A report published by researchers from Glasgow Caledonian University has found presence of Hepatitis E Virus (HEV) in shellfish samples purchased from local supermarkets.

The samples that tested positive for the virus represent 2.9% of the 310 samples purchased. The virus was found in eight blue mussels and one oyster. The shellfish tested in the study were bought from four supermarkets in the Glasgow area and a fishmonger on the east coast, although the individual outlets have not been named.

It is the first time that HEV has been detected in commercially sold shellfish in Scotland.

The researchers hope that these findings may encourage further research that will help address the gaps in the knowledge in respect to foodborne transmission of HEV in Scotland and the rest of the United Kingdom.

The most recent figures from 2016 show the number of laboratory-diagnosed cases of HEV in Scotland increased to 206 from just 13 in 2011. Previous cases of HEV were linked to contaminated pork meat and soft fruit in Europe.

Prof Linda Scobie, principal investigator of the GCU study, said: "We don't know at what point in the food processing chain this contamination occurred.

"There are significant gaps in our knowledge with HEV in the UK, we don't know how much virus is required to cause infection, unlike the norovirus where you only need a few particles to cause acute illness.

"What we do know is more people are being diagnosed and if they have particular medical conditions then they are at risk of becoming very ill."

Unlike oysters, which are traditionally eaten raw, mussels are less likely to pose a risk of HEV infection to consumers because they are normally cooked before being eaten.

The authors, writing in the academic journal Food and Environmental Virology, said: "The present study is the first to demonstrate the occurrence of HEV in commercially harvested Scottish mussels sold at retail, albeit at low levels, 2.9%."