James Wood The National Centre for Immunisation Research (NCIRS) The effects of internal travel restrictions on the geographic spread of a pandemic Wednesday 29th, March 14:05-14:55pm, Carslaw Building Room 373. In the event of an emergent pandemic of influenza, various types of control measures will be used in order to slow the geographic spread of the virus. Restrictions on travel may be part of such measures and thus it is important to model the consequences of imposing these restrictions. Most previous studies have focused on travel restrictions for external border control, however here I want to concentrate on the role of internal travel restricitons in limiting the spread of influenza within Australia. Due to its large geographic area and low population density, in which the population is largely confined to several major coastal cities, Australia provides an appropriate environment in which to seriously consider implementing restricitons. This may also be facilitated by its political structute as a federation of states In this talk I'll give some background on mathematical models of epidemics, and then construct a simple model of internal spread of an influenza epidemic, incorporating the effects of travel restrictions. The results indicate that travel restrictions can be effective if the basic reproduction number is low, but their effectiveness quickly drops for higher values of this parameter.