The SARS-CoV-2 epidemic outbreak: a review of plausible scenarios of containment and mitigation for Mexico

Manuel Adrian Acuna-Zegarra; Andreu Comas-Garcia; Esteban Hernandez-Vargas; Mario Santana-Cibrian; Jorge X. Velasco-Hernandez

In the examples illustrated above, we see that if the time necessary to achieve the contact rate reduction is either θ = 30 or θ = 90 days (differing for more than two months), the outbreak sizes are similar which to us indicate the existence of a threshold value θ * such that the cumulative incidence is reduced if θ < θ * . In summary large learning times do not have an impact on the size of the epidemic. Figure 10 shows that if T θ is closer to the time of detection of the first cases (in this example, 10 infected people), then the cumulative incidence can be reduced more efficiently and underlines the importance of reducing the effective contact rate quickly. Figure 10 (b) shows that although the time it takes to get the contact rate reduction is high (θ = 90 days), we still can obtain a large reduction in the final cumulative incidence provided we have a quick response to enforce reduced contacts and a large target reduction in the effective contact rate. Figure 11 shows that when T θ = 15 days, regardless of the time θ it takes to obtain the contact rate reduction, the final cumulative incidence is very low for large reductions in contact rates (q 1 small) or high for low reductions in contact rate (q 1 large). Figure 10 (a) and 12 show the importance of reducing the contact rate for flattening the epidemic curve. On any scenario, a large reduction of the effective contact rate is necessary (Figure 12 (a)). Figures 12(b) shows an example where an insufficient reduction of the contact rate (40%), leads to a very weak reduction on the final cumulative incidence.