Canary Islands performed just over 100 PCRs per day throughout the archipelago when the confinement began in mid-March, and currently performs more than 3,000 most days. That figure, which has meant multiplying by 30 the number of tests carried out to detect the coronavirus, hides a good part of the explanation for what is happening now in the islands, where until the beginning of March a maximum of five or six cases were detected per day, and now almost 400 are diagnosed in a single day.
Therefore, the alarming data on the spread of Covid-19 in the Canary Islands - and in particular in Lanzarote - do not necessarily mean that this second wave - at least until now - has affected the islands much more. In fact, the seroprevalence study that was promoted throughout Spain a few months ago, carrying out random tests as a survey, concluded that 2.3% of the population in the Canary Islands would have already passed the disease until the month of June. And that means about 50,000 people, when until that moment just over 2,000 had been diagnosed, which would mean that 96% were not detected at the time.
Now, the total number of accumulated cases since February in the archipelago stands at 7,952, after the figure has tripled only in the month of August. But despite the worrying number - especially while infections continue to not stop - it still does not reach even 17% of the estimate that the seroprevelance survey gave a few months ago. Thus, the only certainty is that more cases are now detected, but not necessarily more than in March or April. And this is largely influenced by the fact that the number of PCRs performed has multiplied. In the worst moments of the first wave, the tests did not reach 1,000 per day and more than 100 cases were detected per day, and now between 3,000 and 4,000 are carried out and between 300 and 400 positives are detected per day.
Ten times more cases but half as many hospitalizations
This would also explain the other big difference between the first and second wave of the pandemic, which involves the severity of the cases detected. In the case of Lanzarote, at the end of March there were 22 people hospitalized, nine of them in the Intensive Care Unit, with only 55 active cases. However, this Thursday there were 533 active cases and only 13 hospitalized (of which only one is in the ICU). The other 520 are in home isolation, most of them without even having symptoms.
This has been attributed to the profile of those affected, since now the majority have been young people in whom the disease does not manifest itself in the same way. However, we must also not lose sight of the fact that at the beginning of the pandemic, tests were not carried out on people with mild symptoms (much less on asymptomatic people), since resources were lacking and were allocated to patients with severe symptoms. And this means that many people - and in particular many young people - were able to pass the disease in the first months without finding out or without having a diagnosis.
Now, however, the new protocol requires testing for any symptom compatible with Covid, and is also being done to close contacts of anyone who tests positive. And that is what has brought out hundreds of cases of asymptomatic people throughout the archipelago. In other words, it is not that the disease is now milder or that the virus has “weakened” - something that most experts deny - but that for each serious case, many more mild and asymptomatic cases are detected than before, which increases the total number compared to those handled in March and April.
From 114 cases in a month and a half to almost 400 daily
Until March 14, when the state of alarm was decreed in Spain, the Canary Islands had only detected 114 cases of coronavirus throughout the archipelago in a month and a half (the first was a tourist diagnosed on January 31 in La Gomera, which was also the first case in the country), but in that entire period fewer tests were carried out than are now carried out in a single day. In fact, in February not even 40 PCRs were carried out daily throughout the archipelago, and in the first days of March it did not usually reach 100. In that month and a half, the maximum that was diagnosed in a day throughout the Canary Islands was 19 positives, just on March 13, while in the previous weeks, the figure ranged between none and ten on the worst days.
From March 14, the number of tests rose to more than 200 per day, two days later to more than 400 and at the end of March almost 800 PCRs were already carried out daily, with which more and more cases were emerging (exceeding one hundred daily), despite the fact that the confinement had already begun (the date on which a positive is confirmed is not the date on which the contagion occurs, because the symptoms - in case there are any - take time to appear).
It was in mid-April when the number of PCRs in the Canary Islands really multiplied, reaching figures closer to those of now, with an average of 2,000 tests per day and some days in which more than 3,000 were exceeded, but by then the country had already been in confinement for a month. There, the trend that had been occurring was broken, and the increase in the number of tests did not mean an increase in the number of diagnoses, which at that time was in a range between 30 and 80 cases per day; while later in May they did not reach 20 per day and in June it became almost residual, with less than ten cases per day throughout the archipelago and less than five on many days (none in the case of Lanzarote), so the number of PCRs was also reduced.
