Newer tests aid chlamydia screening in teens. (Nucleic acid Amplification).

Rampant chlamydial infection in U.S. adolescents and new, highly sensitive tests have convinced some physicians to request a urine sample every time a teenager walks through the door.

Urine tests that use nucleic acid amplification techniques have become available in the last 2 years and offer a teen-friendly screening method that data show to be much more sensitive than previous urine tests and more convenient than traditional culture of endocervical samples.

With chlamydia rates as high as 236 of every 1,000 (24%) among sexually active U.S. females aged 15-19 years old, it makes sense to offer urine testing to every teenager a physician sees, and especially to adolescent patients who refuse a pelvic exam or don't need a pelvic exam, Dr. Felicia H. Stewart said in an interview.

The Centers for Disease Control and Prevention recommends annual chlamydial screening for sexually active adolescents and women aged 20-25 years, as well as for older women with a new sex partner or multiple sex partners.

Of the estimated 3 million U.S. cases of chlamydial infection each year, 46% occur in 15- to 19-year-old girls and another 46% occur in 20- to 24-year-old women, according to the CDC.

Many physicians practice under the mistaken notion that routine screening means they should size up a patient's risk for chlamydia before deciding to test. That approach is too conservative, said Dr. Stewart of the department of ob.gyn. at the University of California, San Francisco. "I would do it for all sexually active young women who came in through the door."

Explain the test carefully to the teenagers and tell them you screen everyone for chlamydia, so that they don't feel singled out, she added.