Measles cases inched up slightly in the U.S. this past week, with a new county impacted in Texas and Colorado reporting a new outbreak.

There are 1,088 confirmed measles cases in the U.S., up 42 from last week, the Centers for Disease Control and Prevention said Friday. Texas, where the nation's biggest outbreak raged during the late winter and spring, reported 10 additional cases this week for a total of 738.

There are three other major outbreaks in North America.

One in Ontario, Canada, has resulted in 1,888 cases from mid-October through May 27. Another in Alberta, Canada, has sickened 628 as of Thursday. And the Mexican state of Chihuahua had 1,693 measles cases and three deaths as of Wednesday, according to data from the state health ministry.

Since the outbreak in Texas, New Mexico and Oklahoma began, two elementary school-aged children in the epicenter in West Texas and an adult in New Mexico have died of measles. All were unvaccinated.

Other states with active outbreaks — which the CDC defines as three or more related cases — include Colorado, Kansas, Michigan, Montana, North Dakota, Ohio, Pennsylvania and Tennessee.

Measles is caused by a highly contagious virus that’s 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?

There are a total of 738 cases across 35 counties, most of them in West Texas, state health officials said Friday.

Throughout the outbreak, 94 people have been hospitalized. McLennan County, which includes the city of Waco, was added to the state's list of counties with active cases.

State health officials estimated less than 1% of cases — fewer than 10 — are actively infectious. Fifty-six percent of Texas’ cases are in Gaines County, where the virus started spreading in a close-knit, undervaccinated Mennonite community. The county has had 409 cases since late January — just over 1.7% of the county’s residents.

The April 3 death in Texas was an 8-year-old child, according to Health Secretary Robert F. Kennedy Jr. Local health officials 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 child was 6.

How many measles cases are there in New Mexico?

New Mexico added one new case on Friday for a total of 79.

Seven people have been hospitalized since the outbreak started. Most of the state’s cases are in Lea County. Sandoval County near Albuquerque has six cases, Eddy County has three, Doña Ana County has two and Chaves and Curry counties have one each.

An unvaccinated adult died of measles-related illness March 6. The person did not seek medical care.

How many cases are there in Oklahoma?

Oklahoma held steady Friday with a total of 14 confirmed and three probable cases.

The state health department is not releasing which counties have cases.

How many cases are there in Colorado?

Colorado has seen a total of seven measles cases in 2025 and one outbreak with three related cases, which the state health department announced Thursday.

All three cases appear to stem from an international flight that landed at Denver International Airport in mid-May. Two people with confirmed cases live in Arapahoe County, near Denver — one unvaccinated child under the age of 5 and an unrelated vaccinated adult. The other person was an out-of-state traveler who was infectious on the flight and stayed at a hotel near the airport. State health officials said Thursday there is no evidence of further spread.

The other counties with cases in 2025 are Pueblo, Jefferson and Archuleta counties with one each and Denver with two.

How many cases are there in Kansas?

Kansas has a total of 64 cases across 11 counties in the southwestern part of the state, with two hospitalizations. All but five of the cases are connected, and most of the cases are in Gray County.

How many cases are there in Michigan?

Michigan has a steady eight confirmed cases of measles, with an outbreak of four connected cases in Montcalm County in the western part of the state that health officials say is tied to the Ontario outbreak.

How many cases are there in Montana?

Montana has 13 measles cases as of Thursday. Ten are in Gallatin County, which is where the first cases showed up — Montana’s first in 35 years.

Flathead County has two cases and Hill County has one case.

Health officials said there is potential for community transmission in Hill County. There are outbreaks in neighboring North Dakota and the Canadian provinces of Alberta, British Columbia and Saskatchewan.

How many cases are there in North Dakota?

North Dakota, which hadn't seen measles since 2011, is up to 29 cases as of Thursday. Two of the people have been hospitalized, and all of the people with confirmed cases were not vaccinated.

There are 13 cases in Williams County in western North Dakota on the Montana border. On the eastern side of the state on the Minnesota border, there are eight cases in Grand Forks County and seven cases in Cass County. Burke County, in northwest North Dakota on the border of Saskatchewan, Canada, has one case.

How many cases are there in Ohio?

Ohio remained steady for a second week at 34 measles cases and one hospitalization, according to the Ohio Department of Health. That count includes only Ohio residents.

The state has two outbreaks: Ashtabula County near Cleveland has 16 cases, and Knox County in east-central Ohio has 20 — 14 among Ohio residents and the rest among visitors.

Allen, Cuyahoga, Holmes and Defiance counties have one case each.

How many cases are there in Pennsylvania?

Pennsylvania remains steady at 15 cases overall in 2025 as of Thursday, including international travel-related cases in Montgomery County and one in Philadelphia.

An outbreak of eight measles cases in Erie County in far northwest Pennsylvania has remained steady since it began in mid-April.

How many cases are there in Tennessee?

Tennessee has had six measles cases since early May, but no change since. Health department spokesman Bill Christian said all cases are the middle part of the state, and that “at least three of these cases are linked to each other” but declined to specify further. The state also did not say whether the cases were linked to other outbreaks or when Tennessee’s outbreak started.

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

Measles cases also have been reported in Alaska, Arkansas, California, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, Minnesota, Missouri, Nebraska, New Jersey, New York, Rhode Island, Vermont, Virginia and Washington.

Cases and outbreaks in the U.S. are frequently traced to someone who caught the disease abroad. The CDC says more than twice as many measles have come from outside of the U.S. compared to May of last year, and most of those are in unvaccinated Americans returning home. In 2019, the U.S. saw 1,274 cases and almost lost its status of having eliminated measles.

What do you need to know about the MMR vaccine?

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

Getting another MMR shot as an adult is harmless if there are concerns about waning immunity, the CDC says. 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 vaccine made from “killed” virus should be revaccinated with at least one dose, the agency said.

People who have documentation that they had measles are immune, and those born before 1957 generally don’t need the shots because so many children got measles back then that they have “presumptive immunity."

Measles has a harder time spreading through communities with high vaccination rates — above 95% — due to “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.

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 dangerous complications 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.