2008). In the present study, environmental samples from sewage and shellfish were analysed in order to evaluate the role of environmental surface water contamination as a possible route for transmission of RVs, NoVs and AdVs. Moreover, in order to study the similarity of viruses found in the environment and those causing clinical problems in the community, we compared environmental strains with clinical strains collected from children with symptoms of sporadic acute gastroenteritis in Monastir, Tunisia (Sdiri-Loulizi et?al. 2009a). The analysis of various physicochemical parameters of sewage treated Fulvestrant research buy
by the three STP showed that the three stations returned effluent conformed to the Tunisian standard NT106��02 (Sdiri-Loulizi. Submitted) and reduced organic pollution to acceptable levels. However, 43��3, 18��4 and 33��3% of treated sewage samples were positive for one of the enteric viruses in STP-1, STP-2 and STP-3, respectively. The viruses entering the STP are returned to Veliparib concentration
the environment, and could theoretically re-infect susceptible populations. Detection of enteric viruses in treated sewage reveals the difficulty in completely eliminating viruses utilizing present sewage treatment methods. Sewage treatment processes are only partially effective at removal of viruses, and discharge of STP effluents may constantly release human viruses into the marine environment. Once in the environment, viruses can survive for weeks and months, either in water or by attaching themselves to particulate matter and accumulating into sediments. The persistence of NoV in the environment can be attributed to the physical stability of the virions, while persistence of NoV in a population can be ascribed to low infectious dose of as few as 10 to 100 viral particles, prolonged asymptomatic shedding and great genetic and antigenic diversity (Hansman et?al. 2004; D��Souza et?al. 2006; Siebenga et?al. 2007). According to our data, STP2 had the highest enteric virus reduction rate (31 positive samples in raw sewage versus only seven in treated sewage, P?<?0��001), which can be explained by the technique used for sewage treatment. In fact, STP2 uses a process of activated and dehydration sludge, which is reported to be the most efficient technique for elimination <a href="http://www.selleck.cn/products/lgk-974.html
">LGK 974 of bacteria and enteric viruses (Schwartzbrod et?al. 1985; Hurst 1989). The detection rate of enteric viruses in our study (42��8%) was similar to the results described in other studies in Venezuela, France and Brazil (Arraj et?al. 2008; Miagostovich et?al. 2008; Rodriguez-Diaz et?al. 2009). In our study, RV was the most frequent virus detected in sewage samples (32%). Similarly, a clinical diarrhoeal disease survey in Tunisia revealed that RV was the most predominant viral agent responsible for infantile acute gastroenteritis (Sdiri-Loulizi et?al. 2008).