Overseas
- World Health Organization (WHO). Sexually transmitted infections (STIs)
- European Centre for Disease Prevention and Control (ECDC)
- Centers for Disease Control and Prevention (CDC), US
Fact Sheet
- Centers for Disease Control and Prevention (CDC), US. Syphilis - CDC Fact Sheet (Detailed)
- Centers for Disease Control and Prevention (CDC), US. Congenital Syphilis - CDC Fact Sheet
- Centers for Disease Control and Prevention (CDC), US. Syphilis & MSM (Men Who Have Sex With Men) - CDC Fact Sheet
Infectious Disease Textbook
- Centers for Disease Control and Prevention (CDC), US. Health Information for International Travel (Yellow Book) – Chapter on Sexually Transmitted Diseases (May 2017)
- Centers for Disease Control and Prevention (CDC), US. Health Information for International Travel (Yellow Book) – Chapter on Perspectives: Sex & Tourism (May 2017)
Clinical Information and Management
- European Centre for Disease Prevention and Control (ECDC). EU case definition (June 2018)
- Centers for Disease Control and Prevention (CDC), US. What Health Care Providers Can Do
- Centers for Disease Control and Prevention (CDC), US. Syphilis Pocket Guide for Providers
- Centers for Disease Control and Prevention (CDC), US. Sexually Transmitted Diseases Treatment Guidelines – Syphilis (2015)
- Centers for Disease Control and Prevention (CDC), US. Syphilis Self-Study Module