Vaginal swabs are the specimens of choice when screening for Chlamydia trachomatis and Neisseria gonorrhoeae: results from a multicenter evaluation of the APTIMA assays for both infections.

BACKGROUND: Vaginal swabs were recently U.S. Food and Drug Administration-cleared for detecting Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) using Gen-Probe Incorporated's APTIMA COMBO2 Assay (AC2). We assessed the APTIMA CT Assay (ACT) for CT, APTIMA GC Assay (AGC) for GC, and AC2 for both organisms using patient- and clinician-collected vaginal swabs. METHOD: Women attending family planning, obstetrics and gynecology, or sexually transmitted disease (STD) clinics had first-catch urines (FCUs), patient-collected vaginal swabs, clinician-collected vaginal swabs, and endocervical swabs tested by ACT, AGC, and AC2. A second endocervical swab and FCU were tested using BD ProbeTec (Becton Dickinson) for CT and GC. We calculated sensitivity and specificity using vaginal swabs to detect CT and GC. RESULTS: Of 1,464 subjects enrolled, 180 had CT and 78 GC. ACT sensitivities and specificities for patient-collected vaginal swabs were 98.3% and 96.5%, respectively; for clinician-collected vaginal swabs, 97.2% and 95.2%, respectively. AGC sensitivities and specificities for patient-collected vaginal swabs were 96.1% and 99.3%, respectively; for clinician-collected vaginal swabs, 96.2% and 99.3%, respectively. AC2 results were similar. If an FCU tested positive for CT or GC, >94% of matching vaginal swabs were positive. Positive endocervical swabs showed slightly less concordance (>90% and >88%, respectively). More infected patients were identified using vaginal swabs than FCUs. With AC2, 171 CT-infected patients were identified using FCUs and 196 using patient-collected vaginal swabs. This difference was more pronounced for CT than for GC. CONCLUSIONS: Vaginal swab specimens allowed sensitive and specific detection of CT and GC in the APTIMA assays. Vaginal swabs identified as many infected patients as endocervical swabs and more than FCUs, and may well be the specimen of choice for screening.

Women find it easy and prefer to collect their own vaginal swabs to diagnose Chlamydia trachomatis or Neisseria gonorrhoeae infections.

BACKGROUND: Self-collected specimens can be used to screen asymptomatic women for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). We surveyed women's opinions on ease and preferences as to sampling after collecting their own vaginal swab and urine and a physician collection of vaginal swab and cervical swab. METHODS: In 7 North American cities, a questionnaire was used for women after they participated in a clinical trial of nucleic acid amplification testing of various specimens. A total of 1,090 women consenting to gynecologic sampling for CT and GC (82% of those sampled) volunteered to complete the survey. We analyzed the data for ease of self-collection and preferences for a vaginal swab, urine, or cervical swab. RESULTS: The average age was 26.6 years; 59.6% were black, 25.5% white, 11% Hispanic, 1.9% Asian, and 2% unknown. Thirty-five percent had more than one sex partner in the past 6 months, 84.9% had been previously tested for a sexually transmitted infection (STI), and 49.2% had experienced an STI. A total of 90.4% found it very easy to self-collect a vaginal swab. This was not influenced by age, education, or study site. Seventy-six percent preferred a vaginal swab over a pelvic examination, 60% over a urine collection, and 94% indicated that they would be tested more often if a vaginal swab was available. CONCLUSION: Self-collected vaginal swabs were easy to collect and patients preferred them over urine and cervical swabs.

Rapid detection of influenza A and B viruses in clinical specimens by Light Cycler real time RT-PCR.

BACKGROUND: the influenza viruses cause morbidity and mortality annually among children and elderly. Surveillance and rapid diagnosis is imperative in the reference laboratory, as clinical symptoms are insufficient for proper diagnosis. OBJECTIVES: this study involved the design of a rapid detection method for influenza A and B viruses using real time RT-PCR from clinical specimens. Methods were specifically designed for use on the Light Cycler. The sensitivity and specificity were also to be determined. STUDY DESIGN: the identification and discrimination of influenza A and B viruses employs two dual probe systems based on fluorescence resonance energy transfer (FRET) technology. Following submission by physicians participating in the Florida sentinel influenza network, 58 specimens were chosen for testing using both tissue culture and Light Cycler methods. RESULTS: of the 35 identified positive for influenza virus via tissue culture isolation, the Light Cycler results matched identification and typing with 100% agreement. However, the Light Cycler recognized 16 additional specimens that were positive for the presence of the virus. RT-PCR and nucleotide sequencing confirmed the presence of influenza A virus in these specimens. Using tenfold serial dilutions, the sensitivity of the Light Cycler method was determined to be 0.01 TCID50. The lower limit of RNA detection was determined as 1.6 x 10(-7) microg for influenza A virus, and 1.2 x 10(-7) microg for influenza B virus. Specificity of the Light Cycler method was determined by testing specimens containing adenovirus, parainfluenza virus and echovirus, all of which yielded negative results with no discernible background. CONCLUSIONS: overall, this newly developed method of simultaneous detection and typing of influenza types A and B using the Light Cycler proves to be more sensitive than tissue culture isolation, with corresponding specificity. This technique may be valuable for surveillance and rapid identification of influenza for early diagnosis.

Evaluation of the Hybrid Capture 2 CT/GC DNA tests and the GenProbe PACE 2 tests from the same male urethral swab specimens.

BACKGROUND: A previous study demonstrated that Digene's Hybrid Capture 2 (HC2) DNA tests for detection of and (CT/GC) could be performed using cervical swab specimens collected in GenProbe transport media with significantly greater sensitivity for the detection of than with the GenProbe PACE 2 system. GOAL: The goal was to assess the performance of HC2 tests in comparison with GenProbe PACE 2 tests for the detection of CT/GC in male urethral swab specimens. STUDY DESIGN: A total of 1,202 male urethral swab specimens were collected in GenProbe PACE transport medium. All specimens were first tested with the PACE 2 system, followed by masked HC2 CT/GC testing. The GenProbe AMPLIFIED CT Assay (AMP CT) and PCR/SHARP Signal System (SHARP) were used for adjudication of discrepant results. RESULTS: The prevalence rates for this population were 8.4% for and 14.6% for, based on the adjudicated results. The relative sensitivity and specificity for the detection of were 97.0% and 99.8% for HC2 and 69.3% and 98.3% for PACE 2, respectively. The relative sensitivities for the detection of were 98.9% for HC2 and 99.4% for PACE 2, with the same specificity of 99.9% for both tests. Agreement between the two testing methods was 95.4% for and 99.6% for. CONCLUSION: The HC2 test is compatible with the GenProbe collection medium, with significantly greater sensitivity than the GenProbe PACE 2 test for detecting and similar sensitivities for detecting.