COVID19 update, April 10, 2020: all models are wrong, but some are useful.

“All models are wrong, but some are useful.” Thus spake one of the leading lights of statistics in the 20th Century, George E. P. Box FRS

Models can be useful however — if you remember that a map is not the territory, a representation is not an object, and a model is not reality. Sadly, the distinction between a theory and a model is lost on most people who are not scientists themselves (and sadly, on some people who call themselves scientists).

We hear a lot in the media about how pessimistic predictions of some modelers later had to be revised downward by nearly two orders of magnitude. Lots of snickering, for sure, but understand the incentive structure here. If you ask a modeler, “just how bad can this get?” and she gives you her worst-case estimate — and later the data coming in cause a drastic revision downward — you will normally be grateful. If she comes instead with a best-case estimate, and it later turns out to be much worse, you are likely to blame the modeler “if only you’d warned me, I’d have pushed for much harder measures”…

That said, some of the “models” now being referred to aren’t really models in the usual sense at all, but rather nonlinear regression fits to actual data, with uncertainty bands provided. I’m sure that whatever function the IHME people use for fitting COVID19 statistics in various countries is a bit more sophisticated than sigmoid functions, but the “total deaths” graphs look quite similar to a sigmoid to this mad scientist’s eye.

The nice thing about such “phenomenological models” [*] is that they are trivially adjusted to new data as they come in: add the data point, refit, get your new uncertainty band, and presto!

In this morning’s DIE WELT, I read an interview with a mathematics professor named Moritz Kaßmann at the University of Bielefeld , who got interested in this subject early on as one of his students returned from Wuhan and gave him the heads-up “this [expletive] is going to hit in Germany as well”.

Anyway, he had a good look at the German COVID19 statistics, and noted that they were surprisingly well fitted by the following (for people in my day job) very simple function:

f(t) = A exp(Bt – Ct^2) = A exp(Bt) exp(-Ct^2)

where ln(x) represents the natural logarithm of x, A corresponds to the number of cases at t=0, the exp(Bt) term corresponds to the exponential growth phase and the Gaussian term exp(-C t^2) corresponds to the damping phase, which is stronger as C grows larger, and absent if C=0 (since exp(0)=1).

Now if you take the logarithm of the data ln f(t), this fit becomes simplified to a quadratic regression

ln f(t) = ln(A) + B t – C t^2

At low t, this function will show exponential growth, but at longer t, the Gaussian damping will become more prominent, and eventually a turnover will occur. Now let’s apply this to the active cases in Germany, for example (data taken from the Johns Hopkins website):

data points in blue, regression curve in orange

Active cases are defined as “diagnosed – cured – deceased”.

Well, if such a simple and “parsimonious” (in terms of only having 3 parameters) model has such a high “coefficient of determination” — R^2 = 0.9977 means that 99.77% of the variance in the data is reproduced by the fitted curve — there has to be something to it. You don’t find such high R^2 values under a horse’s tail, pardon my Dutch.

Extrapolating the fitted function will get more uncertain as you leave the actual data range, to be sure, but we are clearly just days from the plateau phase between April 14 and 19.

Here Prof. Kaßmann discusses his method (in German) on YouTube:

He notes that a lot of discussion in Germany centers on the “doubling rate” (how much time it takes for the number of cases to double), but that the methods for evaluating teh doubling rates are kind-of slapdash: extracted from the daily growth rate or the moving average over 5 days thereof. With a fit function like this, it can be evaluated analytically using just 

t2= ln(2)/( -2 C t + B)

Where -2 C t + B is the first derivative of – C t^2 + B t + A — if you like, the slope of the tangent of the curve at point t.

Note that for large enough t, t2 becomes negative as the curve turns over : at that point –t2 becomes the halving rate.  According to “Kaßmann ’s slope trick”, the doubling rate for active cases in Germany is already in the once-a-month region. 

