Widespread school closures help reduce the spread of serious flu epidemics and pandemics, but the costs of such measures, including loss of classroom time for children and work absences for caregivers, have some experts looking for better solutions.

New, model-based research published in PLOS Computational Biology suggests that targeted school closures may help reduce the spread of pandemic influenza with fewer effects on parents and children than more traditional policies, such as nationwide school closures.

Although previous studies have explored the impact of closing schools to reduce influenza transmission, most of these analyses have focused on the costly approach of nationwide closures, considered too burdensome by a number of countries during the 2009 swine flu pandemic.

The modeling study evaluates the impact of four different school closure interventions: Nationwide, countywide (all schools in a county), reactive school-by-school (entire school when student absenteeism exceeds a certain threshold), and reactive gradual closure (classes first, then grades, and finally the entire school), by simulating an influenza epidemic.

“We investigated the effect that different closure strategies would have on the dynamics of the pandemic in the United Kingdom, with an extensive analysis on the implementation characteristics of closures, namely the duration of each closure event, the timeout between two consecutive closures and the fraction of absent students used as a threshold for triggering closure,” researchers wrote in the study.

They found national closure of schools made a systematically lower impact on the reduction of influenza transmission, but entailed high social costs as it "would involve students (and consequently their caregivers) and school staff of the entire country all at once,” researchers wrote. The study also found reactive, gradual, and county closure had a similar impact on influenza spread. However, they found gradual and county closures resulted in fewer unnecessary closures.

“These approaches entail lower social costs than nationwide closure since they involve a lower number of students and parents who must stay away from work to take care of them,” researchers said in a statement.

Based on their findings, researchers conclude targeted school closure policies, particularly gradual and countywide closures, may limit the impact of future influenza pandemics. However, health authorities must balance economic and social costs with the the severity of the threat to public health.

Souce: Fumanelli L, Ajelli M, Merler S, Ferguson N, Cauchemez S. Model-Based Comprehensive Analysis of School Closure Policies For Mitigating Influenza Epidemics and Pandemics. PLOS Computational Biology. 2016.