Epidemiology and Infection

Original Papers

Pandemic influenza

Model predictions and evaluation of possible control strategies for the 2009 A/H1N1v influenza pandemic in Italy


a1 Predictive Models for Biomedicine & Environment, Bruno Kessler Foundation, Trento, Italy

a2 Department of Mathematics, University of Trento, Trento, Italy

a3 National Center for Epidemiology Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy


We describe the real-time modelling analysis conducted in Italy during the early phases of the 2009 A/H1N1v influenza pandemic in order to estimate the impact of the pandemic and of the related mitigation measures implemented. Results are presented along with a comparison with epidemiological surveillance data which subsequently became available. Simulated epidemics were fitted to the estimated number of influenza-like syndromes collected within the Italian sentinel surveillance systems and showed good agreement with the timing of the observed epidemic. On the basis of the model predictions, we estimated the underreporting factor of the influenza surveillance system to be in the range 3·3–3·7 depending on the scenario considered. Model prediction suggested that the epidemic would peak in early November. These predictions have proved to be a valuable support for public health policy-makers in planning interventions for mitigating the spread of the pandemic.

(Accepted May 14 2010)

(Online publication June 14 2010)


c1 Author for correspondence: Dr M. Ajelli, Predictive Models for Biomedicine & Environment, Bruno Kessler Foundation, Via Sommarive 18, I-38123 Trento Povo, Italy. (Email: ajelli@fbk.eu)