I made similar graphs for Belgium and for Israel: I get basically the same shape, 8 days and 4 days shifted right, respectively. The coefficients of determination for these primitive fits are 0.9974 and 0.9976, respectively.

We are not out of the woods yet — this is not the time to get cocky. But the light at the end of the tunnel is becoming visible. And thus, as a sustained shutdown will wreak increasing havoc on the economy, this is the time to get serious, creative, and agile about “back to normal” measures. In particular the food supply chain cannot be left untended. Society can live without rock concerts, soccer games, or discos. It can definitely live with telecommuting for IT professions. But it cannot live without agriculture and food processing, or (G-d forbid) the price we pay in lives might well exceed the toll from the virus.

To my Jewish readers, mo`adim le-simcha. To my Christian readers, have a meaningful Good Friday, and soon a happy Easter.

[*] The term “phenomenological” refers to a fit that aims to reproduce data (the numbers as they are) but does not make any physical, chemical,… model assumptions about the form of the equation.

COVID19 update, April 9, 2020: Passover quick takes

Happy Passover to my Jewish readers! Some quick takes on the holiday:

(1) Germany’s Minister of Health Jens Spahn is looking at reopening the country, reports DIE WELT (in German). He sees two main preconditions: (a) numbers keep evolving in the right direction; (b) businesses will be compliant with hygiene and distance requirements 

Spahn on video: “The Easter Weekend will be a fork in the road.” Paraphrasing: If we remain compliant, we may soon be on the road to renormalization. If we become lax and complacent, we may be stuck with this for a long time.

DIE WELT also reports that Chancellor Angela Merkel is reluctant to open early, as she is afraid that a flare-up following a hasty reopening will instead lead to a much longer shutdown

(2) A European Union think tank is drafting a “European roadmap for an exit from the COVID-19 epidemic” , and Die Welt obtained a copy. Their recommendations echo some of what the German decision makers are mulling, but urge a coordinated response of all European countries. At the same time, they recommend that specific lockdown relaxation decisions be taken at a local (district or province, not national) level — such that if a flare-up does occur, the affected district can be separately placed in renewed lockdown, rather than the entire country.

Also, enough time should be left between relaxation steps to assess their impact. 

Fundamentally, blanket “one size fits all” measures should give way to targeted measures

(3) De Standaard (in Dutch) reports hopeful signs from Belgium where total COVID19 hospitalization keeps dropping. 

(4) Via Instapundit, a peculiar result from a French cancer research team, where of a group of 2,500 high-risk cancer patients that were administered the antioxidant methylene blue as part of their therapy (for reasons unrelated to COVID19), allegedly not a single patient got infected by COVID19. The researchers hypothesize that the changes in cellular pH induced by methylene blue impede the replication of the virus, in the same manner as they hypothesize (hydroxy)chloroquine work

This particular institute seems to be exploring the controversial theory of Otto Warburg (Nobel Prize in Medicine 1931 for “discovery of the nature and mode of action of the respiratory enzyme”)  that cancer is primarily a metabolic disease. (Mainstream oncology considers the metabolic peculiarities of cancer cells an effect, rather than a cause.)

(5) Some New York physicians, who look at the terrifying death rate among adults placed on “ventilators” (read: lung intubation), now favor keeping patients off invasive respiration as long as possible, as they suspect that long-term intubation is itself a stressor.

(6) CDC director Robert Redfield says actual mortality will be much lower than models predicted.

(7) As Zoom has become so popular during this epidemic, and contains a number of cyber vulnerabilities, here are some cyber security recommendations from CheckPoint Software 

(8) Roger Seheult MD, host of the YouTube channel MedCram, has an update on ivermectin and COVID-19 that makes its possible mechanism quite clear to people other than molecular biologists.

