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

We also assume that isolation measures are not perfect and individuals escape from isolation regardless of infection status at an exponential average time of 1/ω and also that individuals suspend, forget or relax sanitary measures at the rate ω. It is also assumed that the isolation time is always larger than the total time of duration of disease comprising the incubation time, 1/γ, and the infectiousness time 1/η. Therefore 1/ω > 1/γ + 1/η. We further assume that a fraction ρ of the exposed individuals develop the asymptomatic disease and that 1 − ρ become symptomatic. The contact rates before isolation is enforced are β i a and β i a for symptomatic and asymptomatic individuals. Following the ideas set in the previous section we define two time-dependent contact rates for the isolated population that can be consulted in Appendix D.