Sánchez believes that Spain will reach 10,000 cases. We have probably already overcome them

In his appearance this Friday, the Prime Minister Pedro Sánchez announced that they hope that next week Spain reaches 10,000 cases diagnosed with Covid-19. At the time of his intervention, the data in our country showed 4,209 infected and 120 deceased.

The problem with a disease like this — in which 80% of those who contract it does so with slight discomfort, even if they are equally capable of transmitting it — is that it is impossible to know for sure how many undiagnosed cases are currently roaming the country.

However, using the applied statistics it is possible to make an estimate of how many diagnosed would Spain currently offer if we had done as many tests per inhabitant as the country in the world that has stood out the most in this regard: South Korea. The Confidential has collaborated with the German company STAT-UP Statistical Consulting & Data Science to offer an approach to this question and try to better understand the magnitude of the problem facing our country, which has been officially in alarm since yesterday.

The Minister of Health, Salvador Illa, has offered only once, on March 10, the data on how many tests of Covid-19 have been carried out in our territory: 17,500 since the SARS-CoV-2 epidemic crossed our borders , or in other words, 372 tests per million of people. For its part, the government of Seoul, perhaps the country in the world where the recorded data shows a lower case fatality rate, has made 3,691 test for every million inhabitants.

"On the basis that the cases that go undetected are above all the mildest, while the deaths are detected practically all, at least in developed countries, the case fatality rate based on the registered data is higher than the real one ", exposes El Confidencial Ansgar Seyfferth, director for Spain of the German company. "The more underdetection there is, the more pronounced this effect will be."

In other words, South Korea shows such a low case fatality rate (0.84% ​​according to the latest data) in relation to other countries due to the many tests carried out in the Asian country. Spain, for its part, showed yesterday that a 2.8% of those infected end up dying, compared to 6.7% in Italy. The disease is the same in all three countries, and its clinical consequences as well, so the huge differences in mortality They are explained mainly based on two factors: the demographic distribution of the country (the Covid-19 is more lethal from the age of 70) and the number of tests carried out among the population.

Spain and Italy, in this sense, can expect a lethality higher than that of South Korea, where 10.1% of the population is over 70 years old compared to 14.6% in Spain and 17.2% in Germany, according to UN data. As for the number of octogenarians, the two Mediterranean countries also far exceed Asia: 6.2% Spain, 7.4% Italy and 3.4% in South Korea.

"Due to these demographic differences, a fatality rate can be expected for Spain and Italy, respectively, 27 and 45% higher than that of South Korea"explains Seyfferth." The mortality rate of 0.84% ​​in South Korea, adjusted for age, would translate to 1.06% in Spain, when the observed rate is 2.6 times higher, and in Italy it would translate to a 1.21% when the observed rate is 5.5 times higher. "

This figure helps us to calculate how many diagnosed there would really be in our country if the Ministry of Health and the autonomous communities had subjected us to a rate of 3,691 tests for every million inhabitants. "If tests were conducted as comprehensively as in South Korea, one would expect that in Spain 2.6 times more cases were detected than in Spain and 5.5 times more"says the director of STAT-UP, adding that there could be other factors influencing the case fatality rates of the disease.

This would mean that in our country we would have already detected Covid-19 in 11,172 people and in Italy 83,121. With these figures, Spain would exceed the official numbers of infected South Korea. The Italians, for their part, would already be around those of China or, in fact, exceed their 80,945 official cases, but we cannot affirm it since we have not applied this analysis to the country from which the virus arose.

If we had been as exhaustive as South Korea, in Spain we would have detected the Covid-19 in 11,172 people

In summary, more than worrisome numbers for European countries as regards their coronavirus containment strategies is concerned, but somewhat more hopeful regarding the fatality rate of the Covid-19. This is probably the most we can hope to glimpse about the true presence of the epidemic in our country. "Since the Koreans will not detect all cases either, the real case fatality will be even lower and, therefore, the underdetection factor even higher," concludes the German.