title: High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.
abstract: Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks.
authors.affiliation: Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1104 Ljubljana, Slovenia. andrej.steyer@mf.uni-lj.si
authors.forename: Andrej
authors.initials: A
authors.lastname: Steyer
authors.forename: Karmen Godič
authors.initials: KG
authors.lastname: Torkar
authors.forename: Ion
authors.initials: I
authors.lastname: Gutiérrez-Aguirre
authors.forename: Mateja
authors.initials: M
authors.lastname: Poljšak-Prijatelj
mesh_terms: D004196:Disease Outbreaks; D060766:Drinking Water / Q000821:virology*; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005243:Feces / Q000821:virology*; D005618:Fresh Water; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D060587:Groundwater; D006801:Humans; D012328:RNA Viruses / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017524:Slovenia; D014871:Water Microbiology; D014876:Water Pollution; D014881:Water Supply
chemical_list: D060766:Drinking Water