Experts have said that numbers in the outbreak are a severe undercount because many cases are going unreported.

Up till now, there have been an average of about 180 measles cases reported each year since measles was declared eliminated in the US in 2000, according to CDC data.

Since then, 2019 is only other year in which there were more than 1,000 cases, driven by large outbreaks in New York City and a nearby suburb. There were 1,274 confirmed measles cases in 2019, according to the CDC, only 272 more than have been reported in the first five months of 2025.

The CDC publishes data on measles cases each Friday, but it has stopped providing details on the specific number of cases in each state, and its national total does not always capture the latest updates from states.

As of Friday, the CDC was reporting 935 measles cases nationwide. About 13% of those cases have resulted in hospitalization, and only about 4% were in people who had received at least one shot of the measles-mumps-rubella (MMR) vaccine. There have been three measles deaths this year — equal to the total number of deaths in the prior two decades.

There have been at least 12 outbreaks in the US this year, according to the CDC, defined as three or more related cases. In addition to the large outbreak centered in West Texas, other states with outbreaks include Ohio, where there have been more than 30 cases; Montana; and Michigan.

This post appeared first on cnn.com

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