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

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