AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

The mumps virus is a paramyxovirus that shares various epidemiological characteristics with other well-known viral pediatric diseases, such as measles and rubella. The disease is distributed worldwide, and paramyxovirus is highly infectious to nonimmune individuals.

During the 2003 epidemic of severe acute respiratory syndrome (SARS), it was thought that the SARS-causing virus belonged to the paramyxoviridae family. However, current case criteria have determined that SARS follows the clinical, laboratory, and transmission characteristics of a coronavirus named SARS-associated coronavirus (SARS-CoV) and not specifically to the mumps virus.

Humans are the sole reservoir for the mumps virus, and the transmission mode is person to person via respiratory droplets.

Mumps is caused by a specific virus with only one antigenic type known. It contains a single-stranded, negative-sense RNA surrounded by an envelope. One of the 2 glycoproteins on the surface of the envelope mediates neuraminidase and hemagglutinating activity, whereas the other is responsible for lipid membrane fusion to the host cell.

Even though it shares morphologic features of parainfluenza virus type 2, no cross-immunity between the 2 viruses is apparent.

Pathophysiology

After the initial entry into the respiratory system, the virus replicates locally, then follows with a viremic dissemination to target tissues, such as the central nervous system (CNS) and salivary glands, particularly the parotid glands. This fact was a significant contribution from an experimentally induced mumps infection by Henly et al in 1948.

A secondary phase of viremia, found before the immune response, is the result of replication of the virus at the target organs. Viruria is common, via blood transmission of the virus into the kidneys, where active replication occurs. Therefore, impairment of renal function may occur.

Cell necrosis and inflammation with mononuclear cell infiltration is the tissue response. Salivary glands show edema and desquamation of necrotic epithelial cell lining the ducts. Focal hemorrhage and destruction of germinal epithelium may occur, leading to duct plugging.

Frequency

United States

The incidence of mumps, which is more common in the winter and spring, has markedly declined since the introduction of the mumps vaccine. In 1967, when the live-attenuated mumps virus vaccine was introduced in the United States, 185,691 cases occurred. While a minor resurgence of mumps occurred from 1986-1987, in 1991, 4000 cases were reported. The current incidence rate is 1500 cases per year.

Mortality/Morbidity

Death due to mumps is rare; more than one half of the fatalities occur in persons older than 19 years.

Unilateral hearing loss is associated with mumps infection. This devastating complication is rare.

For those who develop meningoencephalitis, the mortality rate is 2%.

• Approximately 10% of all infected patients develop a mild form of meningitis, which could be confused with bacterial meningitis. Encephalitis, transient myelitis, or polyneuritis is rare.
• Orchitis occurs in 10-20% of patients. Subsequent sterility is rare, and oophoritis is quite rare and is usually a benign inflammation of the ovaries.
• Other rare complications include myocarditis, nephritis, arthritis, thyroiditis, pancreatitis, thrombocytopenia purpura, mastitis, and pneumonia. These usually resolve within 2-3 weeks without sequelae.

Sex

• No sex predilection exists.
• For meningoencephalitis, males are affected 3-5 times more often than females.

Age

Incidence rates are currently highest in those aged 5-9 years, followed by those aged 1-4 years, then those aged 10-14 years.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• The incubation period of mumps virus is an average of 16-18 days (in approximately 30-40% of patients), with a range of 12-29 days.
• The period of communicability is usually from 9 days prior to the onset of parotid edema to 1-2 days after onset of swelling and occasionally lasting as long as 7 days after swelling.
• Symptoms include fever, headache, and malaise.
• Within 24 hours, patients usually complain of ear pain, which is localized near the lobe of the ear and aggravated by a chewing movement of the jaw.
• Fever usually subsides after a variable period of up to 1 week and well before the salivary gland edema disappears.

