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ABSTRACTThe BD Max CT/GC/TV (MAX) assay is a true multiplex assay for simultaneous detection of chlamydia (CT), gonorrhea (GC), and trichomonas (TV). We evaluated assay performance for women using endocervical and vaginal swabs as well as urine specimens. A total of 1,143 women were tested for CT, GC, and TV and, subsequently, another 847 (1,990 total women) for CT and GC only, with positivity rates for CT, GC, and TV of 7.1%, 2.3%, and 13.5%, respectively. In men, the performance for CT and GC was determined using only urine specimens. TV performance was not assessed in male urine samples. Among men, 181/830 (21.8%) and 108/840 (12.9%) chlamydia and gonorrhea infections, respectively, were identified. Comparator assays included BD ProbeTec Chlamydia trachomatisQx(CTQ)/Neisseria gonorrhoeaeQx(GCQ), Hologic Aptima Combo 2 (AC2) and Aptima TV (ATV), trichomonas microscopy, and culture. MAX CT sensitivity was 99.3% (95% confidence interval [CI], 96.1% to 99.9%), 95.7% (90.8% to 98.0%), 91.5% (85.8% to 95.1%), and 96.1% (92.2% to 98.1%) for vaginal swabs, endocervical swabs, female urine samples, and male urine samples, respectively. MAX GC sensitivity was 95.5% (84.9% to 98.7%), 95.5% (84.9% to 98.7%), 95.7% (85.5% to 99.8%), and 99.1% (94.9% to 99.8%) in the same order. MAX TV sensitivity was 96.1% (91.7% to 98.2%) for vaginal swabs, 93.4% (88.3% to 96.4%) for endocervical swabs, and 92.9% (87.8% to 96.0%) for female urine samples. Specificity for all organisms across all sample types was =98.6%. Performance estimates for the MAX assays were consistent with estimates calculated for the comparator assays (all Pvalues were >0.1). The availability of a CT/GC/TV multiplexed assay on a benchtop instrument with a broad menu has the potential to facilitate local sexually transmitted infection (STI) testing at smaller laboratories and may encourage expanded screening for these highly prevalent infections.

ABSTRACTTrichomonas vaginalisinfection is highly prevalent in the United States and worldwide. Traditional clinical diagnostic methods fail to identify more than half of these infections that, if left untreated, can result in adverse pregnancy outcomes and an exacerbated risk of both acquisition and transmission of HIV. Women bear a disproportionate amount of the burden of these infections, and testing among populations at risk for this disease should be provided. Molecular technologies have expanded our capacity for laboratory-based detection of infection and can be used on samples already being collected for chlamydia/gonorrhea screening.

ABSTRACTTrichomonas vaginalisis the most prevalent nonviral sexually transmitted infection worldwide, and improved diagnostic methods are critical for controlling this pathogen. Diagnostic assays that can be used in conjunction with routine chlamydia/gonorrhea nucleic acid-based screening are likely to have the most impact on disease control. Here we describe the performance of the new BD T. vaginalisQx(TVQ) amplified DNA assay, which can be performed on the automated BD Viper system. We focus on data from vaginal swab samples, since this is the specimen type routinely used for traditional trichomonas testing and the recommended specimen type for chlamydia/gonorrhea screening. Vaginal swabs were obtained from women attending sexually transmitted disease or family planning clinics at 7 sites. Patient-collected vaginal swabs were tested by the TVQ assay, and the Aptima T. vaginalis(ATV) assay was performed using clinician-collected vaginal swabs. Additional clinician-collected vaginal swabs were used for the wet mount and culture methods. Analyses included comparisons versus the patient infection status (PIS) defined by positive results with the wet mount method or culture, direct comparisons assessed with ? scores, and latent class analysis (LCA) as an unbiased estimator of test accuracy. Data from 838 women, 116 of whom were infected with T. vaginalis, were analyzed. The TVQ assay sensitivity and specificity estimates based on the PIS were 98.3% and 99.0%, respectively. The TVQ assay was similar to the ATV assay (? = 0.938) in direct analysis. LCA estimated the TVQ sensitivity and specificity as 98.3 and 99.6%, respectively. The TVQ assay performed well using self-collected vaginal swabs, the optimal sample type, as recommended by the CDC for chlamydia/gonorrhea screening among women.

