An STI is an infection passed during sexual contact.

• Some STIs infect only your sexual and reproductive organs. Others (HIV, hepatitis B, syphilis) cause general body infections.
• Sometimes you can have an STI with no signs or symptoms. Or the symptoms may go away. Either way, you still have the STI until you get treated.
• STI is spread during vaginal, anal and oral sex, and sometimes by genital touching.
• Some STI s (HIV and hepatitis B) are also spread by contact with infected blood.
• STI germs need to live in warm, moist areas. That's why they infect the mouth, rectum and sex organs (vagina, vulva, penis and testes).