COVID19 update, Eve of Passover edition: eyeing the long road to normality

Ezekiel Emanuel (brother of Rahm Emanuel) — whose ‘peculiar’ views on medical ethics would require a separate blog to fisk them — now calls for a 12-to-18-month lockdown. Bill Gates, not a doctor but somebody I’d expect to at least understand supply chains, argues for a 6-month lockdown until a fast-tracked vaccine would be available.

Only somebody who is completely divorced from any economic and social reality outside medicine would present such extended lockdowns as anything other than “in an ideal world, we’d wish we’d be able to do this. In the real world, this would kill the patient while curing the disease”. Sarah Hoyt has been expressing her fear of the latter repeatedly and stridently on her blog.

Even now, the economic fallout from lockdowns is immense, although perhaps less felt in some countries than in others. France, for instance, routinely goes on a nearly month-long collective vacation in August, and Israel nearly shuts down twice a year around Passover and around the High Holidays. But these are scheduled, cyclical events that these economies have been working around for decades.

There are already the first signs of food supply chain disturbances in the US. (With “just in time delivery” chains, that happens faster perhaps.) In this small country here (Israel), agriculture is more or less business as usual, though the shutdown of cafés and restaurants has meant that some farmers primarily selling to that sector now are having to dump vegetables and dairy products at a loss. Some have gotten creative and have branched out into home delivery.

Instapundit says, “we can keep this up for another two weeks at most, and then we have to start reopening things”. Considering hopeful signs that the epidemic has reached plateau phase in its US epicenters, this may actually be realistic. Austria, where active cases are past the hump, has committed to a phased reopening of the economy. Belgium, where the infection is peaking, is looking at doing the same, as is Denmark. Israel’s initial contingency planning was for reopening in stages after the week-long Passover holiday; it’s not clear whether that is still in the cards, but planning is going on, and the planners openly discuss the trade-offs involved. As one put it: “we might have world-class epidemiological statistics” (Israel’s IFR is well below 1%) “but wreak irreparable damage to our economy that may cause more mortality in the elderly than the virus”.

Some advocates of sustained strident measures quote Tomas Pueyo’s “The Hammer And The Dance” essay without context. Actually, Pueyo argues precisely for an alternative to extended lockdowns. What he called for were:

1) In the “Hammer” phase, carry out as stringent a lockdown as possible, as early as possible, such that the period required for breaking the back of the epidemic is as short as possible (ideally, get effective reproductive number down into the 0.35 range).

2) In the “Dance” phase, reopen things with social distancing & hygiene restrictions in order to keep the effective reproductive number R from exceeding 1.0. Ideally, with abundant statistical data (which he admits may not be available) one would be able to establish a kind of “menu” of R-reduction options, and be able to assemble a combo of the options that give the most benefit for the least economic cost.

What does the latter mean in practice? Just by way of illustration: frequent hand-washing and wearing masks may be nuisances, but do not significantly interfere with economic activity. (Again, the primary benefit of wearing masks is to your fellow person, not to yourself. It will stop you from projecting aerosols of the virus unto others if you are in the asymptomatic phase.) Respecting the personal space of others may seem annoying to Spaniards or Italians (or Israelis, for that matter), but is a way of life to many people elsewhere. I was astonished when last year I visited various stores in Norway where people routinely stayed a meter apart from each other in line, without pushing or becoming impatient. Likewise, many Americans who haven’t been conditioned to dense urban areas like NYC respect personal distance better than most others.

And some aspects of the world economy may change forever, and not necessarily for the worse. Some jobs that can be done just fine by video link or other electronic communications may never return to one-on-one. And conversely, many countries and large corporations will be reconsidering the wisdom of being overly dependent on a single supplier for anything crucial. The diversification process had already started, but will go much further. The PRC is sure to feel the economic repercussions of this — at a level that may jeopardize the survival of its totalitarian regime.

