Norovirus GII.3[P12] Outbreak Associated with the Drinking Water Supply in a Rural Area in Galicia, Spain, 2021
Camille Jacqueline, Manuel del Valle Arrojo, Paloma Bellver Moreira, Maria Asunción Rodríguez Feijóo, María Cabrerizo, María Dolores Fernández-García
Abstract
Noroviruses are likely to be underrecognized in most suspected waterborne outbreaks. Therefore, effective norovirus detection and the early recognition of water as a possible source of infection are important to reduce morbidity as appropriate steps are taken to control the source. In our study, we combined epidemiological, environmental, and microbiological investigations to demonstrate that it was a waterborne outbreak caused by norovirus. Metagenomic sequencing in one norovirus-positive stool sample confirmed norovirus etiology and the absence of other potential pathogens. Detection of fecal indicator bacteria and the fact that the drinking water was not chlorinated suggest a breakdown in chlorination as the cause of the outbreak. This outbreak investigation also demonstrated the importance of timely communication to the public about the risk linked to tap water consumption.