STI is short for sexually transmissible infection- an infection you can get from having sex with someone who has that infection.
Common STIs in remote communities are chlamydia, gonorrhoea, trichomonas and syphilis. HIV is also an STI.
You can have an STI and not know it, because many STIs have no signs or symptoms – that is why it is important to get tested regularly.
Even if you are feeling well, it can be causing damage to your body. You can also pass the infection on to others you have sex with even if you feel well and don’t have symptoms.