by Su Jin Joo, M.D., FAAP, and
Larry Pickering, M.D., FIDSA, FAAP
• Donahue M, Schneider A, Ukegbu U, et
al. “Notes from the Field: Complications
of Mumps During a University Outbreak
Among Students Who Had Received 2
Doses of Measles-Mumps-Rubella Vaccine — Iowa, July 2015–May 2016.”
MMWR Morbidity Mortality Weekly
Rep. 2017;66:390-391, http://dx.doi.
A total of 301 mumps cases were diagnosed among students at the University of
Iowa between July 2015 and May 2016.
Of the 287 students who had clinical information available, 20 (7%) had complications: 15 had orchitis, three had transient hearing loss, two had mastitis and one
had meningitis (one had both orchitis and
transient hearing loss). All 20 students had
documented receipt of at least two doses of
measles-mumps-rubella (MMR) vaccine.
Three students from this outbreak highlight complications.
Student A was a 21-year-old male diagnosed clinically with mumps parotitis two weeks after his roommate had received a mumps diagnosis. Two days after
parotitis resolved, he developed left testicular pain and
swelling. Orchitis was diagnosed, and he was treated
with supportive care.
Student B was a 21-year-old female diagnosed with
mumps parotitis, confirmed with a polymerase chain
reaction (PCR) test on the buccal swab specimen. Eight
days after symptom onset, she noticed tinnitus and diminished hearing in the right ear and was diagnosed
with right sensorineural hearing loss, attributable to
mumps. She was treated with prednisone for a week, and
all symptoms resolved 13 days after onset of parotitis.
Student C was a 21-year-old male who developed left
facial pain and swelling. He was diagnosed with mumps
parotitis, confirmed with a PCR test on the buccal swab
specimen. Twenty-one days after symptom onset, he developed headache, neck stiffness, fever and tachycardia.
Cerebrospinal fluid (CSF) volume was inadequate for
PCR test of mumps; however, CSF profiles were consistent with viral meningitis. His meningeal symptoms
resolved following one week of symptomatic care.
Humans are the only known natural hosts for
mumps. The virus is spread by person-to-person con-
tact with infectious respiratory tract secretions and sa-
liva. Classic manifestations include fever, respiratory
tract symptoms and swelling of one or more of the
salivary glands, usually the parotid glands. Complica-
tions can include orchitis, mastitis, meningoencepha-
litis, hearing loss and pancreatitis. Orchitis commonly
is reported after puberty, but sterility rarely results. Up
to 30% of infections are asymptomatic. Infections in
adults are more likely to result in complications.
Incubation period usually is 16-18 days, but cases
may occur from 12-25 days after exposure. The infectious period is two days before to five days after parotid
gland swelling. Treatment is supportive care. Children
should be excluded from school for five days after onset
of parotid gland swelling.
History of mumps vaccination in U.S.
Reported cases of and complications from mumps
virus decreased substantially after mumps vaccine was
licensed in the U.S. in 1967 and one dose was recommended for all children after 12 months of age in 1977.
Mumps disease further declined after implementation
of the two-dose MMR vaccination recommendation
in 1989 for measles control.
Since 2006, two doses of mumps-containing vaccine
have been recommended for all children. Two doses also
are recommended for adults at risk, including international travelers, college or other post high school students, and health care personnel born in or after 1957.
The effectiveness of the mumps component of MMR
is 78% with one dose and 88% with two doses.
The U.S. has experienced a resurgence of multistate
mumps outbreaks and reported cases over the past de-
cade, even among patients who received two doses of
live attenuated mumps-contain-
ing vaccines. Several outbreaks
involved college students on dif-
ferent campuses in the Midwest
and high school students living in
a close-knit religious community
in New York City. As of May 1, a
total of 2,570 mumps cases were
reported to the Centers for Disease
Control and Prevention (CDC)
from 42 states and the District of
Columbia (see figure).
In 2013, the national MMR
vaccination coverage was 91%
(defined as one or more doses);
however, one in 12 children did
not receive the first dose on time.
MMR vaccine coverage also varied among states from 86% (
Colorado, Ohio and West Virginia) to
96% (New Hampshire). Seventeen states were below
90%, which threatens herd protection.
Mumps outbreaks also can occur in high two-dose
MMR vaccination coverage settings. Several serologic
studies suggest waning of vaccine-induced immunity
over time, with decline of concentration and avidity
of antibodies. In addition, outbreaks in settings with
high population density and contact rates can facilitate
transmission, such as college campuses and close-knit
Some hypothesized that vaccine-induced immunity
may not be as effective against non-vaccine strains;
however, no evidence supports immune escape.
CDC statement on third MMR dose
A third dose of MMR was implemented at the sites
of recent U.S. outbreaks, and attack rates seemed to
decline. Due to the late timing of third doses of MMR
vaccination, it could not be determined whether the
decline was due to the third dose.
Data are insufficient to recommend third doses of
MMR vaccine for mumps outbreak control; however, the CDC has outlined criteria to consider prior
to administering a third dose in a target population
for mumps outbreak control ( https://www.cdc.gov/vac
• Two-dose vaccination coverage of more than 90%.
• Intense exposure settings likely to facilitate transmission (schools, colleges, correctional facilities,
congregative living facilities) or health care settings.
• More than five cases per 1,000 population and
evidence of transmission for at least two weeks in
the target population.
Dr. Joo is a pediatric infectious diseases fellow at
Emory University. Dr.
Pickering was editor of
the AAP Red Book from
2000-’ 12. He is adjunct
professor of pediatrics at
Emory University School
Which of the following are correct?
1. Complications of mumps parotitis include orchitis,
meningoencephalitis, mastitis and transient hearing
2. Mumps can occur in people who have received two
doses of MMR.
3. Complications of mumps can occur in the absence
4. Sterility following mumps-associated orchitis rarely
5. All of the above Ans w er: 5
Dr. Joo Dr. Pickering
Multistate mumps outbreaks make resurgence
See the AAP Red Book for additional information about
Mumps cases as of May 1, 2017
AL, AK, AZ, AR, CA, CO, CT, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NY, NC,
ND, OH, OK, OR, PA, TN, TX, UT, VA, WA, and WI
** Preliminary data reported to CDC. Mumps outbreaks are not reportable
Mumps cases as of May 1, 2017, https://www.cdc.gov/mumps/outbreaks.html