CIDRAP Norovirus can be accurately tracked in wastewater samples, which can help identify outbreaks and trends, according to a new study based on California wastewater surveillance published in Emerging Infectious Diseases.
Norovirus is one of the leading causes of gastroenteritis in the United States, but surveillance is challenging because many cases are unreported, the authors said. As wastewater surveillance has proved useful and accurate for viral detections, including COVID-19, the researchers assessed its usefulness for norovirus.
The authors collected wastewater data from December 17, 2022, through December 17, 2023, from 76 California wastewater utilities, as part of the WastewaterSCAN program.
The authors looked for norovirus viral RNA from wastewater samples and compared findings with Centers for Disease Control and Prevention National Respiratory and Enteric Virus Surveillance System (NREVSS) norovirus test positivity at the national and western US regional level.
Activity peaked in Southern California in February
That data was then cross-referenced with California Norovirus Laboratory Network (NLN)–confirmed GII norovirus outbreaks, which are published monthly.
“We observed positive, statistically significant (p<0.001), moderate-to-strong correlations between California regional and statewide wastewater aggregates and US national and western regional NREVSS test positivity,” the authors said.