Costa Rica obtained for the first time a measurement of the amount of SARS-CoV-2 particles in wastewater, a tool that will allow us to know the evolution of the Virus in different populations and take prompt action in the event of outbreaks.
The analyzes, carried out by the National Water Laboratory of the Costa Rican Institute of Aqueducts and Sewers (AyA), with the support of the Costa Rican Social Security Fund (CCSS), in coordination with the Ministry of Health, revealed the levels of particles in the Center of Temporary Apprehension for Foreigners in Irregular Condition (CATECI), the wastewater treatment plant (WWTP) Los Tajos in San José and the submarine outfall station of the sanitary sewer of Limón, with samples from May and June.
These types of studies complement traditional epidemiological surveillance and can serve as an early warning system for new outbreaks, as well as to verify the prevalence over time of SARS-CoV-2 in a given community.
“This is a great scientific and monitoring advance for the country in the face of the health emergency. At the same time, we have continued the work to determine the presence of the Virus in wastewater, in which 184 samples have been analyzed and the genetic material has been identified in 46 ”, indicated the AyA executive president, Yamileth Astorga.
The authorities recalled that there is no scientific evidence that points to wastewater or drinking water as sources for contagion of COVID-19. The particles of this Coronavirus that are measured in wastewater come from feces excreted by a varied percentage of sick people.
The AyA National Water Laboratory announced that the concentration in wastewater from CATECI went from 30 genomic copies per milliliter (ml) on May 7 to 440 copies / ml on May 13 and up to 570 copies / ml on May 27. May, to decrease again to 30 copies / ml in the samples of June 12. Furthermore, in the samples from a sanitary sewer near CATECI, the concentration went from 80 copies / ml on May 13 to 500 copies / ml on May 27.
At the Los Tajos plant, which treats the wastewater of some 200 thousand people in the capital, 120 copies / ml were recorded in the samples of May 15, while at the preconditioning station of the underwater outfall of Limón, which receives wastewater from about 29,000 people, 30 copies / ml were registered on June 18.
The entities have been carrying out studies to identify SARS-CoV-2 particles in wastewater since April, without measuring quantities. Since April, particles of this Coronavirus have been detected in 46 of 184 samples that have been analyzed, including points throughout most of the country.
During July and August, they have identified Coronavirus particles in sanitary sewer points, wastewater treatment systems and septic tanks in San José, Goicoechea, Puriscal and Moravia, also San Pablo de Heredia, as well as in Nicoya and Santa Cruz Guanacaste, Golfito and Limón.
It is important to highlight that in the last report the presence of the Virus was not detected in wastewater samples from the Manuel Antonio Chapuí National Psychiatric Hospital, the Vilma Curling Rivera CAI, or the Cariari Health Area, Pococí.
In agreement with the epidemiological data, no presence was identified in several points sampled in Los Santos on July 29: the EBAIS of Santa María de Dota, San Andrés de León Cortés, CAIS of San Marcos de Tarrazú.