Child in Los Angeles dies from rare measles-related brain disorder years after infection

A school-aged child in Los Angeles County has died from subacute sclerosing panencephalitis, a rare and almost always fatal brain disorder that develops years after a measles infection. Officials have released few details about the case beyond noting the child contracted measles as an infant, before vaccines were routinely given.

Measles is a highly contagious respiratory illness that spreads easily from person to person and is typically marked by fever, cough and a red rash. The measles virus can persist in the body after the initial infection and mutate over time, triggering SSPE years later. SSPE usually surfaces six to 10 years after the original infection and can progress from mood changes to involuntary movements, severe brain damage and death. In roughly four to 11 per 100,000 measles cases, SSPE develops; there is no cure, though antiviral and anti-inflammatory drugs may slow progression.

Measles can also cause pneumonia, bronchitis and laryngitis, and health officials say the long lag between infection and SSPE underscores the disease’s potential for delayed devastation—even as attention often centers on outbreaks that affect younger children. The Los Angeles County death is among three measles-related fatalities reported this year by the Centers for Disease Control and Prevention.

SSPE remains rare in the United States, with only about four to five cases reported annually. The disease’s death toll remains high—about 95 percent—because there is no cure. Public health researchers emphasize that brain imaging and clinical history are key to diagnosis and management, though treatment is palliative.

Vaccination remains the strongest defense against measles. The MMR vaccine is about 97 percent effective and has helped prevent more than 60 million deaths worldwide from 2000 through 2023. Researchers including Benedict Michael wrote that declining vaccination rates have been fueled in part by misinformation linking MMR to autism—a claim that has been debunked repeatedly. “Declining vaccination rates stem partly from fraudulent research attempting to link the MMR vaccine to autism — claims by a now-discredited doctor that have been thoroughly debunked,” Michael wrote in The Conversation.

Public health data show vaccination coverage slipping in some pockets of the country. For the 2024–25 school year, about 92.5 percent of kindergarteners had received the MMR vaccine, down from 95 percent in the 2019–20 school year. The drop in immunization rates coincides with broader hesitancy, contributing to ongoing measles transmission and leaving infants who are too young to be vaccinated more vulnerable.

“This case is a painful reminder of how dangerous measles can be, especially for our most vulnerable community members,” Los Angeles County Health Officer Dr. Muntu Davis said in a statement last week. “Infants too young to be vaccinated rely on all of us to help protect them through community immunity. Vaccination is not just about protecting yourself — it’s about protecting your family, your neighbors and especially children who are too young to be vaccinated.”

The death in Los Angeles County underscores the continuing risk posed by measles as vaccination coverage fluctuates and outbreaks occur in parts of the country. Health officials say staying up to date with MMR vaccination is essential for protecting those who cannot be vaccinated, including infants and immunocompromised individuals.