2026 Local Mumps Situation

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Page originally published 9/21/2026. Last updated 10/6/2026.

County Public Health Services (PHS) has confirmed a mumps outbreak at San Diego State University (SDSU). The first known case experienced symptom onset on Sept. 6. PHS is collaborating with the California Department of Public Health (CDPH) and SDSU officials for management of the outbreak, including testing of known close contacts of people who are ill.

Mumps is a contagious viral illness that spreads easily in close-contact settings, typically within three feet. It can spread through kissing, sharing food or drinks, or exposure to coughs or sneezes. Mumps most commonly causes swelling of the cheeks or jaw area. People are contagious for two days before swelling appears and until five days after symptom onset.

  • Mumps symptoms can include body aches, loss of appetite, fatigue, headache, and fever most commonly followed by swelling of the salivary glands that causes pain and swelling of the cheeks and jaw.
  • Mumps can cause serious complications including:
    • Pain and swelling of the testicles (orchitis) or ovaries (oophoritis) that can cause infertility.
    • Inflammation of the ears that can cause hearing loss. 
    • Infection in and around the brain (meningitis/encephalitis) that can cause disability.

Vaccination is the most effective way to prevent mumps.

  • While 2 doses of MMR vaccine are 88% effective at preventing mumps, the second dose in the series is usually give between 4 to 6 years of age, and immunity to mumps from the MMR vaccine may decrease over time for some people. This means they may no longer be protected against mumps later in life. 
    • Unless they have evidence of mumps immunity from mumps infection, students in college, trade school, and training programs; healthcare personnel; and international travelers should have two (2) doses of the measles, mumps, and rubella (MMR) vaccine.
  • During a mumps outbreak, getting a third dose of the vaccines provides the best protection and helps stop the spread. Health officials may recommend this dose for anyone who may have close contact with someone who has mumps.

Some vaccinated people may still get measles, mumps, or rubella if they are exposed to the viruses. However, symptoms are generally milder, and vaccinated people are less likely to spread the disease to others.

For more information, please visit Fall 2026 Mumps Outbreak Information (SDSU Student Health Services).

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Call the Immunization Unit at (866) 358-2966, or send an email, for more information.