QCOSTARICA – The COVID-19 contagion rate in Costa Rica has been on the decline, falling again this week, to 0.96, its lowest point since last April.
The rate is published every Wednesday by the Central American Population Center of the University of Costa Rica (CCP-UCR), which measures the transmission of the virus that causes the pandemic.
This drop in the contagion rate has been maintained since the end of August: three weeks ago it was at 1.16, falling to 1.07 and the last week to 1.05.
The contagion rate, also called the R rate, indicates how many people each patient could infect, on average.
If it is equal to 1, each person will infect another person on average, and this will keep the infection constant. If it is at 2, on average each person will infect two more people on average, the transmission speed will double.
Ideally, therefore, the R rate should be less than 1, which is a sign that the rate of new cases is slowing down. And that was the case this Wednesday after more than five months of being above 1.
An index of 0.96 means that an individual with the virus could transmit it to 0.96 people on average. Or, viewed another way, 100 people who carry this pathogen could give rise to a generation of 96.
Although these numbers are encouraging, we must take into account that when active cases are in the thousands, as is currently the case, every 1,000 active cases could mean an average of 960 more cases.
Despite the drop in the R rate, the number of daily cases continues to represent a potential threat to the health system.
This index 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.
CCP-UCR researchers warn that R is a highly volatile factor and can undergo big changes quickly.
The analysis for this September 30 takes into account that these infections occurred approximately on September 24. This is based on the incubation period of the virus (time that elapses between infection and the first symptoms), which on average is six days.
Could the current R rate mean we’ve reached the peak of the curve?
CCP demographer, Luis Rosero, believes so.
“The R rate appears to have reached the key threshold of R = 1 by September 15. Upon reaching this threshold, Costa Rica would have also reached the peak of the epidemic curve,” said Rosero.