Detection and Molecular Epidemiology of Norovirus, Rotavirus and Human Astrovirus in Domestic Sewage

To assess the significance of environmental surveillance in the control and prevention of viral gastroenteritis, we analyzed the molecular characteristics of norovirus (NoV), rotavirus(RV),and human astrovirus (HAstV), sequences detected in domestic sewage. Environmental sewage monitoring sites were set up in three cities in Shandong, China. RNA was extracted from seven sewage samples collected each year from 2009 to 2015.RT-PCR detection of norovirus, rotavirus, and human astrovirus was performed. Positive PCR segments were cloned into a T-vector, transformed and sequenced, and genotyping and phylogenic analysis performed. A total of 210 viral sequences belonging to 6NoV I,4NoV II,3RV G,3RV P and 4HAstV were obtained.GI.2,GII.4,G9,P[8],and HAstV-1were the most frequently detected types. Phylogenetic analysis revealed multiple transmission chains in the genotypes of GI.3,GI.6,GII.4,G9,P[8],HAstV-1,and HAstV-4.The results showed not only that sewage contains dramatic information regarding gastroenteritis viruses, but also that environmental surveillance is an important approach in monitoring the regional circulation of specific viruses.