Model to estimate epidemic patterns of influenza A (H1N1) in Mexico

Objective. Apply a mathematical model to estimate the epidemic patterns of influenza A (H1N1) in Mexico during the stages of application and suspension of measures to mitigate the epidemic. Methods. The effective reproductive number (R) for each state of Mexico during and after the application of social distancing measures was estimated by the SIR model (susceptible, infected, and recovered individuals) based on data published by the Ministry of Health of Mexico. Results. From the beginning of the outbreak until suspension of school activities (28 April-13 May 2009), the national median of R was 1.13. In the following period (14 May-17 July 2009) the national median of R decreased to 1.01. Conclusions. It was demonstrated that several epidemic scenarios occurred at the national level. It is suggested that heterogeneous patterns at the state level be taken into account in decision-making on the adoption of measures to mitigate influenza epidemics.