Severe infantile measles encephalitis occurred three months after neonatal measles

A 3-month-old girl who developed severe measles encephalitis after neonatal measles is reported. Her mother had measles when she was ten days old and she was admitted to our hospital with low grade fever, Koplik spot, and mild exanthema seventeen days after birth, and she recovered in 7 days without any complication. At three months of age, she was readmitted because of intractable seizures. The levels of IgM and IgG antibodies against measles in the cerebrospinal fluid were elevated. The measles virus genome, amplifying the region encoding the nucleocapsid protein, was detected from the brain specimen by reverse transcriptase-polymerase chain reaction. Magnetic resonance imaging showed a focal destructive lesion and diffuse cerebral atrophy. The electroencephalogram did not show periodic synchronous discharges. Although the neonatal measles was believed to be relatively mild in severity, the possible development of measles encephalitis should be carefully monitored in an infant who had neonatal measles.