AIMS: This study investigates enteric viruses in wastewater during an outbreak of acute hepatitis caused by hepatitis A virus (HAV) in a large metropolitan area. Emphasis is given to caliciviruses and hepatitis A virus. METHODS AND RESULTS: Metagenomic analysis was performed to characterize enteric viruses excreted by the population of Detroit MI, during a hepatitis A outbreak that occurred in 2017 and 2018. Additionally, hepatitis A virus (HAV), norovirus GII, and sapovirus were quantified, using qPCR, in 54 untreated wastewater samples collected over the course of four months. Correlation analysis was performed to identify associations between the number of disease cases and HAV concentrations in wastewater. HAV obtained the highest relative abundance among other enteric viruses detected in wastewater metagenomes. Metagenomic analysis also detected several other enteric viruses including astrovirus, enterovirus, and hepatitis E virus. Average sapovirus concentrations of 1.36x106 gc l-1 were significantly greater than norovirus GII concentrations (2.94x104 gc l-1 ). Additionally, norovirus GI and GII along with sapovirus GI.1 were detected using metagenomics. HAV loads in wastewater were significantly correlated with the number of disease cases reported one week after wastewater sampling. CONCLUSIONS: Surveying untreated wastewater is a promising method for detecting early signs of hepatitis A outbreaks and for routine environmental monitoring of enteric viruses circulating in the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Authors demonstrate the usefulness of metagenomics for genogrouping and enteric viral surveillance. This article is protected by copyright. All rights reserved.
AIMS: This study investigates enteric viruses in wastewater during an outbreak of acute hepatitis caused by hepatitis A virus (HAV) in a large metropolitan area. Emphasis is given to caliciviruses and hepatitis A virus. METHODS AND RESULTS: Metagenomic analysis was performed to characterize enteric viruses excreted by the population of Detroit MI, during a hepatitis A outbreak that occurred in 2017 and 2018. Additionally, hepatitis A virus (HAV), norovirus GII, and sapovirus were quantified, using qPCR, in 54 untreated wastewater samples collected over the course of four months. Correlation analysis was performed to identify associations between the number of disease cases and HAV concentrations in wastewater. HAV obtained the highest relative abundance among other enteric viruses detected in wastewater metagenomes. Metagenomic analysis also detected several other enteric viruses including astrovirus, enterovirus, and hepatitis E virus. Average sapovirus concentrations of 1.36x106 gc l-1 were significantly greater than norovirus GII concentrations (2.94x104 gc l-1 ). Additionally, norovirus GI and GII along with sapovirus GI.1 were detected using metagenomics. HAV loads in wastewater were significantly correlated with the number of disease cases reported one week after wastewater sampling. CONCLUSIONS: Surveying untreated wastewater is a promising method for detecting early signs of hepatitis A outbreaks and for routine environmental monitoring of enteric viruses circulating in the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Authors demonstrate the usefulness of metagenomics for genogrouping and enteric viral surveillance. This article is protected by copyright. All rights reserved.