Measles Cases and Outbreaks

What to know

Updated on July 11, 2024. Starting 6/14/2024, CDC will update this page the second and fourth Friday of the month.

Map of airplanes traveling across the globe

Measles cases in 2024

As of July 11th, a total of 167 measles cases were reported by 24 jurisdictions: Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New Mexico, New York City, New York State, Ohio, Oregon, Pennsylvania, Vermont, Virginia, Washington, West Virginia, and Wisconsin.

There have been 13 outbreaks (defined as 3 or more related cases) reported in 2024, and 66% of cases (110 of 167) are outbreak-associated. For comparison, 4 outbreaks were reported during 2023 and 48% of cases (28 of 58) were outbreak-associated.

U.S. Cases in 2024

U.S. Cases in 2024

Total cases

Age
Under 5 years:
5-19 years:
20+ years:
Vaccination Status
Unvaccinated or Unknown:
One MMR dose:
Two MMR doses:
U.S. Hospitalizations in 2024

U.S. Hospitalizations in 2024

Percent of Age Group Hospitalized
Under 5 years:
5-19 years:
20+ years:

What to Know

Measles is an airborne, extremely infectious, and potentially severe rash illness. Before the measles vaccine was introduced, an estimated 48,000 people were hospitalized and 400–500 people died in the United States each year.

Measles is not a seasonal virus. However, measles is often spread over times of high travel (ex: spring break) or in situations where unvaccinated persons are in close quarters (ex: summer camp).

Did you know that measles can be found around the world? Measles can live in the air for 2 hours after an infectious person leaves the space. Before any international travel, evaluate if your family needs early vaccine doses.

After you return, watch your health for 3 weeks and call your healthcare provider if you or your child gets sick with a rash and fever.

Two doses of MMR vaccine are 97% effective at preventing measles, 1 dose is 93% effective. It is uncommon for someone fully vaccinated to develop measles. However, breakthrough infections (when someone becomes infected after they have been vaccinated) can occur, especially in communities experiencing an outbreak where high levels of measles virus are circulating. The number of breakthrough infections (approximately 5% of total) is consistent with what we have seen in previous years.

Prevent measles and talk to your healthcare provider about the measles, mumps, and rubella (MMR) vaccine, especially if planning to travel.

Keep Reading: About MMR Vaccine

Measles was declared eliminated in the United States in 2000. This was thanks to a very high percentage of people receiving the safe and effective measles, mumps, and rubella (MMR) vaccine. In recent years, however:

  • U.S. MMR coverage among kindergarteners is now below the 95% coverage target—much lower in some communities—and is decreasing.
  • Global measles activity is increasing, meaning more chances of an unvaccinated person infected with measles abroad returning to the United States.

CDC is creating models to show how measles outbreaks could occur and spread in the United States. These models can be used to help health departments better identify communities at highest risk and manage healthcare resources.

Weekly Measles Cases by Rash Onset Date

2023–2024* (as of July 11, 2024)

*2023–2024 case counts are preliminary and subject to change.

Measles Cases in 2024

as of July 11, 2024

Yearly Measles Cases

as of July 11, 2024

*2023–2024 case counts are preliminary and subject to change.

History of Measles Cases

Measles was officially eliminated from the United States in 2000, meaning there is no measles spreading within the country and new cases are only found when someone contracts measles abroad and returns to the country. Achieving measles elimination status in the United States was a historic public health achievement. The below figure illustrates how common measles was before vaccines and how vaccine policy enabled elimination.

Line chart of reported measles chases in the United States from 1962–2023
*2023 data are preliminary and subject to change. †Elimination is defined as the absence of endemic measles transmission in a region for ≥ 12 months in the presence of a well-performing surveillance system.

MMR Vaccine Coverage for Kindergarteners by School Year (2009–2023)

The measles, mumps, and rubella (MMR) vaccine is very safe and effective. When more than 95% of people in a community are vaccinated (coverage >95%), most people are protected through community immunity (herd immunity). However, vaccination coverage among U.S. kindergartners has decreased from 95.2% during the 2019–2020 school year to 93.1% in the 2022–2023 school year, leaving approximately 250,000 kindergartners at risk each year over the last three years. To dive into vaccine coverage data for MMR, visit VaxView.

At local levels, vaccine coverage rates may vary considerably, and pockets of unvaccinated people can exist in states with high vaccination coverage. When measles gets into communities of unvaccinated people in the United States, outbreaks can occur.

Previous Years

During January 1–December 31, 2023, a total of 58 measles cases were reported by 20 jurisdictions: California, Colorado, District of Columbia, Florida, Hawaii, Idaho, Illinois, Kentucky, Maryland, Missouri, New Jersey, New York City, Ohio, Oregon, Pennsylvania, Texas, Utah, Virginia, Washington, and Wisconsin.

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

From January 1 to December 31, 2022, a total of 121 measles cases were reported by 6 jurisdictions. *

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

From January 1 to December 31, 2021, a total of 49 measles cases were reported by 5 jurisdictions. *

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

From January 1 to December 31, 2020, 13 individual cases of measles were confirmed in 8 jurisdictions.*

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

From January 1 to December 31, 2019, 1,274 individual cases of measles were confirmed in 31 states.

This is the greatest number of cases reported in the United States since 1992. The majority of cases were among people who were not vaccinated against measles. Measles is more likely to spread and cause outbreaks in U.S. communities where groups of people are unvaccinated.

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

From January 1 to December 31, 2018, 382 individual cases of measles were confirmed in 28 jurisdictions.*

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

For more information please see the following reports:

*Jurisdictions refer to any of the 50 states, New York City, and the District of Columbia.

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