Travel patterns and traveller behaviour and their relationship to the importation of infectious disease into Australia

Abstract

The importation of infectious diseases into Australia via international travel poses a continuing and evolving threat to national disease control. There is an increasing need to understand the contribution of air travel to the spread of infectious diseases globally. Although travel has been a means of infectious disease dissemination throughout history, the speed, reach and volume of modern air transportation results in the rapid spread of infectious diseases globally. Air travellers may still be within the incubation period of most infectious diseases when they arrive at their destination and all countries are vulnerable to the importation of infectious diseases. Travellers play a significant role in the spread of infectious diseases across international borders, through their travel patterns and behaviours. Responsible travel through the adoption of effective preventative practices is crucial to the comprehensive control of infectious diseases on a global scale. The main aim of this thesis was to describe the travel patterns and health behaviours of travellers and their potential impact on the epidemiology of infectious disease in Australia. In controlling imported infectious diseases, it is important to first quantify the burden of infectious diseases in travellers and to identify the changing patterns of travel and the contribution of the traveller to the risks of disease importation. Three separate studies were conducted to address the aims of this thesis. The first was an airport study of travellers departing Sydney bound for destinations in Asia and Bangkok airport bound for destinations in Australia. This study assessed travel patterns and traveller demographic characteristics, symptoms consistent with infection and contact with febrile persons and pre-travel health care seeking behaviour, vaccine uptake and risk perception. The second study was a national telephone survey to determine the incidence of travel in the Australian population. A separate national telephone survey of Australian adults was also undertaken to identify factors that influence the uptake of pre-travel advice and travel vaccines in Australian travellers and compares the vaccination status of travellers and non-travellers. These studies identified a range of travel patterns and traveller characteristics unique to Australian resident travellers and visitors to Australia. Travel is a common pursuit among Australian adults, with many reporting symptoms consistent with infection prior to departure and few reporting pre-travel preventative practices. Several population sub-groups have a greater propensity for travel, including Australian migrants, who may be at increased risk of infectious diseases owing to a lower uptake of pre-travel health care seeking and vaccine uptake than Australian born travellers. The risk perception results indicate that opportunities exist to modify traveller behaviour and improve the uptake of pre-travel preparations. Data on travel patterns and behaviours as they relate to the importation and transmission of infectious disease are lacking in Australia and the studies included in this thesis represent new and important knowledge of the travel patterns and traveller behaviour relevant to the spread of infectious diseases via air travel to Australia. These studies identify high-risk sub-groups of travellers, determine the proportion of the Australian population engaging in international travel and quantify the proportion of Australian travellers who prepare for the infectious diseases risks associated with travel through pre-travel preventative practices. The findings from this series of cross-sectional surveys of travellers can inform travel medicine and border control policy and practice. Strategies are required to address poor uptake of pre-travel health advice and vaccination in travellers, particularly migrant Australians. Empirical data obtained in this thesis is of use for modelling infectious disease transmission on a global scale, and to inform pandemic planning and border control measures.