Members of the public are still urged to stay away from University Hospital Llandough following an outbreak of the winter vomiting bug Norovirus.
Cardiff and Vale University Health Board, which first issued the warning on Saturday, said precautions will continue over the next few weeks in a bid to contain the spread.
Cardiff and Vale University Health Board is recommending people stay away from Llandough Hospital following an outbreak of norovirus.
Norovirus is an extremely common bug, which is not normally dangerous.
Cardiff and Vale University Health Board has warned that "the effects can be more serious" for ill and vulnerable patients.
Visitors have been asked not to go to University Hospital Llandough in Penarth unless absolutely necessary over the next few weeks, after an outbreak of norovirus.
Cardiff and Vale University Health Board says the so-called winter vomiting bug is affecting a number of patients on two wards at the hospital.
There is an urgent appeal for O negative blood donors to come forward after many people were taken ill over Christmas with the norovirus sickness bug.
The National Blood Service says because many donors contracted the disease they cancelled their appointments and stock levels went down.
Six wards have been closed to new patients at the Prince Charles Hospital in Merthyr Tydfil due to an outbreak of Norovirus. Cwm Taf Health Board say 'rigorous' control procedures are in place to prevent the spread of the virus.
Visitorsand staff are being asked not to come to hospital if they are displayingsymptoms or have suffered an episode of diarrhoea or vomiting in the last 48hours.
People with symptoms of the winter vomiting bug Norovirus are still being warned to stay away from hospitals to prevent it spreading.
Thirty-eight cases were confirmed over the weekend on 11 wards across North Wales.
Symptoms can include nausea and diarrhoea, fever, headache and aching limbs. The bug can last for between 12 and 60 hours.
38 patients in five hospitals in north Wales are experiencing symptoms related to the winter vomiting bug, norovirus.
Betsi Cadwaladr health board said that 11 wards are currently affected in Ysbyty Glan Clwyd, Colwyn Bay hospital, Ysbyty Gwynedd, Dolgellau hospital and Wrexham Maelor.