2025 Measles Outbreak Information

Measles is the single most contagious infection in human history, caused by a virus.

Measles causes a widespread rash and flu-like symptoms, including a fever, cough, runny nose, sore throat, body aches, lethargy, and more. The measles rash is distinctive and spreads over three days. It usually begins on the face, forehead, and hairline with lesions that are distinctive to the disease. As it grows, the spots spread downward into a neck rash. It continues to the torso and then to the hands and feet.

Measles is not just a little rash and fever that clears up in a few days. 25% of people who get measles are hospitalized, 20% will get pneumonia, and between 1-3 out of every 1,000 will die ^[2]. Another 1 out of every 1,000 people infected with measles will experience inflammation of the brain, and 20% of those with brain inflammation, who survive, will have long-term brain damage and disabilities because of it ^[2]. 

Measles is easily spread from person to person. When an infected person talks, coughs or sneezes, the virus is released into the air and enters another person’s body through the nose, mouth or throat. People can also become sick if they come in contact with the mucus or saliva (spit) from an infected person. The measles virus can live on contaminated surfaces and in the air for up to two hours. If other people breathe the contaminated air or touch the contaminated surface, then touch their eyes, noses, or mouths, they can become infected. Measles may be transmitted from 4 days before through 4 days after rash onset

“Exposed” means you’ve been in a situation where you can catch the virus from someone who already has measles. For example, you can be exposed to the measles virus by being in the same room, home, office, or waiting room with someone who has measles or by being there up to 2 hours after the person with measles has left. People are less likely to get sick with measles if they have been appropriately vaccinated. Approximately 90 percent of people who are not immune will get measles if they are exposed to someone with the disease. 

Immunity means protection from disease. People who may have been exposed to measles, need to show proof of immunity.

Generally, a person is considered immune if they:

1. Had measles in the past, and have laboratory confirmation to prove it, OR
2. Have laboratory evidence (a blood test that shows whether the body has antibodies to fight off the virus) of immunity, OR
3. Have written documentation of adequate vaccination with measles-containing vaccine in the past (often given as MMR [measles, mumps, and rubella] vaccine)
   • One or more doses of a measles-containing vaccine administered on or after the first birthday for preschool-age children and adults not at high risk
   • Two doses of measles-containing vaccine for school-age children and adults at high risk, including college students, health care personnel, and international travelers, OR
4. Were born before 1957
   • Adults born before 1957 are likely to have had measles disease as a child and are generally (but not always) considered not to need vaccination

People born before 1957 lived through several years of epidemic measles before the first measles vaccine was licensed. As a result, these people are very likely to have had the measles disease. Surveys suggest that 95% to 98% of those born before 1957 are immune to measles. 

Not necessarily. People who have documentation of receiving LIVE measles vaccine in the 1960s do not need to be revaccinated. People who were vaccinated prior to 1968 with either inactivated (killed) measles vaccine or measles vaccine of unknown type should be revaccinated with at least one dose of live attenuated measles vaccine. This recommendation is intended to protect those who may have received killed measles vaccine, which was available in 1963-1967 and was not effective.

If you’re unsure whether you’re immune to measles, you should first try to find your vaccination records or documentation of measles immunity. Another option is to have a doctor test your blood to determine whether you’re immune, but this option is likely to cost more and may take two doctor’s visits. 

• Contact your health care provider (previous, current, out-of-state)
• Check your patient portal
• Check school records (including college)
• Check with prior employers (especially if you worked for a childcare facility or healthcare facility)
• Check your military records if you were enlisted
• Check with your Obstetrician
• Check your state’s Immunization Registry (for out of state records)
• Complete this Authorization to Release Information form for us to check for vaccines in the Montana State ImMTrax Registry (this will not include vaccines from another state unless a Montana healthcare provider added them). Authorization Release of Information

Please visit the CDC website for additional suggestions on how to locate your vaccination records: Staying Up to Date with Your Vaccine Records | Adult Vaccines | CDC

• Call your health care provider as soon as possible to discuss your exposure so special arrangements can be made for you to be evaluated without putting other patients and medical office staff at risk. A person infected with measles can be infectious before they have any symptoms of the disease. Your health care provider is the best person to determine if you are immune to measles based on your vaccination record and any medical conditions you might have.
• If you or your child are not immunized, you should stay home (quarantine) and away from work, school, and public places for 21 days (from the date you were exposed) to ensure you/your child do not become infected and pass measles to others.
• If you have not been vaccinated, measles vaccine may help prevent disease if given within 72 hours of first exposure. Immune globulin (a blood product containing antibodies to the measles virus) may prevent or lessen the severity of measles if given within 6 days of first exposure.
• If you are immunized, or have other proof of immunity to measles, you do not need to be quarantined and may continue with your normal activities. Small number of people can still develop symptoms and become infectious.  Watch for symptoms for 21 days past the exposure date.

