School closure policies at municipality level for mitigating influenza spread: a model-based evaluation

Area of Science:

• Epidemiology
• Public Health
• Mathematical Modeling

Background:

• Influenza poses a significant global public health risk annually, with pandemic potential.
• School-aged populations are highly affected, making school closure policies a consideration for mitigation.
• The cost-benefit analysis and applicability of school closure policies require careful evaluation.

Purpose of the Study:

• To evaluate the effectiveness of reactive school closure strategies for influenza mitigation.
• To assess the impact of gradual school closure policies based on absenteeism.

Main Methods:

• An individual-based model of influenza transmission was developed, integrating sociodemographic, time-use, and contact data.
• The model was calibrated using 2009 pandemic data.
• Three reactive school closure strategies based on student absenteeism were simulated.

Main Results:

• Gradual school closure strategies could reduce attack rates by 20-25% and peak incidence by 50-55%, with approximately three weeks of lost schooling.
• These strategies showed stability against variations in policy timing and absenteeism thresholds.
• Pandemic characteristics like reproduction number and age-specific susceptibility critically influence policy effectiveness.

Conclusions:

• Reactive gradual school closure policies show potential for mitigating influenza spread.
• Policy effectiveness is contingent on the level of intervention and specific pandemic features.
• Strategies utilize readily available data (absenteeism, ILI incidence), enhancing real-world applicability.