However, after the end of the state of alarm and the confinement, in July the cases began to increase again, exceeding 10 per day again and reaching some up to 45. But the real rebound came in August, and then the number of tests was multiplied again. Until July 28, between 1,000 and 1,300 were being done daily, and since that date they began to increase until reaching almost 4,000 in the last days.
The days with the highest peaks of cases coincide with more PCRs performed
Since then, a constant has been repeated: the days in which more PCRs are done, more cases are detected. The last example was experienced this Thursday, when a new record of confirmed cases in the Canary Islands was notified in a single day: 381. That same day, a record had also been set in the number of tests carried out, with 3,976. Three days before, when there was a decrease in the number of daily cases, the reality is that the number of PCRs carried out had also decreased, specifically to 2,649, according to data released by the Ministry of Health of the Canary Islands Government.
The same situation was repeated last week, when the highest peak of cases was recorded until that moment, also coinciding with the day in which the most tests had been done until then: 3,529. And this indicates that there is a direct relationship between the number of tests that are carried out and the number of cases that are detected. The more PCRs, the more positives are detected, at least while the chain of infections is active. In fact, that trend was only broken during the state of alarm, after several weeks of confinement had already passed.
Canary Islands, the third community that performs the fewest PCRs per inhabitant
Despite having multiplied the number of tests in recent weeks, the Canary Islands is still below the average of Spain in the number of PCRs performed per inhabitant. In fact, according to the latest data published by the Ministry of Health, until August 27 it was the third community that had carried out the fewest tests (99.61 per 1,000 inhabitants), only behind Murcia (93.52) and Andalusia (63.74). The average for Spain until that day was 136.23, with communities such as Asturias, Navarra, La Rioja and the Basque Country above 200 and Madrid with 172.75 per inhabitant.
It should also be noted that the communities that have the most cases do not necessarily do more tests, as reflected in that data. In the case of Asturias, it is by far the community that has the fewest cases per inhabitant in recent weeks, while the Canary Islands has been climbing more and more positions in that table.
In addition, as in many other communities in Spain, the archipelago also far exceeds the limit established by the World Health Organization on the number of tests that must be carried out for each positive case. Specifically, the WHO points out that less than 5% of the tests that are carried out should be positive to consider that the situation is controlled. In the case of the Canary Islands, the average for the last few days has been around 11%, which more than doubles that limit. It was precisely this Wednesday, when a record of confirmed positives was set but also of tests carried out, when that average was lowered to 9.5%.
In any case, the figures are very far from those that the Canary Islands had at the beginning of the pandemic, when close to 17% of the PCRs that were carried out gave positive, and less than a tenth of those that are done now were done. This data, once again, points to the fact that it is not necessarily that there are more cases now, but that a good part of those that existed were not detected then.
The Government expects to double the number of tests this month
The risk now is that as the contagion curve continues to grow, the number of serious cases will also increase, and with it the number of deaths and the saturation of hospitals. In fact, along with the new restrictions that are being approved, there is the importance of also detecting asymptomatic people, to prevent them from continuing to spread the disease, since not having symptoms does not mean that they cannot infect.
Since mid-March, this was avoided with the confinement, which managed to reduce the contagion curve, despite the fact that many patients had not even been diagnosed. Without any social contact, the spread stopped. However, now that more drastic measures are being avoided, due to the economic impact it would have in a situation that is already critical, it becomes vital to diagnose and isolate all cases, and the impossibility of doing so is what is leading to increase the restrictions.
In addition, the Government of the Canary Islands has announced that during September it expects to double the number of tests carried out in August, when they had already gone from 40,131 carried out in July to 67,564. As for Lanzarote, which is one of the most affected islands, 2,251 PCRs were carried out in July and 5,756 in August, which is among other things what has allowed more cases to be detected.
At the moment, the vast majority are mild or asymptomatic, so the real risk of not stopping the transmission is not that this figure continues to increase, but that serious cases that require hospitalization begin to skyrocket. Until now, with ten times more cases diagnosed, the hospitalized until Thursday on the island were half as many as at the end of March, but that figure continues to grow and this Friday they have gone from 11 to 13. Regarding deaths, the first wave left six, and the second so far has claimed one.
