Age-Specific Patterns of Influenza Activity in Utah: Do Older School Age Children Drive the Epidemic?

Area of Science:

• Epidemiology
• Public Health
• Virology

Background:

• Influenza (flu) is a contagious respiratory illness.
• Understanding influenza transmission patterns is crucial for public health interventions.
• Pediatric populations often play a significant role in the spread of seasonal influenza.

Purpose of the Study:

• To determine the age group that experiences the earliest peak of medically-attended, laboratory-confirmed influenza infections.
• To analyze the timing of influenza peaks across different age demographics in Utah over 12 seasons.

Main Methods:

• Retrospective analysis of medically-attended, laboratory-confirmed influenza cases.
• Data collected across 12 consecutive influenza seasons in Utah.
• Comparison of peak influenza activity timing among age groups: 0-4 years, 12-18 years, and adults ≥65 years.

Main Results:

• Medically-attended influenza infection consistently peaked first in older children (12-18 years).
• Peak activity in older children preceded that in younger children (0-4 years) by over 2 days.
• Peak activity in older children occurred more than 6 days before the peak in adults aged 65 years and older.

Conclusions:

• Older children (12-18 years) serve as an early indicator for influenza outbreaks in Utah.
• This finding suggests targeted public health messaging and interventions for this age group could be beneficial.
• The early peak in adolescents may precede wider community transmission, impacting other age groups.