Although overshadowed in the headlines by a sharp increase in measles cases, mumps too is making a comeback, with outbreaks throughout 2014 and early 2015. Many of today’s clinicians have never seen a case of mumps, let alone experienced an outbreak. Here’s what to look for and what to do if mumps makes its appearance in your practice.
In 2014, 1,151 cases of mumps were reported in the United States.1 By contrast, the typical annual rate has been in the low hundreds since 1989, when the CDC recommended a two-dose measles-mumps-rubella (MMR) vaccination regimen.1,2
Yet mumps has resurged in the past decade, with large outbreaks in 2006 (6,584 cases) and 2009-2010 (4,603 cases).3 Mumps outbreaks tend to occur among vaccinated young adults, such as college students, sports players, and campers, who live in close quarters.4
The 2014 outbreak centered around the Ohio State University campus in Columbus.5 That outbreak was declared over in October, with a total of 484 cases—more than in the entire US in 2013.1 In late 2014, at least 20 players and two officials in the National Hockey League became infected with mumps.6 More recently, Idaho announced that a 21-case outbreak that began at the University of Idaho’s Moscow campus had spread to Washington, with two additional cases reported there.7 What is responsible for these outbreaks, and what can the primary care clinician do to prevent or mitigate them?
EPIDEMIOLOGY The mumps virus is part of the Rubulavirus genus of the Paramyxoviridae family. It affects the central nervous system (CNS) and glands—most commonly, the parotids. Uniquely human, mumps virus is found in saliva, cerebrospinal fluid, blood, breast milk, infected tissues, and urine.8,9 It is transmitted through contact with respiratory secretions and/or saliva, direct contact, or through fomites (eg, bedding, doorknobs).10
Before development of an effective vaccine, mumps was a universal childhood disease in the US; by age 14, most children had been infected.11 In the absence of widespread vaccination, mumps epidemics will occur every three to five years—as they still do in parts of the world without effective vaccination programs.12
As a result of widespread vaccination in the US, mumps incidence declined from 152,209 cases in 1967 to 2,982 cases in 1985 (see “Mumps and the MMR Vaccine”). Cases were reduced even further when administration of a second MMR dose was introduced in 1990.13 By 2000, the Healthy People 2010 goal was to eliminate mumps altogether.14
