[1] Victorian Cytol Serv, Melbourne, Vic 8002, Australia
[2] Univ Sydney, Natl Ctr Immunisat Res & Surveillance, Childrens Hosp Westmead, Discipline Paediat & Child Hlth,Sch Publ Hlth, Sydney, NSW 2006, Australia
[3] Melbourne Sexual Hlth Ctr, Carlton, Vic 3053, Australia
[4] Univ Melbourne, Sch Populat Hlth, Carlton, Vic 3053, Australia
[5] Royal Womens Hosp, Clin Microbiol & Infect Dis, Melbourne, Vic 3052, Australia
[6] Royal Childrens Hosp, Dept Clin Microbiol, Melbourne, Vic 3052, Australia
[7] Univ Melbourne, Dept Obstet & Gynaecol, Fac Med Dent & Hlth, Melbourne, Vic 3053, Australia
[8] Univ Melbourne, Murdoch Childrens Res Inst, Melbourne, Vic 3052, Australia