49 patients at Ysbyty Gwynedd in Bangor have tested positive for coronavirus linked to an outbreak of the virus within the hospital.
The hospital currently has 75 patients with Covid-19, but over half of those cases have been connected to the outbreak which is effecting five adult wards.
A programme of testing for both staff and patients is currently underway, with warnings that more cases within the hospital are likely to be found.
Dr Karen Mottart, Medical Director at Ysbyty Gwynedd, said: ''As we continue with a programme of additional testing, we expect to find more cases in patients and staff who are not currently symptomatic. This approach will help us build an accurate picture of the current situation, enabling us to safely manage patients and prevent any unknown potential transmission.
“The virus is still circulating in our communities, and with the new variants that are more transmissible, more patients with COVID-19 have been admitted into our hospitals than at any other time during the pandemic.
"A significant risk is that a patient can test negative for COVID-19 while the virus is in its incubation period, and then test positive after being admitted to hospital. All hospitals face the challenge of balancing the risk of infection while providing care for those who need it.
“Please help us to reduce the risk of infection by only attending our hospital sites if it is absolutely necessary. Visiting remains restricted, except for limited circumstances, but people should continue to attend appointments unless they are told otherwise.”
All those who have tested positive are being isolated in line with Public Health Wales policies.