Hepatitis E virus genotype 3 in echinoderms: First report of sea urchin (Paracentrotus lividus) contamination

Hepatitis E virus (HEV) deriving from manure application runoffs and faecal waste spill over of swine and human origin bypass wastewater treatment plants and contaminate coastal waters. Shellfish bioaccumulate enteric viruses such as HEV from fecally contaminated coastal waters and under current European Regulations, shellfish sanitary status surveillance is mandatory but only by means of bacterial faecal indicators. The sea urchins are under the same regulations and their vulnerability to fecal contamination has been pointed out. Since they are consumed raw and with no steps to control/reduce hazards, sea urchin contamination with enteric viruses can represent a food safety risk. Hence, the aim of the present study was to screen sea urchin gonads destined for human consumption for the presence of HEV. HEV was detected and quantified in gonads of sea urchins collected in north Portugal by a reverse transcription-quantitative PCR (RT-qPCR) assay targeting the ORF3 region, followed by genotyping by a nested RT-PCR targeting the ORF2 region. Sequencing and phylogenetic analysis clustered the HEV sequence within genotype 3, subgenotype e. This the first study reporting HEV contamination of sea urchins. We hypothesize that like shellfish, sea urchins can also be a food vehicle for HEV transmission to humans.