An article written in one of the most important newspaper of the country has showed some facts to take into account about the development of the pandemia in the Metropolitan Area of Buenos Aires:
The coronavirus pandemic in Argentina is going through a defining moment. Daily numbers can dazzle and not let see what really happens. Last week there was talk of a record of cases. And it was true. But that title hid something. Something that has been expected for a long time and, if the math does not fail and social responsibility accompanies, one would be on the way to achieving it.
The following statistical analysis, based on official figures, is conditioned by the variable of the registration: the greater the gap between positive tests and real cases, the more flawed the information can be. But it is the only one available. As a correction factor for this margin of error, it should be noted that the ability to record grew. The number of PCR tests performed doubled between June and July, and today they are about 14 thousand per day. About 3,000 were made in mid-May and 1,500 in April.
First data: in an unprecedented event since the pandemic began, the number of new cases of coronavirus accounted for last week in Capital had a significant reduction. There were 489 less inhabitants detected. We have to wait a few days to know if this trend is consolidating, especially to evaluate the results of the light quarantine that began on Monday, July 20.
This diagnosis should not come as a surprise. The Covid motorcycle, due to the managed quarantine, began to slow down unbridled a while ago, although the daily information does not emphasize that. However, despite having been achieved to put the plague back on an exponential slide, it was and still is imperative that the measures that allowed it do not decline until that the so-called “herd immunity” on the rise can do the job of compensating for the lean confinement while there is no vaccine available.
An analysis of the curve since the start of the pandemic in Argentina -with the exceptions of the inevitable under-registration already stated- allows us to account for this behavior: May 15 was the peak of acceleration of cases in the City and just over a month later, on June 19, it was verified in the surrounding municipalities of the city. Since then, the number of infections - although it may not seem so at first glance - increased more and more slowly in the metropolitan area. That is, the drawing of the curve has never been so vertical since then and tended to horizontal.
This encouraging fact, however, would not allow the quarantine to be relaxed much more than it already is, nor to neglect preventive measures. On the contrary, they should take more care than ever to avoid a setback in their livestock. If these indicators continue on the same path, it is likely that the authorities will not have to back down again in the isolation phase of the Metropolitan Area.
A clarification is needed: although the percentage growth of cases is getting smaller, that final number still grows. The issue is how much it grows, and that the volume of active infected people must be sustainable for the health system - particularly intensive therapies - so that no patient is left without a hospital bed in case they have to be hospitalized. For that 5 percent of patients the difference between life and death may depend on that availability. The more or less harsh quarantine is also a consequence, and especially, of the vacant sanitary space. So the peak acceleration of the curve is one thing and the peak of cases is another. The further the transmission speed is lowered, the less painful it will be to pass that demonic point.
That said, the numbers are telling. And curiously they show that there have actually been two acceleration peaks of infections, both in the City and in the GBA. The first, in both districts, was registered on April 10, three weeks after quarantine has begun. A premature spike from hangover from pre-confinement cases. Then the intensity of new cases dropped, to grow again a few weeks later, at the beginning of May in the City and seven days later, in the Province. The second peak speed - and for now the last - was even more evident. It happened on May 15 in the City and on June 19, in the Province.
This does not mean that after these last spikes in speed, infections have not continued to increase in volume, but that they did so - at least in the records - at a decidedly lower rate. In other words, the contagiousness index (R0) decreased.
Weekly periods were taken to make these calculations, which gives an average of daily cases in a span of seven days. That puts aside speculation about whether the high amount of a single day has to do with the chance of the dragging of non-centralized figures in previous reports. With this measurement logic, that variable becomes less important. What can be seen, week by week, is how much the Covid has pressed the accelerator both among Buenos Aires City and Province of Buenos Aires residents, the two populations in the country most affected by the pandemic.
In that first peak identified on April 10 (from there the transitory drop coincides with the first effects of the quarantine started on March 20), the City curve climbed 54 percent in one week and the Province curve 60 percent. Then the speed growth rate decreased. And May 1 was the first floor of acceleration of the curve in Capital, with a weekly increase of 30 percent. While in the GBA the same happened on May 8, with a rise of 22 percent.
From that moment, as a result of the relaxation of the insulation, there was a sustained growth in the speed of the curve. It behaved like this until May 15 in the City, when the hot tachometer came to mark an intersemanual increase of 65 percent. In the province, the speed did not stop rising until June 19, when that increase from one week to the next was 50 percent.
From that point on, the curves began to slow down week by week. Here is a summary: from May 15 to 22 in the City, 62 percent grew; through May 29, 60 percent; as of June 5, 37 percent; as of June 12, 33 percent; as of June 19, 30 percent; as of June 26, it had a slight rebound, to 33 percent; as of July 3, 25 percent; as of July 10, 23 percent; and as of July 17, 21 percent.
According to the closing of data from the last week, on Friday, July 24 in the City, the number of cases grew by just 16.8 percent and in the GBA almost double, 30.3 percent. But the speed of the Buenos Aires curve is also in a downward progression. It was 49 percent between June 19 and 26 and the following weeks it scored 40, 35 and 36, to finally reach the last record of 30 percent.
Obviously, as the case base is higher, the weekly balance remains a high sum. But the important thing is that, far from being shot, the curve transforms the phantom with a sharp peak into a less challenging hill. A mechanism in which, in addition, 44 percent of already recovered patients begin to have their weight as a universe of immune allies.
A peculiarity for nothing less, also, in the case of the Capital: since the acceleration of the curve fell from 22 to 16.8 percent in the last week, the number of new cases accumulated in seven days decreased: 7,479 now, against 7,968 the previous one. With this, the daily average decreased from 1,138 to 1,068.
In the GBA, although the speed of the curve has decreased, it has not yet done enough so that this is reflected, too, in the absolute numbers of a week. In the last one, it added 20,686 new cases, while in the previous one there had been 18,109, with a daily average that went from 2,587 to 2,955. In any case, the trend seems to indicate that, if the same course were followed, it would not be so far from achieving that result: in the last week the accumulated amount fell 6 percentage points in the Conurbano. To achieve fewer cases this week, next Friday should drop another 7 points. That day, surely, the authorities will announce once again how the quarantine will continue.
NOTES: GBA and Conurbano are two of the names given to the whole of the municipalities surrounding the city of Buenos Aires. Also, due to the length of the article I used Google Translator, so my apologies is something is not correct.