A study of enteric viruses in raw and treated sewage from two secondary treatment plants, which received sewage from Oslo city (plant A) and small municipalities in Hedmark county in Norway (plant B), showed high levels of noro-, adeno-, and bocavirus throughout the year. A seasonal variation was observed for adeno- and GII norovirus with higher levels during winter and bocavirus that had more positive samples during winter. The virus concentrations in raw sewage were comparable in the two plants, with medians (log10 genome copies per liter) of 6.1, 6.3, 6.0, and 4.5 for noro GI, noro GII, adeno-, and bocavirus, respectively. The level of hepatitis E virus was not determined as it was below the limit of quantification. The mean log10 virus reduction was 0.55 (plant A) and 1.44 (plant B) with the highest reduction found in the plant with longer hydraulic retention time. The adenoviruses were dominantly serotype 41, while serotype 12 appeared sporadically. Of the 102 raw and treated sewage samples that were tested, eight were positive for hepatitis E virus of which four were from treated sewage. Two of the four obtained gene sequences from hepatitis E virus originated from the rural sewage samples and showed high similarity with a genotype 3 strain of hepatitis E virus detected in local piglets. Two other hepatitis E virus sequences obtained from urban sewage samples showed high similarities with genotype 3 strains isolated from urban sewage in Spain and a human genotype 1 isolate from India. The study gives information on the levels of noroviruses in raw and treated sewage, which is valuable to risk assessment, information indicating that some infections with hepatitis E viruses in Norway have a regional origin and that human bocavirus 2 and 3 are prevalent in the Norwegian population.
Human bocavirus (HBoV) can cause respiratory diseases and is detectable in the stool samples of patients with gastroenteritis. To assess the prevalence of HBoV in children hospitalized with acute gastroenteritis in Novosibirsk, Russia, as well as its genetic diversity and the potential role in the etiology of gastroenteritis in this region, a total of 5502 stool samples from children hospitalized with gastroenteritis from 2010 to 2012, n=5250, and healthy children, n=252, were assayed for the presence of HBoV DNA by semi-nested PCR. The HBoV DNA was found in 1.2% of stool samples from children, with gastroenteritis varying from 0.5% in 2012 to 1.7% in 2011. The prevalence of HBoV in healthy children was 0.3%. HBoV strains were detected throughout the year with an increase in the fall-winter season. In 87% of cases, HBoV was detected in children before 1 year of age. All known HBoV genetic variants have been detected in Novosibirsk, although with different prevalences: HBoV2>HBoV1>HBoV4>HBoV3. At the beginning of 2011, HBoV2 replaced HBoV1 as the most prevalent variant. The median age of children with detected HBoV1 was 8.3months, and that with HBoV2 was 8.0 months. All HBoV-positive samples were assayed for the presence of the rotaviruses A and C, norovirus GII, astrovirus, enterovirus, adenovirus F, Salmonella spp., Campylobacter spp., Shigella spp., and EIEC. HBoV1 and HBoV2 as single agents were found in 45.8% and 60% samples, respectively, although this difference was not statistically significant. In the case of co-infections, HBoV was most frequently recorded with rotavirus A and norovirus GII. This study demonstrated that the detection rate of HBoV in stool samples from children with gastroenteritis was low, although both HBoV1 and HBoV2 could be found as the sole agents in children with gastroenteritis in Novosibirsk.
Human bocavirus (HBoV) was discovered in 2005 and is associated with respiratory tract symptoms in young children. Three additional members of the genus Bocavirus, HBoV2, -3, and -4, were discovered recently from fecal specimens, and early results indicate an association between HBoV2 and gastrointestinal disease. In this study, we present an undifferentiating multiplex real-time quantitative PCR assay for the detection of these novel viruses. Differentiation of the individual bocavirus species can be subsequently achieved with corresponding singleplex PCRs or by sequencing. Both multiplex and singleplex assays were consistently able to detect =10 copies of HBoV1 to -4 plasmid templates/reaction, with dynamic quantification ranges of 8 logs and 97% to 102% average reaction efficiencies. These new assays were used to screen stool samples from 250 Finnish patients (median age, 40 years) that had been sent for diagnosis of gastrointestinal infection. Four patients (1.6%; median age, 1.1 years) were reproducibly positive for HBoV2, and one patient (0.4%; 18 years of age) was reproducibly positive for HBoV3. The viral DNA loads varied from