Wastewater monitoring shows spread of new Covid-19 variant Eris in several regions of Latvia

RIGA - Wastewater monitoring shows the spread of the new Covid-19 variant Eris in Salaspils, Jekabpils, Daugavpils, Jelgava, Talsi and Limbazi, Riga Technical University (RTU) External Communication Department Head Dita Araja informed LETA.

A new variant of Covid-19, Eris, has been detected in Latvia and has been spreading in other parts of the world since the summer, especially in China and the United States, according to official national wastewater monitoring, during which the presence of SARS-CoV-2 has been identified and monitored in wastewater in 16 municipalities.

The monitoring has been carried out for two years by a team of scientists and experts from RTU, the Scientific Institute of Food Safety, Animal Health and Environment BIOR and the Latvian Biomedical Research and Study Centre (BMC).

Eris has not yet been confirmed in Latvia by laboratory tests, but monitoring of wastewater can help detect the presence of the virus and the spread of new mutations much more quickly.

According to Araja, wastewater samples are collected in 16 municipalities, with the frequency of sampling adapted to the epidemiological situation in the country.

Currently, the new variant has been detected in Salaspils, Jekabpils, Daugavpils, Jelgava, Talsi and Limbazi. Based on more than two years of knowledge on the trends of the virus in Latvia, the team of experts estimates that the number of Eris cases is currently not high, meaning that individual cases, where about ten people may have been infected in a city, are quite difficult to identify with routine medical examinations.

Jurijs Perevoscikovs, Director of the Infectious Disease Risk Analysis and Prevention Department at the Center for Disease Prevention and Control, explains that the new omicron strain Eris appeared later in Latvia than in some other countries and is spreading slowly throughout the country. It is likely to become dominant after some time, like its other predecessors, which have caused moderate upsurges in incidence.

Perevoscikovs stresses that Covid-19 has not yet been detected in Eris infected persons, as widespread population screening is no longer appropriate in the face of changing risks, and is being carried out mainly in hospitalized patients. Thus, wastewater monitoring is now an epidemiologically important source of information to track changes in viral prevalence, which reflects changes in infection rates, and allows early detection of mutations and new strains.

Although the new mutations in Covid-19 are not as devastating as those experienced in the early days of the virus, the variant is receiving increased attention from the World Health Organization because it is different from previous forms of the virus. Data from the European Center for Disease Prevention and Control show that the average prevalence of Eris in European Union countries is 60 percent, but there is no evidence that this variant of SARS-CoV-2 causes more severe illness, Perevoscikovs said.

Overall, wastewater monitoring data show that the prevalence of Covid-19 has been increasing in Latvia since the end of August, which can be explained by the start of school and the return of people from the countryside to the cities after their summer holidays.