Physical

• The clinical manifestations appear to be a direct result of virus spread to other sites, which illustrates the extensive tissue tropism of mumps.
• After the initial presentation of fever, headache, and earache, the parotid gland enlarges and rapidly progresses to maximum size in 1-3 days.
• • As the edema progresses, the lobe of the ear is displaced upward and outward.
  • Pain and tenderness may be intense during this period, and symptoms rapidly subside after swelling reaches its peak. The parotid gland gradually decreases in size in 3-7 days. Commonly, one parotid gland swells before the other. Only 25% of patients with mumps have bilateral parotitis. Stensen duct opening may be erythematous and edematous.
  • Sublingual gland involvement, most commonly bilateral, is considered the least common manifestation of mumps. The sublingual gland is palpated on the floor of the mouth and submental area. In severe and extensive cases, the edema may extend to the presternal area due to an obstruction of the lymphatic vessels by the compression of the enlarged salivary glands.
  • Submaxillary gland edema, palpable underneath and anterior to the angle of the mandible, may be accompanied by edema spreading onto the cheek and downward onto the neck. If parotitis does not simultaneously occur, it is difficult to differentiate from cervical adenitis. Wharton duct opening may be erythematous and edematous.
• Epididymo-orchitis is the second most common manifestation of adult mumps, which is usually preceded by parotitis. Unilateral involvement is found in 20-30% of the patients, whereas bilateral involvement occurs in fewer than 2% of cases.
• • Orchitis presents acutely with fever, chills, nausea, vomiting, and lower abdominal pain. After the fever, the testes begin to rapidly swell. The size increase could be slight or as much as 4 times normal size. As the fever decreases, the pain and edema subside. Loss of turgor is noticed with as many as 50% of cases demonstrating atrophy. Absolute sterility sequela is rare, with impairment of fertility found in 13% of patients.
  • Oophoritis is associated with pelvic pain and tenderness. It is noted in 7% of postpubertal females. Impairment of fertility is not evident.
• Meningoencephalitis is the most frequent complication in childhood. The true incidence is difficult to determine because of the subclinical infection of the CNS, but clinical findings have been reported in as many as 10% of cases. The mortality rate is 2%, with males being affected 3-5 times more often than females.
• • The pathogenesis is described as a primary infection of the neurons and/or postinfection encephalitis with demyelination.
  • Parotitis may appear simultaneously with the primary neuron infection, or it may appear 10 days after the parotitis in the postinfection type.
  • The illness presents with fever, headache, nausea, vomiting, nuchal rigidity, and change of sensorium. Mumps is a common cause of aseptic meningitis, which usually is indistinguishable from other causes, such as enteroviruses and herpes or pox viruses. The cerebrospinal fluid (CSF) has less than 500 cells/mm³, mostly lymphocytes. Mumps virus can be isolated in the CSF.
• Pancreatitis is a severe but, fortunately, rare manifestation. A sudden onset of epigastric pain and tenderness occurs accompanied by fever, chills, nausea, and vomiting. Elevated amylase level is found with mumps regardless of the presence of pancreatitis. Lipase is a more specific indicator of pancreatic involvement, and measurements of it should be obtained. After 1 week, the patient generally completely recovers.
• A diffuse tender swelling of the thyroid gland may occur about 1 week after parotitis, with the development of antithyroid antibodies.
• Myocarditis is a serious and extremely rare manifestation. The only reported ECG findings are depression of ST segments and bradycardia in 13% of adults with myocarditis.
• Mastitis is uncommon in either sex.
• Unilateral deafness, permanent or transient, has a low incidence (1:15,000), but mumps is the leading cause of deafness.
• Ocular manifestations include dacryadenitis, optic neuritis, uveokeratitis, scleritis, and central vein thrombosis.
• Arthralgia is associated with erythema and edema of the joint; recovery is complete.
• Thrombocytopenia purpura may be present (infrequent).

