Epidemiological monitoring of SARS-CoV-2 in waste water, Slovenia

The epidemiological surveillance of SARS-CoV-2 in wastewater is a complementary surveillance system for SARS-CoV-2 infections, which enables spatial and temporal surveillance of SARS-CoV-2 infections at population level. It works on the principle of quantitative analysis of the excreted ribonucleic acid (RNA) virus in wastewater that flows into treatment plants. Based on analyses of the loads of waste water with the extracted virus RNA, we can obtain information on the prevalence of the virus in the observed population, which is represented by all connected to an individual treatment plant, regardless of whether they have expressed disease signs, can only be mildly expressed or are free of disease signs. Although SARS-CoV-2 is a virus that causes respiratory disease, 48.1% of patients also excrete SARS-CoV-2 through bowel movements. Monitoring of SARS-CoV-2 in wastewater is carried out in all 12 statistical regions in the Republic of Slovenia. The monitoring includes 16 urban waste water treatment plants (UWWTPs), which receive waste water from 730,887 (34.4%) of the population of Slovenia in 33 municipalities.