Mumps

What is mumps?

Mumps is an infection caused by a type of virus called a paramyxovirus. It is very contagious and spread in saliva, the same way as a cold or flu. This means it can be caught from an infected person coughing, sneezing, etc. Or, from touching infected objects, for example, door handles.

Mumps infection is less common since the introduction of the measles, mumps and rubella (MMR) vaccine in the UK. (See separate leaflet called 'MMR Immunisation' for more information.) Mumps infection is now most common in children who have not received the vaccine.

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

What are the usual symptoms of mumps?

• Swelling and pain of one or both parotid glands are the usual main symptoms. The parotid glands are the main salivary glands. They are just below the ears and you cannot normally see or feel them. The salivary glands make saliva which drains into the mouth.
• The mouth may feel dry.
• Chewing and swallowing may be sore.
• Fever (high temperature), headache, feeling tired and being off food may develop for a few days.
• Mild abdominal (tummy) pain may occur.

The swelling of the parotid glands usually lasts 4-8 days. Mumps is normally a mild illness, but complications sometimes occur. This is why immunisation is important.

There may be no symptoms, or only very minor ones. It is thought that about 3 in 10 people who contract the mumps virus have no symptoms. Rarely, complications alone occur without the usual symptoms occurring first.

You are most infectious from around two days before your symptoms develop to around nine days after your symptoms started. The immune system makes antibodies during the infection. These clear the virus and then provide lifelong immunity. It is therefore very rare to have more than one episode of mumps.

What are the possible complications of mumps?

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 testes (testicles) are sometimes affected. One 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 develops a painful swollen testis. Occasionally, both testes are affected. In very rare cases this may cause infertility.
• Brain inflammation (encephalitis or meningitis) is an uncommon complication. It typically causes drowsiness, headache, stiff neck, wanting to keep out of the light, and vomiting. Although alarming, meningitis caused by the mumps virus usually clears after a few days without any long-term problems.
• Hearing loss can occur in around one in twenty 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.
• If you develop mumps in the first 12-16 weeks of a pregnancy, it may increase the risk of miscarriage. (However, the mumps virus is not thought to cause malformations or defects in an unborn baby.)

How is mumps diagnosed?

Mumps is most commonly diagnosed by your symptoms and the type of glands that are enlarged in your body. However, some people have a swab taken from their mouth to obtain some saliva. This is sent to the laboratory to confirm the diagnosis.

What is the treatment for mumps?

There is no drug that kills the mumps virus. For most people, mumps improves over a week with no long-term problems.

Treatment aims to ease symptoms until the body's immune system clears the virus.

• You do not usually need any treatment if your symptoms are mild.
• Paracetamol or ibuprofen can be beneficial to ease fever and pain.
• Give children lots to drink, particularly if they have a 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.

When to seek medical help?

Most children are back to normal within 7-10 days. Seek medical help if you suspect that a complication is developing (described above).

Should people with mumps keep away from others?

Yes. Mumps is very infectious. It takes 14-21 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.

Children immunised against mumps are unlikely to catch mumps. However, immunisation is not 100% effective. Also, some adults may not be immune and some children may have a poor immune system. So, people with mumps should stay off school, nursery, college or work and avoid other people as much as possible. This is as soon as mumps is suspected and for five days from the onset of parotid gland swelling.

Mumps immunisation

An effective vaccine to prevent mumps is available. It is part of the MMR vaccine. This is routinely offered to all children aged 12-15 months in the UK. A second dose is offered as part of the routine pre-school booster programme at four years of age.

A previous history of having mumps does not mean that you do not need MMR vaccine. This is because the diagnosis of mumps is not an easy one to make. For example, someone thought to have had mumps may in fact have had another viral infection. Also, it does not do any harm if you have had mumps in the past and then have the MMR vaccine.

Immunisation gives very good protection, and so mumps is now rare in the UK. However, in recent years there has been an increase in the number of cases of mumps, usually seen in children who have not been immunised with MMR.

References

• Mumps, Clinical Knowledge Summaries (December 2009)
• Guidelines on Mumps, Health Protection Agency (various dates)
• Hviid A, Rubin S, Muhlemann K; Mumps. Lancet. 2008 Mar 15;371(9616):932-44. [abstract]
• Pearce A, Law C, Elliman D, et al; Factors associated with uptake of measles, mumps, and rubella vaccine (MMR) and BMJ. 2008 Apr 5;336(7647):754-7. Epub 2008 Feb 28. [abstract]