Epidemiological surveillance of human enteric viruses by monitoring of different environmental matrices. Water Science and Technology, 54(3), 239-244

Department of Experimental Pathology, Medical Biotechnologies, Infectology and Epidemiology, University of Pisa, via S Zeno 35, 56127 Pisa, Italy.
Water Science & Technology (Impact Factor: 1.11). 02/2006; 54(3):239-44. DOI: 10.2166/wst.2006.475
Source: PubMed


In the aim of studying possible relations between viruses detected in clinical specimens and the ones found in different environmental matrices, in the period May 2004 to April 2005, the collection of faecal samples from gastroenteritis cases and the monthly monitoring of raw and treated wastewater, river water, seawater and mussels were carried out. The viruses considered for environmental monitoring were adenovirus, rotavirus, enterovirus, norovirus, hepatitis A virus (HAV) and Torque teno virus (TTV): they were searched for with PCR and RT-PCR and confirmed by gene sequencing. Faecal coliforms and somatic coliphages' counts were also determined. The surveillance of case detected 45 positive faecal samples out of 255 (17.6%) while 35 of 56 environmental samples (62.5%) resulted positive for at least one of the considered viruses. The detection of the same viral strain in the faeces of gastroenteritis cases and in water was possible for adenovirus and rotavirus, which were also predominant in environmental matrices; thus they could be considered as a reference for risk assessment.


Available from: Marco Verani, Mar 03, 2015
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    • "The WWTP was monitored routinely for the presence of several human viruses in inflow and outflow waters, primarily for surveillance purposes. Sampling periods were chosen according to previous clinical and environmental data (Carducci et al. 2006). Particular attention was paid to winter and spring months, which are characterized by higher circulating gastroenteritis viruses and by greater meteorological variability. "
    [Show abstract] [Hide abstract] ABSTRACT: The purpose of wastewater treatment is to minimize chemical and microbial contamination of recipient waters. The present study evaluated the impacts of meteorological variables, such as temperature and rainfall, on the removal of human viruses and indicators by a wastewater treatment plant servicing Pisa, Italy. Data were obtained during four sampling campaigns from 2007 to 2010. Wastewater sewage samples were analyzed for human adenovirus (HAdV) and norovirus using quantitative molecular techniques. In parallel, Escherichia coli, enterococci and somatic coliphages were measured, and meteorological and chemical data were recorded. We detected a continuous presence of HAdV in both influent and effluent samples with an average removal rate of 2.01 log Genomic Copies/l. An association between meteorological parameters and viral removal rates was detected only for rainfall and HAdV removal during a specific sampling campaign. No correlation was found between viral data and microbial, chemical and physical ones. Viral removal rates were not strongly influenced by meteorological conditions and were unrelated to other process indicators routinely monitored. Our results suggest that HAdV is a suitable parameter to assess the viral removal efficiency of wastewater treatment plants, particularly in the case of heavy rainfall.
    Full-text · Article · Mar 2013 · Food and Environmental Virology
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    • "TTV has been detected in serum, saliva, breast milk, tears, semen and cervical smears, and has been shown to be secreted via bile [Okamoto et al., 1998; Ukita et al., 1999] into feces [Ross et al., 1999; Lin et al., 2000; Matsubara et al., 2000; Braham et al., 2009], where the virus was visualized by electron microscopy [Itoh et al., 2000]. As a consequence of TTV excretion, the virus has been reported in sewage [Vaidya et al., 2002; Haramoto et al., 2005b; Carducci et al., 2006, 2008] and even in rivers [Haramoto et al., 2005a; Carducci et al., 2006; Diniz-Mendes et al., 2008]. Whether all five TTV genogroups are excreted in feces and the frequency of these events are presently unknown. "
    [Show abstract] [Hide abstract] ABSTRACT: Torque teno virus (TTV, genus Alphatorquevirus, family Anelloviridae) is a DNA virus, highly prevalent in populations from around the world. TTV isolates have been classified into five main phylogenetic groups (1-5) showing a large genetic distance between them. The presence of TTV has been detected in feces. However, whether all five TTV genogroups are excreted in feces and the frequency of these events are presently unknown. The presence of TTV DNA was assessed in feces from 135 Brazilian (0-90 years old) patients with gastroenteritis by using three PCR methods, including real-time PCR. One hundred twenty one (91.1%) samples were positive with at least one method. Using a genogroup-specific assay, it was shown that all genogroups were present. Thirty-seven (27.4%), 27 (20.0%), 57 (42.2%), 29 (21.5%), and 33 (24.4%) fecal samples contained TTV isolates belonging to genogroups 1-5, respectively. Coinfections with two, three, four, and five TTV genogroups were found in 23 (17.0%), 15 (11.1%), 7 (5.2%), and 7 (5.2%) fecal samples, respectively. Thus, 52 (38.5%) samples contained more than one TTV genogroup. Viral loads ranged from 2.6 to 6.5 log genome equivalents per gram of feces. However, only moderate variations of viral load were noted depending on genogroup and number of coinfecting TTV genogroups. These results show a high prevalence and a diversity of TTV isolates in feces.
    Full-text · Article · Jun 2011 · Journal of Medical Virology
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    • "A close genetic relationship was observed among sewage and clinical viral isolates showing that viral strains could have been disseminated into the environment. Thus, they could be considered as a reference for risk assessment (Carducci et al. 2006; Villar et al. 2007). The analysis of nucleotide sequence variations in environmental isolates can provide useful information for addressing epidemiological questions, such as pathways for viral spread, since several studies have suggested that different sequences may be related to the geographical origin of the virus (Morace et al. 2002). "
    [Show abstract] [Hide abstract] ABSTRACT: The effluents of a sewage treatment plant may contain infectious human viruses representing a major public health issue. In the present study, an 8months survey was conducted in order to evaluate the presence of enteroviruses (EV), adenoviruses (AdV), and hepatitis A viruses (HAV) in untreated and treated sewage samples collected from a primary treatment municipal wastewater plant, located in the northeastern Greece. Reverse transcriptase-polymerase chain reaction (RT-PCR) and nested polymerase chain reaction techniques have been applied for viral nucleic acid detection. Positive samples were confirmed by sequencing, and comparative phylogenetic analysis was performed on the isolated viral strains. EVs, AdVs, and HAV have been detected in 40% (10/25), 40% (10/25), 4% (1/25) of the samples collected from the plant’s inlet, and in 12% (3/25), 44% (11/25), 0% (0/25) of the samples collected from the plant’s outlet. Adenovirus types 3 (Ad3), 10 (Ad10) and 41 (Ad41), and hepatitis A virus type H2 have been recognized, while for enteroviruses Coxsackie type A2 and Echovirus types 27 and 30 have been recorded. The results suggest that treated sewage may still contain human viruses and thereby represent a potential health hazard. Moreover, their possible reuse in agriculture or elsewhere must be considered with concern. Furthermore, this study shows the usefulness of molecular methods for virus detection, typing and virological quality analysis of sewage treatment plants. KeywordsWastewater-Enterovirus-Adenovirus-Hepatitis A virus-Virus detection
    Full-text · Article · Jun 2010 · Food and Environmental Virology
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