Mumps is an acute viral illness. Although parotitis and orchitis were
described by Hippocrates in the 5th century BCE, until relatively
recently mumps was viewed primarily as an illness that affected
armies during times of mobilization. In 1934, Johnson and
Goodpasture showed that mumps could be transmitted from infected
patients to rhesus monkeys and demonstrated that mumps was
caused by a filtrable agent present in saliva. This agent was later
shown to be a virus. Mumps was a frequent cause of outbreaks
among military personnel in the prevaccine era, and was one of the
most common causes of aseptic meningitis and sensorineural deafness
in childhood. During World War I, only influenza and gonorrhea
were more common causes of hospitalization among soldiers.
Outbreaks of mumps have been reported among military personnel
as recently as 1986.

MUMPS VIRUS
Mumps virus is a paramyxovirus in the same group as parainfluenza
and Newcastle disease virus. Parainfluenza and Newcastle disease
viruses produce antibodies that cross-react with mumps virus. The
virus has a single-stranded RNA genome.
The virus can be isolated or propagated in cultures of various
human and monkey tissues and in embryonated eggs. It has been
recovered from the saliva, cerebrospinal fluid, urine, blood, milk,
and infected tissues of patients with mumps.
Mumps virus is rapidly inactivated by formalin, ether, chloroform,
heat, and ultraviolet light.

PATHOGENESIS
The virus is acquired by respiratory droplets. The virus replicates in
the nasopharynx and regional lymph nodes. After 12-25 days a
viremia occurs which lasts from 3 to 5 days. During the viremia, the
virus spreads to multiple tissues, including the meninges, and glands
such as the salivary, pancreas, testes, and ovaries. Inflammation in
infected tissues leads to characteristic symptoms of parotitis and
aseptic meningitis.

CLINICAL FEATURES
The incubation period of mumps is 14-18 days (range,
14-25 days). The prodromal symptoms are nonspecific, and
include myalgia, anorexia, malaise, headache, and low-grade fever.
Parotitis is the most common manifestation, and occurs in 30%-
40% of infected persons. Parotitis may be unilateral or bilateral and
any combination of single or multiple salivary glands may be affected.
Parotitis tends to occur within the first 2 days and may first be
noted as earache and tenderness on palpation of the angle of the
jaw. Symptoms tend to decrease after 1 week and have usually
resolved after 10 days.
Up to 20% of mumps infections are asymptomatic. An additional 40%-
50% may have only nonspecific or primarily respiratory symptoms.

COMPLICATIONS
Central nervous system (CNS) involvement in the form of
aseptic meningitis is common, occurring asymptomatically (inflammatory
cells in cerebrospinal fluid) in 50%-60% of patients.
Symptomatic meningitis (headache, stiff neck) occurs in up to 15%
of patients and resolves without sequelae in 3-10 days. Adults are at
higher risk for this complication than children, and boys are more
commonly affected than girls (3:1 ratio). Parotitis may be absent in
up to 50% of such patients. Encephalitis is rare (less than 2 per
100,000).
Orchitis (testicular inflammation) is the most common complication
in postpubertal males. It occurs in up to 50% of postpubertal
males, usually after parotitis, but may precede it, begin simultaneously,
or occur alone. It is bilateral in up to 30% of affected males.
There is usually abrupt onset of testicular swelling, tenderness, nausea,
vomiting, and fever. Pain and swelling may subside in 1 week,
but tenderness may last for weeks. Approximately 50% of patients
with orchitis have some degree of testicular atrophy, but sterility is
rare.
Oophoritis (ovarian inflammation) occurs in 5% of postpubertal
females. It may mimic appendicitis. There is no relationship to
impaired fertility.
Pancreatitis is infrequent, but occasionally occurs without parotitis;
the hyperglycemia is transient and is reversible. While some
single instances of diabetes mellitus have been reported, a causal
relationship has yet to be conclusively demonstrated; many cases of
temporal association have been described both in siblings and individuals,
and outbreaks of diabetes have been reported a few months
or years after outbreaks of mumps.
Deafness caused by mumps virus occurs in approximately 1 per
20,000 reported cases. Hearing loss is unilateral in approximately
80% of cases and may be associated with vestibular reactions.
Onset is usually sudden and results in permanent hearing impairment.
Electrocardiogram (EKG) changes compatible with myocarditis
are seen in 3%-15% of patients with mumps, but symptomatic
involvement is rare. Complete recovery is the rule, but deaths have
been reported.
Other less common complications of mumps include arthralgia,
arthritis, and nephritis. An average of 1 death from mumps per year
was reported in 1980-1999.
Mumps
LABORATORY DIAGNOSIS
The diagnosis of mumps is usually suspected based on clinical
manifestations, in particular the presence of parotitis.
Mumps virus can be isolated from clinical specimens, including
saliva, urine, and cerebrospinal fluid. If virus isolation is attempted,
the specimen should be collected within the first 5 days of illness.
Serology is the most common method used to diagnose mumps.
Complement fixation (CF) and hemagglutination inhibition (HI)
antibody tests for mumps are relatively insensitive, and results may
not be reliable. Tests that have demonstrated reliability include neutralization,
enzyme immunoassay (EIA), and radial hemolysis antibody
tests. Neutralization assays are time consuming and not generally
available for routine diagnostic use.
The EIA is widely available commercially and is more sensitive than
the CF, HI, or radial hemolysis. It is available for both IgM and
IgG. IgM antibodies usually become detectable during the first few
days of illness and reach a peak about a week after onset. IgG testing
usually requires two specimens separated by several weeks. The
convalescent (second) specimen should show a significant increase
in antibody compared with the acute (first) specimen.

