Author(s): Mariel Marlow, Jessica Leung

Infectious Agent

Mumps virus is an enveloped, single-stranded, negative-sense RNA virus of the family Paramyxoviridae, genus Rubulavirus.

Transmission

Transmission occurs by respiratory droplets or saliva from a person infected with mumps and usually requires close contact for spread. Transmission is most likely to occur 2 days before through 5 days after the onset of parotitis.

Epidemiology

Mumps is endemic throughout the world. On average >500,000 mumps cases are reported to the World Health Organization annually; global mumps incidence is challenging to estimate, however, because mumps is not a notifiable disease in many countries. As of 2018, mumps-containing vaccine is routinely used in 122 countries. Since the mid-2000s, large mumps outbreaks have been reported among populations with high 2-dose measles-mumps-rubella (MMR) vaccine coverage in countries with routine mumps immunization programs. Despite these outbreaks, mumps incidence is still much higher in countries that do not have routine mumps vaccination. The risk for potential exposure among travelers is unknown but could be high in many countries.

Clinical Presentation

The average incubation period is 16–18 days (range 12–25 days). Mumps is an acute systemic illness that classically presents with parotitis (acute onset of unilateral or bilateral tender, self-limited swelling of the parotid) or other salivary gland swelling, usually lasting 5 days. Nonspecific prodromal symptoms of anorexia, low-grade fever, headache, malaise, and myalgias can occur several days before the onset of parotitis. Infections also can be asymptomatic or limited to nonspecific respiratory symptoms. Complications include aseptic meningitis, encephalitis, hearing loss, mastitis, oophoritis, orchitis, and pancreatitis, any of which can occur in the absence of parotitis. Fully vaccinated people can get mumps but are at much lower risk for mumps and mumps complications.

Diagnosis

Mumps is usually clinically defined as acute parotitis or other salivary gland swelling or oophoritis or orchitis, without other apparent cause. Laboratory confirmation of mumps involves detecting mumps virus by real-time reverse transcription PCR (rRT-PCR) or virus isolation by culture. Laboratory confirmation of mumps can be challenging; therefore, mumps cases should not be ruled out by negative laboratory results.

Serologic testing for the presence of IgM antibodies in serum also can aid in the diagnosis of mumps but is not confirmatory. Mumps laboratory testing can be performed by commercial labs, most state and local public health laboratories, and the Centers for Disease Control and Prevention (CDC). See further information on laboratory testing, including optimal timing for specimen collection. Mumps is a nationally notifiable disease.

Treatment

Supportive care is the mainstay of treatment for mumps.

Prevention

Before departure from the United States, travelers aged ≥12 months who do not have acceptable evidence of mumps immunity (as documented by 2 doses of a mumps virus–containing vaccine, laboratory evidence of immunity, laboratory confirmation of disease, or birth before 1957) should be vaccinated with 2 doses of MMR vaccine ≥28 days apart, or 1 dose of MMR if they previously received 1 MMR dose. Measles-mumps-rubella-varicella (MMRV) vaccine is licensed for children aged 12 months through 12 years and can be used if vaccination for measles, mumps, rubella, and varicella is indicated for this age group. There is no recommendation for infants aged <12 months to receive vaccination against mumps before international travel; the Advisory Committee on Immunization Practice (ACIP) recommends, however, that infants aged 6–11 months receive 1 dose of MMR vaccine before departure to protect against measles. There is no recommendation for a third dose of MMR vaccine for travelers to countries experiencing mumps outbreaks.

CDC website: Mumps