(Epidemic Parotitis)

ByBrenda L. Tesini, MD, University of Rochester School of Medicine and Dentistry
Reviewed/Revised Jun 2023 | Modified Aug 2023

Mumps is a contagious viral infection that causes painful enlargement of the salivary glands. The infection may also affect the testes, brain, and pancreas, especially in adolescents and adults.

  • Mumps is caused by a virus.

  • Symptoms include chills, headache, poor appetite, fever, and a feeling of illness, followed by swelling of the salivary glands.

  • The diagnosis is based on typical symptoms.

  • Treatment is aimed at relieving symptoms.

  • Most children recover with no problems, but infection can lead to meningitis or encephalitis.

  • Routine vaccination can prevent the infection.

Children become infected with mumps by breathing in small airborne droplets of moisture coughed out by an infected person or by having direct contact with objects contaminated by infected saliva.

The infection does not usually occur in children younger than 2 years, particularly those younger than 1 year.

One infection with the mumps virus usually provides lifelong immunity, which means a person who has had mumps once most likely will not get it again.

Mumps is less contagious than measles. In heavily populated areas, it occurs year-round but is most frequent in late winter and early spring.

Outbreaks mainly occur among people who have not been vaccinated and have not had mumps before. However, outbreaks have occurred among people who have been vaccinated, probably because some people do not develop immunity after vaccination and, in some others, immunity may decrease over time. Also, some people may not have received the recommended number of vaccine doses. Before routine immunization, mumps occurred most commonly among school-aged children. Now, however, the infection has become more common among adolescents and adults because of waning immunity.

Vaccination has significantly decreased the number of mumps cases in the United States. However, mumps still occurs at low rates. A 2006 mumps outbreak in the United States caused 6,584 cases . Since that time, sporadic outbreaks, mainly at college campuses and in other close-knit communities, have contributed to cases fluctuating from a low of 229 in 2012 to another high of 6,369 in 2016. These outbreaks have highlighted the need for continued use of vaccination.

Like measles, mumps may be spread by people traveling from areas where mumps is more common and acquiring mumps while abroad before returning to the United States. These infected travelers then transmit the infection, especially in places where many people group together (such as college campuses) or among people in close-knit communities that live in crowded conditions or that limit contact with outsiders.

Locating the Major Salivary Glands

Symptoms of Mumps

Mumps symptoms begin 12 to 24 days after infection. Most people develop chills, headache, poor appetite, a general feeling of illness (malaise), and a low to moderate fever. These symptoms are followed in 12 to 24 hours by swelling of the salivary glands (parotitis), which is most prominent on the second day and lasts 5 to 7 days.

Some children simply have swelling of the salivary glands without the other symptoms. The swelling results in pain when chewing or swallowing, particularly when swallowing acidic liquids, such as citrus fruit juices. The glands are tender when touched. At this stage, the temperature usually rises to 103 or 104° F (about 39.5 or 40° C) and lasts 1 to 3 days.

About 25 to 30% of people do not develop symptoms.

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Mumps is characterized by painful enlargement of the salivary glands.
Photo courtesy of Sylvan Stool, MD.

Complications of mumps

Mumps may affect organs other than the salivary glands, including the

  • Testes

  • Brain and tissue covering the brain

  • Pancreas

After puberty, about 30% of unvaccinated and 6% of vaccinated infected males develop inflammation of one or both testes (orchitis). Inflammation of the testes causes swelling and severe pain. Once healed, the affected testis may be smaller, but testosterone production and fertility are usually unaffected.

In women, inflammation of the ovaries (oophoritis) is less commonly recognized, is less painful, and does not impair fertility.

Mumps leads to inflammation of the layers of tissue covering the brain (meningitis) in 1 to 10% of people who have swelling of the salivary glands. Meningitis causes headache, vomiting, and a stiff neck.

Mumps also causes inflammation of the brain (encephalitis) in 1 out of 1,000 people. Encephalitis causes drowsiness, coma, or seizures. Most people recover completely, but some have permanent nerve or brain damage, such as deafness or paralysis of the facial muscles, usually affecting only one side of the body. Mumps is thought to be a major cause of one-sided deafness in children in parts of the world where vaccination rates are low.

Inflammation of the pancreas (pancreatitis) may occur toward the end of the first week of infection. This disorder causes abdominal pain, severe nausea, and vomiting. These symptoms disappear in about a week, and the person recovers completely.

Other complications, such as swelling of the liver, kidneys, or heart muscle, occur but are extremely rare. Complications are less common among people who have been already been vaccinated.

Diagnosis of Mumps

  • A doctor's evaluation

  • Laboratory tests

Doctors diagnose mumps based on the typical symptoms, particularly when they occur during an outbreak of mumps.

Laboratory tests can be done to identify the mumps virus and its antibodies. Such tests may be used to confirm the diagnosis but are usually done to document outbreaks for public health purposes.

A spinal tap is done for people who have signs of meningitis or encephalitis.

Treatment of Mumps

  • Acetaminophen or ibuprofen for discomfort

Boys or men with inflammation of the testes need bed rest. The scrotum may be supported with an athletic supporter or by an adhesive-tape bridge connected between the thighs. Ice packs may be applied to relieve pain.

If pancreatitis causes severe nausea and vomiting, fluids may be given by vein (intravenously), and people should not eat or drink anything for a few days.

Prognosis for Mumps

Almost all people with mumps recover fully without problems, but in rare cases symptoms may worsen again after about 2 weeks.

Prevention of Mumps

  • MMR vaccine

There is no longer a separate vaccine just for mumps. The measles-mumps-rubella (MMR) vaccine is a combination vaccine that contains live but weakened measles, mumps, and rubella viruses. The MMR vaccine is one of the routine immunizations of childhood and is given to children in most nations that have a robust health care system. The MMR vaccine and the varicella (chickenpox) vaccine are also available as a combined vaccine (MMRV vaccine).

Two doses of MMR vaccine are routinely recommended. The first dose is given between 12 and 15 months of age but can be given to children as young as 6 months during a measles outbreak or before international travel. The second dose is given between 4 years and 6 years of age.

Children who were less than 1 year of age when immunized still need 2 more doses after their first birthday.

In some children, the vaccine causes mild fever and a rash, but people are not contagious. The MMR vaccine does not cause autism (see MMR vaccine and concerns about autism).

The MMR vaccine generally provides lasting immunity.

MMR is a live vaccine and is not given during pregnancy.

During an outbreak, people who have been vaccinated but who have an increased risk of developing mumps (such as college students or others living in areas where there has been an outbreak of mumps) may be given a third dose.

For more information about who should and who should not receive the MMR vaccine, see Administration of MMR Vaccine. See also Side Effects of MMR Vaccine.

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