Michigan, Pennsylvania join states with measles outbreaks. Here's what to know

Michigan officials confirmed a new measles outbreak Thursday near Grand Rapids, bringing the U.S. to eight states with active vaccine-preventable disease outbreaks. Earlier this week, Pennsylvania declared an outbreak in Erie County as well.

Last week, U.S. measles cases topped 700, with  reporting most of them. Two unvaccinated elementary school-aged children died from measles-related illnesses near the epicenter of the outbreak in rural West Texas. An adult in New Mexico who was not vaccinated also died of a measles-related illness.

Even as the virus continued to spread and the U.S. Centers for Disease Control and Prevention redeployed a team to West Texas, Health Secretary Robert F. Kennedy Jr. claimed in a televised Cabinet meeting on April 10 that measles cases were plateauing nationally. The U.S. has more than double the number of measles cases it saw in 2024.

States with active outbreaks — defined as three or more cases — include Indiana, Kansas, Michigan, Oklahoma, Ohio, Pennsylvania, Texas and New Mexico.

The multistate outbreak across Texas, New Mexico, Oklahoma, and Kansas confirms health experts' fears that the virus will take hold in other U.S. communities with low vaccination rates and that the spread could last a year. The World Health Organization has said cases in  are linked to the Texas outbreak.

Measles is caused by a highly contagious virus that is airborne and spreads easily when an infected person breathes, sneezes, or coughs. It is preventable through vaccines and has been considered eliminated from the U.S. since 2000.

Here's what else you need to know about measles in the U.S.

How many measles cases are there in Texas and New Mexico?

Texas's outbreak began in late January. State health officials said Friday that 36 new cases of measles have been reported since Tuesday, bringing the total to 597 across 23 counties, most of them in West Texas. Two more Texans were hospitalized, for a total of 58 throughout the outbreak, and Reeves County logged its first case.

State health officials estimated Tuesday that about 4% of cases — fewer than 25 — are actively infectious.

Sixty-five percent of Texas's cases are in Gaines County, population 22,892. The virus started spreading in a close-knit, undervaccinated Mennonite community. The county has logged 364 cases since late January, just over 1% of its residents.

The April 3 death in Texas was that of an 8-year-old child, according to Kennedy. Health officials in Texas said the child did not have underlying health conditions and died of “what the child's doctor described as measles pulmonary failure.” A unvaccinated child with no underlying conditions died of measles in Texas in late February — Kennedy said the age was 6.

New Mexico announced five new cases Tuesday, bringing the state’s total to 63. Three more people are in the hospital, for a total of five since the outbreak started. Doña Ana County reported its first case. Most of the state's cases are in Lea County. Two are in Eddy County and one is in Chaves County.

State health officials say the cases are linked to Texas’s outbreak based on genetic testing. New Mexico reported its first measles-related death in an adult on March 6.

How many measles cases are there in Kansas?

Health officials announced Wednesday that Kansas has 37 cases in eight counties in the southwest part of the state.

Finney, Ford, Grant, Gray, and Morton counties each have fewer than five cases. Haskell County has the most, with eight cases; Stevens County has seven; and Kiowa County has six.

The state's first reported case, identified in Stevens County on March 13, is linked to the Texas and New Mexico outbreaks based on genetic testing, a state health department spokesperson said. But health officials have not determined how the person was exposed.

How many measles cases are there in Oklahoma?

Cases in Oklahoma remained steady at 12 total cases Tuesday: nine confirmed and three probable. The first two probable cases were “associated” with the West Texas and New Mexico outbreaks, the state health department said.

A state health department spokesperson said measles exposures were confirmed in Oklahoma City and Tulsa, Rogers and Custer counties, but wouldn't say which counties had cases.

How many measles cases are there in Ohio?

The Knox County outbreak in east-central Ohio has infected a total 20 people as of Tuesday, according to a news release from the county health department, but seven of them do not live in Ohio. In 2022, a measles outbreak in central Ohio sickened 85.

The Ohio Department of Health confirmed 30 measles cases in the state on Thursday. There are 14 cases in Ashtabula County near Cleveland, 14 in Knox County and one each in Allen and Holmes counties. The state count only includes Ohio residents.

The outbreak in Ashtabula County started with an unvaccinated adult who had interacted with someone who had traveled internationally.

How many measles cases are there in Indiana?

Indiana confirmed six connected cases of measles in Allen County in the northeast part of the state — four are unvaccinated minors and two are adults whose vaccination status is unknown.

The cases have no known link to other outbreaks, the Allen County Department of Health said April 9.

How many measles cases are there in Pennsylvania?

In far northwest Pennsylvania, Erie County health officials declared a measles outbreak Monday after finding two new cases linked to a measles case confirmed March 30.

The state has had nine cases overall this year, six of which are not linked to the outbreak, including international travel-related cases in Montgomery County and one in Philadelphia.