EPIDEMIOLOGY
OCCURRENCE
Mumps occurs worldwide.

RESERVOIR
Mumps is a human disease. While persons with asymptomatic or
nonclassical infection can transmit the virus, no carrier state is
known to exist.

TRANSMISSION
Transmission of mumps occurs through airborne transmission or
direct contact with infected droplet nuclei or saliva.

TEMPORAL PATTERN
Mumps incidence peaks predominantly in late winter-spring, but the
disease has been reported throughout the year.

COMMUNICABILITY
Contagiousness is similar to that of influenza and rubella, but less
than that for measles or varicella. The infectious period is considered
to be from 3 days before to the 4th day of active disease; virus
has been isolated from saliva 7 days before to 9 days after onset of
parotitis.
11
SECULAR TRENDS IN THE UNITED STATES
Mumps became a nationally reportable disease in the United States
in 1968. However, an estimated 212,000 cases occurred in the
United States in 1964. Following vaccine licensure, reported
mumps decreased rapidly. Approximately 3,000 cases were reported
annually in 1983-1985 (1.3-1.55 cases per 100,000 population).
In 1986 and 1987 there was a relative resurgence of mumps. The
peak was in 1987, when 12,848 cases were reported. The highest
incidence of mumps during the resurgence was among older schoolage
and college-age youth (10-19 years of age) who were born
before recommendations for routine mumps vaccination. Mumps
incidence in this period correlated with absence of comprehensive
state requirements for mumps immunization. Several mumps outbreaks
among highly vaccinated school populations were reported,
indicating that high coverage with a single dose of mumps vaccine
did not always prevent disease transmission, probably because of
vaccine failure.
Since 1989, there has been a steady decline in reported mumps
cases, from 5,712 cases to a provisional total of 231 cases in 2001,
the lowest annual total ever reported. As more children, adolescents,
and adults received two doses of MMR vaccine, the number
of reported cases of mumps has continued to decrease. Because
many reported cases are not confirmed by laboratory testing, it is
likely that many of the cases lacking laboratory confirmation are, in
fact, not due to infection with mumps virus. Experience in states
that have conducted more complete laboratory testing for confirmation
suggests that case investigation, combined with appropriate laboratory
testing, will result in many suspected cases being discarded
and a resulting decrease in reported mumps morbidity. Laboratory
confirmation helps ensure that only true mumps cases are reported.
Prior to vaccine licensure in 1967, and during the early years of vaccine
use, most reported cases occurred in the 5-9 year age group;
90% of cases occurred among children 15 years of age and younger.
In the late 1980s there was a shift towards older children. Since
1990, persons age 15 years and older have accounted for 30% -
40% of cases per year (42% in 2002). Males and females are affected
equally.
Eighty percent or more of adults in urban and suburban areas with
or without a history of mumps have serologic evidence of immunity.

CASE DEFINITION
The clinical case definition of mumps is an acute onset of unilateral
or bilateral tender, self-limited swelling of the parotid or other salivary
gland lasting >2 days without other apparent cause.
Mumps
MUMPS VACCINE
CHARACTERISTICS
Mumps virus was isolated in 1945 and an inactivated vaccine was
developed in 1948. This vaccine produced only short-lasting immunity,
and its use was discontinued in the mid-1970s. The currently
used Jeryl Lynn strain of live attenuated mumps virus vaccine was
licensed in December 1967.
Mumps vaccine is available as a single antigen preparation, combined
with rubella vaccine, or combined with measles and rubella
vaccines. The ACIP recommends that combined measles-mumpsrubella
vaccine (MMR) be used when any of the individual components
is indicated.
Mumps vaccine is prepared in chick embryo fibroblast tissue culture.
MMR is supplied as a lyophilized (freeze-dried) powder and is
reconstituted with sterile, preservative-free water. The vaccine contains
small amounts of human albumin, neomycin, sorbitol, and gelatin.

