In a paper submitted April 1, 2020, a group of researchers from Italy and Switzerland had estimated, via evaluation of available data from different countries and from statistical modelling, that by March 25, 2020, over 10 percent of the Italian population had already been infected by the novel Coronavirus (i.e. more than 6 million people), and that the highest probability was for the epidemic to end in Italy “within the first week of April or few days later.”1
The authors based their modelling scenarios on the number of deceased, as they rightly assessed that this be the most reliable number regarding the spread of the epidemic available at this time. Actual testing only covers a small proportion of the population, and is highly unreliable, for reasons we have mentioned in passing in a previous article2 and which have been corroborated by significant anecdotal evidence we collected in our own personal environment, including among friends and colleagues in the medical community. For their assumptions regarding further development of the pandemic and its eventual halt, the authors drew on official data from China and fitted their projection curve to the curve derived from this data.
Independently, a poll conducted by a leading market research institute, coordinated by a renowned epidemiologist from the University of Milan, led to a very similar estimate for the actual infection level. The poll had asked a representative sample of the population for symptoms observed on themselves (and had duly corrected, as the authors assure, for the subjective nature of the obtained data).3
As would be expected given limited testing activity and even capacity in most western countries, many other indications have surfaced for much higher prevalence of COVID-19 infections than official data reveal.4
All this implies, of course, that the actual death rate from COVID-19 is far lower than was initially feared, and will eventually settle at significantly less than half a percent of those infected. The reason for the initial fear of a much higher lethality, one can speculate, is that the Chinese were confronted with a situation that in reality was, just as is now the case in Italy, much further developed than initially estimated, so that the Chinese likely thought they had a viral disease as lethal as SARS 2003 on their hands, only that it appeared to spread significantly faster. This initial assessment and the drastic actions taken based on it then shaped much of the public perception of COVID-19 in the West, including ours.
In the little over a week since the publication of the two mentioned estimates, it has become clear that the estimate made by the first-cited group for a plateauing of the pandemic in Italy at around the time of this writing does not conform to reality. While the number of daily new deaths has shown signs of declining, the number of total deaths continues to rise at a much higher rate than foreseen: Instead of an estimated total of roughly 13,000 deaths by the time of this writing and clear signs of plateauing, this number has already surpassed 18,000.5 The estimated number would have required the lockdown to yield significant results and to halt the pandemic in Italy before herd immunity is achieved. The actual number conforms, in our view, much more closely to our own estimate, long held and mentioned in a previous post,6 calling for effective saturation around the end of April. By “effective saturation” we mean herd immunity and therefore essentially the end of the pandemic as regards Italy, not simply a plateauing of active case numbers that would drag out the pandemic for many more months, with even more devastating economic consequences, and with many more people dying “because of” instead of “of” COVID-19.7
The actual development of the numbers indicates:
- Indiscriminate lockdown measures do not work as expected at least in a significant part of the western world. Social interaction cannot be totally prevented (people have to go out to buy food), and where there is interaction, there is the risk of infection. For the South Korean solution to rigorously test almost everyone and then isolate only those tested positively it is obviously far too late.
- The phenomenon of significant pre- and possibly even completely asymptomatic spread of the virus on the one hand and the unreliability of testing on the other, both due to the observed typical course of the infection with initial massive viral replication in the throat that starts declining around symptom onset (so that if people wait – or are put off – for too long to be tested, testing may yield a false negative result), contribute to a much faster course of the pandemic than most have imagined.
- Therefore, over the coming weeks (Italy) to possibly two months that it should take to effectively achieve herd immunity in most of the western world, the focus should be put on how best to protect the especially vulnerable and how best to manage those infections that either threaten to or do indeed get out of hand, in order to maximize those patients’ chances of recovery. Calls in recent days for an at least partial continuation of the lockdown for another 12 to 18 months, until a vaccine may (or not) be available, seem, viewed in light of the above, much misplaced.
- The COVID-19 infection in Italy: a statistical study of an abnormally severe disease: https://www.medrxiv.org/content/10.1101/2020.03.28.20046243v1.full.pdf
- Coronavirus, l’indagine: “Almeno 5 milioni di italiani infettati”: https://www.adnkronos.com/fatti/cronaca/2020/04/02/coronavirus-indagine-almeno-milioni-italiani-infettati_LA4OJM0QbWxViiwQfAsJEO.html
- E.g. from measuring SARS-CoV-2 titers in wastewater, as has been done in a major urban treatment facility in Massachusetts: https://www.medrxiv.org/content/10.1101/2020.04.05.20051540v1