World Health Organization. Global incidence and prevalence of selected curable sexually transmitted infections -2008. http://www.who.int/reproductivehealth/publications/rtis/stisestimates/en/ (2016年11月1日アクセス可能)
V Bremer, U Marcus, O Hsmouda. Syphilis on the rise again in Germany-results from surveillance data for 2011. Euro Surveil 2012; 17(29): pii20222.
EJ Savage, K Marsh, S Duffell, et al. Rapid increase in gonorrhea and syphilis diagnoses in England in 2011. Euro Surveil 2012; 17(29): pii20224.