Students heading to university are being urged to ensure they are fully immunised against mumps as cases in the UK continue to rise.
Universities have called for students to be immunised against mumps
Doctors report around 1,800 to 2,000 suspected cases of mumps each week.
The latest outbreak is thought to be caused by adults, born before 1988 and not offered routine MMR cover, mixing at university.
The Health Protection Agency (HPA) is appealing to school leavers who have not been vaccined to get treatment.
There have already been large outbreaks of mumps in several colleges and universities.
It is estimated around 30% of first year students have not previously had two doses of the vaccine.
HPA figures show there were 46,124 notifications of suspected mumps cases in England and Wales in the first 30 weeks of 2005.
It compares to 5,154 notifications during the same period last year and 2,685 in 2003.
After laboratory tests around 60 to 75% of notifications for mumps are confirmed to be genuine cases.
Dr Rosemary McCann, the HPA's immunisation leader in the North West of England, said mumps was a nasty disease which could have serious side-effects, including deafness.
She said older teenagers and young adults who "missed out on the protection of two doses of MMR vaccine" were particularly vulnerable.
"When these youngsters mix and mingle in close proximity in universities or further education colleges, we can have real problems," she said.
She added the HPA "strongly supported" calls by university vice-chancellors that students should ensure they are properly vaccinated before entering further education this autumn.
Dr McCann said the MMR vaccine was "safe, proven and effective" and that two doses provided "lifelong protection".
In May experts writing in the British Medical Journal warned the UK was "in the grip of a nationwide mumps epidemic".
They reported the highest attack rate was among those born between 1983 and 1986.
There are also some cases in younger children due to the fall in uptake of the vaccine among infants.
This followed concern among parents after research in 1998 suggested a link between MMR and autism - a claim rejected by the vast majority of medical experts.