HARVARD UNIVERSITY, State University of New York, Boston University, Indiana University, Sacred Heart University, University of San Diego... the list of college campuses where healthcare personnel needed to manage and contain outbreaks of mumps during the 2015-2016 academic year is extensive. Mumps is listed as one of the CDC's Nationally Notifiable Conditions. In 2016, the CDC reported the highest incidence of mumps cases in the last decade. As of November 2016, 45 states reported mumps cases and 6 states reported more than 100 cases, largely within college and university settings, for a total of 2,879 infected patients.1 This is more than double the number of reported mumps cases in 2015. Many of the students diagnosed with mumps had been vaccinated appropriately. This article takes a close look at mumps and discusses what nurses need to know to protect patients from this resurging infection.

Epidemiology

Mumps is an acute viral infection caused by the paramyxovirus, a member of the Paramyxoviridae family.1,2 Those born before 1967 likely remember a time when mumps was a common childhood viral infection; in fact, 186,000 cases were typically reported each year.1 When a live attenuated mumps vaccine was licensed in 1967, it was administered to patients between ages 12 months and 15 months.3 A single dose was determined to be 78% to 91% effective in preventing mumps, and the number of mumps cases in the United States dropped substantially. However, outbreaks were still noted among school-age children. So, in 1989, the Advisory Committee on Immunization Practices (ACIP) recommended adding a second dose for children in grades K-12 and college-age students. The addition of state-mandated immunization laws and a 2006 ACIP recommendation for a second mumps vaccination to be given at ages 4 to 6 years further promoted the use of the measles-mumps-rubella (MMR) vaccine.4 A second dose is also recommended for all college students. This led to a remarkable 99% decrease in the number of mumps cases in the United States.1

Transmission

Mumps is usually spread via respiratory droplets, fomites, or saliva and replicates mainly in the upper respiratory mucosa.3,5 The incubation period is approximately 12 to 25 days from exposure to symptom onset, after which the classic presentation of mumps, acute parotitis, may appear.2 The virus is most communicable several days before and after the onset of parotitis.1

To prevent the spread of mumps, the CDC recommends a 5-day period after onset of parotitis for isolation of persons with mumps in either community or healthcare settings, and use of standard precautions and droplet precautions.6

Clinical manifestations

Acute parotitis, or the painful swelling of one or both of the parotid glands, is characteristic of mumps.1,5,7 The clinical case definition of mumps by the World Health Organization is the "acute onset of unilateral or bilateral tender, self-limited swelling of the parotid or other salivary gland, lasting two or more days and without other apparent cause."8

Nonspecific signs and symptoms that may precede parotitis include low-grade fever, headache, anorexia, myalgia, and malaise.9 However, some patients with mumps are asymptomatic or present with only nonspecific or predominantly respiratory symptoms.5

The infection generally lasts a week or two, but if signs and symptoms don't improve or become worse, the patient should notify his or her primary care provider.10

Complications

Although some parents may regard mumps as a benign childhood illness, potentially serious complications can occur. (See Complications of mumps). Although generally rare, complications occur more frequently among adults than children.7

Diagnosis

During a mumps outbreak, the diagnosis of mumps should be confirmed with lab testing including a positive immunoglobulin (Ig)M mumps antibody, a significant rise in IgG titers between acute and convalescent specimens, and a positive mumps virus culture or positive virus detection by real-time reverse transcriptase polymerase chain reaction.1,11

The CDC recommends collecting fluid from the parotid duct as the best source for a viral culture within 3 to 8 days after the onset of parotitis.1 Clinicians must use caution in interpreting lab data because false-positive or false-negative results may occur due to other causes of parotitis or the patient's vaccination status.1

Treatment

Because mumps is caused by a virus, treatment is limited to supportive care, including rest, over-the-counter analgesics and antipyretics, increased fluid intake, applying warm or cool compresses to swollen parotid glands, and eating a mechanical soft diet.10

Prevention

Vaccination is the best way to prevent mumps.1 Adverse reactions are usually minor and self-limiting. The most common adverse reactions are local pain and induration at the site of vaccination, low-grade fever, and/or a mild rash.12 The MMR vaccine is a live virus vaccine. It's contraindicated for anyone who is severely immunocompromised and those with a history of a severe allergic reaction to the vaccine or any of its components, including neomycin.12,13 The MMR vaccine shouldn't be administered to anyone who is pregnant, and pregnancy should be avoided for 30 days after receiving the vaccination.

