LAUSR

The spread of infectious diseases by the international and national movement of people, animals, insects and products has a documented history dating back several centuries. The role of humanmovements has been fundamental to this, and has increased as global travel has risen in amount and speed. This has been exemplified by international epidemics of influenza, antimicrobial resistant bacteria, SARS coronavirus, dengue, chikungunya virus, Zika viruses and many others. Foodborne pathogens have also regularly come to our attention for their ability to move internationally, and outbreaks of salmonellosis due to importation of contaminated foods are well described. An extensive collection of non-typhoidal Salmonella and related species isolated from human, food, animal and environmental sources has been accumulated within Western Australia (WA) since the mid-20th century, and has proven an important historical source of information about the role of humans in the dissemination ofmicroorganisms across and within diverse ecosystems. It is clear that the movement of microorganisms into and out of Australia is by no means a new phenomenon, and that humans have been important contributors to that spread. These are important markers of our impact on established and pristine ecosystems. It had been postulated that increases in human visitors to the Antarctic might be responsible for the introduction of new Salmonella species into the sub-Antarctic wildlife. The WA collection provided an opportunity to look in more detail at the impact of humans and their accompanying animals arising from the establishment of the various Antarctic research bases and the increasing tourist traffic. Estimates from the International Association of Antarctica Tour Operators showed a rise in tourist numbers into the Antarctic waters from 13 475 ship passengers in 2000–01 to 44 402 in 2016–17. Most tourist activities currently take place off-shore, i.e. there is limited time on the land. On-land activities are nearly all carried out by the smaller number of staff in the research stations, who have introduced dogs and other domesticated animals.