Regular testing and treatment does not reduce the numbers of urban teenage girls who contract chlamydia, according to a study by the Indiana University (IU) School of Medicine published in the Journal of Infectious Diseases.

During the study, the number of infected teenage girls changed little—even though they were screened every three months and given necessary treatment.

At the study’s onset, 10.9 percent of the teenage girls were infected with the sexually transmitted disease. After 18 months, 10.6 percent were infected. By year four of the study, approximately 10.4 percent were infected.

“The high rate of reinfection we found in our study strongly suggests there may be some real limits on what we can do to control chlamydia without doing a better job of controlling chlamydia in young men,” Dr. J. Dennis Fortenberry, pediatrics professor at the IU School of Medicine said in a statement issued by the university.

The most common bacterial STD, chlamydia is connected to increased risk of pelvic inflammatory disease, increased susceptibility to HIV, and various pregnancy and infertility complications.

Chlamydia is more common in sexually active teens than in any other age group.