# Story Highlights
# First study of its kind shows nearly 3 million teen girls have an STD
# HPV, which can cause cervical cancer, is the most prevalent
# Nearly half of all African American females tested had at least one STD
# Doctors: Screening, vaccination, prevention among highest health priorities

CHICAGO, Illinois (AP) -- At least one in four teenage girls nationwide has a sexually transmitted disease, or more than 3 million teens, according to the first study of its kind in this age group.

A virus that causes cervical cancer is by far the most common sexually transmitted infection in teen girls aged 14 to 19, while the highest overall prevalence is among black girls -- nearly half the blacks studied had at least one STD. That rate compared with 20 percent among both whites and Mexican-American teens, the study from the federal Centers for Disease Control and Prevention found.