Mumps

Mumps is a contagious disease caused by a virus. The classic symptom of mumps is swelling of the salivary glands under the ears, resulting in a tender, swollen jaw.

In children, mumps is usually a mild disease. However, mumps can occasionally cause complications, especially in adults. Complications include:

• Meningitis (infection of the covering of the brain and spinal cord)
• Deafness (temporary or permanent)
• Encephalitis (swelling of the brain)
• Orchitis (swelling of the testicles) in males who have reached puberty
• Oophoritis (swelling of the ovaries) and/or mastitis (swelling of the breasts) in females who have reached puberty

Current Events

Mumps in the United States

As of September 11, 2025, the United States reported 226 mumps cases* across 34 jurisdictions. For this year, the top 5 states in the order of the most are: California (29); New York (20); Illinois (19) and Ohio (16) with reported mump cases.

*2025 jurisdictions refer to any of the 50 states, New York City, and the District of Columbia (Washington D.C.).

Before mumps vaccine was available in the United States, most children got mumps by the time they reached adolescence.

Reported cases decreased by more than 99% after both the mumps vaccination program started in the United States in 1967 children regularly received two doses of MMR vaccine. Cases decreased from 152,209 in 1968 to 231 in 2003.

Large outbreaks happened in settings where people have intense or frequent close contact, like college campuses, close-knit communities, and large gatherings.

Mumps cases decreased compared with the previous six years, possibly due to social distancing and other COVID-19 prevention measures. However, mumps continued to circulate across the U.S. despite these measures. From April 1, 2020 to December 31, 2020, 32 health departments reported 142 mumps cases.

Mumps in Hawaii 2025

As of October 7, 2025, there is one laboratory confirmed case of mumps identified in Kailua-Kona, Hawaii.

• Attended an event at Harold H. Higashihara Park in Kailua-Kona on Thursday, Sept. 25, between 4:30 and 6 p.m.

People who were at the event should also self-monitor for symptoms until October 20 (25 days after exposure). Individuals who develop symptoms should isolate immediately, contact their healthcare provider and should isolate for five days after symptom onset. There may be individuals who were exposed to mumps at this event and have not been identified by DOH.

Healthcare providers should evaluate patients who report exposure at the event for symptoms of mumps and verify their vaccination status. There is no post-exposure prophylaxis for mumps, though vaccine may be offered to exposed individuals who are not up-to-date with measles, mumps, and rubella (MWR) vaccine. If providers have any questions please refer to medical advisory.

DOH issued news releases to inform the public of potential exposure to mumps at a location on Hawaii Island.

Why is this a public health concern in Hawaii?

Mumps is a contagious viral illness that can on rare occasions cause serious complications in those infected including brain infection, deafness, and infertility. It can result in outbreaks that sicken large numbers of people, putting them at risk of these complications. Hawaiʻi previously experienced a significant mumps outbreak from March 2017 through October 2018, with 1,009 confirmed cases statewide. Most cases were on Oʻahu, but Hawaiʻi, Kauaʻi, and Maui counties also had confirmed cases.

This case is community-acquired and not travel-related, suggesting that mumps may currently be circulating on Hawaiʻi Island. DOH is closely monitoring suspected cases to prevent further spread.

Mumps is preventable through vaccination. It is concerning how easily the mumps virus spreads. DOH encourages all Hawai’i residents to check their vaccination records and ensure they and their families are fully protected with the two doses of MMR (measles, mumps, rubella) vaccine. Refer to the Hawaii State Immunization System (HiSIS) website to learn more on how to obtain your official immunization record on the HiSIS Public Portal.