How many measles cases are there in Michigan?

Montcalm County has three linked measles cases near Grand Rapids in western Michigan. State health officials say the cases are tied to a large measles outbreak in Ontario, Canada.

As of Thursday, the state had seven confirmed measles cases, but the remaining four are not part of the Montcalm County outbreak. Michigan's last measles outbreak was in 2019.

Where else is measles showing up in the U.S.?

Measles cases also have been reported in Alaska, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Kentucky, Maryland, Minnesota, New Jersey, New York, Rhode Island, Tennessee, Vermont, and Washington.

The U.S. Centers for Disease Control and Prevention define an outbreak as three or more related cases. As of Friday, the agency counted  that qualified as outbreaks in 2025.

In the U.S., cases and outbreaks are frequently traced to someone who caught the disease abroad. It can then spread, especially in communities with low vaccination rates. In 2019, the U.S. saw 1,274 cases and almost lost its status of having eliminated measles. So far in 2025, the CDC's count is 712.

Do you need an MMR booster?

The best way to avoid measles is to get the  (MMR) vaccine. The first shot is recommended for children between 12 and 15 months old and the second between 4 and 6 years old.

Scott Weaver with the Global Virus Network, an international coalition, said people at high risk for infection who got the shots many years ago may want to consider getting a booster if they live in an area with an outbreak. These may include family members living with someone who has measles or those especially vulnerable to respiratory diseases because of underlying medical conditions.

Adults with “presumptive evidence of immunity” generally don’t need measles shots now, the CDC said. Criteria include written documentation of adequate vaccination earlier in life, lab confirmation of past infection or being born before 1957, when most people were likely to be infected naturally.

A doctor can order a lab test called an MMR titer to check your levels of measles antibodies, but experts don't always recommend it and health insurance plans may not cover it.

The CDC says getting another MMR shot is harmless if there are concerns about waning immunity.

People who have documentation of receiving a live measles vaccine in the 1960s don’t need to be revaccinated, but people who were immunized before 1968 with an ineffective measles vaccine made from “killed” virus should be revaccinated with at least one dose, the agency said. That also includes people who don’t know which type they have.

What are the symptoms of measles?

Measles first infects the respiratory tract, then spreads throughout the body, causing a high fever, runny nose, cough, red, watery eyes and a rash.

The rash generally appears three to five days after the first symptoms, beginning as flat red spots on the face and then spreading downward to the neck, trunk, arms, legs and feet. When the rash appears, the fever may spike over 104 degrees Fahrenheit, according to the CDC.

Most kids will recover from measles, but infection can lead to  such as pneumonia, blindness, brain swelling and death.

How can you treat measles?

There’s no specific treatment for measles, so doctors generally try to alleviate symptoms, prevent complications and keep patients comfortable.

Why do vaccination rates matter?

In communities with high vaccination rates—above 95%—diseases like measles have a harder time spreading. This is called “herd immunity.”

But childhood vaccination rates have declined nationwide since the pandemic and more parents are claiming religious or personal conscience waivers to exempt their kids from required shots.

The U.S. saw a rise in measles cases in 2024, including an outbreak in Chicago that sickened more than 60.

What is measles?

Measles is a respiratory virus that can survive in the air for up to two hours. According to the U.S. Centers for Disease Control and Prevention, up to nine out of 10 people who are susceptible will get the virus if exposed.

Most kids will recover from measles if they get it, but infection can lead to dangerous complications like pneumonia, blindness, brain swelling, and death.

Is the vaccine safe?

Yes, the measles, mumps and rubella (MMR) vaccine is safe and highly effective in preventing measles infection and severe cases of the disease.

The first shot is recommended for children between 12 and 15 months old, and the second for children between 4 and 6 years old. The vaccine series is required for kids before kindergarten in public schools nationwide.

Before the vaccine was introduced in 1963, the U.S. saw some 3 million to 4 million cases per year. Now, there are usually fewer than 200 in a normal year.

There is no link between the vaccine and autism, despite a now-discredited study and health disinformation.

Why do vaccination rates matter?

In communities with high vaccination rates — above 95% — diseases like measles have a harder time spreading through communities. This is called “herd immunity.”

But childhood vaccination rates have declined nationwide since the pandemic and more parents are claiming religious or personal conscience waivers to exempt their kids from required shots.

The U.S. saw a rise in measles cases in 2024, including an outbreak in Chicago that sickened more than 60. Five years earlier, measles cases were the worst in almost three decades in 2019.

Gaines County has one of the highest rates in Texas of school-aged children who opt out of at least one required vaccine, with nearly 14% of K-12 children in the 2023-24 school year. Health officials said that number is likely higher because it doesn’t include many children who are homeschooled and whose data would not be reported.

What are public health officials doing to stop the spread?

Health workers are hosting regular vaccination clinics and screening efforts in Texas, as well as working with schools to educate people about the importance of vaccination and offering shots.

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