IMMUNOGENICITY AND VACCINE EFFICACY
Mumps vaccine produces an inapparent, or mild, noncommunicable
infection. More than 97% of recipients of a single dose develop
measurable antibody. Clinical efficacy has been estimated to be
95% (range, 90%-97%).The duration of vaccine-induced immunity
is believed to be greater than 25 years, and is probably life long in
most vaccine recipients.

VACCINATION SCHEDULE AND USE
At least one dose of mumps vaccine, as combination MMR vaccine,
separated by at least 4 weeks, are routinely recommended for all
children. All persons born in or after 1957 should have documentation
of at least one dose of MMR. The first dose of MMR should
be given on or after the first birthday. Mumps-containing vaccine
given before 12 months of age should not be counted as part of the
series. Children vaccinated with mumps-containing vaccine before
12 months of age should be revaccinated with two doses of MMR
vaccine, the first of which should be administered when the child is
at least 12 months of age.
A second dose of MMR is recommended to produce immunity to
measles in those who failed to respond to the first dose. Data
indicate that almost all of the persons who do not respond to the
measles component of the first dose will respond to a second dose of
MMR. Few data on the immune response to the rubella and
mumps components of a second dose of MMR are available.
However, most persons who do not respond to the rubella or
mumps component of the first MMR dose would be expected to
respond to the second dose of MMR.
The second dose of MMR is not generally considered a booster
dose because a primary immune response to the first dose provides
long-term protection. Although a second dose of vaccine may
increase antibody titers in some persons who responded to the first
dose, available data indicate that these increased antibody titers are
not sustained. The combined MMR vaccine is recommended for
both doses to assure immunity to all three viruses.
The second dose of MMR vaccine should be given routinely at age
4-6 years, before a child enters kindergarten or first grade. The adolescent
health visit at age 11-12 years can serve as a catch-up opportunity
to verify vaccination status and administer MMR vaccine to
those children who have not yet received two doses of MMR. The
second dose of MMR may be administered as soon as 4 weeks (i.e.,
28 days) after the first dose.
Adults born in 1957 or later who do not have a medical contraindication
should receive at least one dose of MMR vaccine
unless they have documentation of vaccination with at least one
dose of measles, rubella, and mumps-containing vaccine or other
acceptable evidence of immunity to these three diseases. Some
adults at high risk of measles exposure may require a second dose of
measles vaccine. This second dose should be administered as combined
MMR vaccine (see Measles chapter for details).

MUMPS IMMUNITY
Generally, persons can be considered immune to mumps if they
were born before 1957, have serologic evidence of mumps immunity,
have documentation of physician-diagnosed mumps, or have
documentation of vaccination with at least one dose of live mumps
vaccine on or after their first birthday. The demonstration of
mumps IgG antibody by any commonly-used serologic assay is
acceptable evidence of mumps immunity. Persons who have an
“equivocal” serologic test result should be considered susceptible to
mumps unless they have other evidence of mumps immunity.
Live mumps vaccine was not used routinely before 1977 and the
peak incidence was in 5 to 9-year-olds before the vaccine was introduced.
Most persons born before 1957 are likely to have been
infected naturally between 1957 and 1977. As a result, persons
born before 1957 generally may be considered to be immune, even
if they did not have clinically recognizable mumps disease.
However, as with measles and rubella, this 1957 cutoff date for susceptibility
is arbitrary and vaccination with MMR should be considered
during mumps outbreaks for persons born before 1957 who
may be exposed to mumps and may be nonimmune. Laboratory
testing for mumps susceptibility before vaccination is not necessary.

POSTEXPOSURE PROPHYLAXIS
Neither mumps immune globulin nor immune globulin (IG) is
effective postexposure prophylaxis. Vaccination after exposure is not
harmful and may possibly avert later disease.
Mumps
ADVERSE REACTIONS FOLLOWING VACCINATION
Mumps is a very safe vaccine. Most adverse events reported following
MMR vaccine (such as fever, rash, and joint symptoms) are
attributable to the measles or rubella components. No adverse reactions
were reported in large-scale field trials. Subsequently, parotitis
and fever have been reported rarely. A few cases of orchitis (all
suspect) also have been reported.
Rare cases of CNS dysfunction, including cases of deafness, within
2 months of mumps vaccination have been reported. The calculated
incidence of CNS reactions is approximately one per million doses
of antigen, a rate lower than the reported background encephalitis
rate of 2-6/10,000. The Institute of Medicine (1993) concluded that
evidence is inadequate to accept or reject a causal relationship
between the Jeryl Lynn strain of mumps vaccine and aseptic meningitis,
encephalitis, sensorineural deafness, or orchitis.
Allergic reactions, including rash, pruritus, and purpura have been
temporally associated with vaccination, but are transient and
generally mild.

