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

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 κ 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 (κ = 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.     

Comparing first-void urine specimens,self-collected vaginal swabs,and endocervical specimens to detect Chlamydia trachomatis and Neisseria gonorrhoeae by a nucleic acid amplification test

We set out to determine the prevalences of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction as well as to determine the prevalence of Trichomonas vaginalis by culture in a large and diverse national sample of non-health-care-seeking young women entering the military; we also sought to compare the abilities of three different techniques of collecting specimens (first-void urine, self-collected vaginal swab, and clinician-collected endocervical swab) to identify a positive specimen. A cross-sectional sample of young women was voluntarily recruited; as a part of their routine entry pelvic examination visit, they completed a self-administered reproductive health questionnaire and provided first-void urine (used to detect C. trachomatis and N. gonorrhoeae) and self-collected vaginal swabs (used to detect C. trachomatis, N. gonorrhoeae, and T. vaginalis). The number of positive tests divided by the number of sexually active women screened by each sampling method determined the rates of prevalence. The rate of infection with any of the three sexually transmitted diseases (STDs) tested was 14.1%. The total positive rates for each STD (identified by >/=1 specimen) were the following: for C. trachomatis, 11.6%; N. gonorrhoeae, 2.4%; and T. vaginalis, 1.7%. The proportions of positives identified by specimen type were, for C. trachomatis and N. gonorrhoeae, respectively, endocervix, 65 and 40%; urine, 72 and 24%; and vagina, 81 and 72%. The proportions of positives when specimen results were combined were, for C. trachomatis and N. gonorrhoeae, respectively, cervix plus urine, 86 and 49%; cervix plus vagina, 91 and 93%; and vagina plus urine, 94 and 79%. We concluded that STDs were epidemic in this population. Self-collected vaginal swabs identified the highest number of positive test results among single specimens, with the combined cervix-vagina results identifying the highest number of positive results. Self-collected vaginal swab collections are a feasible alternative to cervical specimen collections in this population, and the use of multiple types of specimens increases the positive yield markedly.     

Co-infections with Ureaplasma parvum,Mycoplasma hominis and Chlamydia trachomatis in a human immunodeficiency virus positive woman with vaginal discharge

A 30-year-old human immunodeficiency virus (HIV)-1 infected woman presented with vaginal discharge and associated vulval irritation. The vaginal swabs tested positive for Ureaplasma parvum and Mycoplasma hominis by both culture and polymerase chain reaction (PCR). The specimen also tested positive for Chlamydia trachomatis deoxyribonucleic acid (DNA) by cryptic plasmid and omp1 gene PCR assays. The patient was successfully treated with azithromycin based on the antibiotic susceptibility testing results of U. parvum and M. hominis by microbroth dilution. Since sexually transmitted infections enhance the transmission of HIV, HIV-positive patients should be screened routinely for these pathogens.     

Performance of the Abbott RealTime CT/NG for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.Chlamydia trachomatis and Neisseria gonorrhoeae are the two most prevalent bacterial sexually transmitted infections (STIs) reported to the Centers for Disease Control and Prevention (CDC) (2). Together these two infections accounted for over 1.5 million cases of STIs in 2008. The CDC estimates that sexually transmitted diseases (STDs) cost the health care system $1.5 billion annually. Since these infections, especially chlamydia, are most often asymptomatic, the CDC recommends yearly screening for chlamydia in all sexually active women ages 16 to 25 years. Since coinfections are common, many diagnostic test platforms assay for both organisms. Although there are several commercial assays available for performing nucleic acid amplification tests (NAATs), which are now recommended by the CDC as the test of choice, new assays and new platforms are needed by both private and public health programs.The Abbott RealTime CT/NG assay is a new real-time PCR assay for the direct, qualitative detection of the plasmid DNA of Chlamydia trachomatis and the genomic DNA of Neisseria gonorrhoeae in female endocervical or vaginal swab specimens, in male urethral swab specimens, and in male and female urine specimens from symptomatic and asymptomatic individuals. There were several sets of objectives of this study: (i) to determine the performance characteristics of the Abbott RealTime CT/NG assay compared to those of other amplified assays using specimens obtained from symptomatic and asymptomatic male and female subjects from clinical sites with high or low prevalence of Chlamydia trachomatis and/or Neisseria gonorrhoeae; (ii) to demonstrate the precision of the Abbott RealTime CT/NG assay using a precision panel consisting of combinations of high and low concentrations of Chlamydia trachomatis and Neisseria gonorrhoeae specimens; (iii) to evaluate the clinical sensitivity, clinical specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Abbott RealTime CT/NG assay in symptomatic and asymptomatic individuals from high- and low-prevalence sites; (iv) to compare the performance of the new Abbott assay with that of the Gen-Probe Aptima Combo 2 assay for female endocervical and vaginal swabs, male urethral swabs, and male and female urine specimens; (v) to compare the performance of the Abbott assay with those of the Becton Dickinson ProbeTec ET Chlamydia trachomatis and Neisseria gonorrhoeae amplified DNA assays (ProbeTec ET) for female endocervical swabs and male and female urine specimens; and (vi) to evaluate the procedure for self-collection of a vaginal swab specimen using the Abbott multi-Collect specimen collection kit.     

