The serological survey will begin, at the earliest, on Monday and will last eight weeks
The eyes are fixed on May 9. It is the last day of the extension of the state of alarm that the Government will request this Wednesday in Parliament and it is, according to Pedro Sánchez himself, the date from which the first measures of relaxation of confinement can be taken, if the epidemic continues to decrease. A tool that Health advertised as the key to deciding those first steps was a serological survey that will show the level of incidence in Spain. But it will not be ready by then: it will start next Monday and will last eight weeks.
It was scheduled to start last week, but “certain adjustments”, Fernando Simón, Health spokesman, explained on Tuesday, have been delaying its start. The ministry shared with the communities on Monday a plan to develop this survey, which aims to find out the actual number of those infected and potentially immune to the disease. The document, to which EL PAÍS has had access, shows that after a period of training and testing, the surveys will begin, at the earliest, on the 27th.
They will be done in health centers, except in cases where a home visit is essential. Several autonomous communities consulted have explained that they are preparing the resources. Antonio Fernández Pro-Ledesma, president of the Spanish Society of General and Family Doctors, assures that they have no more information than that provided by the media: “We have sufficient capacity and versatility, but we cannot continue to do more with the same means . It will be necessary to see the methodology and how it will be carried out. ”
The survey will be carried out on 36,000 households selected by the National Institute of Statistics. They are distributed throughout the Spanish territory and proportionally cover all age sectors of the population pyramid. There will be about 90,000 people, according to the document. Each will pass two different types of tests three times, with a three-week gap between sample and sample. A rapid immunochromatography test will be done,It detects in 10 minutes with a simple prick on a finger both IgM immunoglobulin (the first antibodies that are generated) and IgG (the most durable). In addition, a more complete blood test will be done with a technique called Elisa, which analyzes in depth the amount of immune response that has been generated. With these two tests, repeated three times, the aim is to have the most complete picture possible of the immunity generated, how it evolves over time and whether there are infections along the way.
In the first two weeks, that is, until May 10 if the most optimistic deadlines are met, a first round will have already been carried out, so it will be possible to count on preliminary results that will arrive, in any case, after Decisions have been made about the first steps of deconfusion.
Simón explained this Tuesday that this survey is an “important tool, but not the only one.” Without it, the measures will have to be taken based on other factors: the actual transmission of the disease, for which, according to Health, 100,000 tests per day are already being done, and healthcare capacity. “We cannot allow, at the risk of new epidemic waves, even if potentially minor, the system to suffer the tension it has suffered again,” said Simon.
What does the survey contribute to this? Several experts consulted answer that information; essential to really know the disease, to what extent there have been no symptoms, where and how it has spread. Even if it’s still dormant without us knowing. “For concrete measures, such as letting children out, perhaps it is not very useful, but for the most general ones, yes ”, explains a spokesperson for the Spanish Society of Preventive Medicine, Public Health and Hygiene (SEMPSPH). “It will also be crucial for new waves, to prepare the systems based on the impact that it has had on one site or another. It will not be the same in an autonomous community where there are a good number of people who have passed the infection than in another with very little, ”he continues, always making the caveat that the degree of immunization achieved by people who have passed covid-19.
José Martínez Olmos, an expert in public health and general secretary of Health between 2005 and 2011, believes that the survey is one more tool for making decisions, but “not essential”. “Although it will start later, the important thing is that it is done very well. It would be advisable to have the best possible information on the incidence in the population, but while what you have to do is prepare the system and keep an alert on epidemiological surveillance in case cases arise, locate them, isolate them and, if necessary, reverse “