Map shows measles cases across U.S.

Measles cases popping up across the United States, including an outbreak in Texas that has led to the death of a child, are prompting questions about where exactly the illness has been detected.

Measles is one of the most contagious infectious diseases, and in some cases can cause severe infections in the lungs and brain that can lead to cognitive issues, deafness or death. But doctors and health officials say the vaccine, which is normally given as part of the combination measles-mumps-rubella (MMR) vaccine, is highly safe and effective.

While most people’s symptoms improve, about 1 in 5 unvaccinated people who get measles will be hospitalized. About 1 out of every 1,000 children with measles will develop brain swelling that can lead to brain damage, and up to 3 of every 1,000 children who become infected will die, the CDC says. 

Here’s where cases have been reported in the U.S. 

States with measles cases in 2025

Click or hover over a state for details. The largest outbreak so far this year has been in West Texas, but cases have been reported in a number of other states as well.

The Texas outbreak is primarily affecting children and teenagers in the state, nearly all of whom were unvaccinated. State and local health officials confirmed the patient who died was an unvaccinated school-aged child. 

Measles cases in U.S. by year

The highest number of confirmed cases in the U.S. in recent years was 1,274 in 2019, driven by outbreaks in New York, California and Washington state, but most years the total has been much lower. Click or hover over the chart for more details.

Health experts point to lower vaccination rates as a reason for increases in preventable diseases like the measles.

CDC data shows about 93% of kindergarteners in the U.S. were vaccinated against measles during the 2021-2022 school year and only 92.7% in the 2023-2024 school year. This is down from 95.2% during the 2019-2020 school year — a critical threshold to keep people safe. 

“When more than 95% of people in a community are vaccinated, most people are protected through community immunity (herd immunity),” the CDC states.