Mumps (090)

Epidemic Parotitis • Parotitis

The Facts

Mumps is a viral infection of the salivary glands, especially the parotid glands that run along the angle of the jaw in front of and below each ear. Children between the ages of 5 and 10 are most likely to contract mumps. Being infected once gives you lifelong immunity.

Mumps is most common around the month of March. It usually appears in scattered individual cases, though there are occasional local epidemics among unvaccinated children. It's less infectious than chickenpox or measles. Unvaccinated adults who never had the disease are at much higher risk of complications than children, but mumps rarely causes serious problems.

A vaccine for mumps dramatically reduced the incidence of the disease since its introduction in 1967. In the 1950s, Canada had about 30,000 cases a year. With the advent of the vaccine the number of reported cases dropped by 99%.

Causes (1, 2, 4, 5)

Mumps is caused by an organism called a paramyxovirus. It's transmitted via the mouth by tiny drops of saliva from talking, sneezing, sharing drinks, kissing, or coughing. The virus can land on an object that others then handle. Once it's on your hand, there's a good chance it will find its way into your mouth, especially if you're a young child.

Mumps is contagious for about a week before the glands swell, and about 9 days afterwards, so people can transmit it before they know they have it. This is common for most viral diseases.

Symptoms and Complications (4, 5)

Up to one-third of people infected feel no symptoms. Others have a low-grade fever, headache, weakness, fatigue, and loss of appetite starting 14 to 24 days after they are actually infected.

About a day after the onset of fever, the parotid gland near the ear begins to swell and ache – this makes chewing and swallowing painful. The body's temperature rises to 39.5°C to 40°C (103°F to 104°F).

The swelling and tenderness worsens over the next 3 days and may extend forward of the jaw and, for some, down the neck, depending on whether other salivary glands are involved. In the majority of mumps cases, both the right and left parotid glands are swollen. The fever typically lasts only 1 to 3 days but can persist for a week. The swelling of the glands tends to resolve after about one week.

That's usually as far as it goes, even in adults. 1 in 5 adolescent or adult males, however, suffers orchitis, an infection and inflammation of the testicles. This can be very painful, but it almost never results in sterility. Women can get an infection in the ovaries, but it's mild and harmless.

1 in 30 people infected get pancreatitis (inflammation of the pancreas) with vomiting and abdominal pain that quickly clears up. A similar number develop hearing problems due to otitis media, which is also a temporary side effect of mumps.

Any viral disease carries some risk of severe complications like encephalitis (brain inflammation) or meningitis (inflammation of the membranes around the brain and spinal cord) during or after the initial infection. The risk of developing encephalitis with mumps is about 1 in 5,000, and for meningitis the risk is 1% to 10%. There is a very small risk of miscarriage in women who get infected while pregnant.

Making the Diagnosis (4, 5)

The blood test to detect mumps is fairly complex and time-consuming. Although any family doctor can recognize most cases of mumps by physical examination, blood testing is done for public health reasons, especially since there are some other viruses that can cause symptoms similar to mumps. A spinal tap may be done for people who shows symptoms of meningitis or encephalitis.

Treatment and Prevention

Mumps is caused by a virus, and we can't cure viral diseases. Fortunately, our immune system can deal with mumps, so the treatment for mumps is to wait for it to go away. Eating soft foods and avoiding acidic foods such as orange juice can help cope with the symptoms.

You can fight fever, headache, and muscle pains with acetaminophen* or ibuprofen. Never give acetylsalicylic acid (ASA) to children with a viral infection, as its use in these circumstances is linked to a dangerous condition called Reye's syndrome.

Orchitis (swelling of the testicles) requires bed rest for a day or two. Letting the testicles hang increases swelling, so they should be propped up. A tape bridge between the thighs may help, as may an ice pack wrapped in a towel.

You can easily prevent mumps with the highly safe and effective measles, mumps, and rubella (MMR) vaccine. It is usually given to children after 1 year of age, just when they're starting to lose the natural immunity that is transmitted from their mother prior to birth. Many programs give boosters a few months or years later, usually before a child begins school.

It's recommended that unvaccinated young adults get immunized. Older adults are almost certain to be immune. If you lived as a child with a sibling who had mumps, you can assume you're immune. The vast majority of adults are immune. You can also help prevent mumps by avoiding contact with people who have mumps, washing your hands regularly, and not sharing drinks.

If you are thinking of getting pregnant and have never had the disease or an MMR shot, you should be vaccinated before getting pregnant. Talk to a doctor about your options.

*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.

[references]

1. General information on Mumps. Public Health Agency of Canada. [Online] 2008 Mar 13. [cited 2010 Apr 14]. Available at URL: http://www.phac-aspc.gc.ca/mumps-oreillons/index-eng.php#occur
2. Facts About Mumps For Adults. National Foundation for Infectious Diseases [Online] 2009 Aug. [cited 2010 Apr 14] Available from URL: http://www.nfid.org/pdf/factsheets/mumpsadult.pdf
3. Mumps. Canadian Immunization Guide 6th ed. 2006. http://www.phac-aspc.gc.ca/publicat/cig-gci/index-eng.php
4. Gershon, A. Mumps. In: Harrison's Principles of Internal Medicine. 17th ed. [Online]. Available from: McGraw-Hill's Access Medicine; 2008 [cited 2010 Apr 11 Available for URL: http://accessmedicine.com.myaccess.library.utoronto.ca/content.aspx?aID=2871684&searchStr=mumps#2871684
5. Mumps (Epidemic Parotitis), In: The Merck Manual for Healthcare Professionals [Online]. Available from: Merck Manuals Online Medical library; 2009 Nov [cited 2010 Apr 11]. Available from URL: http://www.merck.com/mmpe/sec14/ch193/ch193d.html?qt=mumps&alt=sh
6. Albrecht MA. Mumps.UpToDate. Last updated May 17, 2019. Accessed November 1, 2019.
7. Merck Manual – Consumer Version. Mumps. https://www.merckmanuals.com/en-ca/home/children-s-health-issues/viral-infections-in-infants-and-children/mumps. Last revised June 2023. Accessed October 27, 2023.