It is estimated that in 2000 there was:
- 18.9 million new cases of STIs
- 68 million total cases of STIs- a combination of new infections and long-term infections

About half of the new cases occurred in 15- to 24- year olds, even though they make up only 25% of the sexually active population. Three STIs- human papillomavirus (HPV), trichomoniasis, and chlamydia- accounted for 88% of all new cases of STIs among 15- to 24- year olds.

Reviewed by: Jennifer A. Shuford, MD, MPH
Date: October 2008

Reference:
Weinstock H, Berman S, Cates W, Jr. Sexually transmitted infections among American youth: incidence and prevalence estimates, 2000. Perspect Reprod Health. 2004;36(1):6-10.