Rectal swabs are a reliable method of assessing the colonic microbiome

BackgroundAdvances in genome sequencing have enabled detailed microbiome analysis; however, the ideal specimen type for sequencing is yet to be determined. Rectal swabs may offer a rapid and convenient modality for colonic microbiome analysis. The aim of this study is to evaluate the use of rectal swabs compared to faecal specimens.Methods and resultsTwenty health professionals participated in this study and provided a faecal specimen, a self-collected rectal swab and a rectal swab taken by a clinician. DNA was extracted and 16S rRNA gene sequencing was carried out for microbiome analysis.Alpha diversity was higher in swabs compared to faecal specimens; however, the difference was only significant when comparing clinician-obtained swabs to faeces.Analysis of beta diversity consistently showed that few taxa were affected by sample type. We found sample type accounted for only 6.8% of community variation (R2 = 0.067, p < 0.001, permanova). Notably, there were only six genera identified in clinician-obtained swabs that were not also found in the self-taken swabs.ConclusionsBoth self-collected and clinician obtained rectal swabs are a reliable method of analysing the colonic microbiome. Obtaining specimens for microbiome analysis is often time-critical due to therapy, such as antibiotics, influencing the microbiome. Rectal swabs are shown to be a valid and convenient modality for microbiome analysis.     

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.     

Performance of a Rapid Self-Test for Detection of Trichomonas vaginalis in South Africa and Brazil

Women participating in studies in Brazil (n = 695) and South Africa (n = 230) performed rapid point-of-care tests for Trichomonas vaginalis on self-collected vaginal swabs. Using PCR as the gold standard, rapid self-testing achieved high specificity (99.1%; 95% confidence interval [CI], 98.2 to 99.6%) and moderate sensitivity (76.7%; 95% CI, 61.4 to 88.2%). These tests may be considered an alternative to syndromic management in resource-poor settings.     

Equal Performance of Self-Collected and Health Care Worker-Collected Pharyngeal Swabs for Group A Streptococcus Testing by PCR

A process employing patient- or parent-collected pharyngeal swabs for group A Streptococcus (GAS) testing would expedite diagnosis and treatment, reduce patient exposure to the health care setting, and decrease health care costs. Our aim was to determine the concordance between patient- or parent-collected (self-collected) and health care worker (HCW)-collected pharyngeal swabs for detection of GAS by PCR. From 9 October 2012 to 21 March 2013, patients presenting with a sore throat meeting criteria for GAS testing and not meeting criteria for severe disease were offered the opportunity to collect their own pharyngeal swab. The HCW also collected a swab. Paired swabs were tested by GAS real-time PCR, allowing semiquantitative comparisons between positive results. Of the 402 participants, 206 had a swab collected by the patient and 196 a swab collected by the parent. The percent positivity results were 33.3% for HCW-collected swabs and 34.3% for self-collected swabs (P = 0.41). The overall concordance between the two collection strategies was 94.0% (95% confidence interval [CI], 91.3 to 96.0). Twenty-four of the paired swabs had discordant results, with 10 and 14 positives detected only with the HCW- and self-collected swabs, respectively (P = 0.41). The person collecting the swab in the self-collected arm, the order of collection, and prior swab collection training did not influence results. Among the 124 specimens that were positive by both collection methods, the amount of GAS DNA was higher in the self-collected versus the HCW-collected swabs (P = 0.008). Self-collected pharyngeal swabs provide a reliable alternative to HCW collection for detection of GAS and offer a strategy for improved health care delivery.     

The Emergence of Streptococcus anginosus Group as a Cystic Fibrosis Pathogen

Molecular profiling studies have identified potential emerging pathogens, such as Streptococcus anginosus group, that may play a role in cystic fibrosis (CF) lung disease by either directly causing infection or upregulating the virulence factors of classic CF pathogens, such as Pseudomonas aeruginosa. Routine surveillance of CF pathogens using traditional microbiology culture guides treatment and management of CF patients; however, routine CF culture protocols have not been modified to select for, detect, and further determine the role these emerging pathogens play in the progression of CF lung disease.     

