Management of unprotected sexual encounters.

After "unprotected" sexual encounters, sexual history guides risk assessment and testing for sexually transmissible infections (STIs). Chlamydia trachomatis infection is the most prevalent bacterial STI. Sexually active young people (aged < 25 years) should have annual chlamydia testing. Opportunistic STI testing is indicated for population groups at increased risk of STI, including young people, gay and other homosexually active men, and Indigenous people. Gay and other homosexually active men should be regularly tested for HIV, syphilis, chlamydia and gonorrhoea. Indigenous people should be regularly tested for syphilis, chlamydia and gonorrhoea. Postexposure antiretroviral prophylaxis may be indicated after high-risk sexual encounters.