• If you would like to self-refer your exposure to Lewis & Clark Public Health nurses, please fill out this form: https://form.jotform.com/LC_PH/self-referral-measles-exposure

   

Two doses of MMR vaccine is reported to be  97% effective [1].

What this means:

• Those who are vaccinated against measles are 97% less likely to catch it.
• And if they do, their illness is often milder and less likely to spread.

Getting 2 doses of vaccine is important, because some people (about 2-5 per 100) do not become protected (immune) after just one dose of vaccine. 

MMR Vaccine Information Sheet(PDF, 207KB)

In the USA, measles vaccine is almost always given as a combination with vaccine against 2 other viruses: mumps and rubella. This combination vaccine is called MMR (measles, mumps, and rubella) and it gives protection against all 3 viruses. 

MMR Vaccine Information Sheet(PDF, 207KB)

A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions. The risk of MMR vaccine causing serious harm, or death, is extremely small. Getting MMR vaccine is much safer than getting any of these three diseases. Most people who get MMR vaccine do not have any problems with it.

Mild Problems

• Fever (up to 1 person out of 6)
• Mild rash (about 1 person out of 20)
• Swelling of glands in the cheeks or neck (rare)

Moderate Problems

• Seizure (jerking or staring) caused by fever (about 1 out of 3,000 doses)
• Temporary pain and stiffness in the joints, mostly in teenage or adult women (up to 1 out of 4)
• Temporary low platelet count, which can cause a bleeding disorder (about 1 out of 30,000 doses)

Severe Problems (very rare)

Serious allergic reaction (less than 1 out of a million doses)

MMR Vaccine Information Sheet(PDF, 207KB)

Priorix MMR Vaccine: Package Insert(PDF, 326KB)

11 DESCRIPTION PRIORIX (Measles, Mumps, and Rubella Vaccine, Live) is a suspension for subcutaneous injection. PRIORIX is supplied as a sterile, lyophilized antigen component which is reconstituted at the time of use with the accompanying sterile water diluent. The lyophilized antigen component is a whitish to slightly pink powder. PRIORIX contains the Schwarz strain of live attenuated measles virus, the RIT 4385 strain of live attenuated mumps virus (derived from the Jeryl Lynn strain), both propagated in chick-embryo fibroblasts from embryonated eggs of specific pathogen-free flocks and the Wistar RA 27/3 strain of live attenuated rubella virus propagated in MRC-5 human diploid cells. The 3 virus strains are cultured in media containing amino acids, a small amount of neomycin sulfate and bovine serum albumin and are stabilized after multiple washing steps in media free from antibiotics and albumin. The attenuated measles, mumps and rubella viruses are then mixed with a stabilizer prior to lyophilization. After reconstitution, each approximately 0.5-mL dose contains not less than 3.4 log10 Cell Culture Infective Dose 50% (CCID50) of measles virus, 4.2 log10 CCID50 of mumps virus, and 3.3 log10 CCID50 of rubella virus. Each dose also contains 32 mg of anhydrous lactose, 9 mg of sorbitol, 9 mg of amino acids, and 8 mg of mannitol. Each dose may also contain residual amounts of neomycin sulphate (≤25 mcg), ovalbumin (≤60 ng), and bovine serum albumin (≤50 ng), from the manufacturing process. After reconstitution, PRIORIX is a clear peach- to fuchsia pink-colored suspension. PRIORIX contains no preservative. The tip caps of the prefilled syringes of sterile water diluent contain natural rubber latex. The plungers of the syringes and the stoppers of the lyophilized antigen component vials are not made with natural rubber latex. 

