Measles? That’s a disease medical science conquered long ago, right?
Not quite right. While modern vaccines have the disease largely under control, frightening — sometimes deadly — outbreaks still occur. And cases are on the rise this year, alarming officials nationwide.
Measles outbreaks in West Texas and New Mexico now total more than 250 cases, and two unvaccinated people have died from measles-related causes. Recently, measles cases were reported in Orange County — an infant returning home after international travel on Feb. 19 — and in Los Angeles County a person returning to LAX from China on March 11.
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 in the U.S. since 2000. But outbreaks still arise like the cases that erupted in the Southwest U.S. this week. And, though not that common, so do deaths — a school-age child died of measles in Texas last month, and New Mexico reported its first measles-related death in an adult last week.
While most people afflicted experience complete recoveries, it’s not a disease to be taken lightly, experts say.
Measles cases reported in the U.S. this year — including five in California — are likely to increase given the ongoing outbreak in West Texas and bordering New Mexico, according to the Los Angeles County Department of Public Health. Outbreaks have grown in these states in recent weeks, particularly in communities where vaccination levels are lower.
“To prevent an outbreak from happening, you need to vaccinate about 95% of the susceptible population because measles is so contagious. It’s just about the most contagious pathogen that we know,” said Dr. Timothy Brewer, a professor of medicine in the division of infectious diseases at the David Geffen School of Medicine at UCLA and of epidemiology at the UCLA Fielding School of Public Health.
“In California, our vaccination rates are about 95%,” Brewer said. “In Texas, they’re below that — and at least as of 2023, it was running around 90-94% in Texas. I suspect they’ve dropped even further since then, that’s definitely what’s contributing to the outbreak in Texas.”
Even a small decline in vaccination can significantly increase the likelihood of an outbreak. Measles can “easily cross borders” in any community where vaccination rates are below 95 percent, according to the U.S. Centers for Disease Control.
“Measles is the most contagious infectious disease, and is easily spread person to person through the air, so there is a concern of an outbreak whenever we see an increase in cases,” said Dr. Anissa Davis, Long Beach health officer.
All measles cases diagnosed in California this year involved recent international travelers. Prior to this case, the last case of measles in a Los Angeles County resident was reported in February 2024.
