University of Otago - Department of Public Health, University of Otago - Department of Public Health, University of Auckland - Faculty of Medical and Health Sciences, University of Otago - Department of Public Health, University of Melbourne - Peter Doherty Institute for Infection and Immunity, University of Melbourne - Victorian Infectious Disease Reference Laboratory, University of Otago - Department of Public Health, Starship Children's Health, University of Otago - Department of Biochemistry, University of Auckland - Faculty of Medical and Health Sciences, Northland District Health Board, University of Otago - Department of Public Health, Counties Manukau District Health Board, University of Otago - Department of Oral Sciences, University of Otago - Department of Public Health and University of Auckland - Faculty of Medical and Health Sciences