DE STANDAARD (in Dutch) looks at six possible strategies for “back to normal” in Belgium, which I will briefly summarize

1. Test and trace. Main downside, aside from required testing capacity, is privacy invasion through phone app. (South Koreans don’t GAF)

2. Gradually opening schools and businesses, while continuing distance learning and telecommuting in such sectors where this is feasible. Mass events (concerts etc.) remain off the menu

3. Immunity testing and immunity passes — those who have them can go back to work. Main downsides: antibody tests not yet reliable enough; not proven that one cannot get reinfected after getting cured; probably fewer people have immunity than many advocates think.

4. Masks for everyone. Main downsides: not enough masks for everybody; false sense of security; people not used to using them start futzing with them and touching their faces, which (if hands contaminated) makes it worse

5. Variolation [they call it instead “Hotel Corona”] of younger people to build up “herd immunity”. Main downside: not clear if this is really as safe for young people as generally thought. Erika Vlieghe, head of the Infectious Diseases Dept. at U. Of Antwerp, mentions genetic predisposition to overreacting immune system (“cytokine storm”) in some people.

6. Miscellaneous “out of the box” approaches, such as staggered lockdowns (alternating odd and even ID numbers, alternating male and female, alternating odd and even DOBs) to ensure fewer people in public spaces at any one time; release one region/province at a time while keeping the remainder on lockdown, keeping excess hospital capacity available in the other regions in case of a flare-up in the opened region;…

Meanwhile, the observation that China is trying to rewrite the history of the virus is not just the province of “les déplorables” in the US: the center-right German daily Die Welt — as “establishment” as you can get — has an article arguing exactly that (Alas, they have plenty of Полезные идиоты in the mediatainment complex.)

To my fellow Jews, have a wonderful Passover, with or without electronic means of distance participation in the Seder.

And to all, my best wishes for health, well-being, safety, and may we soon see the light at the end of the tunnel.

COVID19 update, April 7, 2020: hemoglobin, COVID19, and hydroxychloroquine; miscellaneous updates

A potentially HUGE finding in a preprint suggests a radically different mechanism for hydroxychloroquine’s action in COVID19. TL;DR in layman language: that a lot of the hypoxyia (oxygen starvation) of severe COVID-19 patients is due to hemoglobin in red blood cells being disrupted by the virus (as it is by the malaria pathogen), and that hydroxychloroquine protects hemoglobin in both diseases. A layman’s discussion can be found here.

“Masgramondou” has an origin hypothesis for the outbreak that sounds disturbingly plausible to anyone who subscribes to the “incompetence before malice” or “c*ck-up before conspiracy” principle.

How helpful is soap against COVID-19? If yes, why? The American Chemical Society has a helpful YouTube video

The leader article of German center-right daily Die Welt is entitled: “the end of globalization as we know it”

Ventilator outcomes discussed by Roger Seheult MD . In another video, he weighs in on the beneficial effect of sauna baths for immunity in general and in COVID-19 in particular (hat tip: Mrs. Arbel) Finnish statistics so far look enviable.

My friend Tom Knighton lives in  Dougherty County in rural GA, which found itself coping with a fierce COVID-19 outbreak following a “super-spreader” event at a funeral. But it seems they are now seeing the proverbial light at the end of the tunnel.

Israel, which saw super-spreader events during Purim parties a month ago, is now taking the drastic step of imposing a curfew from a few hours before the Passover seder until the next morning. Seders are to be done strictly in the home, nuclear family only, no guests. 

Japan, which was very reluctant to do so, finally declares pandemic emergency

And Instapundit minces no words in USA Today .

UPDATE: via David Bernstein, interactive COVID-19 map of the New York City metropolitan area. Counterintuitively, Manhattan is not the worst hit pro capita: that extremely dubious honor falls to the nearer commuter counties.
NY Gov. Andrew Cuomo, hovewer, points to an apparent “flattening of the curve” in hard-hit NYC.

COVID19 update, April 6, 2020: BREAKING: Austrian Chancellor announces “back to normal” schedule; how is the rest of Europe doing? (UPDATED)

German center-right daily Die Welt reports that Austrian Chancellor Sebastian Kurz has announced his country’s return-to-normality schedule.

