Wastewater surveillance system in Lithuania

The European Commission issued recommendation on a common approach to establish a systematic surveillance of SARS-CoV-2 and its strains in wastewaters in the EU (available at recommendation_covid19_monitoring_wastewaters.pdf (europa.eu)) that encourages Member States to put in place as soon as possible a national wastewater surveillance system targeted at data collection of SARS-CoV-2 and its strains in wastewaters. In response to this, Lithuania has implemented a wastewater surveillance system and wastewater has been tested for the SARS-CoV-2 virus and its strains since November of 2022. 

In Vilnius, Kaunas and Klaipėda wastewater treatment plants, wastewater samples are taken weekly by the specialists of treatment plants in line with sampling schedule coordinated with the National Public Health Laboratory (NVSPL). 

The testing of wastewater samples for the presence of the SARS-CoV-2 virus and its strains in wastewater is conducted by NVSPL, and the results of the tests are sent to NVSC. 

The method of surveillance the presence of the virus and/or its strains in wastewater is part of epidemiological surveillance, which allows to identify the possible dynamics of infection with the SARS-CoV-2 virus, the spread of strains, and provides additional information that would help prepare for future pandemics and apply measures to limit the spread of infection.

Trends in indicators that are included in wastewater monitoring may indicate an increase or decrease in the number of virus particles in wastewater. The advantage of such monitoring is that by comparing the indicators of incidence in population and wastewater monitoring, it is possible to determine whether there are both symptomatic and asymptomatic patients in the area. Considering the epidemiological situation and the prevalence of various SARS-CoV-2 variants in the world and in Lithuania, tracking virus genomic sequences in wastewater can also be an early signal about the spread of dangerous variants or, possibly, the emergence of new variants. 

Wastewater monitoring is an integral part of the epidemiological surveillance of COVID-19, and a way to estimate trends and changes in viral circulation at the population scale. Not only the general examination of the wastewater is important, but also the sequencing.

In week 2/2023, the testing of wastewater from the aircraft is to start. Several European countries (such as Belgium, the Netherlands and Austria) have already introduced such testing. Guidance on testing aircraft wastewater can be found here EU4S (europa.eu). 

For more information on wastewater monitoring in Europe visit https://wastewater-observatory.jrc.ec.europa.eu/ 

In Lithuania, wastewater is tested in accordance with the description of the procedure for monitoring the SARS-CoV-2 virus and its strains in wastewater, approved by Order No. V-1627 "On approval of the description of the procedure for monitoring SARS-CoV-2 virus and its strains in wastewater" of Minister of Health of the Republic of Lithuania of 18 November 2021. 
Up to now, wastewater monitoring-based epidemiological method has been successfully used to estimate the consumption of drugs or pharmaceutical substances in population.