An outbreak of the winter vomiting bug which forced hospital bosses to ban visitors from wards was caused by someone bringing mussels in for a patient, it has emerged.
Over Christmas, Northumbria Healthcare NHS Trust will partially lift the restriction on visitors, introduced after norovirus spread across a number of sites.
Officials have traced its spread to a visitor bringing in mussels for an inpatient at Wansbeck General Hospital in Ashington, Northumberland.
It is thought to have affected at least 180 people.
Shellfish can harbour the norovirus infection.
The trust said it was working hard to allow visitors in to see patients over Christmas.
On Friday, restrictions remained in place except for relatives of patients receiving end-of-life care.
The trust hoped to relax the rules on certain wards over the weekend.
Outpatient departments have not been affected.
For more information visit northumbria.nhs.uk