1. Sexual and Reproductive Health Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea;
2. Public Health Interventions Research Group, The Kirby Institute, UNSW, Sydney, Australia;
3. Department of Microbiology and Infectious Disease, The Royal Women’s Hospital, Parkville, VIC, Australia;
4. Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, VIC, Australia