[1] Ctr Dis Control & Prevent, Atlanta, GA USA
[2] Medecins Sans Frontieres Australia, Glebe, NSW, Australia
[3] Global Polio Eradicat Initiat, Melbourne, Vic, Australia
[4] Monash Univ, Sch Publ Hlth & Prevent Med, Clayton, Vic, Australia
[5] Burnet Inst, Melbourne, Vic, Australia