A stochastic equation-based model of the value Of international air-travel restrictions for controlling pandemic flu

International air travel can be an important contributing factor to the global spread of infectious diseases, as evidenced by the outbreak of Severe Acute Respiratory Syndrome in 2003. Restrictions on air travel may therefore be one response to attempt to control a widespread epidemic of a disease such as influenza. We present results from a stochastic, equation-based, global epidemic model which suggest that air travel restrictions often provide only a slight delay in the epidemic. This delay may give valuable time in which to implement other disease control strategies; however, if other strategies are not implemented, the use of travel restrictions alone may lead to a more severe epidemic than if they had not been imposed. Our results also indicate that the particular network of cities chosen for modeling can have a great influence on the model results.