Current vaccination recommendations include administering two doses of the MMR vaccine to all eligible children. Children between ages 1 and 12 years can get a combination vaccine called MMRV, which contains both MMR and varicella (chickenpox) vaccines.1,14 Mumps can occur even in vaccinated persons, but high vaccination rates assist in limiting the number of cases, duration, and spread of the infections.1

Some adults, generally anyone 18 or older, should also be vaccinated against mumps with the MMR vaccine. According to the National Foundation of Infectious Diseases, adults born in 1957 or later, including nonpregnant women of childbearing age who don't have a medical contraindication, should receive at least one dose of the MMR vaccine unless they have proof of acceptable immunity or have already received at least one dose of the MMR vaccine.15 In addition, healthcare providers, college students, and international travelers should receive two doses of the MMR vaccine unless acceptable evidence of immunity is confirmed by serologic testing.15

Why outbreaks occur

Although mumps is no longer a common illness in this country, periodic outbreaks still occur-particularly in the winter and spring. Much like with many other infectious diseases, mumps outbreaks usually occur in crowded living environments and may be associated with exposure to strains of the mumps virus contracted outside of the country.16 In addition, because no vaccine is 100% effective, even with relatively high coverage rates, some properly vaccinated individuals will become infected.

The current recommended two-dose vaccination series is 80% to 92% effective in preventing clinical disease during outbreaks in this country.17 In an identified outbreak, identifying those who aren't vaccinated and implementing catch-up vaccinations to those who aren't up to date is essential.

According to the ACIP, administering a third dose of the MMR vaccine may be appropriate in specific outbreak situations, including the occurrence in intense exposure settings likely to facilitate transmission and in circumstances when attack rates (that is, >5 cases of mumps per 1,000 population) are high and transmission is ongoing.16

Understanding attack rates

Nurses should know how to compare attack rates between vaccinated and unvaccinated patients to understand the protective effect of the vaccines. For example, in an outbreak of 45 reported cases of mumps, 24 patients with mumps were vaccinated and 21 weren't vaccinated. In this example, the absolute number of vaccinated cases is higher than the absolute number of unvaccinated cases, which may be misleading. The investigation determined that 800 vaccinated individuals were exposed to mumps. Another 70 people who weren't vaccinated were exposed. So, the attack rate in the vaccinated group is 24/800 or 3%, while the attack rate in the unvaccinated group is 21/70 or 30%. The unvaccinated were 10 times as likely to become infected with the mumps virus, illustrating the importance of vaccination in containment efforts.1

Nursing considerations

Teach patients and families about the importance of vaccination and infection control measures, such as respiratory hygiene/cough etiquette, and signs and symptoms of possible complications, including when to notify their healthcare provider.10

Nurses need to understand and follow state and local regulations regarding reporting cases of mumps and other communicable diseases.1 Nurses within the United States should contact their state health department for reporting requirements. An excellent reference for information about reporting cases of mumps to the CDC can be found in chapter 9 of the Manual for the Surveillance of Vaccine-Preventable Diseases (6th edition, 2013).

COMPLICATIONS OF MUMPS3

* Aseptic meningitis

* Encephalitis

* Orchitis

* Oophoritis

* Deafness

* Arthritis

* Pancreatitis

* Myocarditis

* Thyroiditis

* Interstitial nephritis.

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