Validation of an Aptima-format Finnish new variant of Chlamydia trachomatis (FI-nvCT) surveillance assay, 2019.

The Finnish new variant of Chlamydia trachomatis (FI-nvCT) is escaping diagnostics in Finland, Norway and Sweden. We have developed and validated an Aptima-format nucleic acid amplification test (NAAT) designed specifically to detect the FI-nvCT. This NAAT has high sensitivity (100%) and specificity (100%) for the FI-nvCT strain, enabling further investigation of the geographic distribution, prevalence and transmission of this diagnostic-escape mutant in screening populations in Europe.

Design and Validation of Transcription-Mediated-Amplification Nucleic Acid Amplification Tests for Mycoplasma genitalium.

Mycoplasma genitalium is a sexually transmitted bacterium linked to adverse sexual and reproductive health outcomes in women and men. M. genitalium is difficult to culture, and in the absence of validated amplified molecular methods for diagnosis of infection, there is no reference standard available for use as a comparator for the validation of new M. genitalium diagnostic tests. We evaluated the analytical and clinical performance of three transcription-mediated amplification (TMA) tests for M. genitalium, each targeting unique rRNA sequences, for use as a composite comparator for clinical validation of the Aptima Mycoplasma genitalium (AMG) assay, an in vitro diagnostic (IVD) TMA test that targets 16 s rRNA of M. genitalium Analytical sensitivity, specificity, and strain inclusivity of all four TMA tests were determined using nine laboratory strains of M. genitalium and 56 nontarget bacteria, protozoa, and viruses. Analytical sensitivity of the tests for M. genitalium ranged from 0.017 to 0.040 genome equivalents/ml. None of the nontarget organisms evaluated cross-reacted with any test. A composite comparator reference standard consisting of the 3 alternate (Alt) TMA tests was used to evaluate the clinical performance of the AMG assay by testing residual vaginal swab, female urine, and male urine specimens obtained from 1,400 adult subjects from three U.S. clinical sites. Using this reference standard to establish infected specimen status, the sensitivity, specificity, and overall agreement of the AMG IVD assay were 100%, 99.9%, and 99.9%, respectively. These results demonstrate the utility of molecular composite reference standard methodology for the clinical validation of future IVD tests for this organism.

Treatment of first-void urine with Aptima Transfer Solution increases detection of high-risk HPV E6/E7 mRNA.

Because of its non-invasive nature urine testing may enable increased screening for HPV in women who avoid cervical sampling. Comparisons have shown fewer HPV positives in urine. The objectives were to compare first-void urine (FVU) treated with proteinase K (PK) to untreated FVU and cervical samples collected from women attending a colposcopy clinic using an Aptima HPV mRNA assay, and comparing the HPV rates to cytology and pathology results. Female FVU (n = 433) was treated with Aptima Transfer Solution (ATS) containing PK within 24 h or after months of storage. Untreated female FVU samples were HPV-positive in 20.8-27.6% compared to 34.4-45.6% of ATS-treated FVU and 44.9-48.4% of PreservCyt samples. Good overall agreement for HR-HPV detection between ATS-FVU and PreservCyt was observed (81.1%; k 0.63). Validation of ATS treatment was performed on 356 male FVU, detecting 6.7% HPV positive compared to 3.4% of untreated samples (p = 0.059). Although HPV presence in ATS FVU and PreservCyt samples were similar, significantly more women with abnormal cervical cytology and histopathology were HPV-positive in cervical specimens than in ATS-treated FVU.

Urinary Meatal Swabbing Detects More Men Infected With Mycoplasma genitalium and Four Other Sexually Transmitted Infections Than First Catch Urine.

Urinary meatal swabs compared with urine showed higher infection rates for Mycoplasma genitalium (15.3% vs 12.6%, P = 0.035), Chlamydia trachomatis (11.3% vs 9.3%, P = 0.039), Neisseria gonorrhoeae (1.4% vs 1.1%, P = 1.00), Trichomonas vaginalis (8.0% vs 1.7%, P < 0.001), and high-risk human papillomavirus (5.9% vs 3.4%, P = 0.078) respectively.

