Occurrence of Norovirus, Rotavirus, Hepatitis a Virus, and Enterovirus in Berries in Argentina

Berries have been implicated as the probable vehicle of infection in multiple outbreaks of norovirus and hepatitis A virus (HAV). These foods often receive minimal or no processing and may be exposed to virus contamination at each stage of production. In an increasingly globalized world, berries have a wide distribution and can give rise to the spread of diseases in distant parts of the world. With the aim of describing the virological quality of the berries cultivated in Argentina, a total of 184 soft fruits of different varieties (strawberries, blueberries, raspberries, blackberries, currants, pomegranate arils, cassis, and elder) were collected during the periods 2016–2018 and 2020. Viral particles were eluted and concentrated by polyethylene glycol precipitation according to ISO 15216-2:2019 guidelines. Genome detection of norovirus (NoV) genogroups I (GI) and II (GII), HAV, rotavirus, and enterovirus was performed by real-time RT-PCR with TaqMan probes. Positive samples were amplified by conventional RT-PCR and the amplicons were purified and sequenced in both directions. Phylogenetic analysis was performed using the Neighbor-Joining method based on the evolutionary model Kimura-2-parameters. NoV GII.6 was detected in 1/184 (0.5%) of the soft fruits, corresponding to a raspberry sample obtained during the fall of 2017. No presence of other human enteric viruses was found in the other berries analyzed. The collected data are the first in Argentina in relation to the prevalence of enteric viruses in berries and is useful as reference data for a risk assessment of soft fruits as vehicles of foodborne pathogenic viruses.