School environments are indeed thought to play an important role in the community spread of infectious diseases such as influenza because of the high mixing rates of school children. The closure of schools is therefore often proposed as an efficient mitigation strategy. It comes however with high social and economic costs, making less disruptive interventions highly desirable. We thus design models of micro-interventions and compare the outcomes of alternative mitigation measures. In particular, we find that targeted class closure affords strong mitigation effects: closing a class for a fixed period of time (equal to the sum of the average infectious and latent durations) whenever two infectious individuals are detected in that class decreases the attack rate by almost 70% and significantly decreases the probability of a severe outbreak. The closure of all classes of the same grade mitigates the spread almost as much as closing the whole school.
Our model of targeted class closure strategies based on readily available information on symptomatic subjects and on limited information on mixing patterns, such as the grade structure of the school, show that these strategies might be almost as effective as whole-school closure, at a much lower cost. This may inform public health policies for the management and mitigation of influenza-like outbreaks in the community.