Detection of Trichomonas vaginalis DNA by Use of Self-Obtained Vaginal Swabs with the BD ProbeTec Q ^x Assay on the BD Viper System

Abstract

f Trichomonas vaginalis is 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. vaginalis Q x (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.

Clinical and Laboratory Testing for Trichomonas vaginalis Infection

“…This assay is based on strand displacement amplification (SDA) of DNA extracted from patient samples with ferric oxide (31). SDA is an isothermal process of real-time amplification and detection of light emission with excellent sensitivity and specificity (Ͼ95% and Ͼ99%, respectively) (31).…”

Combined Testing for Chlamydia, Gonorrhea, and Trichomonas by Use of the BD Max CT/GC/TV Assay with Genitourinary Specimen Types

“…Screening for asymptomatic infections among at-risk men or women, or diagnosis of infection among symptomatic patients seeking health care, should be performed using nucleic acid amplification tests (NAATs) as recommended by the CDC for chlamydia and gonorrhea (15). Likewise, NAATs also promise to become the gold standard for trichomonas detection, as this is the most sensitive test method available (16)(17)(18). Rapid point-of-care options for trichomonas detection among women are available, including wet-preparation microscopy, which performs poorly; a dipstick immunochromatographic assay (OSOM; Sekisui, Lexington, MA); and an isothermal amplification assay (AmpliVue; Quidel, San Diego, CA), of which the latter two perform well (19).…”

Clinical Evaluation of the Cepheid Xpert TV Assay for Detection of Trichomonas vaginalis with Prospectively Collected Specimens from Men and Women

“…vaginalis in women (11, 18), the Xpert TV assay can provide on-demand results in 63 min or less, with early termination for positive results within 40 min. This quicker turnaround time makes the GeneXpert platform ideal for use in high-risk settings where diagnosis and treatment could ideally take place in real time for optimal public health control of this STD.…”