The majority of people under the age of 13 are protected after the MMR immunisation of infants was introduced in the UK in 1988. People over 25 are expected to have developed natural immunity.

However, those aged 13 to 25 are unlikely to have natural immunity and are too old to have benefited from the vaccination.

Mumps is caused by a virus, which is spread in the course of normal social contact and those aged 17 to 20, mixing with others in educational settings, have been found to be most at risk.

Mumps can cause great discomfort and, in a small number of cases, there may be serious complications. Early signs include fever, loss of appetite, aches and headache followed by swelling of the glands under and in front of the ear, usually starting on one side before moving to the other.

“We keep a close eye on the incidence of mumps in Tayside and it is apparent there has been a slow but steady rise in the number of confirmed cases of infection,” said Christopher McGuigan, NHS Tayside Department of Public Health. “It is important to stress the numbers of people affected are still quite small. However, we believe it is appropriate to make people aware of the increase. Students aged 17 to 20 who have not had mumps should consider contacting their GP.”

Government figures last month showed uptake of the MMR vaccine continues to fall short of targets. Only 88% of two-year-olds are receiving the injection — the same as the previous quarter and below the 95% target. In contrast, rates for vaccinations against other childhood diseases, such as diphtheria, were above 95%.

The three-in-one vaccine has been blamed by some for the rise in childhood autism although a link has never been proved and 10 of the authors of a paper which raised fears of a possible link have issued a partial retraction.

Between November 2003 and June this year, the Scottish Centre for Infection and Environmental Health confirmed 681 cases of mumps across the country, compared to just 13 cases last year.