QCOSTARICA – The presence of the delta variant of SARS-CoV-2, the virus that causes covid-19, increased in our country, so much so that by the last week of September, it represented 96.4% of the samples studied in the genomic analysis led by the Costa Rican Institute for Research and Teaching in Nutrition and Health (Inciensa).
For the second week of August, this variant constituted 65.8% of what was analyzed.
On Monday morning, Inciensa shared the data from the genomic analyzes carried out between August 8 and October 2: of 180 samples studied, 159 (88.33%) identified this Variant of Concern (VOC).
So far, 384 of the analyzed genomes in Costa Rica have been delta genomes. It is the most reported variant, although the first cases were detected in June, when other VOCs, such as alpha and gamma, had already been circulating for at least four months.
According to Inciensa, this trend is normal and to be expected, as it is very similar to that observed in other nations such as the United States and the United Kingdom, where delta is still predominant.
The delta variant, identified for the first time in India, is classified as VOC because it is considered up to twice as transmissible and hospitalizations are more common in people who do not have the full vaccination schedule.
It should be noted that, given the limited capacity of our country to carry out this type of analysis due to its high cost, not even 1% of the cases reported are analyzed here, a number that is expected at least in more developed countries.
This analysis is led by Inciensa and has the active participation of the laboratories of the Caja Costarricense de Seguro Social) CCSS and DE private laboratories of the country, in addition to the analysis of professionals from the Faculty of Microbiology of the University of Costa Rica (UCR ) and the National University (UNA).
Less presence of other VOCs
The increased presence of delta has also been accompanied by a declining presence of the other VOCs: alpha (first seen in the UK), beta (emerging in South Africa) and gamma (first reported in Brazil and Japan).
For example, in the last sequencing, there was no longer the presence of alpha (which was predominant in May and June throughout the country) or beta (which had very few reported cases). Of gamma, 14 cases were registered in the analysis of the last week of September and the first days of October. This last report registered gamma in all the provinces, except in Guanacaste.
This situation is not exclusive to Costa Rica, since last September, the World Health Organization (WHO) warned that delta had already displaced the other three variants of concern, which came to constitute about 1% of what was analyzed at the world level.
In fact, the WHO stopped considering three Variants of Interest (VOI), previously called epsilon, eta and iota, as they no longer represented a greater risk of transmission, severity or disease. lower the effectiveness of vaccines or expose them to reinfections.
The latter is common to occur in VOIs, since in them the suspicions that viruses have “special abilities” are observed only at the genetic level and are not proven, so subsequent studies can rule them out.
Mu and lambda keep circulating
The VOI mu and lambda maintain their presence in Costa Rica, but in a lesser way. Within the analyzes, two mu cases emerged, both in San José, and four labmda, in San José, Heredia and Guanacaste.
Mu, seen for the first time in Colombia, has been detected throughout the country and already has 66 cases, but the only two seen in this analysis show that it has lost strength. The WHO considers mu to be of interest because it “has a constellation of mutations that have potential immune escape properties” and this could make some vaccines ineffective.
Lambda, which was registered in Peru, already has 16 cases in our country, of which 25% were seen between the end of September and October 2. The WHO believes that the genetic changes seen in this variant could make its transmission more efficient.
