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 werecollected 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 astrovirusesin 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 ofgroundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. (Absract truncated at 2000 characters)
COBISS.SI-ID: 28690905
International foodborne norovirus outbreaks can be difficult to recognize whenusing standard outbreak investigation methods. In a novel approach, we provide step-wise selection criteria to identify clusters of outbreaks that may involve an internationally distributed common foodborne source. After computerized linking of epidemiologic data to aligned sequences, we retrospectively identified 100 individually reported outbreaks that potentially represented 14 international common source events in Europe during1999-2008. Analysis of capsid sequences of outbreak strains (n = 1,456),showed that aprox. 7% of outbreaks reported to the Foodborne Viruses inEurope database were part of an international event (range 2%-9%), compared with 0.4% identified through standard epidemiologic investigations. Our findings point to a critical gap in surveillance and suggest that international collaboration could have increased the number of recognized international foodborne outbreaks. Real-time exchange of combined epidemiologic and molecular data is needed to validate our findings through timely trace-backs of clustered outbreaks.
COBISS.SI-ID: 29115353
Rotaviruses are the leading cause of gastroenteritis in children and they exist widely in water environments. Ingestion of 10-100 viral particles is enough to initiate disease, what calls for extremely sensitive detection methods. In this study we have confirmed the validity of a recently published method for rotavirus concentration and detection based on the combination of methacrylate monoliths and real-time reverse transcription-quantitative PCR (RT-qPCR). The method was used to concentrate rotaviruses from different tap water and environmental water samples collected in Slovenia within years 2007 and 2009. The performance of virus concentration using monolithic supports was improved in comparison to the one of tangential ultrafiltration upon application of both methods on a range of environmental samples. Several samples were successfully concentrated on-site after successful adaptation of the method to field requirements. In such on-site format, the combination of concentration using CIM and detection using RT-qPCR detected as low as 30 rotavirus particles/ml, spiked in an environmental water sample.
COBISS.SI-ID: 2291791