Cambridge University Hospitals NHS trust, which runs Addenbrooke’s and the Rosie, is urging the public to stay away due to increased cases of norovirus and flu at the sites.

Visiting hours are now being restricted to 3pm to 5pm and 6.30pm and 8pm as a mark of the rise in escalation but the message is clear – if it’s not absolutely necessary for you to come to hospital please stay away.

Children are being told not to visit unless it is on compassionate grounds and if it has been agreed in advance by the ward manager.

A CUH spokesman said: “Four wards are currently affected by symptoms of norovirus and two by flu and measures are being taken to stop the spread of these highly contagious viruses.

“Anyone with norovirus symptons – diarrhoea and vomiting – should not visit the hospital, including the food areas, until they have been free from symptoms for 48 hours. “If you are unwell and require medical advice, please contact NHS 111 and only attend the hospital if advised or in an emergency.

CUH medical director Dr Ashley Shaw said: “The hospital has a clear escalation plan for infection control and we go out to the public when we need their help to control the spread of infection.

“Having an increased number of patients with norovirus and flu presents huge challenges around isolating infectious patients in a hospital that is already very busy.

“The public can play their part in helping us manage these outbreaks by staying away unless it is absolutely necessary to come to hospital.”