The country has been on lockdown since March 16, and recent statistics strongly suggest the epidemic is under control in Austria. (At present, the country has 12 008 confirmed infections, 220 dead, and 3,463 recovered.) To wit, I include the following graphs from worldometers:

“Active” refers to patients not yet cured or deceased
As you can see, the number of recoveries exceeds the number of new patients now
  • Summarizing from the German text:
  • Starting April 14 (the Tuesday after Easter), small businesses of all kinds — other than cafés and restaurants, etc. — are allowed to reopen with restrictions, as will larger stores dealing in building/DIY or garden supplies. (Such stores tend to be either outdoors or in very large halls in that part of the world.)
  • Starting May 1, also larger businesses — again, other than cafés, restaurants, etc. — will be allowed to reopen, as will (indoor) shopping malls.
  • Starting May 15, cafés and restaurants will be allowed to reopen

Die Welt adds that Kurz’s Danish colleague Mette Fredriksen has likewise indicated wanting to gradually reopen business in her country after Easter, but has not committed to a specific time table.


ADDENDUM: what about elsewhere in Europe?

  • Italy is seeing its smallest daily new cases count since March 19, and its smallest number of daily deaths since March 20. From the Worldometers data, I calculate their latest daily growth rate as 3.3%, which corresponds to doubling every 3 weeks or so.
  • Belgium yesterday marked the first day that net hospital bed occupancy dropped, according to De Standaard (in Dutch): admissions were less than the sum of discharges and deaths. Daily new cases have been fluctuating around 1,250 since March 26.
  • In Spain, daily deaths have been dropping for 3 days in a row now, and active cases appear to be leveling off. New cases are at the lowest level since March 23.
  • Germany has its lowest number of new cases since March 23. The “new cases” and “new recoveries” lines are on the way to the magic crossover point
  • Norway has its smallest number of new cases since March 19.
  • France has an anomalous spike in daily new cases on April 3, but daily deaths have been going down for 3 days in a row now.
  • The UK still is looking for first light at the end of the tunnel

And from Italy, an amazing human interest story: La Repubblica reports (in Italian) that Ada Zanusso, age 103 [!], beat back COVID-19. 21 other residents of her assisted living facility, 100km from Milan, succumbed the disease, but “somebody up there forgot me”. She stays in touch with her so Giampiero [Italian for John Peter], who says “she still reads without glasses, she is curious, always wants to know what we’re up to.” The spunky lady will turn 104 in August. Let’s raise a glass to her!

UPDATE 2:  Belgian PM presents 10-member GEES (group of experts [for a lockdown] exit strategy) reports De Standaard (in Dutch). This group, a mixture of doctors, epidemiologists, and economists, has been working behind the scenes for some time, apparently. Immunity testing and tracking via phone app are reported to be two cornerstones of the strategy, inspired by the work of a group from Oxford.

Israel has informally been talking about “after Passover” through much of the crisis, but no clear time table appears to exist as of yet. The epidemic is clearly slowing down here, but has not yet reached the plateau phase like in Belgium, let alone started receding like in Austria. A variety of creative solutions are being coined by scientists, including this one of an age-stratified exit.

In the UK, sadly, things are still looking glum, with now PM Boris Johnson moved to the ICU.

Now out on Kindle: Operation Flash, Episode 3: Spring Awakening

The third installment of the alternate history series where Hitler and Himmler were assassinated in March 1943.
A desperate military situation forces Carl Goerdeler’s Emergency Reich Government (ERG) to make a bargain with the devil.
Across the Channel, Winston Churchill plays for time as he pursues a separate peace with Goerdeler.
Two old acquaintances make the first steps on a long march toward national atonement.
And meanwhile, the ERG’s deadliest enemy lurks within its gates…

COVID19 update, April 5, 2020: Australia and the seasonality enigma

Australia is a very large country, sure enough, but human settlement is mostly limited to a coastal zone. Still, except perhaps for downtown Sydney and Melbourne, population densities are nowhere near what New Yorkers would take for granted.

