QCOSTARICA – The contagion rate, also called the R rate, of covid-19 in Costa Rica has dropped significantly from last week, 25.8%, and to the lowest levels since the week of October 20.
This is pointed out by the analysis “Una pandemia en perspective” (a pandemic in perspective), by the Hispanoamericana University.
The review of the last seven days resulted in a rate of 0.89. Last week it as at 1.12, which was the highest value since the beginning of the pandemic.
Why this abrupt change?
Among other things, this indicator is very fickle, because it depends on various factors such as people’s behavior and the number of diagnostic tests that are performed.
The contagion rate represents the speed with which this virus spreads in the country and indicates, on average, how many people each carrier of the SARS-CoV-2 virus, which causes covid-19, would infect.
If the contagion rate is equal to 1, each person will infect, on average, another, and this will keep the transmission constant. If it is at 2, on average each person will infect two more and the transmission speed will double.
Ideally, R should be less than 1, which is a sign that the rate of new cases is decreasing. If the index is higher than 1, the evolution of the disease will have greater speed.
With a rate of 1 the infection would remain constant.
A rate of 0.89 means that each carrier of the virus would infect 0.89 people or, in other words, of 100 people with the pathogen would transmit it to 89. A week ago those 100 people would have given rise to a generation of 112 infections, and two ago, to 106.
If we take into account the incubation period of the virus, the number of infections reported today, occurred between seven and 14 days ago, so this is an index that shows its delays.
The R rate does not have to do with the number of cases, but with the transmission speed or the speed with which the virus spreads.
Nor does it measure how aggressive it is, but how its movement and evolution is in a certain place.
“The virus continues to show signs of its erratic and volatile behavior in the country, without showing signs of having a predictable trend.
“It seems that it plays with us, sometimes encouraging optimism, and then shortly after, striking us another blow. It is then up to us to make sure their intentions are not fulfilled. In this endeavor, the whole country has to get involved,” says the report coordinated by physician and epidemiologist Ronald Evans.
Around the provinces, not all show the same behavior, but in all the R rate fell in relation to last week.
- Guanacaste is the province with the highest rate, with 1.
- San José and Limón have the next highest level, both at 0.94.
- Alajuela and Heredia follow, with 0.87 each.
- Cartago, with 0.85 and Puntarenas, with 0.83, are the lowest
“To date, there is no week that has registered an R less than 1.0 in all the provinces,” says the report.
Not to be trusted. Having a low R rate is good news, yes, but this does not specifically mean fewer infections, but a lower speed.