1 Crawford School of Public Policy, Australian National University, Canberra, ACT, Australia. Electronic address: thomas.longden@anu.edu.au.
2 Centre of Excellence for Biosecurity Risk Analysis, School of Biosciences and School of Ecosystem and Forest Sciences, University of Melbourne, Melbourne, VIC, Australia.
3 Curtin School of Population Health, Curtin University, Perth, WA, Australia.
4 Crawford School of Public Policy, Australian National University, Canberra, ACT, Australia; National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia.