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

On March 23rd authorities of Mexico City ordered the closure of cinemas, theaters, and other public places as a preventive measure. We show in Figure 16 the incidence and cummulative incidence under reductions in contact rates of 25%, 50% and 75%, and for θ = 7 days. Our simulations show that for these reductions in contact rates, a reduction of up to 91% in incidence can be obtained. However, if we take the first 35 weeks after the arrival of the first imported case, Figure 16 (b) shows that depending on the contact rate reduction, we could reach a similar situation to that of Wuhan with 69 050 total cases, (q 1 = 0.75), or a medium level situation with 10 800 total cases (q 1 = 0.50) or a more manageable situation with 4 351 total cases, (q 1 = 0.25). Figure 17 shows the scenario for different θ, the time it takes to get the desired contact rate reduction. In this case isolation also begins on March 23rd and the reduction in contact rates is 60%. We observe that by increasing the value of this parameter, the peak and cumulative incidence will be higher. For example, if the time it takes to reduce the contact rates is θ = 7 days, then the cumulative incidence 16 weeks after the arrival of the first imported case will be 6 532, while if the time is θ = 15 days, then the incidence rises to 8 909. Finally, if the time it takes to reduce contact rates is 30 days, then the cumulative incidence rises to 14 980. It is important to note that although the value of the cumulative 19 . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Figure 16 : (a) Incidence and (b) cumulative incidence for the isolated population. The time to obtain the target contact rate reduction is 7 days. Black, red and blue lines correspond to reductions in contact rate of 25%, 50% and 75%, respectively. Horizontal axis is time in days and the vertical axis is number of individuals.