Kingston University students have been urged to attend emergency immunisation clinics this week, after 20 suspected cases of mumps were reported in the last month.

Five students have already been diagnosed with the highly contagious virus, which causes swelling of the neck and face, fever and earache, as well as deafness and severe abdominal pain in more serious cases.

In males over 12, it can lead to inflammation of the testicles and - in rare cases - sterility.

More cases at the university are suspected, leading to fears of a repeat of the last scare there in 2005, when 548 vulnerable staff and students were given emergency vaccinations.

The university has already sent a warning email to all campus-goers highlighting the risks of mumps and detailing how they can get protected at campus drop-in clinics.

One male student at the university who contracted the disease said severe tiredness and pain from inflammation in his body had left him heavily behind in his revision. The student, who wished to remain anonymous, said: "It was so painful, one of my testicles became inflamed and swelled up to at least three times the size - I had been vaccinated but still managed to catch it."

Dr Paul Crook, consultant in communicable disease control at the South-west London Health Protection Unit, said: "We are working closely with Kingston University to help prevent further cases of mumps. We strongly recommend that students at the university who have not been immunised with two doses of MMR take this opportunity to ensure they are adequately protected from the virus."

Laura Woods, a third year Kingston University student who has also contracted mumps, is now housebound during a vital stage in her university course.

She said: "It feels like a worse version of the flu, it makes you ache and feel really tired and run-down.

"I'm not allowed out of my house and can't go to lectures, which is not good with only two weeks to go."

Gill Deane, head of the university's health and counselling service, said: "We take the health of our students and staff very seriously and are confident that the steps we are taking working with the health protection unit will minimise the impact of the illness on campus.

"About 140 vaccinations have now been given and we would urge any students who have not been immunised to get in touch with their GP, or attend one of the drop-in immunisation sessions."

The final drop-in clinic will be open at the university between 6pm and 8pm on May 8.