1. World Health Organization. Global Prevalence and Incidence of Selected Curable Sexually Transmitted Infections: Overview and Estimates (WHO, Geneva, 2001).
2. World Health Organization. Projections of Mortality and Burden of Disease to 2030 (WHO, Geneva, 2005).
3. World Health Organization Regional Office for South-East Asia. Guidelines for Sexually Transmitted Infections: Prevalence Study. Report No. SEA-STD-41 (WHO, Geneva, 2001).
4. Mehmet, G. & Ledger, W. J. Syphilis in pregnancy. Sex Transm. Infect. 76, 73–79 (2000).
5. Peeling, R. W. & Ye, H. Diagnostic tools for preventing and managing maternal and congenital syphilis: an overview. Bull. World Health Organ. 82, 439–446 (2004).