Other common STIs


(Chlamydia trachomatis)

Health effects
  • Chlamydia is frequently asymptomatic, with approximately 50% of males and 70% of female infections not experiencing any noticeable symptoms.
  • In women, Chlamydia may cause chronic pelvic pain, pelvic inflammatory disease, and infertility.
  • In men, it may cause pain during urination, milky discharge, and inflammation of the testicles. 
Resistance and treatment
  • Chlamydia is susceptible to common antibiotics; however, there are some rare cases of antibiotic resistance.
  • The recommended treatment of chlamydia is an oral dose of doxycycline or azithromycin, with a test of cure typically 2 weeks after treatment.


(Treponema pallidum)

Health effects
  • Syphilis infections can be one of three stages, primary, secondary, or tertiary depending on how long a person has been infected with syphilis.
  • Primary syphilis is generally associated with one or more sores (ulcers) around the place of infection (i.e. genitals, cervix, mouth, anus).
  • Symptoms of secondary syphilis include: skin rash, swollen lymph nodes, and a fever. Often primary and secondary symptoms are mild and may go unnoticed.
  • Tertiary (latent) syphilis often occurs many years after the initial untreated infection. Symptoms can be severe, these include damage to the heart, eyes, nerves, brain, liver, spinal cord, bones, birth related problems, and can result in fatality.
Resistance and treatment
  • Syphilis can be treated with an injection of benzathine penicillin. The length of antibiotic treatment depends on the extent of the infection (i.e. primary, secondary or tertiary).
  • Treatment of syphilis can cure the infection; however, damage associated with the infection many not be cured (e.g. skin rash, damage to organs etc.).
  • Syphilis resistance to certain antibiotics (i.e. macrolides) is increasingly common (>50% in Australia). This is particularly problematic for people that are allergic to penicillin.
Learn more about common bacterial STIs
Disclaimer: See a health professional if you are experiencing any symptoms. Diagnostic test results must be correlated with clinical history, epidemiological data, laboratory data and any other data available to the clinician.