The mystery behind a rare measles-related killer, plus 3 strategies to protect young children

LOS ANGELES (KABC) -- After Los Angeles County Health officials announced the death of a school-aged child due to a rare measles complication, many want to know what SSPE is and the best strategies for preventing it. What's most alarming is how it can take root during the most vulnerable period in a child's life.

Between birth and 12 to 15 months, before a baby usually gets the measles vaccine, an infant is vulnerable.

"It's not really well understood how it happens, but it seems like somehow the measles virus stays latent in the brain," said Dr. Nava Yeganeh, the Medical Director for Vaccine Preventable Disease Control with the L.A. County Department of Public Health.

In very rare instances, she said an early-life measles infection can lead to a fatal progressive brain disorder called SSPE. This can typically occur up to 10 years after measles infection.

This week, health officials reported the death of a school-aged child.

The symptoms are devastating and universally fatal.

"It starts off with personality changes, emotional outbursts, and then, there tends to be, like, motor changes and potentially seizures as well. And then from there, it keeps on unfortunately, progressing," she said.

Can it happen if you get measles as an adult? It's not known.

But Yeganeh says SSPE is more likely to happen when infected before age 5. In California, health officials have documented more than a dozen cases.

"They found that the incidence was about 1 in 600, if you had the measles infection prior to 12 months of age. And about 1 in 1,000 or 1,300, in children who had the measles infection less than 5 years of age," Yeganeh said.

It's a tragedy that is vaccine preventable.

So, what can you do to protect a baby not yet eligible for their first dose of the MMR vaccine?

"If you're going to a place where they have measles, or if you're traveling internationally, you should get that child a vaccine," she said.

Ask your pediatrician about it if traveling.

"And number two, is trying to make sure that you are immunized if you're pregnant, making sure that you have antibodies to measles, because those antibodies are transferred to the fetus," she said.

The third strategy is herd immunity and making sure every child is vaccinated. Doctors say this protects infants, the community and those who are immunocompromised.