CDC says that at least 3.2 million teens aged 14 to 19 are currently infected. This accounts for 26 percent of the total girls that have human papilloma virus, chlamydia, genital herpes or trichomoniasis.
However the authors have warned that since the study only tested for the four most common sexually transmitted diseases, the number would be even higher if less-common diseases such as HIV/AIDS, syphilis and gonorrhea were included.
The total prevalence among American teens is greater than the study's rate of 26 percent. Half of the 838 girls who participated in the study reported ever having sex and of those, 40 percent were infected with an STD.
African American girls were particularly at risk: 48 percent of all African American girls were infected with an STD. That compared with 20 percent among both whites and Mexican-American teenagers.
The most common STD overall was human papillomavirus, or HPV, with an infection rate of 18.3 percent. Almost 3.9 percent of the teens were found to have Chlamydia while trichomoniasis was found in 2.5 percent and herpes in 1.9 percent.
Among teens who had an STD, 15 percent had more than one. According to a CDC estimate STDs cost almost US$15 billion to treat annually in the United States. Also, more than half of those infected are under 24 years old, said CDC.
The study analyzed data from 838 teenagers who participated in a national health study in 2003 and 2004 where researchers used the nationally representative sample to project rates across the United States. The results were released Tuesday at an STD prevention conference in Chicago.
