Comparison of Methods for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae Using Commercially Available Nucleic Acid Amplification Tests and a Liquid Pap Smear Medium

Annual screening for Chlamydia trachomatis infection is currently recommended for sexually active women 15 to 25 years old and for women older than 25 if they have a new or multiple sex partners and have not used condoms during the previous 3 months. Annual screening for cervical abnormalities using the Pap smear has achieved a substantial reduction in morbidity and mortality from cervical cancer. Screening for Neisseria gonorrhoeae infection has likely contributed significantly to the reduction in the rates of gonococcal infection. The introduction of liquid Pap smear methods using exfoliated cervical cells presents an opportunity to screen for these three conditions using one specimen. We evaluated the preservation of C. trachomatis and Neisseria gonorrhoeae DNAs from ThinPrep liquid media (PreservCyt; Cytyc Corp., Boxborough, Mass.); tested the feasibility of using a clinical specimen of this medium for the detection of cytologic abnormalities, C. trachomatis, and N. gonorrhoeae; evaluated the agreement between ligase chain reaction (LCR) performed on PreservCyt and LCR performed on a cervical specimen; and compared the performance of LCR performed on PreservCyt to those of LCR performed on a cervical specimen, culture, PCR performed on a cervical specimen, on urine, and on a vaginal specimen (a multiple-site infection status standard), and transcription-mediated amplification (for C. trachomatis only) from 255 sexually active adolescent women. The agreement between LCR performed on PreservCyt and LCR from a cervical swab in LCx transport medium was high (for C. trachomatis, agreement = 0.97 and kappa = 0.92; for N. gonorrhoeae, agreement = 0.99 and kappa = 0.96). Test performances were similar for LCR-urine, LCR-cervix, and LCR-ThinPrep, with sensitivities from 93 to 99% for C. trachomatis and 81 to 83% for N. gonorrhoeae and specificities from 95.5 to 99% for C. trachomatis and 99.1 to 99.6% for N. gonorrhoeae using a PCR-based multiple-site infection status standard. This is the first study to examine the agreement between liquid cytologic media and multiple nucleic acid amplification tests for the detection of C. trachomatis and N. gonorrhoeae from patient samples. Cytologic fluid shows promise for simultaneous screening for cytologic abnormalities and sexually transmitted infections

The effect of correct and consistent condom use on chlamydial and gonococcal infection among urban adolescents.

OBJECTIVE: To evaluate the relationship between self-reported correct and consistent condom use and chlamydial and gonococcal infection. DESIGN: Cross-sectional study. SETTING: An urban adolescent health care clinic. Patients A total of 509 adolescent girls tested for Chlamydia trachomatis and Neisseria gonorrhoeae infection by urine nucleic acid amplification tests. Main Outcome Measure Effect of condom use on infection rates of chlamydia and gonorrhea. Consistent condom use was defined as using condoms for every act of vaginal sex and correct use as consistent use without any of the following: beginning sex without a condom, taking it off before finishing sex, flipping it over, condom breakage, or condom slippage. RESULTS: A total of 95% of the participants were African American, with a mean age of 16.6 years. Chlamydia prevalence was 21% (105/509) and gonorrhea prevalence was 7% (36/509). Condom errors were reported by 316 (71%) of 442 participants who had reported using a condom at least once in the previous 3 months. Consistent use was reported by 176 patients (35%); however, both correct and consistent use was reported by only 80 patients (16%). After adjusting for confounders, correct and consistent use was protective for chlamydia (odds ratio, 0.4; 95% confidence interval, 0.2-1.0) and highly protective for gonorrhea (odds ratio, 0.1; 95% confidence interval, 0-0.7). CONCLUSION: Our findings indicate that assessing both correctness and consistency of use is important for evaluation of condom effectiveness