• Oral and anal sex, kissing, close intimate contact


  • Primary: Chancre. A painless red papule or shallow ulcer on penis, around anus, and/or in mouth.
  • Secondary: Systemic symptoms. May include a generalized or localized rash, headache, myalgias, etc.
  • Early latent: asymptomatic and infected within the last 12 months
  • Late latent: asymptomatic and infected more than 12 months ago
  • Organ involvement: Uveitis and/or retinitis; hepatitis; meningitis; nephritis, etc


  • Blood test. Request “syphilis serology” on an Ontario Public Health Laboratory requisition.
  • Negative: A nonreactive syphilis screening test.
  • Positive: This will include (1) a reactive syphilis screening test, (2) a reactive confirmatory Treponema pallidum particle agglutination (TP-PA) if not done previously, and (3) an RPR titer.


  • Primary, secondary and early latent:
    • Benzathine Penicillin (Bicillin) 2.4 million units IM as a single dose.
    • Alternate: Doxycycline 100 mg BID for 14 days
  • Late latent:
    • Benzathine penicillin (Bicillin) 2.4 million units IM weekly for 3 weeks.
    • Alternate: Doxycycline 100 mg BID for 28 days
  • Neurosyphilis, ocular syphilis and/or other organ involvement should be managed by, or in consultation with, an infectious diseases specialist.