Causes

Mumps is caused by a paramyxovirus that has one antigenic type. It contains a single-stranded, negative-sense RNA surrounded by an envelope.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Suppurative or recurrent parotitis
Parotid calculus
Coxsackievirus infection
Parainfluenza type 3 infection
Mixed tumors, hemangiomas, lymphangiomas of the parotid gland
Mikulicz syndrome
Uveoparotid fever
Human immunodeficiency virus (HIV) infection
Meningoencephalitis
Allergic reaction, rare

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Generally, no laboratory studies are needed if the ED presentation is typical for mumps.
• Mumps virus can be isolated in a cell culture inoculated with throat washings, urine, or spinal fluid.
• Serum amylase level is elevated in mumps parotitis and pancreatitis. Serum lipase level is elevated in pancreatitis.
• The complete blood count (CBC) may be elevated with a predominance of lymphocytes.

Imaging Studies

• If considering meningoencephalitis, head CT, precontrast, prior to lumbar puncture, is recommended.

Other Tests

• The complement fixation (CF), neutralization, or hemagglutination inhibition (HAI) test or an enzyme immunoassay (EIA) can be used to serologically confirm infection or vaccination.

Procedures

• If considering meningoencephalitis, perform a lumbar puncture to eliminate causes other than mumps.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

• A live-virus vaccine should be subcutaneously administered, in the form of the combination MMR (mumps, measles, rubella) vaccination. Antibodies develop in 95% of all susceptible persons after a single dose.
• • MMR vaccine should be given routinely to children aged 12-15 months. A second dose of MMR vaccine is recommended for those aged 4-6 years in accordance with recommendations for routine measles vaccination. If this dose is missed, it should be given before age 12 years.
  • Revaccination is indicated because mumps can occur in highly vaccinated populations. MMR vaccine is not harmful if given to a patient already immune to one or more of the other viruses.
  • Mumps vaccination is imperative to patients approaching adolescence and adulthood. Persons should be considered susceptible unless they have documentation of at least 1 dose of vaccine on or after the first birthday, documentation of physician-diagnosed mumps, serologic evidence of immunity, or birth date before 1957. Vaccination should be offered before traveling even though it is not a requirement of entry to many countries.
  • Precautions and contraindications to vaccination include the following: Children with minor illnesses with or without fever can be vaccinated. Allergic reactions to vaccination occasionally occur but tend to be minor. Most children with egg sensitivity can be safely vaccinated. Skin testing with MMR vaccine does not reliably predict which children will have a hypersensitivity reaction.
  • Live mumps vaccine should be given 2 weeks before or 3 months after administration of immunoglobulin or blood transfusion because of the theoretical possibility that the antibody will neutralize the vaccine virus and inhibit a successful immunization.
  • Patients with immunodeficiencies (eg, those on large doses of steroids, radiation, or chemotherapy) should not receive live-virus vaccine. The exceptions are patients with symptomatic HIV who are not severely immunocompromised; these patients should receive MMR vaccine. Vaccinating close susceptible contacts can reduce the risk of exposure for patients with altered immunity.
  • Vaccines should not be administered during pregnancy.
• Standard immune globulin is ineffective against mumps.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goal of pharmacotherapy is to immunize the child.

Drug Category: Vaccines

Vaccines are used to induce active immunity.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Admit patients to the pediatric floor if signs of toxicity or dehydration are present.

Further Outpatient Care

• Arrange for a follow-up visit with the primary care physician within 1-2 days.

Deterrence/Prevention

• Droplet precautions are recommended until 9 days after the onset of parotid swelling.
• • Children should be excluded from school and childcare centers for 9 days from the onset of parotid gland swelling.
  • If outbreaks occur in the school or childcare center, all should be vaccinated.
  • Those who have been exempted from vaccination for medical, religious, or other reasons should be excluded from school or day care until at least 26 days after the onset of parotitis in the last person with mumps in the affected school.

Complications

• Hearing loss
• Meningitis/encephalitis
• Orchitis
• Oophoritis
• Pancreatitis
• Transient myelitis
• Polyneuritis
• Myocarditis
• Nephritis
• Arthritis
• Thyroiditis
• Thrombocytopenia purpura
• Mastitis
• Pneumonia

Prognosis

• Most patients completely recover.

