Irene Hartmann
04/27/2020 - 18:37
- Clarín.com
- Society
Despite everything (quarantine, uncertainty, rising poverty ...) the tide of numbers on coronaviruses in Argentina seems to be finding some order . The registered figures show that the long-awaited "peak" that is so sought after may not take the form of a monster of unstoppable national scope, but manifests itself as intense but geographically isolated peaks in the districts that in recent weeks have accelerated in the rhythm contagious by Covid-19. That is, the City and the province of Buenos Aires.
Hence, with Santa Fe and Córdoba, the two districts in which practically half the country's population live have rejected the “recreational outings” announced by President Alberto Fernández over the weekend. In the words of the deputy head of the Buenos Aires Government, Diego Santilli, they were not authorized because "the cases continue to increase."
To those in detail, those sayings seem contradictory. It happens that at the national level the photo is not exactly that of an increase but rather that of a slowdown. In the words of Pablo Groisman, mathematician and researcher at the UBA-Conicet Faculty of Exact Sciences, “ the curve is slowing down . A nice way to look at it is with the charts that the President showed, indicating how long it took for cases to double . It is a phenomenon that cannot be changed because the pandemic supposes exponential growth: the issue is how often the cases double. At first this happened every 3 days, then every 10 and now every 17 days . If there had been no quarantine and the duplication was still every 3 days,we would have about 50,000 infected ”.
President Alberto Fernández, at the press conference on April 25, when he announced the "recreational outings", in the context of the coronavirus epidemic.
Instead, we are reaching 4,000. Beyond that in the last week almost a quarter of the total was added, 951 new infected that set a new record of infections , when looking at the "overview" week by week, the percentage of new cases (compared to the total accumulated) is in clear decline.
Thus, while from March 30 to April 5 there were 89% more infected than the previous week, from April 6 to 12 it fell to 42%; from 13 to 19, 33%; and the last week, less than 30% .
Although it is true that this “dynamic” scenario could be substantially modified by the gradual release from quarantine, it is a fact that jurisdictions such as Buenos Aires or CABA live parallel realities .
Day to day
In a review of the bulletins issued by the Ministry of Health of the Nation, it can be seen that the Autonomous City of Buenos Aires had, in the last week (the "epidemiological" No. 8), a significant percentage increase in infections , in contrast with the drop that this district had had in epidemiological weeks 6 and 7, surely due to the mandatory isolation.
Military men distribute food during a compulsory quarantine day this Monday in a neighborhood of La Matanza, province of Buenos Aires. EFE / Juan Ignacio Roncoroni
Thus, on Sunday, April 5, 70% more new cases were registered than a week ago. On April 12, the impact of the quarantine was already seen and that figure fell to 33% (compared to the previous week, always). On April 19, the decline continued and touched the floor of 20% of new cases over the accumulated total. But this Sunday, 42% more cases were reported . In this last figure the words of Santilli quoted above resonate.
The province of Buenos Aires has a similar reality. On April 5, 82% of new cases could be collected over the accumulated one week before. A week later, on April 12 (quarantine through), it fell to 44% . But already on April 19 it started to rise again and for two weeks 52% of new cases have been registered compared to the previous week.
And Córdoba and Santa Fe ? Those provinces were also refractory to the presidential proposal to relax home isolation, but the percentages do not help to understand the measure.
In fact, in the last four weeks, Córdoba went from increasing its new cases of coronavirus by 90% on April 5 (compared to the previous week) to just 5% this Sunday. In Santa Fe, the decrease was from 95% to the current 9% . The caution will eventually have to be linked with these provinces are home to Córdoba capital and Rosario, the two most populated cities in the country after Buenos Aires.
However, the city and the province of Buenos Aires function as "witness cases" . By comfortably exceeding the percentage of new cases in the country, they show that slightly opening the "tap" of isolation is not at all free.
Is the peak a myth?
One of the questions that comes back every so often is when will the peak be , which at this point seems like a myth.
Javier Farina, an infectologist from the Argentine Society of Infectious Diseases (SADI) was clear: “If I have between 100 and 200 new cases every day, as is the case now, each time it will represent less of the total accumulated. In other words, the 100 do not represent the same today as they did a month ago. But that in a week you have had 900 cases also speaks of the magnitude of the epidemic. It means that this is also going to be a trend and that it is going to be difficult to maintain that there are only 900 cases every week. Due to the transmission characteristics of this virus and the R0 ("R zero") , which is a multiplying factor, in the long run, it will also favor that this curve incline its slope towards verticality . What we want to avoid is that this occurs in a short period of time ”.
A woman with a mask, cycling through the streets of Buenos Aires, in the context of the quarantine by the Covid-19. EFE / Juan Ignacio Roncoroni
The R0 thing - the rate of reproduction of contagions - is quite an issue. In the city of Buenos Aires, the rate is 1.35 . In other words, for each person infected, one more person and "a little bit" are infected. The Ministry of Health of the Nation does not offer a global calculation of the country and in the province of Buenos Aires they told this medium: “We are not calculating that data. We plan to start estimating it but we have to close the methodology. ”
It will seem abstract, but it is convenient to try to understand it because from there the magnitude of the “peak” of infections will be deduced .
As Groisman explained, a model with which all this is seen classifies individuals according to different categories: "You rate the population among susceptible, infected and removed ."
"Removed is an unpleasant concept because it includes both the recovered and the deceased. That impresses a little. But mathematically they are in the same category because they do not infect ”, he explained.
What is Coronavirus? How is it spread and what are its symptoms?
Watch the specialThus, "either we are susceptible to becoming infected -something that is currently happening to 44 million people- or we are infected and therefore we can infect others." That's where R0 becomes relevant.
According to the mathematician, “the peak is the peak of infected people ( that is, the total spread in the official parts, less the recovered and deceased ) that is infecting others at the moment. In an epidemic, the curve always grows at first, but peaks, which is the largest number of infected people there can be at a time. The idea is that this peak is as low as possible. " That is, there are the least amount of infected at the same time infecting others.
For this reason, the countries that maintain the R0 between zero and one , have a practically controlled situation, since not all the infected infect another person. For Groisman, “it makes sense to think that there will be high peaks in certain districts where things are more complicated . It all depends on the measures that are taken… if we continue with forty total, the peak would take a long time to arrive, but, as we already know, it is not feasible to do something like this ”.
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