According to worldometers., Australia has 5,687 cases, and thus far “only” 35 fatalities. Most cases are in the two most populous states, New South Wales (where Sydney is the largest city) and Victoria (with Melbourne as the largest population center), followed by Queensland (Brisbane being its largest city).

The country has been on what is locally denoted Level 2 lockdown. All arrivals to the country are mandated to self-quarantine for 2 weeks.

But this is possibly the most hopeful graph.

How is this possible? The mind wonders whether Australia coming out of an (unseasonably hot) summer could have something to do with it? After all, seasonality of flu viruses is a well-known phenomenon — but does that even apply to SARS-nCoV-2? To be sure, some things will apply to any viral infection — the vitamin D one gets from being in the sun sure is welcome to the immune system, and of course, in humid weather you don’t get the dried-out mucous membranes that are good ports of entry.

So what about hot and humid locales elsewhere? As of the time of writing, Hawaii has just several 351 cases and 3-4 deaths right now, despite the most populous island (Oahu) being densely populated. The tropical city-state of Singapore has coped well, but this could be explained by other factors without invoking the weather — particularly long-standing preparation since the 2003 SARS epidemic. Puerto Rico has so far just 475 cases with 20 deaths.
But then there is Ecuador, on the literal equator, currently being ravaged by the epidemic, with the largest city Guayaquil being completely overwhelmed. And in the US, despite its famously swampy weather, Louisiana has been hit very hard, particularly New Orleans with a death rate per capita twice that of NYC. (This has been attributed to “super-spread” events at Mardi Gras. I cannot help noting that Belgium’s largest outbreak also has been traced to a Carnival festival in the provincial town of Alken that was not canceled, and several infection foci in Israel have been traced to Purim celebrations.) In fact, hot and humid Florida has a similar number of COVID19 cases as Louisiana — despite having eight times the population!

Clearly, there is more here than meets the eye.

Meanwhile, in Belgium, for the first time during the epidemic, the daily hospital bed occupancy goes down, as the sum of discharged and deceased patients exceeds the number of new admissions.

And Instapundit links to a story about a team from Monash University that has found that the simple antithelmintic Ivermectin — which has been used in humans and animals for decades, in areas where parasitic worm infections are common — kills SARS-nCoV-2 in vitro within 48h.

Finally, Derek Lowe (h/t Cedar Sanderson) has a clear and informative discussion of antibody testing.

COVID19 update, April 4, 2020: a brief look at Israel

The first case on Israeli soil was a returnee from the Diamond Princess cruise ship, who however stayed in isolation. A tourist returning from Italy appears to have been “Patient Zero”.

Israel was quick to stop flights with China. On 21 February, all returnees from South Korea or Japan were requested to go in 14-day home quarantine; subsequently the country placed a blanket 14-day home quarantine on all returnees rather than single out specific countries. At one point, 200,000 Israelis were in home quarantine — this number has dropped precipitously as most of the travel-related quarantines expired and were only partly compensated by new quarantinees who lived or worked with somebody who tested positive.

Unlike most countries, Israel counts everyone who tests positive as a patient, including asymptomatic cases. The only way to get off the list is to test negative.

As of the time of writing, 7,851 Israelis have tested positive, and the disease has claimed 44 lives so far (an apparent IFR of 0.6%). 126 patients are in serious condition, of which 108 on ventilators.

Most of the mild and asymptomatic cases are in home isolation, but several hotels have been commandeered by the government as an isolation option for asymptomatic and mild patients. About 700 patients avail themselves of this option at the time of writing. Once checked in, one can only leave after testing negative. Once checked in, one can only leave after testing negative for active virus.

The age profile of patients (like the population pyramid generally) is definitely younger than in the hardest-hit European countries, which is one factor that accounts for the low IFR.

