Why lockdown? Simplified arithmetic tools for decision-makers, health professionals, journalists and the general public to explore containment options for the novel coronavirus

Gerry Killeen; Samson Kiware

Supplementary Figure 1 . The predicted trajectory of a successfully contained national COVID-19 epidemic in the United Republic of Tanzania, achieved without any contact tracing and isolation. In this simulation, a rigorous 15-week lock down was initiated from week 5 onwards and complemented by complete containment of imported cases, as well as contact tracing and isolation of confirmed cases. Rigorous lock down was assumed to achieve 90% reduction of exposure behaviours by 90% of the population. Complete 100% containment of imported cases assumes that all inbound international visitors are fully isolated for three weeks, 2,3,5,7,69,70,78 except those coming from countries that may be certified as free of local transmission by WHO in the future. However, these simulations differ from figure 1 in that absolutely no contact tracing and isolation was assumed. Predicted successful national containment and elimination though prompt, rigorous lockdown, and then sustained with complete containment of imported cases, despite lack of contact tracing and isolation . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.