40 new cases of measles reported in Texas as outbreak grows to 198: Officials

(GAINES COUNTY, Texas) — The number of measles cases associated with an outbreak in western Texas has grown to 198, with 40 cases reported over the last three days, according to new data released Friday.

Almost all of the cases are in unvaccinated individuals or in individuals whose vaccination status is unknown, with 80 unvaccinated and 113 of unknown status. At least 23 people have been hospitalized so far, according to the Texas Department of State Health Services (DSHS).

Just five cases have occurred in people vaccinated with one dose of the measles, mumps, rubella (MMR) vaccine.

Children and teenagers between ages 5 and 17 make up the majority of cases, followed by children ages 4 and under.

So far just one death has been reported in an unvaccinated school-aged child, according to DSHS. The child did not have any known underlying conditions, according to the department.

The Texas death was the first measles death recorded in the U.S. in a decade, according to data from the Centers for Disease Control and Prevention.

A possible second measles death was recorded on Thursday after an unvaccinated New Mexico resident tested positive for the virus. The New Mexico Department of Health said the official cause of death is still under investigation.

Gaines County is the epicenter of the outbreak, with 137 cases confirmed among residents, according to DSHS. More than 90% of cases have been identified in just six counties, which account for less than 1% of the state’s total population, the department said.

State health data shows the number of vaccine exemptions in Gaines County have grown dramatically.

Roughly 7.5% of kindergarteners in the county had parents or guardians who filed for an exemption for at least one vaccine in 2013. Ten years later, that number rose to more than 17.5% — one of the highest in all of Texas, according to state health data.

The CDC has separately confirmed 164 cases in nine states so far this year in Alaska, California, Georgia, Kentucky, New Jersey, New Mexico, New York, Rhode Island and Texas.

The total, however, is likely an undercount due to delays in reporting from states to the federal government.

The majority of nationally confirmed cases are in people who are unvaccinated or whose vaccination status is unknown. Of the cases, 3% are among those who received one dose of the MMR shot and 2% are among those who received two doses.

Measles is one of the most contagious diseases known to humans. Just one infected patient can spread measles to up to nine out of 10 susceptible close contacts, according to the CDC.

Health officials have been urging anyone who isn’t vaccinated to receive the MMR vaccine.

The CDC currently recommends that people receive two vaccine doses, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective, and two doses are 97% effective. Most vaccinated adults don’t need a booster.

Texas health officials are recommending — for those living in the outbreak area — that parents consider an early dose of MMR vaccine for children between ages 6 months and 11 months and that adults receive a second MMR dose if they only received one in the past.

Earlier this week, the CDC said in a post on X that it was on the ground in Texas, partnering with DSHS officials to respond to the measles outbreak.

Measles was declared eliminated from the U.S. in 2000 due to the highly effective vaccination program, according to the CDC. However, CDC data shows vaccination rates have been lagging in recent years.

ABC News’ Youri Benadjaoud contributed to this report.