Israel started introducing social distancing measures mid-March, but only started actively enforcing them later, then tightened them to the point of placing roadblocks. Everybody is confined to a 100m radius from home, except for shopping for essentials or medicines, to work at an essential job, or such. As of Thursday masks were made mandatory outside the home.

The effect of these measures can be seen in the COVID19 statistics about 10 days downstream: note the “kink” in the graph below that marks transition from doubling every 3 days, to doubling every 5 days or more.

Bnei Brak, a predominantly chareidi (fervently Orthodox) borough of Tel-Aviv, accounts for nearly 15% of all cases nationwide. This community regards considers communal religious study and activities to be its very reason for existence, and has hence been slow to embrace social raison d’être, especially as it eschews secular media sources. Recently the area has been placed on full lockdown.

Meanwhile elsewhere, even the WaPo is now assuming that the official fatality figures out of China are <understatement>severe underestimates</understatement>.

COVID19 update, April 3, 2020: what does Iceland‘s unique dataset tell us?

Iceland is a small island nation with a thriving biotech industry. As such, it adopted a (to my knowledge) somewhat unique strategy: aside from contact tracing measure, local biotech company deCODE (an AmGen subsidiary) allows anyone who shows up to be tested. (This type of “big data” gathering seems to be part of their business model: they also did genetic testing for about half the adult population in the past )

As of the time of writing of this article about 20,930 people, i.e., 6% of the total population got tested — by far the highest proportion of tests in the population anywhere. (For perspective: to reach the same amount of coverage in the US you’d need to test about 20 million people. The US has tested about 1/20th of that number. )

As of this morning, Iceland has 1,319 cases, of which 4 (four) people have died, 44 people are hospitalized (12 of them in ICU), and 1,031 are in home isolation. 284 have recovered from the infection. 7,166 people are currently in quarantine, 8,945 have completed quarantines.

Now beware of comparing apples with oranges: the official government COVID19 page for Iceland speaks of 1,319 infections, not sick people. (It appears Israel similarly counts everybody who tests positive as a patient.) So the apparent enviably low 4/1319*100%=0.3% is really an IFR (infection fatality rate), not a CFR (case fatality rate).

[Iceland’s chief epidemiologist Thorolfur] Guðnason is quoted here as saying “Early results from deCode Genetics indicate that a low proportion of the general population has contracted the virus and that about half of those who tested positive are non-symptomatic.”.

Note, Iceland did not engage in any lockdowns — gatherings over 25 are forbidden, but otherwise economic life goes on. Instead, aggressive test & trace and quarantines are the order of the day. While the country’s low population density might seem to help, nearly two-thirds of the population is concentrated in and around the capital Reykjavik — which especially by US standards is fairly dense.

Elsewhere I read that not only was Iceland able to trace the source of the infection in most cases, but even to distinguish between different mutants of the virus.

“We can determine the geographic origin of the virus in every single [virus] in Iceland,” he said, adding there are specific, minor mutations for the virus that came from Italy, Austria and the UK. “There was one that is specific to the west coast of the United States,” [Stefansson] added.

[He] wonders whether mutations in the virus are “responsible, in some way, for how differently people respond to it — some just develop a mild cold, while some people need a respirator,” or whether a person’s genetics dictates their condition. “Or is it a combination of these two?” he asks.

“Keep in mind that the screening is now randomized, but voluntary so there is some bias in the data,” the Directorate of Health said in a statement, adding that a “randomized screening program has started and a blood serum screening for antibodies is planned.

COVID19 update in brief, April 2, 2020: (1) Belgium followup; (2) German RKI recommends masks for everyone, Israel mandates them in public

A very busy day at the (remote) day job, so just a brief update:
(1) Following up on the earlier report from De Standaard (in Dutch) reports a grim peak of 183 dead in a single day, for a total of  1,011 in a country with 11 million people.

