Mumps

What is mumps?

Mumps is a contagious viral infection caused by a type of virus called a paramyxovirus. It is spread in saliva, the same way as a cold or other upper respiratory tract infection. This means it can be caught from an infected person coughing, sneezing, etc or from touching infected objects, such as door handles.

Cases of the mumps infection have been less common since the introduction of the measles, mumps and rubella (MMR) vaccine in the UK. Mumps infection is now most common in children who have not received the vaccine. The MMR vaccine is given in two doses, one at a year old and the other in the "pre-school booster" at about 3 years 4 months. Both doses are essential to reduce risks. Whilst the risk of measles is reduced by 96% by the MMR vaccine, the risk of mumps is reduced by 86%.

It is very unusual for children aged under 1 year to have mumps.

The most common symptoms of mumps are:

• Painful swellings of one or both parotid glands are the usual main symptoms. The parotid glands are the main salivary glands which are just below the ears; they make saliva which drains into the mouth. They cannot normally be seen or felt but swelling of these glands can be very dramatic and make the face look puffy, sometimes called a 'hamster face'. These swollen glands usually last for 4-8 days.

• The mouth may feel dry.

• Chewing and swallowing may be sore.

• High temperature (fever), headache, feeling tired and being off food may develop for a few days. These symptoms may occur before you develop swelling of your parotid gland.

• Mild tummy (abdominal) pain may occur.

It is thought that about 3 in 10 people who contract the mumps virus have no symptoms.

Mumps is usually a mild illness but complications sometimes occur. This is why immunisation is important. Rarely, complications can develop without the usual symptoms occurring first.

The immune system makes antibodies during the infection. These clear the virus and then provide lifelong immunity. It is therefore rare to have more than one episode of mumps.

Mumps is very infectious. It takes 14-25 days to develop symptoms after being infected. Affected people are infectious from about six days before until about five days after a parotid gland begins to swell.

Although children immunised against mumps are much less likely to catch mumps, some adults may not be immune and some children may have a poor immune system (immunosupression).

So people with mumps should stay off school, nursery, college or work and avoid other people as much as possible. This is from as soon as mumps is suspected and for five days from the onset of parotid gland swelling.

Mumps is most commonly diagnosed by your symptoms and the type of glands that are swollen. However, since the introduction of the MMR vaccine, all cases should be confirmed by a sample (swab) taken from the mouth to obtain some saliva. This will be arranged by the Health Protection Agency - mumps is a "notifiable disease" which means they are informed of all suspected cases.

There is no medicine that kills the mumps virus. For most people infected by the mumps virus, their condition improves over a week with no long-term problems.

Treatment for mumps aims to ease symptoms until the body's immune system clears the virus:

• Treatment is not needed if the symptoms are mild.

• Paracetamol or ibuprofen can ease fever and pain.

• Children should be encouraged to drink plenty of fluids, particularly if they have a high temperature (fever). Fruit juice may stimulate the parotid gland to make more saliva, and cause more pain. Water is best if this occurs.

• A warm flannel held against a painful parotid gland can be soothing.

The outlook for young children with mumps is very good. Teenagers and adults with mumps are more likely to develop complications, which may include one (or more) of the following:

• The testicles (testes) are sometimes affected. One testicle (testis) may become inflamed, swollen and painful for about a week. This is uncommon in young children. However, about 1 in 4 males who get mumps over the age of 12 years will develop a painful swollen testis. Occasionally, both testes are affected. Half of these males affected will have a reduction in the size of the affected testicle and 1 in 10 will have a reduction in their sperm count (though infertility is uncommon).

• Brain inflammation (encephalitis or meningitis) is an uncommon complication. It typically causes drowsiness, headache, stiff neck, wanting to keep out of the light and being sick (vomiting). Although alarming, meningitis caused by the mumps virus usually clears without any treatment after a few days, without any long-term problems.

• Hearing loss can sometimes occur in people with mumps. This is usually only transient and usually improves with time. Very rarely, mumps can cause permanent deafness.

• Inflammation of the pancreas, heart and other organs are rare complications.

• Developing mumps in the first 12 weeks of a pregnancymay increase the risk of miscarriage. However, the mumps virus is not thought to cause malformations or defects in an unborn baby.

Most children are back to normal within 7-10 days. Medical help should be requested if a complication is suspected.

Mumps vaccine

An effective vaccine to prevent mumps is available. It is part of the MMR vaccine. This is routinely offered to all children aged 12-13 months in the UK. A second dose is offered as part of the routine preschool booster programme at between 3 years and 4 months to 5 years of age.

Catch-up programmes for older children have been offered during outbreaks.

A previous history of having mumps does not mean that you do not need an MMR vaccine because the clinical diagnosis may have been incorrect. (Mumps can sometimes be confused with other viral illnesses.) There is no harm from having the MMR vaccine if you have had mumps in the past.

Immunisation gives good protection, and so mumps is now rare in the UK. See the separate leaflet called MMR Immunisation for more details.