Is measles infection at 5 years or older a concern?

Measles at Age 5 or Older Remains a Serious Concern

Measles infection at age 5 or older is absolutely a concern and should never be dismissed as benign—while the highest risk for subacute sclerosing panencephalitis (SSPE) occurs with infection before age 5, children aged 5 and older still face significant risks of acute complications including encephalitis (1 in 1,000 cases), pneumonia, and death (1-2 per 1,000 cases). 1

Why Age 5+ Measles Cases Matter

Acute Complications Remain Severe

• Encephalitis occurs in approximately 1 in 1,000 measles cases at any age, with survivors often experiencing permanent brain damage and mental retardation 1
• Death occurs in 1-2 per 1,000 reported measles cases in the United States, with pneumonia and acute encephalitis being the most common causes 1
• The disease is frequently complicated by diarrhea, middle ear infection, and bronchopneumonia regardless of age 1

SSPE Risk Persists Beyond Age 5

While the highest risk for SSPE occurs in children who contract measles before age 5 2, 3, this does not mean older children are immune to this devastating complication:

• SSPE can develop with a median latency period of 9.5 years (range: 2.5-34 years) after measles infection 3
• The condition is reported in 6.5 to 11 per 100,000 measles cases overall 2
• SSPE remains invariably fatal with no cure, only supportive care 2, 4

Public Health Urgency

• One confirmed measles case constitutes an urgent public health situation requiring immediate investigation and control measures 1, 5
• Measles is highly contagious through aerosols, remaining infectious from 4 days before through 4 days after rash onset 5
• The 1989-1991 U.S. measles resurgence resulted in over 55,000 cases and 120 deaths, demonstrating the ongoing threat when vaccination coverage drops 5

Critical Management for Any Age

Immediate Actions Required

• Isolate immediately for at least 4 days after rash onset 5
• Contact local/state health department immediately—do not wait for laboratory confirmation 1, 5
• Administer 200,000 IU vitamin A orally on day 1 (100,000 IU for children <12 months)—this is the only evidence-based intervention proven to reduce measles mortality 1, 5
• For complicated measles (pneumonia, otitis, croup, severe dehydration, neurological problems), give a second dose of 200,000 IU vitamin A on day 2 1, 5

Diagnostic Confirmation

• Collect blood for measles-specific IgM antibody testing during first clinical encounter 5
• If IgM negative within 72 hours of rash onset, obtain second specimen at least 72 hours after rash onset 5

Treatment Protocol

• Treat secondary bacterial infections with appropriate antibiotics 5
• Provide oral rehydration therapy for diarrhea 1, 5
• Monitor nutritional status and enroll in feeding programs if indicated 1, 5

Common Pitfalls to Avoid

• Do not delay vitamin A supplementation—administer on day 1 as this directly impacts mortality 1, 5
• Do not assume vaccination history provides complete protection—approximately 5% of children who receive only one dose of MMR fail to develop immunity 5
• Do not underestimate transmission risk—strict airborne precautions with N95 respirators are required for all healthcare personnel 5
• Do not dismiss measles as "mild" in any age group—complications can be severe and life-threatening 1, 6

The Bottom Line

The notion that measles at age 5 or older is "no concern" is dangerously incorrect. While children infected before age 5 have the highest SSPE risk 2, 3, measles at any age carries substantial risks of acute complications including encephalitis, pneumonia, and death 1. Every measles case requires immediate public health notification, isolation, vitamin A supplementation, and vigilant monitoring for complications 1, 5.