MMR II Vaccine: Package Insert(PDF, 382KB)

M-M-R II vaccine is a sterile lyophilized preparation of (1) Measles Virus Vaccine Live, an attenuated line of measles virus, derived from Enders' attenuated Edmonston strain and propagated in chick embryo cell culture; (2) Mumps Virus Vaccine Live, the Jeryl Lynn™ (B level) strain of mumps virus propagated in chick embryo cell culture; and (3) Rubella Virus Vaccine Live, the Wistar RA 27/3 strain of live attenuated rubella virus propagated in WI-38 human diploid lung fibroblasts. {21,22} The cells, virus pools, recombinant human serum albumin and fetal bovine serum used in manufacturing are tested and determined to be free of adventitious agents. After reconstitution, each approximately 0.5 mL dose contains not less than 3.0 log10 TCID50 (tissue culture infectious doses) of measles virus; 4.1 log10 TCID50 of mumps virus; and 3.0 log10 TCID50 of rubella virus. 8 Each dose is calculated to contain sorbitol (14.5 mg), sucrose (1.9 mg), hydrolyzed gelatin (14.5 mg), recombinant human albumin (≤0.3 mg), fetal bovine serum (<1ppm), approximately 25 mcg of neomycin and other buffer and media ingredients. Product contains no preservatives.

IG is a medical way to prevent measles from becoming more serious in some people after they are exposed to the virus. It will be given to some infants <12 months of age, pregnant women, persons with weakened immune systems, and others who for medical reasons cannot get the vaccine.  You discuss the risks and benefits of getting immune globulin with your health care provider. Vitamin A should only be taken after consultation with your provider to prevent toxicity. 

Quarantine is for non-immune people who have been in contact with someone with measles. It is an important part of stopping measles spreading in the community, especially to high risk people. Quarantine means staying at home and away from daycare/school/work, group and social activities, sports and recreation events and public places like cinemas and shopping malls. 

People who are non-immune and have been exposed to someone with measles and are in the period where they could still get sick from it. 

Although the incubation period (time between being exposed to the measles virus and the appearance of the first symptoms) is usually 10-14 days, sometimes it can take longer from the time someone is exposed to measles until the time they get sick from it. Quarantine should continue through 21 days from last exposure. Quarantine should only occur in consultation with public health authorities, who will be able to help you determine the appropriate dates for quarantine. 

If you were able to receive the vaccine within 72 hours after first exposure to someone with measles, you might not need to be quarantined. However, if you receive the vaccine after 72 hours, you should be quarantined for 21 days.  

See above: “How do you know if someone is immune to measles?” Household members who are immune to measles do not need vaccine. Household members who are not immune, or are not sure whether they are immune, should consider getting vaccine. 

No. Entering the home where a person is quarantined is highly discouraged unless the visitors are immune.

If you do not get measles, you cannot spread it to others. However, because you are still in the period where you could become ill, you may not know you are infectious. You can spread the disease up to 4 days before you develop a rash. Therefore, it is best to limit contact with those in your household and they should review their immune status. Please see above: “How do you know if someone is immune to measles?”. 

No, measles cannot be spread via clothing.

When an infected person talks, coughs or sneezes, the virus is released into the air and enters another person’s body through the nose, mouth or throat. People can also become sick if they come in direct contact with the mucus or saliva (spit) from an infected person. Also, measles virus can live for up to two hours on a surface or in an airspace where the infected person coughed or sneezed. If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses, or mouths, they can become infected. A person who is not infected with the measles virus cannot transmit the virus to others or bring it home to family members and friends. 

It is important for people to wash their hands frequently with soap and water, especially after coughing, sneezing, blowing their nose, going to the bathroom, or having contact with moist materials such as tissues, diapers, and used masks. A minimum of 60% alcohol-based hand sanitizer can also be used instead of soap and water if the hands are not visibly dirty.

If there are other individuals living in the home of the quarantined person who are not immune to measles, the likelihood that they will get sick with measles may be reduced if the quarantined person stays inside their designated room/area, avoids contact with others, and wears a mask when in common rooms.

The quarantined person should not leave the house, except to receive emergency medical care. In this case, yes, the quarantined person should wear a mask. If the quarantined person will not be able to wear the mask at all times because they are a baby or a child, this should be discussed with the medical facility before arrival. 

No, pets do not get infected with or spread the measles virus. 

If you become ill with measles-like symptoms, including fever, rash, runny nose, cough, loss of appetite, and “pink eye”, seek medical attention but remember to call your health care provider before going to the medical office and inform them that you were exposed to someone with measles or that you have symptoms of measles so that special arrangements can be made to prevent exposure to other patients and medical office staff. You should not go to work or school if you are sick.

http://www.cdc.gov/measles/

Common Ingredients in FDA-Approved Vaccines | FDA

Vaccines Licensed for Use in the United States | FDA

Vaccine Basics | Vaccines & Immunizations | CDC

Appendix B for the Pink Book-Vaccine Excipient Summary