A new study reveals one in four teenage girls has a sexually transmitted disease. The Centers for Disease Control screened more than 8- hundred teen girls and found the most common STDs were Chlamydia and the Human Papillomavirus or HPV. The CDC says whats even more concerning is the STD rate among black teens.... almost half have an STD, but not because theyre having riskier sex. "Many African Americans remain at high risk because of the high prevalence in the community. In that respect, community risk really trumps individual risk." Less than half of young women who get pregnancy tests and emergency contraception are screened for STDs. The CDCs encouraging more clinics in schools and doctors who treat both patients and their partners.