Young people new to university are at risk of viral infections

GP Phil White said he has seen more cases in the past month than for the whole of 2002 and 2003 combined.

He said the cases were youngsters who had not had a booster MMR jab and many had also attended this year's Eisteddfod, where it could have spread.

An Eisteddfod spokeswoman said no illness was reported at the festival.

Dr White said there was "anecdotal evidence" that some of the cases could be linked to the National Eisteddfod which was held earlier this month on the Faenol Estate.

But he blamed the Wales-wide drop in MMR vaccine uptake for the cluster of mumps cases at the surgeries he takes at Felinheli and Menai Bridge, Gwynedd.

Mumps facts Mumps is an acute viral illness transmitted by contact with saliva from infected people Symptoms begin with a headache and fever for a day or two before swelling of the parotid glands Rarely, mumps has been linked with sterility in adolescent and adult males

By April this year, almost 1,400 cases had been reported to the Health Protection Agency compared to 1,700 cases for the whole of 2004.

Public health experts warned that many of the cases were among young people who had missed the combined measles, mumps and rubella vaccination, which was introduced in 1988.

Dr White said: "It could not be anything to do with the Eisteddfod but anything which makes youngsters congregate together gets these things going.

Universities want students to be vaccinated against mumps

"The MMR vaccine level has dropped in the very little ones and they are age group which usually gets the mumps.

"It's raging like wildfire through the infants and youngsters, and big brothers and sisters get it because they have only part immunity.

"Some of these older children are between 15 and 20 and have had only had one MMR vaccination and their second, booster vaccine was only an MR jab - for measles but not mumps."

He said young people going to college or university next month should check whether they had received a second MMR jab.

A spokeswoman for the National Eisteddfod said: "We had a doctor on site and we had no cases were reported during the course of the festival."