Measles has been identified in Boulder County, serving as a crucial reminder that the measles virus is highly contagious, spreads rapidly, and can be severe.
Make sure your MMR vaccinations are up to date. Talk to your healthcare provider.
Measles in Boulder County
Measles is a highly contagious viral infection that spreads through the air when an infected person coughs or sneezes. The virus can remain airborne and on surfaces for up to two hours.
Measles causes fever, cough, runny nose, red, watery eyes, and a rash.
It was declared eliminated in the United States in 2000, but cases still occur due to international travel and declining vaccination rates in some communities.
Why Measles is a Concern
Measles is more than a rash. It is a serious illness that can lead to severe complications such as pneumonia, brain swelling, hearing loss, and, in some cases, death. Infants, young children, pregnant people, older adults, and those with weakened immune systems are especially at risk. Up to 30% of people who get measles develop one or more complications.
The virus spreads easily through the air and can remain active on surfaces for several hours, making it challenging to control once it begins to spread. If someone has measles, up to 90% of non-immune people nearby will also become infected.
Symptoms of measles generally appear seven to 12 days (up to 21 days) after a person is exposed to the virus. Initial symptoms typically include:
- High fever (which may spike to more than 104°F)
- Cough
- Runny nose
- Red, watery eyes
Two to three days after symptoms begin, small white spots—known as Koplik spots—may appear inside the mouth.
Three to five days after the first symptoms appear, a rash develops. It usually begins at the hairline and spreads downward to the face, neck, trunk, arms, legs, and feet. As the rash appears, fever may rise even higher.
Measles is a serious disease that can lead to severe health complications, especially in young children and people with weakened immune systems.
MMR Vaccine
The measles, mumps, and rubella (MMR) vaccine is the best way to prevent measles. One dose is about 93% effective at preventing infection. Two doses provide approximately 97% protection against developing measles and lifelong immunity for most individuals.
- Children: The first dose should be given at 12 to 15 months of age, followed by a second dose at 4 to 6 years of age.
- Adults: Anyone born after 1957 should ensure they have had two documented doses of the MMR vaccine or confirmed immunity through a lab test.
- Babies ages 6 to 11 months should receive one early dose of the MMR vaccine before international travel.
- Adults vaccinated between 1963 and 1967: Some people in this group may have received a less effective version of the vaccine. Consult with your healthcare provider to determine if an additional dose is recommended.
If you’re unsure about your vaccination status, it is safe to receive another dose.
What to Do if You’re Having Symptoms
If you think you or your child may have been exposed to measles and are showing symptoms:
- Call your health care provider right away.
- Do not visit a clinic or doctor’s office without calling ahead first. This can help prevent the virus from spreading to others.
- Stay home and avoid contact with other people.
- If you must be around others, wear a mask.
People with measles can spread it to others starting four days before the rash appears and up to four days after.
What to Do if You’ve Been Exposed, without Symptoms
If you think you may have been exposed to measles but are not showing symptoms:
- If you’re unvaccinated or unsure if you’re immune, contact your healthcare provider. You may need a post-exposure vaccine or immune globulin.
- In some cases, you may need to stay out of school, work, or other group settings for up to 21 days, depending on guidance from your local health department.
Measles remains a common disease in many parts of the world, with cases continuing to be reported across the United States. International travel significantly increases the risk of exposure. People who are not protected against measles can become infected while traveling and may spread the virus when they return.
Before Traveling
- Make sure all travelers are fully vaccinated with the MMR vaccine.
- Children should receive their first MMR dose between 12 and 15 months and a second dose between 4 and 6 years.
- Infants ages 6 to 11 months should get one early dose before traveling internationally.
- Adults should have documentation of two MMR doses or confirmed immunity.
If you are unsure of your vaccination status, consult your health care provider. A simple blood test can confirm immunity, or you may be able to safely receive another dose.
Travelers who are unvaccinated or under vaccinated put others at risk—especially infants, older adults and people with weakened immune systems.
Get current measles-related travel notices and additional information.
Learn More About Measles
Stay informed with the latest updates from Boulder County Public Health on measles and other key health topics.
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