ABSTRACTTests for Chlamydia trachomatisand Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being =99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being =99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts.

ABSTRACTThe next-generation amplification test for Chlamydia trachomatisand Neisseria gonorrhoeae(Roche cobas 4800), a fully automated system, was compared head to head, using female samples, to Gen-Probe Aptima Combo 2 and BD ProbeTec using Viper. Endocervical swabs, female urine, and endocervical samples in liquid-based cytology medium were run on at least two of three platforms. A total of 4,316 samples were evaluated, and 281 chlamydial and 69 gonococcal infections were identified. Estimates of sensitivity and specificity were obtained relative to the patient infection standard (PIS) and using latent class analysis (LCA). Chlamydia sensitivity estimates ranged from 86.9 to 95.6% using PIS and 97.6 to 98% using LCA. Specificity was =99.6% for all sample types. Sensitivity ranged from 95.6 to 100% using PIS and 96.9 to 100% using LCA for the detection of gonococcal infections. Specificity for gonococcal infections was =99.8%. cobas 4800 performance was equivalent to the comparator assays (all Pvalues, >0.05), and the fully automated system provides high laboratory efficiency.

ABSTRACTTrichomonas vaginalisPCR using reagents from a commercially available assay for Chlamydia trachomatisand Neisseria gonorrhoeaewas evaluated for detection of infection in women and men attending a sexually transmitted disease clinic. Evaluations included three primer sets, endocervical swabs, vaginal swabs and urine, and various storage conditions. The TVK3/TVK7 primer set was optimal in our hands with sensitivities ranging from 69.5 to 96.8%. In all comparisons, T. vaginalisPCR performed better than routine diagnostics using microscopy for women and culture for men (P> 0.05). The assay performed well for all sample types tested, and vaginal swabs were stable for up to 7 days at ambient temperature. Using samples prepared for, and reagents from, the C. trachomatis-N. gonorrhoeaePCR assay allowed incorporation of T. vaginalisPCR diagnosis into routine clinical testing.

ABSTRACTThe COBAS AMPLICOR CT/NG test for Neisseria gonorrhoeaecross-reacts with certain strains of nonpathogenicNeisseriaspecies. In some strains, the target sequence is identical to that of N. gonorrhoeae, whereas other strains have a small number of mismatches within the regions recognized by the primers or probe used in the COBAS AMPLICOR NG test. These cross-reactive strains are occasionally present in urogenital specimens, causing false-positive results in the COBAS AMPLICOR NG test. Analysis of the data generated in a large multicenter clinical trial showed that 2.9% of the specimens gave signals betweenA660s of 0.2 and 3.5 but that one-half of these equivocal specimens did not contain N. gonorrhoeae. Most of these equivocal specimens were correctly classified as true positive or true negative by retesting in duplicate and defining a PCR-positive result as two of three results with an A660of =2.0. If specimens had been classified as positive or negative based on a single test result using a cutoff of anA660of 0.2, specificity would have ranged from 96.2 to 98.9% depending on specimen type, sex, and presence of symptoms. By employing the equivocal zone-retesting algorithm, specificity increased to 98.6 to 99.9% with little effect (0.1 to 4.9% decrease) on sensitivity in most specimen types, enabling the test to achieve a positive predictive value of at least 90% in populations with a prevalence of 4% or higher. In lower-prevalence populations, the test could be used to screen for presumptive infections that would have to be confirmed by an independent test.

