The COVID-19 pandemic has imposed several dilemmas for managers in the public sector, with school reopening being among the most complex decisions. The present article presents a microsimulation model of the pandemic course considering various scenarios within the confines of a classroom in the city of Belo Horizonte, Brazil. For that, a susceptible-infectious-recovered (SIR) model was integrated with a random graph model, associating epidemiological characteristics with sociometric and sociodemographic factors. Social contact rates projected for Brazil in the European POLYMOD project were adapted for the city of Belo Horizonte to simulate the number of contacts among individuals considering a Poisson distribution. The simulation used as reference a group of 20 students and their families. The projected scenarios discriminated three age groups with their respective rate of daily social contacts: 0 to 5 years (0.01), 6 a 14 years (1.80), and 15 to 19 years (0.20). The simulations showed clear differences between these age groups, depending on the initial number of infected individuals and on the use or not of face masks in the school. The results confirm that the absence of adequate mitigation measures entails a considerable increase in transmission in the school setting.
