This Year’s Mumps Outbreak Was the Largest in a Decade


Mumps are on the rise for the first time in a decade in the United States. According to the Centers for Disease Control and Prevention, as of November 5, there were 2,879 cases of mumps across 45 states and the District of Columbia.

Mumps is a contagious virus that is spread through saliva and mucus. The CDC recommends that all children get two vaccines that protect against measles and mumps, but it’s not 100 percent effective.

In light of the uptick in reported mumps cases, the Advisory Committee on Immunization Practices — a panel of medical experts who meet three times a year to suggest vaccination guidelines for the U.S. — is considering adding a third mumps vaccine.

Electron micrograph of the ultra-structure of mumps virus. Credit: Dr Graham Beards, CC BY-SA 4.0
Electron micrograph of the ultra-structure of mumps virus. Credit: Dr Graham Beards, CC BY-SA 4.0

“Studies that have tried to examine the effectiveness of a third dose of MMR vaccine to control mumps outbreaks were limited because vaccination occurred after the outbreak started to decline,” Huong McLean, an associate research scientist at the Marshfield Clinic Research Foundation, which has partnered with the CDC on the issue, told CNN.

According to the CDC, before the mumps vaccination program in the U.S. started in 1967, nearly 186,000 cases of the contagious virus were reported each year. However, the real number could have been much higher due to underreporting. Since the vaccine program was introduced, there has been more than a 99 percent decrease in mumps cases.

Before 2016, the largest outbreak in recent history was in 2006, when more than 6,500 cases of mumps were reported. Most of the people impacted were college students living in the Midwest campuses.

Dr. Manisha Patel, a medical officer at the CDC, explained to CNN that each year the number of mumps cases fluctuates between a few hundred to a couple thousands, with most of the outbreaks concentrated in just a small number of areas. This year, a majority of the mumps cases reported were due to two outbreaks in Arkansas and Iowa. Arkansas reported about 1,870 cases, and Iowa had 683 cases, according to the CDC.

In Iowa, a majority of the mumps outbreak was concentrated in a university setting, with additional cases in the community. Indiana, Illinois, Massachusetts and Oklahoma also reported more than 100 cases of mumps this year, with most of the cases on university campuses. In Massachusetts, most of the cases of mumps occurred at Harvard.

“The underlying theme of where outbreaks do occur are in congregate settings,” Dr. Patel said.

Dr. Patel explained that the close crowding in settings like college campuses is ideal for spreading the disease. Mumps is typically contracted by close contact, such as sneezing, kissing and sharing utensils or lipsticks.

“It is important to understand that if you have a room of 100 people who have been vaccinated with the mumps vaccine and you expose them to mumps, you’re still gonna get 12 people who will develop mumps,” Dr. Patel said. “The MMR vaccine effectiveness is 88 percent with two doses.”

Symptoms of mumps include fever, headache, muscle aches, tiredness and loss of appetite. For many adults, their salivary glands also swell, causing puffy check and a swollen jaw. In more sever cases, particularly for adults, mumps can cause deafness and inflammation of the brain, ovaries, breast tissue or testicles.

Since mumps is a virus, it does not respond to antibiotics. Most doctors recommend bedrest and over-the-counter pain relievers.

Danielle Tarasiuk

Danielle Tarasiuk is a multimedia journalist based in Los Angeles. Her work has been published on, Yahoo! Sports, KCET, and NPR-affiliate stations KPCC and KCRW. She’s a proud Sarah Lawrence College and USC Annenberg alumn.