Detection and Molecular Characterization of Norovirus in Wastewater in New Orleans

Abstract

Norovirus is a leading cause of nonbacterial acute gastroenteritis worldwide and has significant morbidity and mortality in low- and middle-income, as well as high-income countries. The present study aimed to determine the genotype distribution of human noroviruses in influent and effluent wastewater at a wastewater treatment plant in New Orleans area. A total of fifteen norovirus genotypes belonging to three genogroups (genogroup I [GI], GII, and GIV) were detected. GI.6 and GII.12 were the most commonly detected norovirus genotypes, and were detected primarily in spring and summer. Three GI genotypes and one GII genotype were detected in effluent, with no apparent seasonal pattern. GII genotypes, which are responsible for the largest proportion of human gastroenteritis cases, were most frequently detected (54.29% of detected genotypes). Four genotypes (GI.1, GI.6, GII.12, and GII.4 Sydney) that cause the majority of human norovirus cases in the United States were detected. The results of the present study demonstrate the importance of environmental and molecular surveillance of norovirus in wastewater in order to mitigate human outbreaks from waterborne transmission, as well as other region-specific routes, such as the consumption of contaminated shellfish.