Health Minister Edwina Hart issued the warning after a spot check at Llandough Hospital, near Cardiff, by the Healthcare Inspectorate Wales (HIW).

It said wards had "a poor standard of cleanliness with high levels of dust".

The Cardiff and Vale University Health Board assured the HIW the issues identified would be addressed "as soon as possible".

The HIW said operating theatres, anaesthetic rooms and recovery areas had "an acceptable standard of cleanliness.

SPOT CHECK FINDINGS

• General standards of cleanliness in public corridors was poor and cluttered with equipment
• Beds were visibly dusty
• Some staff had not received infection control training in the last 12 months
• Staff had a tendency to over-rely on the use of gloves
• The visit was made as part of HIW's rolling programme of hospital visits.

It looked at the state of cleanliness on two wards for elderly patients and the operating theatre department.

A spokesman for the Wales Assembly Government said: "The Health Minister Edwina Hart expects the health board to consider the report carefully and take swift action to address concerns."

"The minister has warned the NHS that the spot checks will continue as we continue to improve cleanliness and infection control."

Llandough Hospital is currently undergoing a refurbishment programme.

The health board has two weeks to submit an improvement plan to HIW after the report has been published.