MumpsBefore immunisation nearly everybody caught mumps, typically between 5 and 10 years of age. Mumps rarely causes anything more than a mild illness. One third of those who catch it do not get ill at all.
The incubation period (the time from contact with someone with the illness to the first signs of developing the disease) is usually 17-19 days but may be as long as four weeks.
Mumps typically causes a painful swelling of the salivary glands on the sides of the face under the ears. This may be accompanied by a fever, headache, weakness and sore throat. The whole illness usually lasts for 1-2 weeks. Though mumps is generally a mild illness, complications do occasionally occur. Mumps can cause meningitis, though mumps meningitis is not like the serious (bacterial) meningitis that can kill within 24 hours. It is nearly always harmless; the most children are likely to suffer is a mild headache and a stiff neck. Nearly all make a complete recovery.
Swelling of the testicles (orchitis) is rarely a problem before puberty, at around 12 years of age. However, around a quarter of males who contract mumps after puberty will get orchitis - a painful swelling of usually one, but occasionally both, testicles. However, it is extremely rare for this to cause infertility, partly because it is usually affects only one testicle.
About 1 in 3,000 children suffer from encephalitis - inflammation of the brain - and most make a full recovery. A permanent hearing loss may occur in about1 in 30,000 cases of mumps, more commonly in adults and less so in children.
Picture courtesy CDC