[1] Mahidol Univ, London Sch Hyg & Trop Med, Communicable Dis Policy Res Grp, Fac Publ Hlth & Policy, Bangkok 10400, Thailand
[2] Papua New Guinea Inst Med Res, Goroka, Papua N Guinea
[3] WHO Country Off, Port Moresby, Papua N Guinea
[4] London Sch Hyg & Trop Med, Fac Publ Hlth & Policy, Communicable Dis Policy Res Grp, London WC1, England