What are STIs



A sexually transmissible infection is an STI

  • STIs are infections that can be passed from one person to another during unprotected sexual or close genital-to-genital (intimate) contact
  • A sexual contact is a person you have genital or oral sex/ contact with
  • Genital or oral sex includes the insertion of penis into the vagina, anus or mouth. Insertion of fingers, sex-toys and other objects may transmit certain STIs if the object is contaminated. 
  • Intimate genital skin-to-skin contact with another person, without insertion, can transmit viruses like warts or cold sores/ herpes. However, these viruses are very common and most people who are sexually active would have been exposed to these viruses.
  • Activities such as kissing, mutual masturbation and masturbation hardly ever transmits STIs, although you may be exposed to the cold sore virus which is common, if you have never had it before
  • STIs can infect the back of the throat, the penis, vagina/ vulva, cervix (womb), anus and genital skin
  • STIs are caused by microscopic organisms such as bacteria, viruses or parasites
  • Unplanned pregnancy is also a possible outcome of unprotected sex
  • STIs do not always cause signs or symptoms
  • Treatment for STIs is varied, see your GP or call Melbourne Sexual Health Centre to speak with a nurse

There are a number of other sexual health conditions affecting the genitals which are not sexually transmissible.  

See our Sexual Health Fact Sheets for more detailed information about STIs and sexual health conditions