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

As for the full the full, timely intervention package simulated in figure 1 (Compare with figure S1), removing contact tracing from the less rigorous but extended lock down intervention package has only a modest effect on the overall containment trajectory ( Figure 4E and F), with only 797 more cases and 3 additional fatalities. Under a the far more extreme conditions of a failed containment campaign, followed by a resurgent, full-blown epidemic, contact tracing becomes a rather pointless exercise, even for targeting clinical disease management. At the peak of the epidemic, when over 4 million new symptomatic cases may occur per week and even mortality rate may outstrip testing capacity (Figure 2 ), so case confirmation success rates may plummet to below 0.2%.