Evaluating the impact of curfews and other measures on SARS-CoV-2 transmission in French Guiana

Andronico, Alessio; Tran Kiem, Cécile; Paireau, Juliette; Succo, Tiphanie; Bosetti, Paolo; Lefrancq, Noémie; Nacher, Mathieu; Djossou, Félix; Sanna, Alice; Flamand, Claude; Salje, Henrik; Rousseau, Cyril; Cauchemez, Simon

While general lockdowns have proven effective to control SARS-CoV-2 epidemics, they come with enormous costs for society. It is therefore essential to identify control strategies with lower social and economic impact. Here, we report and evaluate the control strategy implemented during a large SARS-CoV-2 epidemic in June–July 2020 in French Guiana that relied on curfews, targeted lockdowns, and other measures. We find that the combination of these interventions coincided with a reduction in the basic reproduction number of SARS-CoV-2 from 1.7 to 1.1, which was sufficient to avoid hospital saturation. We estimate that thanks to the young demographics, the risk of hospitalisation following infection was 0.3 times that of metropolitan France and that about 20% of the population was infected by July. Our model projections are consistent with a recent seroprevalence study. The study showcases how mathematical modelling can be used to support healthcare planning in a context of high uncertainty.