The replacement and population behavior of conventional PCR (smear sampling) using rapid antigen testing are probably the two factors that contributed the most to halving the incidence of the novel coronavirus in Madrid last month.
The three experts were careful about data analysis, soil Point out these reasons as possible causes of fall registered in the area. The cumulative incidence of the virus started at 735 (September 30) and data was recorded on Wednesday with 339 infections.
The Madrid administration, headed by Isabel Díaz Ayuso, has made many decisions with the central government in response to the epidemic, and is focusing on its actions. For example, he believes that “surgical” closures and restrictions for certain health areas in the area are “effective”. However, according to experts, data analysis is more comprehensive and should take into account changes in epidemic combat strategies.
Rapid test introduction
“Several changes have been made that affect the way cases are counted, so it is worth taking a closer look at these data. The type of diagnostic test used, the environment of use and the criteria for application. “Miguel Ángel Royo, a preventive medicine and public health expert and spokesman for the Spanish Epidemiological Association, said.
“One of the changes in pandemic strategy is the introduction of rapid antigen testing,” stresses Royo. It is a cheaper and faster diagnostic tool that allows early isolation.
However, these tests cannot be compared to PCR. “They don’t have the same sensitivity or the same criteria of use,” he explains about this method of diagnosing covid-19, which is “for close contact with people with symptoms during the first five days of the disease.” Explains.
If you think about it, Miguel Ángel Royo refers to a newspaper based in Madrid. From the end of September after starting the mass population testing, rapid tests that replaced some of the PCR began to be used. [indivíduos] Unspecified “.
During the last two weeks of September, Madrid’s testing strategy has undergone major changes. From the age of 21, antigen testing began to be used and the use of PCR declined. At the same time, local enforcement measures, such as limiting the number of attendance to the meeting from 10 to 6, and certain closures in the healthcare sector, where the virus outbreak rate is highest, took effect at the time. As of September 30th, CRP testing has been restricted and will no longer be performed to end contact with covid-19 patients.
In two weeks, the area increased from 170,000 CRP to less than 73,000 from October 4-10, when the number of infections declined.
conclusion: From September 30 to September 9, Madrid conducted 255,087 rapid tests, of which only 1,025 were positive for the disease.. “If you do this in the context of a high prevalence, such as close contact for low prevalence, such as these antigens, in this same number of tests, fewer cases will be detected,” explains the expert. Test types and features for use will change.
write soil On September 20, the autonomous community recorded 28,154 positive cases cumulative over the past 7 days, and 16,715 on October 4. “The reduction in incidence is similar to a reduction in the total number of tests and a gradual replacement of parts of the PCR,” Royo points out.
However, experts recognize that they “may be part of” the reduction in cases related to restrictions applied over the past few weeks, but reject cases applied to primary health areas as they are still being reformed to have an effect.
Saúl Ares of the Spanish Higher Commission for Scientific Research (CSIC) shares the same opinion at the time “close the nightlife at 1 am, and if you are 2 meters away from a safe place, smoking is prohibited on the street and reduced dose”. In space.
The “noise” of the media began when returning to work and school after the holidays, which will be the cause of changing citizens’ behavior.
Change in population behavior
In this way, the decrease in the number of cases can be explained by adding the Isabel Díaz Ayuso government’s population testing strategy. “One of the hypotheses we are considering is the behavioral change of most citizens facing the border due to cumulative outbreaks in Madrid. “Ildefonso Hernández, a spokesman for the Spanish Public Health Association and former Director of Public Health at the Ministry of Health, says.
The official also points out that at least 40% of infected people are asymptomatic and that the Ministry of Health is aware that it detects between 60% and 80% of all infected people.
In addition to reducing cases, it also decreases the positive rate, which is the percentage of positives taking into account the tests performed. But this reduction is an illusionSays Saúl Ares. Again, the introduction of antigen testing is evident. The newspaper explains that the positive rate decreases with an increase in rapid tests and a decrease in PCR tests. From 19.50% in the week of the Madrid community’s biggest CRP test (September 21-27) to 9.98% at the end of October, which is now 8.21%.
However, CSIC experts believe that the high-volume use of the antigen may be related to the reduced evolution of the epidemic recorded in Madrid compared to other autonomous regions. Increasing cases in September led to a more preventive attitude with warnings that the population grew.”Mass use of antigens over the past month could mean accelerating the disruption of the delivery chain. “Saúl Ares says.
“It’s audacious to talk about certainty and say something works.”
Restrictions, rapid testing, and civic behavior may be factors explaining the reduction in virus outbreaks in the community, but these are only indicators. “It’s bold to talk about certainty and say that certain measures will work.. We don’t have this data and we can’t get it. All we can see is the global impact of everything that happened over a given period. It is impossible to analyze each possible impact. ”, I believe in public health expert Miguel Ángel Royo.
“Evaluating the effectiveness of an action requires a controlled research environment, which is impossible during the pandemic,” Royo said.
In this regard, this expert advocates a harmonized response, and the measures applied are clear and maintained for a sufficient period of time “without interference and changes in standards”, so that they can understand whether they have affected the control of infectious diseases.
However, he believes that measures that reduce social contact can have the greatest impact. This is a case of surgical obstruction and limits citizens’ movements and reduces social interaction.
The “worried” situation of hospitalization
In addition to measures or strategies applied to control infectious diseases, there is data on outpatient hospitalization and intensive care units (ICUs) and deaths that reflect epidemiological situations. Consider a professional.
Ares has a “real” reduction in this parameter “beginning between the end of September and the beginning of October”. In the fourth week of September, the hospital in Madrid received 2,672 patients, and the following week decreased to 2,369. On October 2nd, 505 people were admitted to the ICU, but as of November 5th, this number is declining in relation to deaths. On September 30, 52 deaths are now at 30 to 40 after peaking daily. A total of 18,369 people in the community of Madrid have died from Corona 19 or are suspected of being infected with the virus.
Royo’s “worried” situation. “We are still at high hospital jobs and high risk levels.” And the problem gets worse as the incidence of the virus increases further in the area. “In the intensive care unit, increasing the incidence with this level of occupancy can be fatal and lead to a hygienic collapse.”, Continue.
Given the current epidemiological context of the community, Ildefonso Hernández undoubtedly said: “What Madrid is doing well is an error. I can’t speak seriously. What you can do seriously is highlight the falls, take appropriate steps to prevent the curve from bursting again, and there is room for a full recovery of your health system. “
If Spain saw a decrease in virus incidence last month, Portugal saw an increase in infection cases
Madrid has reduced the incidence of the virus, but Portugal has seen an increase in new cases of infection over the past month and the same applies to hospital jobs in wards and intensive care units.
The most restrictive measures of the Portuguese government began to take effect within an emergency that took effect on 9 November at 00:00. Cases per 100,000 population.
Municipalities in the metropolitan areas of Lisbon and Porto are taking part in these drastic measures to limit the circulation of public roads between 11pm and 5am on weekdays and from 1pm on the next two weekends.
The effectiveness of these measures will only be seen after 2 weeks or more, as several factors such as testing strategy must be considered. Portugal has already started using quick tests this month., Make sure that DGS “does not recommend broad use, recommends proper use” in accordance with the guidelines effective November 9.
On Wednesday, SBS reported that Portugal had recorded 4,935 cases and an additional 82 deaths in the last 24 hours (highest since the start of the pandemic).