Patient Education

• For excellent patient education resources, visit eMedicine's Common Childhood Illnesses Center, Children's Health Center, and Bacterial and Viral Infections Center. Also, see eMedicine's patient education articles Mumps and Immunization Schedule, Children.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to consider the highly infectious nature of the disease (eg, protection of others, removal from day care)
• Failure to consider other sources if the patient presents with meningoencephalitis

Special Concerns

• Lifelong immunity usually follows clinical or subclinical infection, although second infections have been documented.
• Transplacental antibodies seem effective in protecting infants during their first 6-8 months of life.
• Infants born to mothers who have mumps in the week prior to delivery may have clinically apparent mumps at birth or develop illness in the neonatal period.
• The severity ranges from mild parotitis to severe pancreatitis.
• The serum neutralization test is the most reliable method for determining immunity.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Averhoff FM, Williams WW, Hadler SC. Immunization of adolescents: recommendations of the Advisory Committee on Immunization Practices, the American Academy of Pediatrics, the American Academy of Family Physicians, and the American Medical Association. J Sch Health. Sep 1997;67(7):298-303. [Medline].
• CDC. Revised U.S. surveillance case definition for severe acute respiratory syndrome (SARS) and update on SARS cases--United States and worldwide, December 2003. MMWR Morb Mortal Wkly Rep. Dec 12 2003;52(49):1202-6. [Medline].
• CDC Immunization Schedules. United States Centers for Disease Control and Prevention. Available at http://www.cdc.gov/vaccines/recs/schedules/default.htm.
• Committee on Infectious Diseases, American Academy of Pediatrics. Report of the Committee on Infectious Diseases. In: Red Book. 1998:366-9. [Medline].
• Dobson R. Mumps cases rise among teenagers and young adults. BMJ. Jul 17 2004;329(7458):132. [Medline].
• Gilgen-Anner Y, Heim M, Ledermann HP, Bircher AJ. Iodide mumps after contrast media imaging: a rare adverse effect to iodine. Ann Allergy Asthma Immunol. Jul 2007;99(1):93-8. [Medline].
• Gold E. Almost extinct diseases: measles, mumps, rubella, and pertussis. Pediatr Rev. Apr 1996;17(4):120-7. [Medline].
• Hinman A. Eradication of vaccine-preventable diseases. Annu Rev Public Health. 1999;20:211-29. [Medline].
• Koskiniemi M, Donner M, Pettay O. Clinical appearance and outcome in mumps encephalitis in children. Acta Paediatr Scand. Jul 1983;72(4):603-9. [Medline].
• MMWR Morb Mortal Wkly Rep. Recommended childhood immunization schedule--United States, 1998. MMWR Morb Mortal Wkly Rep. Jan 16 1998;47(1):8-12. [Medline].
• MMWR Morb Mortal Wkly Rep. Severe acute respiratory syndrome (SARS) and coronavirus testing--United States, 2003. MMWR Morb Mortal Wkly Rep. Apr 11 2003;52(14):297-302. [Medline].
• MMWR Morb Mortal Wkly Rep. Status report on the Childhood Immunization Initiative: reported cases of selected vaccine-preventable diseases--United States, 1996. MMWR Morb Mortal Wkly Rep. Jul 25 1997;46(29):665-71. [Medline].
• Niizuma T, Terada K, Kosaka Y, Daimon Y, Inoue M, Ogita S, et al. Elevated serum C-reactive protein in mumps orchitis. Pediatr Infect Dis J. Oct 2004;23(10):971. [Medline].
• Phillips C, Behrman RE, Vaughan VC, eds. Mumps. In: Nelson's Textbook of Pediatrics. 13^th ed. 1987:673-5.
• Sherris JC, Ryan KJ, eds. Mumps. In: Medical Microbiology: An Introduction to Infectious Diseases. 2^nd ed. 1994:517-9.

Article Last Updated: Sep 11, 2007