However, and this is the good news, hospital admissions have held steady between 450 and 650 for the past week. The last day, 584 new admissions were offset by 363 discharges. Out of 5,376 hospital patients with COVID19, 1,114 are in ICU, an increase by 56 (the smallest since March 23). 906 of those need ventilation, an increase by 72.

teven Van Gucht, head of the National Corona Committee, is quoted as saying, ‘The nummer of new admissions fluctuates already for days in the same range, which indicates we’ve reached a plateau. This is surely due to the [social distancing] measures.”

A friend sent me this graph. Note that both the graphs for Belgium and for Israel show a noticeable “inflection point” around 14 days beyond the introduction of social distancing measures.

(2) While Belgium is still reluctant to mandate masks for everyone, Germany’s authority for infectious diseases, the Robert Koch Institute (named after the discoverer of, among others, the tuberculosis bacillus) now recommends masks for everyone. Their prime benefit is said to be stopping asymptomatic infection carriers from spreading the disease.
For the same reasons, Israel’s ministry of health today mandated the wearing of masks in public areas.

COVID19 update, April 1, 2020: not April Fools edition

(1) Dutch scientists discovered that SARS-nCoV-2 can be detected in a city’s wastewater even before anybody realizes they are sick. “[Medema and coworkers] detected genetic material from the coronavirus at a wastewater treatment plant in Amersfoort on March 5, before any cases had been reported in the city, located about 50 kilometers (32 miles) southeast of Amsterdam. “

(2) Chemical and Engineering News, the house organ of the American Chemical Society, has more on remdesivir as well as on another antiviral discovered at Emory, EIDD-2081. While remdesivir needs to be administered intravenously, EIDD-2081 can be given orally. On the other hand, EIDD-2081 hasnever been tested in humans while remdesivir underwent safety testing back in 2015 (as a potential ebola drug.

(3) WIRED has a long story about masks. “Let’s face it: they work”. Most of the evidence concerns other respiratory viruses:

“A 2011 review of high-quality studies found that among all physical interventions used against respiratory viruses—including handwashing, gloves, and social distancing—masks performed best, although a combination of strategies was still optimal.”

Fortunately, the available evidence suggests that for most people in most situations, an N95 is not a necessary form of protection against Covid-19. If we eventually have a surplus of surgical masks, which are much more comfortable and affordable than respirators and still provide excellent protection, they would be an ideal choice for universal masking. In the meantime, homemade masks made from tightly woven yet breathable fabric are the best option and certainly better than nothing. A piece of cloth will never be as good as a manufactured filter, but it can still smother the brunt of a cough or sneeze and impede other people’s respiratory droplets.

Read the whole thing.

Seattle police during the 1918 “Spanish flu” pandemic

(4) According to a new epidemiological analysis in British medical journal THE LANCET: the infection fatality rate (IFR) of COVID-19 is 0.657% (confidence interval 0.389-1.33 %) and the adjusted case fatality ratio (CFR) is 1.38% (confidence interval: 1.23-1.53%). [mention in MSM: ]

(5) Beijing’s “mask diplomacy” appears to be backfiring, as many of the masks and test kits sent out turn out to be defective or substandard.

“Spain’s health ministry last Thursday said it had withdrawn around 58,000 Chinese-made test kits after it emerged that they had an detection accuracy of just 30 percent. The normal accuracy rate is more than 80 percent, local media reported.”

The story of a shipment of 600,000 mouth masks for healthcare workers being disapproved by the Dutch authorities as not meeting basic quality standards is all over the Dutch-language media, e.g., here in De Telegraaf.

(6) GenomeWeb reports that a genetic cancer testing company, that has seen demand slump as “non-urgent” medical tests are put off due to COVID-19, is now retooling for COVID-19 testing.

(7) Israel starts passive immune therapy experiment. This happened only today, as they needed a plasma donor who was not only cured, but had subsequently tested negative for the virus at least twice.