1. Unprotected Sex
2. Multiple Partners
3. Being Under 25 Years Old/Early Age of Sexual Onset
4. Alcohol Use
5. IIllegal Drug Use
6. Trading Sex For Money / Drugs
7. Living In a Community With a High Prevalence of STDs
8. Serial Monogamy
9. Having an STD
10. Using Birth Control Pills As Your Sole Form of Contraception
According to STD.About.com, June 21, 2007