QCOSTARICA – Have we already reached the peak of this wave of covid-19? Demographer and public health worker Luis Rosero assures that it is.
However, he cautions that this does not mean that the wave is over or that the trend cannot be reversed, because it can go on for quite some time at this high point.
“The arrival of the epidemic peak is a moment of, at the same time, celebration and extreme caution. It is the moment from which the situation will begin to improve, but it is also the moment of maximum danger in which the circulation of the virus is at its peak,” stresses Rosero.
How do you know that we are on the crest of the wave?
According to his analysis, published on the page of the Central American Population Center of the University of Costa Rica (CCP-UCR), where he is a researcher, this is because the virus contagion rate has been dropping steadily since April.
The contagion rate, also called the R rate, is an indicator of how many people will infect, on average, a carrier of the SARS-CoV-2 virus, which causes covid-19.
According to his report, the indicator is currently at 0.99, after having been at 1.38 in April. Being below 1 means that each group of active cases will pass the virus to a smaller group. This data, however, contrasts with that given the previous Friday by the Hispano-American University, which placed it at 1.16.
According to the CCP-UCR report, our country “flattened the curve” and, most likely, a decline in the daily contagion curve will begin.
However, the speed of this decline is still unknown. With the previous wave, this peak had a “plateau face”, as it remained constant at a high point between September and December, approximately.
In other countries, the decline was faster and more pronounced.
The document does notice a difference with the highest point of the previous wave in our country: that of this will be an average of 2,500 cases per day, approximately double those seen at the peak of the previous wave in September.
Possible reasons
It is difficult to determine a single reason why the highest point of the wave has already reached. However, the researcher has some hypotheses that could contribute to this.
Before looking at the reasons, it should be taken into account that, given the incubation period of the virus and how long it takes a person to manifest symptoms, the R rate seen today represents the infections that occurred approximately six to eight days ago.
Some possible causes of the current pandemic trend are:
- The sanitary restrictions on circulation and capacity that the authorities began to apply as of Saturday, April 17 (vehicle restriction by license plates on weekends) and were extended in subsequent days.
- The population changed its behavior in response to repeated public messages and news about the seriousness of the situation in the hospitals.
- Depletion of the reservoir of people susceptible to becoming ill in the communities where the virus was circulating (because they have already become ill or because they are already vaccinated).
“The three possibilities are plausible and we do not have the data to determine the contribution of each one of them,”, the document cites.
Rosero indicates that the additional sanitary restrictions initiated on May 18 have not yet had time to act on the contagion rate seen today. And even less can there be an effect of the reduction of the capacity, since it just started this Monday.
Projections with three possible scenarios
The analysis draws two-month projections according to three possible scenarios: one optimistic, one neutral and one pessimistic.
- Optimistic scenario: the contagion rate continues to decrease until it reaches 0.85 and remains there for at least one month. The country could present about 600 cases a day by the end of July.In hospitalizations, the occupancy of beds would begin to decline before June 1 and by mid-July it would be around 600 beds (about 400 in the living room and 200 in intensive care). The daily average of deaths would reach eight within two months.
- Neutral scenario: the contagion rate continues to decline, but at a lower level and reaches 0.95. In this scenario, around July 21 there would be 1,600 daily cases.Admissions could be around 1,000 in the classroom and 400 in an intensive care unit (ICU), for a total of 1,400. The deaths would be between 17 and 18 per day.
- Pessimistic scenario: R begins to rise again and would reach 1.05. By the end of July the cases would be 2,800 a day, on average, and we would begin to rise in a new wave peak.In this situation, there would be about 1,500 hospitalized in the room and just under 600 in the ICU. The number of deaths per day would be close to 25.
End of pandemic wave
It is one thing to get to the crest of the wave and start to go down, and another is for the wave to be over. Rosero indicates that it is not easy to determine when this occurs, as there is no scientific consensus.
The European Union speaks of 50 cases per million inhabitants for the lifting of some restrictions.
In Costa Rica, that would be approximately 250 cases.
“This threshold of 250 daily cases could be reached in mid-August in the optimistic scenario or possibly in September in the neutral scenario,” the report states.
What To do?
The specialist sends recommendations for both authorities and individuals.
For Rosero, lifting all restrictions before reaching the threshold of 250 cases per day can be counterproductive.
“Special care must be taken not to send implicit messages to the population that the danger has passed,” he stressed.
Meanwhile, the population is reminded of the importance of the proper use of masks, of hand hygiene, but especially of avoiding crowds, especially at social events.
“Gatherings with people who do not reside with you before the end of the pandemic wave represents a high risk of becoming infected and transmitting the contagion to others if one is not yet fully vaccinated,” he recommended.
“Therefore, the organization of get-togethers or activities that produce crowds, such as weddings, parties, conventions or concerts should be discouraged while the country is still in this pandemic wave,” Rosero concluded.
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