According to research at least half of teenage girls who become sexual active have developed STD within two years of having started, and for many of these girls the infection occurs by the time they’re 15 years of age.
Researchers followed the habits of 386 urban teens between the ages of 14 and 17 for as many as 8 years. Within 2 years of beginning to have sex half of these girls had become infected with one of many common sexually transmitted diseases. Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis (the organisms that cause Chlamydia), gonorrhea and trichomoniasis were most common. A full quarter of these girls had already had the infection by the them they were 15, most commonly Chlamydia.
“Repeated infections were very common. Within 4 to 6 months (depending on the organism) after treatment of the previous infection, a quarter of the women were re-infected with the same organism.”
As soon as these girls are becoming sexually active they’re susceptible to infection from these diseases. Unfortunately these girls are often going untested because the age of the girl is often lower than that of the age of consent. “These young women are vulnerable to STIs, but because of their younger age, they may not be perceived by health care providers as having STI risk, and thus are not screened in a timely manner. For urban adolescent women, STI screening (especially for chlamydia) should begin within 1 year after first intercourse and infected individuals should be retested frequently, preferably every 3 to 4 months. To my knowledge, this study provides the first data on the timing of the initial STI and subsequent STIs following the onset of sexual activity in urban adolescent women.”