Limitations of Screening Tests for the Detection of Chlamydia trachomatis in Asymptomatic Adolescent and Young Adult Women.

摘要

One hundred sexually active women aged 16 to 25 years who were being seen for a routine gynecologic examination were recruited to participate in this investigation of screening for chlamydial infection in asymptomatic patients. Before clinical examination, the women performed a self-collected screening technique using 2 Dacron swabs, which they inserted approximately 2 inches into their own vagina, swirled, and placed in a transport media for polymerase chain reaction (PCR). They also provided a urine specimen consisting of the first 30 mL of voided urine collected in a sterile container for PCR and ligase chain reaction (LCR). The clinician collected urethral, vaginal, and endocervical swabs, which were cultured and analyzed with PCR, LCR, and nucleic acid amplification tests. Results were available for 139 participants, who had a mean age of 19.1 years and a mean of 10 days since their last sexual encounter. Twenty-two women had a history of chlamydial infection and 8 had a history of other sexually transmitted disease. During clinical examination of these asymptomatic patients, 34% were found to have a vaginal discharge, and 22% had other cervical abnormalities (discharge, mucopus, lesions, friability, inflammation). Chlamydia trachomatis was diagnosed in 30 (22%) women. Among these women, there were 27 (21%) with true C. trachomatis. One hundred twenty-six study subjects had complete results from all 9 clinical tests. Test measures included urethral culture and PCR, self-collected vaginal PCR, clinician-collected vaginal PCR, endocervical culture, PCR, LCR, and urine PCR and LCR. Four patients were positive for all 9 tests, 8 had a single positive test (confirmed by nested PCR testing), and 15 had between 2 and 8 positive results. The characteristics of various tests and different collection sites are shown in. Both PCR and LCR yielded more positive results than culture. They were also more sensitive than culture, although some LCR had a lower specificity than either of the other tests. The positive and negative predictive values were high for all tests. When 2 tests were combined, urine LCR plus endocervical LCR proved the most sensitive but had a somewhat lower specificity than other combination strategies.(Table is included in full-text article.)