Measles-Induced Encephalitis: Treatment and Prevention
Treatment
There is no specific antiviral therapy proven effective for measles encephalitis; treatment is primarily supportive with vitamin A supplementation, monitoring for complications, and maintaining high vaccination coverage to prevent disease occurrence. 1
Acute Measles Encephalitis Management
Initiate supportive care immediately including monitoring of neurological status, seizure management, and maintenance of adequate hydration and nutrition 2
Administer vitamin A supplementation to ALL children with clinical measles regardless of country of residence: 200,000 IU for children ≥12 months, 100,000 IU for children <12 months 3
Monitor for and treat secondary bacterial infections with appropriate antibiotics, as complications frequently include pneumonia, otitis media, and other bacterial superinfections 1
Consider intravenous aciclovir empirically (10mg/kg three times daily) while awaiting diagnostic confirmation, as HSV encephalitis must be excluded and delays in treatment beyond 48 hours worsen prognosis 2
Special Populations: Immunocompromised Patients
In immunocompromised patients with measles encephalitis (measles inclusion body encephalitis - MIBE), treatment duration should be extended to at least 21 days if aciclovir is used empirically, though no specific antiviral has proven efficacy against measles virus 2, 4
Measles encephalitis in immunosuppressed children presents diagnostic challenges as there are no pathognomonic features on history, clinical presentation, EEG, or CT; detection of measles virus antigen in nasopharyngeal secretions or intrathecal antibody synthesis may not be possible in all cases 4
Intrathecal ribavirin has been attempted for subacute sclerosing panencephalitis (SSPE) with limited success and is not standard therapy 5
Diagnostic Approach
Perform lumbar puncture urgently (after CT if indicated) with opening pressure, CSF glucose/protein, cell count, PCR for HSV-1/2, VZV, enteroviruses, and measles-specific antibody testing 2
For SSPE diagnosis specifically, detect intrathecal synthesis of measles-specific antibodies in CSF, which is crucial given the characteristic presentation of insidious onset, personality changes, declining intellectual performance, myoclonic jerks with 1:1 EEG periodic complexes, and progressive deterioration 5
Obtain MRI brain as soon as possible in all suspected encephalitis cases, though CT and EEG abnormalities may be present but are not specific 2, 6
Send blood cultures, nasopharyngeal swabs for measles RNA detection, and serum for measles-specific IgM antibodies to confirm diagnosis 2, 1
Prevention
Measles vaccination is the ONLY effective prevention strategy for all forms of measles encephalitis including SSPE, and MMR vaccine does not increase the risk of SSPE. 5, 7
Primary Prevention Through Vaccination
Administer MMR vaccine at 12-15 months for first dose and 4-6 years for second dose to maintain high population immunity 3
Widespread measles vaccination has essentially eliminated SSPE from the United States, demonstrating the critical importance of maintaining high vaccination coverage 7
The true risk of SSPE following natural measles infection is 4-11 per 100,000 cases, but this substantially underestimates actual risk because only 11% of measles infections are officially reported, making the real risk approximately 10-fold higher 7
Post-Exposure Prophylaxis
Administer MMR vaccine within 72 hours of measles exposure to potentially provide protection in susceptible individuals 3
Ensure healthcare workers and high-risk groups have documented immunity through vaccination or serologic confirmation 3
Critical Misconceptions to Avoid
Do NOT withhold MMR vaccination due to SSPE concerns - the ACIP definitively states that MMR vaccine does not increase SSPE risk, even in persons who previously had measles or received prior measles vaccine 5, 7
When rare SSPE cases occur in vaccinated children without known measles history, evidence indicates these children likely had unrecognized measles infection BEFORE vaccination, and SSPE resulted from that natural infection, not the vaccine 5
Do not confuse SSPE (which occurs months to years after measles infection) with acute post-vaccination encephalopathy (extremely rare at 1 per 2 million doses, occurring around 10 days post-vaccination) or febrile seizures (occurring 5-12 days after MMR at 1 per 3,000 doses without residual neurologic sequelae) 5
Three Distinct Forms of Measles Encephalitis
Measles causes three separate encephalitic syndromes with different timing and populations: 2
Acute post-infectious measles encephalitis (APME) or acute disseminated encephalomyelitis occurring during or shortly after acute infection (1-14 days after rash), may present without typical rash 2
Measles inclusion body encephalitis (MIBE) occurring approximately 6 months after primary infection in immunocompromised patients, often without rash 2
Subacute sclerosing panencephalitis (SSPE) occurring several years after primary infection in immunologically normal individuals 2