F. Lugoli

Rotavirus detection in environmental water samples by tangential flow ultrafiltration and RT-nested PCR.

Environmental monitoring was conducted in Otranto (Italy), from January 2006 to April 2007, to monitor the circulation of rotaviruses in various water matrices (raw and treated sewage, surface waters and seawater) and to identify any correlation with the traditional bacteriological indices (faecal coliforms). The viruses were detected using tangential flow ultrafiltration and reverse transcriptase-nested polymerase chain reaction, whilst detection of feaecal coliform was performed according to standard methods. The results showed widespread viral contamination, particularly in spring, of the matrices tested, with the exception of seawater, which at all times tested negative for the presence of rotaviruses. The typing of the rotavirus strains identified the circulation in the studied area of only two genotypes: G1 (22%) and G2 (78%). The bacterial recoveries confirmed the presence of faecal pollution indicators in all examined samples, sometimes with high values. A very weak correlation was found between the presence of faecal coliforms and the circulation of rotaviruses in the environment. The presence of rotaviruses in the environmental water samples may constitute a potential health risk for the local population.

Identification of HEV in symptom‐free migrants and environmental samples in Italy

Hepatitis E virus (HEV) is considered an emerging pathogen in industrialized countries. The occurrence of HEV genotypes in samples of faeces from asymptomatic migrants arriving on the coasts of South Italy and environmental samples was investigated. Analyses of sequences were used to compare human and environmental genotypes. A total of 40 stool specimens, 12 samples of untreated urban sewage, 12 samples of treated urban sewage and 12 samples of surface water were analysed. Viruses were concentrated from water samples by the tangential flow ultrafiltration technique. The presence of HEV RNA was detected by nested RT‐PCR. Viral isolates were sequenced and phylogenetically characterized. Two (5%) of the 40 faecal samples tested were found to be positive for HEV RNA (G1 and G3 genotypes). The virus was detected in 25% (3/12) of the untreated sewage samples and 25% (3/12) of the surface water samples: all isolates belonged to G3 genotype. None of the treated sewage samples were found to be HEV RNA positive. The virus was detected in the faeces of two asymptomatic subjects, suggesting a potential role for symptom‐free HEV carriers as a human reservoir. G3 HEV strains were detected in the untreated sewage, as observed in similar studies conducted in other European countries but differing from another study conducted in Italy recently. Moreover, our results show the first case of HEV isolated from fresh surface waters.

Enteric Viruses and Fecal Bacteria Indicators to Assess Groundwater Quality and Suitability for Irrigation

According to Italian Ministerial Decree No. 185 of 12 June 2003, water is considered suitable for irrigation if levels of fecal bacteria (i.e., Escherichia coli and Salmonella) are within certain parameters. The detection of other microorganisms is not required. The aim of this study is to determine the bacteriological quality of groundwater used for irrigation and the occurrence of enteric viruses (Norovirus, Enterovirus, Rotavirus, Hepatovirus A), and to compare the presence of viruses with the fecal bacteria indicators. A total of 182 wells was analyzed. Widespread fecal contamination of Apulian aquifers was detected (141 wells; 77.5%) by the presence of fecal bacteria (i.e., E. coli, Salmonella, total coliforms, and enterococci). Considering bacteria included in Ministerial Decree No. 185, the water from 35 (19.2%) wells was unsuitable for irrigation purposes. Among 147 wells with water considered suitable, Norovirus, Rotavirus, and Enterovirus were detected in 23 (15.6%) wells. No Hepatovirus A was isolated. Consequently, 58 wells (31.9%) posed a potential infectious risk for irrigation use. This study revealed the inadequacy of fecal bacteria indicators to predict the occurrence of viruses in groundwater and it is the first in Italy to describe the presence of human rotaviruses in well water used for irrigation.