LONDON - England and Wales are in the grip of a mumps epidemic affecting mostly adolescents and young adults, scientists said on Friday.
More than 5,000 cases of the disease, which causes swelling and pain in one or both of the salivary glands, have been reported in the first fivemonths of 2005.
Last year there were 16,436 sufferers -- four times as many as the previous year.
"The current mumps outbreak has been predominantly in older teenagers and young adults, who have not been offered two doses of MMR," said Emma Savage of the Health Protection Agency, referring to the controversial triple measles, mumps and rubella (MMR) vaccination.
Cases of mumps fell after MMR was introduced in 1988, and the highest outbreak of new cases is in people born between 1983 and 1986, who were too old to be offered the MMR jab.
"This confirms the effectiveness of the current vaccination policy," Savage and her colleagues said in a report in the British Medical Journal.
In a separate study in the journal, Ravindra Gupta and colleagues at St Thomas' NHS Foundation Trust in London warned that younger children could also be at risk because of a fall in MMR vaccinations in two-year-olds.
Uptake of the triple jab dropped from around 92 per cent in 1995 to about 80 per cent in 2003-04 after parents began boycotting it because a study suggested a link to autism or bowel disease. Fears about the safety of the MMR jab have persisted despite a review of the medical evidence which found no link with autism. The British government and the World Health Organisation have also said the vaccination is safe.
"This epidemic underlines the importance of ensuring that all children and young adults have received two doses of MMR," Gupta added.
Most cases of mumps are mild, but when complications occur they can be serious.
Britain's National Health Service (NHS) says about one in four adolescent boys or adult men with mumps develop an inflammation of one or both testes, which can be very painful.
If it affects both testes, there is some evidence to suggest it may lead to sterility, the NHS said on its website.
