The United States is currently grappling with a severe measles outbreak, and a recent case study has highlighted a frightening complication that can emerge years after the initial infection, ultimately proving fatal.

According to the Centers for Disease Control and Prevention (CDC), as of March 6, there have been close to 1,300 measles cases reported across the country in 2026, a figure that could potentially match last year’s unprecedented outbreak.

This year’s outbreak is particularly concentrated in South Carolina, where 662 individuals have been diagnosed with measles since the beginning of the year.

Measles is an extremely contagious disease marked by symptoms such as a cough, fever, and a distinctive rash that begins on the face before spreading to the rest of the body. It also presents tiny white spots inside the mouth, known as Koplik spots.

Although many people recover without lasting effects, measles can, in rare cases, lead to severe complications such as brain inflammation, immune system damage, and secondary infections.

Recently, a report from the Children’s Hospital of Orange County in California detailed the alarming case of a seven-year-old boy. He suffered from seizures and cognitive decline for three months. During his hospitalization, he exhibited heightened reflexes, muscle spasms, and lost the ability to speak.

Doctors learned the boy had contracted measles at seven months old while living in Afghanistan, where the disease is endemic.

An MRI scan of the child’s brain showed swelling and slowed movement of water molecules in the frontal lobe and corpus callosum, a sign of cell injury or death. The doctors diagnosed the boy with subacute sclerosing panencephalitis (SSPE) caused by his measles infection.

The above images show the child’s brain nearly seven years after he was infected with measles. He died a year later of subacute sclerosing panencephalitis (SSPE)

SSPE progresses over months or years after measles and has a mortality rate of 95 percent. The boy in the case study died a year after his symptoms began, doctors wrote in the New England Journal of Medicine. 

As the disease progresses, patients gradually become vegetative. Survival time of SSPE ranges from about 45 days to 12 years, and most patients survive nearly four years after symptoms start. 

There are usually only four to five cases every year in the US, recent studies have estimated. 

The latest CDC figures show 1,281 measles cases so far in 2026. The highest totals have been reported in South Carolina (662), Utah (184) and Florida (109). 

Measles spreads through direct contact with infectious droplets or through the air. Patients with a measles infection are contagious from four days before the rash through four days after the rash appears. Enclosed areas like airports and planes are extremely risky locations for disease transmission. 

It first invades the respiratory system, then spreads to the lymph nodes and throughout the body. As a result, the virus can affect the lungs, brain and central nervous system. 

While measles sometimes causes milder symptoms, including diarrhea, sore throat and achiness, it leads to pneumonia in roughly six percent of otherwise healthy children, and more often in malnourished children.

Measles causes a distinctive rash as pictured in the above stock image. In severe cases, it can also lead to pneumonia and brain swelling (stock image)

Though the brain swelling that measles can trigger is rare, occurring in about one in 1,000 cases, it is deadly in roughly 15 to 20 percent of those who develop it, while about 20 percent are left with permanent neurological damage such as brain damage, deafness or intellectual disability. 

Measles also severely damages a child’s immune system, making them susceptible to other potentially devastating bacterial and viral infections they were previously protected against. 

The disease can best be prevented with a two-dose measles, mumps and rubella (MMR) vaccine, which is given to children once between 12 and 15 months and again at between four and six years.

The shot is 97 percent effective, and the CDC estimates unvaccinated individuals have a 90 percent chance of becoming ill.   

‘The primary way to prevent measles infection and its neurologic sequelae is vaccination,’ doctors wrote in the case study.

Nationwide, 92.5 percent of kindergarteners are fully vaccinated against measles and 3.6 percent have an exemption. 

Before MMR vaccines became available in the 1960s, measles caused epidemics with up to 2.6 million global deaths every year. By 2023, that number had fallen to roughly 107,000 deaths.