Measles (Rubeola)

Learn about measles and discover how to protect yourself and others.

Measles is a highly contagious viral disease caused by the measles virus, also known as rubeola. Infected people can spread the virus to others from four days before the rash appears. The virus can remain viable in the air for up to two hours after the infected person has left the area. Measles can cause fever, cough, runny nose, conjunctivitis, kolpik spots inside the mouth, and a body rash that starts at the head and spreads downwards towards the rest of the body.  

Measles is one of the most contagious viruses in the world and can affect adults as well as children, especially if they are not vaccinated or have waning immunity. Measles cases are increasing worldwide. There have been over five times more measles cases in 2025 than there were in 2024. Although rare in high-vaccination areas, it remains a public health concern, especially in high-density environments like college campuses. 

Prevention

The best protection against measles is the MMR (measles, mumps and rubella) vaccine, which is safe and highly effective. All campus members should ensure their vaccinations are up to date with their healthcare provider.

What campus employees and students can do:

• Check Vaccination Status: Review immunization records to confirm two doses of the MMR vaccine. CDC recommends two doses of MMR vaccine for:
  • Children should receive one dose at 12 months of age and another at 4-6 years.
  • Older children, adolescents, and adults without documented doses of MMR vaccine should get two doses given at least 28 days apart.
• Get Vaccinated: If not vaccinated or unsure about vaccination status:
  • Employees and Student Employees: Although MMR is not a required immunization, MMR vaccine is strongly recommended. Talk to your healthcare provider or visit MyTurn.ca.gov​ to make a vaccine appointment.
  • Students: All incoming and re-admitted graduate and undergraduate students ARE REQUIRED to meet the UC Immunization and Tuberculosis (TB) Screening Requirements. MMR is one of the required vaccinations and may be administered at Student Health Services (SHS). Please visit Student Health Services for more information and the requirements. 
• Before Traveling: Plan to receive the MMR vaccine. It takes your body 2-3 weeks to get the most protection against measles after your last dose. Plan accordingly.
  • Babies 6–11 months of age should receive one dose of MMR vaccine.
  • Ensure everyone 12 months and older is up to date with two doses of MMR vaccine. If they’re not up to date, they should get two doses at least 28 days apart.
  • If you are vaccinated, consult your healthcare provider; you might need a booster.
• Stay Informed: Monitor university communications about measles outbreaks and follow recommendations from health officials. 
• Seek Medical Care: If experiencing symptoms of measles,
  • Stay home and isolate.
    • Employees: Inform your supervisor and do not return to work until cleared by your healthcare provider.
    • Students: Notify Student Health Services by logging on to MyStudentChart and send a message to "Ask-a-Nurse."
  • Contact your healthcare provider.
  • Limit contact with others to prevent exposure, especially unvaccinated and immunocompromised individuals.
  • Wear a mask if you have to go into public spaces.
• Practice Good Hygiene: Wash hands frequently, cover coughs and sneezes, and avoid close contact with those who are sick. 

Symptoms of Measles

Measles begins with a fever (usually ≥101°F / 38.6 C) that lasts a couple of days, and is followed by:

• Cough
• Runny nose
• Red, watery eyes (conjunctivitis)
• Koplik spots(small white spots inside the mouth, seen 2-3 days after initial symptoms)

Symptoms usually begin 10-14 days after exposure.

• Rash: Red, blotchy, maculopapular rash appears 3-5 days after symptoms begin and usually appears on the face, along the hairline and behind the ears, then spreads downward to the neck, trunk, arms, legs, and feet.

Rash duration averages 5-6 days. Those infected can spread measles from about four days before the rash starts to four days afterwards.

When to Suspect Measles

Suspect measles in anyone who:

• Has the symptoms listed above, especially fever with rash
• Travelled internationally or been exposed to international travelers in the last 21 days
• Travelled domestically to the measles outbreak areas
• Is unvaccinated/unknown vaccination status and had contact with a confirmed or probable measles case

If you think you have been exposed to someone with measles, isolate and call your doctor as soon as possible. Your doctor can determine if you have measles by discussing your symptoms and ordering a throat, or nasal swab and a blood test. A doctor can determine if you are immune based on your vaccination record, age, or laboratory evidence and/or make special arrangements to evaluate you.

What To Do When Infected

There is no treatment for measles; the virus needs to run its course, which can be uncomfortable and take several weeks. Treatment is mostly focused on relieving symptoms. Recommendations are rest, adequate nutrition and fluids.

Because the appropriate response to measles exposure can vary based on individual factors — such as your vaccination status, age, and any previous lab evidence of immunity — we strongly recommend that you contact your healthcare provider. They can help determine whether quarantine or isolation is needed and guide you on the right steps to take for your specific situation.

