Developing guidelines for school closure interventions to be used during a future influenza pandemic

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Modeling

Background:

• The 2009 A/H1N1 influenza pandemic highlighted operational challenges in school closure interventions.
• Key issues included activation triggers, closure duration, and strategy type, with significant international variation.
• Computer simulation offers a method to refine school closure guidelines.

Purpose of the Study:

• To investigate the effectiveness of school closure interventions for influenza pandemics using simulation.
• To analyze various school closure strategies, durations, and activation triggers.
• To evaluate the impact of combining school closures with antiviral treatments.

Main Methods:

• An individual-based simulation model was employed.
• Simulations examined influenza pandemics with R0 values of 1.5, 2.0, and 2.5.
• Effectiveness of individual vs. simultaneous closures, 2-8 week durations, and daily diagnosed case triggers were analyzed.

Main Results:

• For R0=1.5, 8-week closures reduced attack rate by 14%; combined with antivirals, reduction was 19%.
• For R0 ≥ 2.0, school closures were less effective (4-9% reduction); combined with antivirals, a ~15% reduction was observed.
• Individual school closure strategies showed greater effectiveness than simultaneous closures.

Conclusions:

• Optimal school closure strategy depends on disease severity and transmissibility (R0).
• For low transmissibility (R0 < 2.0), individual closures triggered by daily case counts are recommended.
• For severe, highly transmissible epidemics (R0 ≥ 2.0), long-duration closures combined with other interventions are advised.