who are discharged should be clinically healthy and have made two negative tests at intervals of 24 hours, but Anders Tegnell does not want to state what the Public Health Authority has in mind.

What are your views on leaving the hospital?

- We think you should agree."

It makes me so angry to read statements from this man, or any Swedish news about COVID-19 for that matter.

It might not be possible to stop it completely, but it might also work. Look at countries like South Korea, Island, New Zealand etc.
One can certainly aim for zero spread and implement strategies to that end if one wanted to.

The goal for traffic related deaths for example, is zero, yet that is never reached.

 

[Cheshire]

Covid-19: Number of Germans infected could be 10 times higher than official estimates

The number of people in Germany infected with covid-19, could be 10 times higher than official government estimates, according to a new study by University of Bonn researchers.1

The Heinsberg study is based on an investigation in Gangelt, a town of around 13 000 people in the North Rhine-Westphalia district of Heinsberg. Following the annual carnival celebration in February, the district became the first area in Germany with a massive covid-19 outbreak.

The study, which has been uploaded to a preprint server, found that about 15% of Gangelt residents had been infected with covid-19, compared with the official infection rate at the time of only 3%. The higher infection rate for the area translated into an infection fatality rate after the coronavirus outbreak of 0.37%.

https://www.bmj.com/content/369/bmj...=hootsuite&utm_content=sme&utm_campaign=usage

 

[Jonathan Edwards]

ii) the number of new cases is stable, and [we were so effectively identifying who should be tested that] the increase in testing is just being wasted on people who don't have the virus? The latter seems pretty unlikely.

I think the bit I bracket out may be non sequitur. I strongly suspect that the vast majority of extra tests are on health care workers who are pretty unlikely to have Covid19 on the day tested. So testing vastly more people is not actually finding any more cases. Health care workers who got the virus were probably being tested before anyway. Others who have the virus are not being tested any more than before - just when they pitch up at hospital sick.

 

[lunarainbows]

Professor in Economics
Comparison of U.K. and other European countries