The County of San Diego Immunization Program Public Health Nursing (IZ PHN) team will coordinate directly with healthcare providers — such as Student Health Services (SHS), the Center for Occupational and Environmental Medicine (COEM), and Environment, Health & Safety (EH&S) — to support medical consultation, testing, case investigation, contact tracing, isolation and quarantine guidance, and sanitation recommendations as needed.

Isolation

Because measles is so contagious, do not leave your home and put others at risk until your doctor says it is safe to be in public. Stay away from schools, work, public areas and vulnerable people (infants, pregnant people or immunocompromised).

When to start isolation? As soon as measles is suspected or confirmed. Ideally, at the onset of fever and respiratory symptoms, before the rash starts.

Duration of Isolation

• Isolate until four full days after the rash appears (the day of rash onset is Day 0).
• People who are immunocompromised (e.g., cancer patients, transplant recipients) may shed virus longer — isolation guidance may be extended; consult with your healthcare provider.

Campus Employees who test positive for measles:

• Do not report to campus until cleared by your healthcare provider (even if you are feeling better).
• Inform your supervisor you are not able to work and find out about your options as a UC campus employee by visiting the Sick Leave/Bereavement
• Call or email COEM, phone 619-471-9210 or coemexposure@health.ucsd.edu.

Students who test positive for measles;

• Do not report to classes or work.
• Notify Student Health Services by logging on to MyStudentChart and send a message to "Ask-a-Nurse."

Healthcare providers are required to notify suspected or confirmed measles cases to the County Health Department.

Quarantine

Quarantine refers to the period of home isolation recommended for non-immune contacts who have not or can’t receive appropriate post-exposure prophylaxis within the specified time period (see some of the recommended guidelines for unvaccinated individuals exposed to measles below).

Only your healthcare provider will determine if you need to quarantine and for how long. If quarantine is implemented by your healthcare provider, it should begin on day seven after the date of first exposure through day 21 after the date of last exposure.

**People with lab-confirmed measles immunity (e.g., past infection, born before 1957 or documented two doses of MMR vaccine) may not need to quarantine. However, it is recommended that they monitor for symptoms for 21 days after exposure. Consult with your healthcare provider to receive appropriate recommendations.

Quarantine Guidelines for Unvaccinated Individuals Exposed to Measles:

If you can get vaccinated within 72 hours of exposure:

• MMR vaccine may provide protection and possibly prevent illness.
• You may still need to be monitored for symptoms for 21 days (the incubation period), but may not need full quarantine depending on public health guidance.

If you cannot get vaccinated or 72 hours have passed:

• You are typically excluded from school, work or public places from day five through day 21 after the last exposure (quarantine).
  • Symptoms can appear 7–14 days after exposure and you can become contagious before the rash appears.

If symptoms develop:

• You should be immediately isolated and tested for measles. Contact your healthcare provider or local health department.

Campus employees who need to quarantine:

• Do not report to campus until cleared by your healthcare provider (even if you are feeling better).
• Inform your supervisor that you are not able to work and find out about your options as a UC campus employee by visiting the Sick Leave/Bereavement
• Call or email COEM, phone 619-471-9210 or coemexposure@health.ucsd.edu.

Students who need to quarantine:

• If you believe you need to quarantine due an exposure, please send a message to Student Health Services by logging on to MyStudentChart and send a message to "Ask-a-Nurse."

Reporting and Notification

If you were exposed or are confirmed with measles and have been on campus in the last four days since symptoms appeared, contact:

• Students: Call the Nurse Triage Line (858-534-3300) or send a message to Student Health Services by logging on to MyStudentChart and send a message to "Ask-a-Nurse" BEFORE scheduling or going into SHS Urgent Care.
• Staff and Faculty: Call or email The Center for Occupational and Environmental Medicine (COEM) at 619-471-9210 or coemexposure@health.ucsd.edu and your healthcare provider.

If outbreaks occur, UC San Diego EH&S and SHS will coordinate with San Diego County Public Health for case confirmation, contact tracing, and campus risk mitigation. If your department experiences an outbreak, contact the EH&S Public Health team.

Resources

• UC San Diego Student Health Services (SHS)
  • SHS Health Requirements for Students
  • SHS Measles Information
• UC San Diego Environment, Health & Safety (EH&S)
• San Diego County Health & Human Services Agency – Measles Information
• Centers for Disease Control and Prevention (CDC) – Measles
• California Department of Public Health, Immunization Branch – Measles
• California Department of Public Health, Measles Investigation Quicksheet (PDF)