A day nursery housing 50 children was shut down temporarily after three girls contracted the most deadly form of the illness.

Health officials revealed later that a fourth child, who did not attend the nursery, had also been taken ill.

The three children, aged 15 months, two and three, attend the Ladybird nursery in Fenstanton, Cambridgeshire.

They are in a stable condition after contracting the meningococcal form of meningitis over the weekend. Two are being treated at Addenbrooke's Hospital, Cambridge and the third at Hinchingbrooke Hospital, Huntingdon.

The fourth child is also under five years of age, but other details have yet to be released.

Ladybird nursery has been closed for a week on the advice of doctors. Other children and staff at the school are being treated with antibiotics as a precaution.

Nightmare

The owner of the nursery, Mary Crosby, said: "It is a nightmare. The very mention of the word meningitis instils fear into the hearts of parents and quite rightly so because it carries such a high mortality rate.

"We have closed for a week and are working very closely with the public health authorities. The parents have been very sensible and very responsible.

"One of the children in hospital is my nephew's little girl so this is very close to home."

Parents with children at the nursery, which caters for children aged between three months and five years old, have been sent advice on how to spot danger signs.

These include:

• Severe headache that is not relieved by normal pain relievers;
• Stiff neck characterised by an inability to put your chin on your chest;
• Extreme dislike of bright lights;
• A rash of red or purple spots or blotches that does not fade when pressed firmly with a clear drinking glass;
• Extreme drowsiness;
• The patient appears to faint on trying to sit or stand.

Other local schools and children's groups in the area have also been alerted.

The incidence of meningococcal disease - meningitis and septicaemia - is now at a record high in the UK with 2,660 reported cases and 243 deaths in 1997.

The disease kills more children between the ages of one and four than any other single cause of death.

'No epidemic'

Dr Roger Buttery, is communicable disease controller for the Cambridgeshire and Huntingdon Health Commission.

He said: "It is a large number. It is the first outbreak of more than two cases in one school in Cambridgeshire since I have been working here. That's 15 years."

Infections spread easily in environments such as nurseries

"We suspect that one person who is carrying disease has possibly had a cold and come into contact with the children."

He added: "It is a major worry. Our concerns now are that these children recover and there are no more cases. All parents have been sent letters advising them what to look for and advised to see their GP if they have any worries."

Dr Buttery said there was no suggestion that Cambridgeshire was in the grip of an epidemic. He said figures showed there had been one case a week in the county on average this year, which is less than the national average.

"I'm sure this is just a blip - although a worrying one - probably caused by children coming into contact with a carrier," he added.

"That carrier may have been a member of staff or a parent or a relative. It's very hard to tell."