CONTRAINDICATIONS AND PRECAUTIONS TO
VACCINATION
Persons who have experienced a severe allergic reaction (i.e., hives,
swelling of the mouth or throat, difficulty breathing, hypotension,
shock) following a prior dose of mumps vaccine or to a vaccine
component (e.g., gelatin, neomycin), should generally not be vaccinated
with MMR.
In the past, persons with a history of anaphylactic reactions following
egg ingestion were considered to be at increased risk of serious
reactions after receipt of measles- or mumps-containing vaccines,
which are produced in chick embryo fibroblasts. However, recent
data suggest that most anaphylactic reactions to measles- and
mumps-containing vaccines are not associated with hypersensitivity
to egg antigens, but to other components of the vaccines (such as
gelatin). The risk for serious allergic reactions such as anaphylaxis
following receipt of these vaccines by egg-allergic persons is
extremely low and skin-testing with vaccine is not predictive of allergic
reaction to vaccination. As a result, MMR may be administered
to egg-allergic children without prior routine skin-testing or the use
of special protocols.
MMR vaccine does not contain penicillin. A history of penicillin
allergy is not a contraindication to MMR vaccination.
Pregnant women should not receive mumps vaccine for theoretic
reasons. There is no evidence that mumps vaccine virus causes fetal
damage. Pregnancy should be avoided for 4 weeks after vaccination
with MMR vaccine.
Persons with immunodeficiency or immunosuppression result-
ing from leukemia, lymphoma, generalized malignancy, immune
deficiency disease, or immunosuppressive therapy should not be
vaccinated. However, treatment with low dose (<2 mg/kg/day),
alternate day, topical, or aerosolized steroid preparations is not a
contraindication to mumps vaccination. Persons whose immunosuppressive
therapy with steroids has been stopped for 1 month may
be vaccinated.
Persons with moderate or severe acute illness should not be vaccinated
until the illness has resolved. Minor illness (e.g., otitis
media, mild upper respiratory infections), concurrent antibiotic therapy,
and exposure or recovery from other illnesses, are not contraindications
to mumps vaccination.
Receipt of antibody-containing blood products (e.g., immune
globulin, whole blood or packed red blood cells, intravenous
immune globulin) may interfere with seroconversion following
mumps vaccination.Vaccine should be given 2 weeks before, or
deferred for at least 3 months following, administration of an antibody-
containing blood product (see chapter on General
Recommendations on Immunization, p. 7, for details).
A family history of diabetes is not a contraindication for vaccination.

VACCINE STORAGE AND HANDLING
Measles-mumps-rubella (MMR) vaccine must be shipped with
refrigerant to maintain 10 degrees C (50 degrees F) or less at all times. Vaccine
must be refrigerated immediately on arrival and protected from light
at all times. The vaccine must be stored at refrigerator temperature
(2-8 degrees C [35-46 degrees F]), but may be frozen. Diluent may be stored at
refrigerator temperature or at room temperature.
After reconstitution, MMR vaccines must be stored at refrigerator
temperature and protected from light. Reconstituted vaccine should
be used immediately. If reconstituted vaccine is not used within 8
hours it must be discarded.

SELECTED REFERENCES
American Academy of Pediatrics. Mumps. In: Pickering L ed. Red
Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk
Grove Village, IL: American Academy of Pediatrics, 2003:439-43.
CDC. Measles, Mumps, and Rubella - vaccine use and strategies for
elimination of measles, rubella, and congenital rubella syndrome
and control of mumps. Recommendations of the Advisory
Committee on Immunization Practices (ACIP). MMWR
1998;47(RR-8):1-57.
Cochi SL, Preblud SR, Orenstein WA. Perspective on the relative
resurgence of mumps on the United States. Am J Dis Child
1988;142:499-507.
Holmes SJ. Mumps. In: Evans AS, Kaslow RA, eds. Viral Infections
of Humans. Epidemiology and Control. 4th ed. New York, NY:
Plenum Medical Book Company; 1997:531-50..
Hirsh BS, Fine PEM, Kent WK, et al. Mumps outbreak in a highly
vaccinated population. J Pediatr 1991;119:187-93.
Orenstein WA, Hadler S,Wharton M. Trends in vaccine-preventable
diseases. Semin Pediatr Infect Dis 1997;8:23-33.
Plotkin SA. Mumps vaccine. In: Plotkin SA, Orenstein,WA, eds.
Vaccines. 4th ed. Philadelphia: Saunders; 2003: 441-70.
Van Loon FPL, Holmes SJ, Sirotkin BI, et al. Mumps surveillance
—United States, 1988 - 1993. In: CDC Surveillance
Summaries, August 11, 1995. MMWR 1995;44:1-14.