Detection of cervical precancerous lesions with Aptima HPV assays using SurePath preservative fluid specimens.

SurePath specimens from women referred to colposcopy were treated with Aptima Transfer Solution (ATS) before testing in Aptima HPV (AHPV) and Aptima HPV 16, 18/45 (AHPV-GT) assays. Untreated SurePath specimens were tested with the cobas HPV test. PreservCyt specimens were assessed for cytology and tested with AHPV. High-grade cervical intraepithelial neoplasia lesions served as the reference standard. Excellent agreement (95.5%; k=0.91) was observed for ATS-treated SurePath specimens between Tigris and Panther systems and between the PreservCyt and ATS-treated SurePath specimens (91.1%, k=0.81) with the AHPV assay on Tigris. Agreement between the AHPV and cobas assays with SurePath specimens was substantial (89.9%, k=0.80). AHPV sensitivity for CIN2+(n=147) was 91.2% for SurePath and PreservCyt. Cobas HPV sensitivity was 93.9% for SurePath specimens. AHPV testing of SurePath specimens was more specific (59.4%) than cobas (54.7%) (p<0.001). Detection and genotyping showed similar absolute and relative risks. ATS-treated SurePath specimens tested with AHPV and AHPV-GT assays showed similar performance with greater specificity than cobas HPV on SurePath specimens. Similar overall results were seen using a CIN3 disease endpoint.

Mycoplasma genitalium Antibiotic Resistance-Mediating Mutations in Canadian Women With or Without Chlamydia Trachomatis Infection.

Testing remnant Aptima specimens from women infected with Chlamydia trachomatis detected 13.4% (53/396) with Mycoplasma genitalium compared with 5.4% (22/406) in matched C. trachomatis-negative women. Overall, 9.4% (provincial ranges of 3-20%) were infected with M. genitalium and resistance mediating mutations were found in 47.3% (26/55) to macrolides and 1.9% (1/53) to fluoroquinolones by sequencing.

Mycoplasma genitalium infection in women attending a sexually transmitted infection clinic: diagnostic specimen type, coinfections, and predictors.

In female sexually transmitted infection clinic attendees, Mycoplasma genitalium was more frequently detected using vaginal (53/73) versus endocervical (43/73) specimens. In women without other sexually transmitted infections, M. genitalium detection (N = 44) was associated with age ≤22 years (odds ratio, 2.53; P = 0.006) and clinical evidence of cervicitis (odds ratio, 2.11; P = 0.03).

Molecular testing for Trichomonas vaginalis in women: results from a prospective U.S. clinical trial.

Trichomoniasis is a common sexually transmitted disease associated with preterm birth, low birth weight, and increased susceptibility to infection with other pathogenic sexually transmitted microorganisms. Nucleic acid amplification tests for Trichomonas vaginalis have improved sensitivity for detecting infected individuals compared to existing culture-based methods. This prospective, multicenter U.S. clinical trial evaluated the performance of the automated Aptima T. vaginalis assay for detecting T. vaginalis in 1,025 asymptomatic and symptomatic women. Vaginal swab, endocervical swab, ThinPrep PreservCyt, and urine specimens were collected. Subject infection status was determined by wet-mount microscopy and culture. Aptima T. vaginalis assay performance was determined for each specimen type by comparison to subject infection status. Of 933 subjects analyzed, 59.9% were symptomatic. Aptima T. vaginalis clinical sensitivity and specificity were, respectively, 100% and 99.0% for vaginal swabs, 100% and 99.4% for endocervical swabs, 100% and 99.6% in ThinPrep samples, and 95.2% and 98.9% in urine specimens. Aptima T. vaginalis performance levels were similar in asymptomatic and symptomatic subjects. This study validates the clinical performance of the Aptima T. vaginalis assay for screening asymptomatic and symptomatic women for T. vaginalis infection.