In the United States, adolescent girls and young women are not being routinely screened for chlamydia, the most commonly reported sexually transmitted disease in the United States, experts warned today at the annual meeting of the American College of Obstetricians and Gynecologists (ACOG) underway in San Diego.

“Although ACOG, the Centers for Disease Control and Prevention (CDC), and the US Preventive Services Task Force recommend annual screening for chlamydia in all sexually active women age 25 and younger, as well as other asymptomatic women at high risk for infection, studies show it isn’t happening,” Dr. Stanley Zinberg, ACOG’s deputy executive vice president, said in a written statement.

It’s estimated that 2 million cases of chlamydia go undiagnosed and untreated each year in the US, often leading to pelvic inflammatory disease, which can cause infertility and ectopic pregnancy. An ectopic pregnancy occurs when the fertilized egg doesn’t implant on the wall of the uterus, but in another location, such as the fallopian tubes. If undiagnosed, an ectopic pregnancy can result in serious illness or death.

According to ACOG, a recent study by the CDC and the Agency for Healthcare Research and Quality found that routine chlamydia screening is highly cost-effective, with the potential to prevent an estimated 60,000 cases of pelvic inflammatory disease, 8,000 cases of chronic pelvic pain, and 7,500 cases of infertility annually if screening guidelines are followed.

Some healthcare providers wrongly believe that STD prevalence is low in their practice, and this may explain why they’re not screening for chlamydia, ACOG points out in a statement.

“As physicians, we need to dispel the stigma and bias that so often surround STDs,” Dr. David E. Soper, professor of ob-gyn at the Medical University of South Carolina in Charleston said in a statement. “The reality is that STDs are diseases of humanity. Humans become infected doing what humans do.”