ABSTRACTThe performance of the Becton Dickinson BDProbe Tec ET SystemChlamydia trachomatisand Neisseria gonorrhoeaeAmplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109 men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results. Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent difference in the results. Without the AC result, sensitivity for C. trachomatisand N. gonorrhoeaewere 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatisand N. gonorrhoeaesensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based assays for these organisms.

ABSTRACTThe fully automated COBAS AMPLICOR CT/NG and semiautomated AMPLICOR CT/NG tests were evaluated in a multicenter trial for the ability to detect Chlamydia trachomatisinfections. Test performance compared to that of culture was evaluated for 2,236 matched endocervical swab and urine specimens obtained from women and for 1,940 matched urethral swab and urine specimens obtained from men. Culture-negative, PCR-positive specimens that tested positive in a direct fluorescent-antibody test or in a confirmatory PCR test for an alternative target sequence were resolved as true positives. The overall prevalences of chlamydia were 2.4% in women and 7.2% in men. The COBAS AMPLICOR and AMPLICOR formats yielded concordant results for 98.1% of the specimens. With the infected patient as the reference standard, the resolved sensitivities of COBAS AMPLICOR were 89.7% for endocervical swab specimens, 89.2% for female urine specimens, 88.6% for male urethral swab specimens, and 90.3% for male urine specimens. When results were analyzed as if only a single test had been performed on a single specimen type, the resolved sensitivity was always higher. The resolved specificities of PCR were 99.4% for endocervical swab specimens, 99.0% for female urine specimens, 98.7% for male urethral swab specimens, and 98.4% for male urine specimens. The internal control revealed that 2.4% of the specimens were inhibitory when initially tested. Nevertheless, valid results were obtained for 98.6% of the specimens because 59.1% of the inhibitory specimens were not inhibitory when a second aliquot was tested. The COBAS AMPLICOR and AMPLICOR CT/NG tests for C. trachomatisexhibited equally high sensitivity and specificity with both urogenital swab and urine specimens and thus are well suited for screening for C. trachomatisinfection.

ABSTRACTThe GeneXpert CT/NG assay (GeneXpert) and the Abbott m2000 RealTime CT (m2000) assay were compared to Amplicor for detecting ocular Chlamydia trachomatis. Discordant specimens were tested by the Aptima CT assay. The m2000 assay sensitivity was 100% (95% confidence interval [CI], 90% to 100%), and specificity was 98.46% (95% CI, 95.2% to 99.2%); GeneXpert sensitivity was 100% (95% CI, 90% to 100%), and specificity was 100% (95% CI, 98.1% to 100%). The m2000 and GeneXpert assays appear to perform as well as the Amplicor assay.

Mycoplasma genitalium(MG) infections are a growing concern within the field of sexually transmitted infections. However, diagnostic assays for M. genitaliumhave been limited in the United States. As most infections are asymptomatic, individuals can unknowingly pass the infection on, and the prevalence is likely to be underestimated. Diagnosis of M. genitaliuminfection is recommended using a nucleic acid test. This multicenter study assessed the performance of the cobas Trichomonas vaginalis(TV)/MG assay (cobas) for the detection of M. genitalium, using 22,150 urogenital specimens from both symptomatic and asymptomatic men and women collected at geographically diverse sites across the United States.

ABSTRACTPrevious epidemiological studies of Chlamydia trachomatisfrequently have required expansion of isolates in tissue culture. The possibility that C. trachomatis omp1might undergo mutation during such expansion has not been examined systematically. We found no differences in the omp1sequences from 10 clinical specimens before and after 20 in vitro passages.

The clinical performance of the Cobas CT/NG assay on the Cobas 6800/8800 systems (Cobas) for the detection of Chlamydia trachomatisand Neisseria gonorrhoeaewas established in a multisite, prospective collection study using male and female urogenital specimens; supportive data from archived specimens were also included. The results obtained with the Cobas assay were compared with the patient infected status derived from a combination of U.S.