Occurrence of Enteric Viruses in Multi-Component Salad Bowls

The expansion of e-commerce and last-mile food delivery has created an increasingly relevant but understudied context for food safety surveillance. However, the occurrence of enteric viruses in ready-to-eat (RTE) foods within this distribution context remains largely unexplored. This study aimed to investigate the presence of enteric viruses in multi-component RTE salad bowls obtained through last-mile delivery. The study was designed to characterize the virological status of products received through this distribution pathway, without attributing any detected contamination specifically to the delivery process itself. A total of 30 salad samples were collected in two independent batches over a two-month interval via a third-party e-commerce platform and delivered directly to the laboratory. Virus concentration was performed using a method based on ISO 15216-1:2017, followed by RNA extraction and reverse transcription quantitative polymerase chain reaction (RT-qPCR) detection of norovirus (NoV) genogroups I (GI) and II (GII), hepatitis A virus (HAV), hepatitis E virus (HEV), human astrovirus (HAstV), and rotavirus (RV). HEV-target RT-qPCR signals were observed in 5 of 30 samples (16.7%); however, all positive signals corresponded to levels below the estimated limit of quantification (LOQ). No RT-qPCR amplification was observed for the other targeted viruses. This study provides initial occurrence data for enteric viruses in multi-component RTE meals obtained through last-mile delivery and supports the inclusion of this food category and emerging distribution pathways in foodborne virus surveillance.