To determine the prevalence of Hepatitis E virus (HEV) in industrialized nations, we analyzed the excretion of HEV strains by the populations of Spain, France, Greece, Sweden, and the United States. Twenty of 46 (43.5%) urban sewage samples collected in Barcelona from 1994 to 2002 tested positive for HEV. We identified 15 HEV strains, which were similar to two HEV isolates previously described in Barcelona in clinical samples and to strains from diverse geographic HEV-nonendemic areas. We also identified two HEV strains in sewage samples from Washington, D.C., and Nancy, France; these samples were also positive for Hepatitis A virus. In addition, we studied the role of pigs as a reservoir for HEV and identified one new swine HEV strain. Our results suggest that HEV may be more prevalent than previously considered in industrialized countries and that variants of the virus circulate simultaneously in one region.

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A novel and simple procedure for concentrating adenoviruses from sea water samples is described. The technique entails the adsorption of viruses to pre-flocculated skimmed milk proteins, allowing the flocs to sediment by gravity, and dissolving the separated sediment in phosphate buffer. Concentrated virus may be detected by PCR techniques following nucleic acid extraction. The method requires no specialized equipment other than that usually available in routine public health laboratories, and due to its straightforwardness it allows the processing of a larger number of water samples simultaneously. The usefulness of the method was demonstrated in concentration of virus in multiple seawater samples during a survey of adenoviruses in coastal waters.

The mechanism of human-to-human transmission of the polyomaviruses JC virus (JCV) and BK virus (BKV) has not been firmly established with regard to possible human exposure. JCV and BKV have been found in sewage samples from different geographical areas in Europe, Africa, and the United States, with average concentrations of 10 2 to 10 3 JCV particles/ml and 10 1 to 10 2 BKV particles/ml. Selected polyomavirus-positive sewage samples were further characterized. The JCV and BKV present in these samples were identified by sequencing of the intergenic region (the region found between the T antigen and VP coding regions) of JCV and the VP1 region of BKV. The regulatory region of the JCV and BKV strains found in sewage samples presented archetypal or archetype-like genetic structures, as described for urine samples. The stability (the time required for a 90% reduction in the virus concentration) of the viral particles in sewage at 20°C was estimated to be 26.7 days for JCV and 53.6 days for BKV. The presence of JCV in 50% of the shellfish samples analyzed confirmed the stability of these viral particles in the environment. BKV and JCV particles were also found to be stable at pH 5; however, treatment at a pH lower than 3 resulted in the detection of free viral DNA. Since most humans are infected with JCV and BKV, these data indicate that the ingestion of contaminated water or food could represent a possible portal of entrance of these viruses or polyomavirus DNA into the human population.JC virus (JCV) and BK virus (BKV) are nonenveloped, icosahedral viruses with double-stranded, negatively supercoiled, circular DNA genomes of approximately 5.13 kb. The polyomavirus genome consists of an early region, a late region, and a regulatory region (RR) containing promoters, enhancers, and the replication origin. The genome is transcribed bidirectionally from the origin. It codes for the early region proteins (large T and small t antigens) that regulate the transcription of the late region proteins (VP1, VP2, VP3, and agnoprotein). JCV and BKV are associated primarily with progressive multifocal leukoencephalopathy (PML) and hemorrhagic cystitis, respectively, and a role for these viruses in human cancer has been suggested (23). Both viruses are found at high frequencies throughout most human populations, and their pathogenicity, which is associated primarily with immunocompromised states, has attracted more attention due to the immunosuppression associated with AIDS. As determined by seroconversion, primary infection with BKV occurs early in childhood, while JCV infection occurs slightly more toward adolescence (17, 36, 51). Initial infection is not apparent and rarely causes clinical disease, although respiratory symptoms or urinary tract disease is sometimes found in the case of BKV (18,21,37). JCV and BKV can be detected in tonsillar tissue (19,32), and the hypothesis that the respiratory tract is the primary site of viral infection has been suggested. After the initial infection, the virus disseminates and establishes a p...

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