Overview

• Los Angeles County public health officials confirmed the child died from subacute sclerosing panencephalitis, a progressive and typically fatal late effect of measles.
• The child was infected with measles as an infant before reaching the recommended age for the first MMR dose at 12 months.
• SSPE can emerge years after the initial infection and has no curative treatment, with survival after symptom onset often measured in one to three years.
• Health authorities note the SSPE risk is about 1 in 600 for infections before age two compared with roughly 1 in 10,000 overall.
• CDC data for 2025 cite 37 U.S. measles outbreaks with about 1,454 cases and three deaths, reinforcing calls to complete the two‑dose MMR series.