An epidemiological study of enteric viruses in sewage with molecular characterization by RT-PCR and sequence analysis

Abstract

The aim of this study was to assess the presence and seasonal frequency of various enteric viruses in wastewater treatment. The detection of astrovirus, norovirus, enterovirus, hepatitis A virus (HAV) and rotavirus was carried out by molecular analyses in concentrated water samples collected over 18 months at the entrance and exit of an activated sludge sewage treatment plant. The reverse transcriptase-polymerase chain reaction (RT-PCR) results were confirmed by sequencing, and comparative phylogenetic analysis was performed on the isolated strains. Genomes of human astrovirus and human rotavirus were identified in 26/29 and 11/29 samples of raw sewage, respectively, and in 12/29 and 13/29 treated effluent samples, respectively. Some rotavirus sequences detected in environmental samples were very close to those of clinical strains. Noroviruses, enteroviruses and HAV were not detected during the study period. This could be related to the small sample volume, to the sensitivity of the detection methods or to local epidemiological situations.Frequent detection of viral RNA, whether infectious or not, in the exit effluent of sewage treatment indicates wide dispersion of enteric viruses in the environment. Consequently, viral contamination resulting from the use of these treated waters is a risk that needs to be addressed.

Detection and Characterization of Waterborne Gastroenteritis Viruses in Urban Sewage and Sewage-Polluted River Waters in Caracas, Venezuela

“…The detection of HuEVs and HAds allowed us to compare occurrence data of enteric viruses in Caracas and in sewage and sewage-polluted aquatic environments worldwide. Our results indicate a relatively high prevalence of HuEVs and HAds in the sewage-polluted waters of Caracas, similar to the results derived from other geographical regions (3,27,32,41,42,43,44,52). Overall, the most frequently detected viruses in the two set of samples analyzed were HuEVs, HRVs, and HAstVs.…”

Rotavirus Genotypes in Sewage Treatment Plants and in Children Hospitalized with Acute Diarrhea in Italy in 2010 and 2011

“…Only a few other studies compared rotavirus strains in samples from pediatric AGE patients and sewage in the same location and year (40)(41)(42)(43). In this study, RVA genotyping and phylogenetic analysis of common VP7 genotype G1, G2, G3, and G9 sequences showed high similarity between clinical and environmental strains.…”

One-year monthly survey of rotavirus, astrovirus and norovirus in three sewage treatment plants in Beijing, China and associated health risk assessment

“…The effluent with enteric pathogens from the sewerage systems, which directly entered into the water environment, was found to be one of the most important causes of waterborne outbreak (Hafliger et al 2000), therefore, Sewerage systems should be regarded as an important nodes to monitor and control human enteric pathogens transmission (Katayama et al 2008). Consequently, viral contamination resulting from the use of these treated waters will produce a risk that needs to be addressed (Arraj et al 2008). Information on the monthly concentration distribution of enteric viruses in sewage treatment plants (STPs) will be useful, not only for understanding their fate but also for assessing the risk of infection through different exposure scenarios (Katayama et al 2008).…”