Evaluation of p16/Ki-67 dual-stain cytology performed on self-collected vaginal and clinician-collected cervical specimens for the detection of cervical pre-cancer

ObjectivesTo compare the performance of dual immunostaining of p16INK4a and Ki-67 proteins performed on self-collected vaginal specimens and clinician-collected cervical specimens, and to evaluate the performance of this technique in predicting high-grade disease.MethodsWomen aged 30–59 years (n = 1005) were recruited at two well-women clinics in Papua New Guinea. Each woman provided both cervical and vaginal specimens that were tested for high-risk human papillomavirus (hrHPV) DNA using the Xpert HPV Test (Cepheid) at point of care. A subset of paired cervical and vaginal specimens (n = 243) were selected to undergo CINTec® PLUS (Roche) p16/Ki-67 dual-stain cytology and liquid-based cytology (LBC).ResultsFifty-five pairs (22%) were excluded from further analysis because the smears were not assessable. Of the 189 remaining paired specimens, 74 pairs (39.1%) were positive for one or more hrHPV genotypes. When comparing results of the dual stain, the overall percent agreement, positive and negative percent agreements and κ value between the cervical and vaginal specimens were 87.8% (CI 82.3–92.1%), 64.6% (CI 49.5–77.8%), 95.7% (CI 91.0–98.0%) and 0.65 (CI 0.51–0.79%) respectively. The sensitivity of the dual stain performed on the cervical specimen to predict high-grade disease, determined by LBC, was superior to that of the dual stain performed on the vaginal specimen: 100% (CI 84.6–100%) versus 68.2% (CI 45.1–86.1%).ConclusionAlthough further evaluation may be warranted, these findings indicate that dual-stain testing of vaginal specimens cannot be advocated as part of cervical screening programmes in low- and middle-income countries. However, dual-stain cytology performed on cervical specimens may have a role in quality assurance in such settings.     

Optimal Positive Cutoff Points for careHPV Testing of Clinician- and Self-Collected Specimens in Primary Cervical Cancer Screening: an Analysis from Rural China

careHPV, a lower-cost DNA test for human papillomavirus (HPV), is being considered for cervical cancer screening in low- and middle-income countries. However, not a single large-scaled study exists to investigate the optimal positive cutoff point of careHPV test. We pooled data for 9,785 women participating in two individual studies conducted from 2007 to 2011 in rural China. Woman underwent multiple screening tests, including careHPV on clinician-collected specimens (careHPV-C) and self-collected specimens (careHPV-S), and Hybrid Capture 2 on clinician-collected specimens (HC2-C) as a reference standard. The primary endpoint was cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) (n = 127), and secondary endpoint was CIN2+ (n = 213). The area under the curves (AUCs) for HC2-C and careHPV-C were similar (0.954 versus 0.948, P = 0.166), and better than careHPV-S (0.878; P < 0.001 versus both). The optimal positive cutoff points for HC2-C, careHPV-C, and careHPV-S were 1.40, 1.74, and 0.85, respectively. At the same cutoff point, careHPV-C was not significantly less sensitive and more specific for CIN3+ than HC2-C, and careHPV-S was significantly less sensitive for CIN3+ than careHPV-C and HC2-C. Raising the cutoff point of careHPV-C from 1.0 to 2.0 could result in nonsignificantly lower sensitivity but significantly higher specificity. Similar results were observed using CIN2+ endpoint. careHPV using either clinician- or self-collected specimens performed well in detecting cervical precancer and cancer. We found that the optimal cutoff points of careHPV were 2.0 on clinician-collected specimens and 1.0 on self-collected specimens.     

Identifying a consensus sample type to test for Chlamydia trachomatis,Neisseria gonorrhoeae,Mycoplasma genitalium,Trichomonas vaginalis and human papillomavirus

ObjectivesSexually transmitted infections (STIs) are a global cause of acute illness. Early detection plays a crucial role in interrupting transmission and preventing complications. However, the accessibility of STI testing is curbed by the lack of an overall preferred sample type. By means of a prospective study in female sex workers (FSW), we compared the sensitivity of samples from different anatomical sites in detecting Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium and human papillomavirus. Besides, we documented the prevalence of each STI in this high-risk population.MethodsWe selected 303 FSW and tested them for each STI by nucleic acid amplification testing on two vaginal and cervical swabs from different manufacturers, cervical smear and first-void urine. The sensitivity of each sample type was compared for each infectious agent in order to identify a consensus sample type.ResultsVaginal swabs were superior to all other sample types, with an overall sensitivity of 86%. The sensitivity was the lowest for first-void urine, detecting only 63% of positive cases. The prevalence was 3.3% (10/299) for Neisseria gonorrhoeae; 9.0% (27/299) for Chlamydia trachomatis; 7.4% (22/298) for Trichomonas vaginalis; 10.8% (32/296) for Mycoplasma genitalium and 55.6% (158/284) for human papillomavirus.ConclusionsWhen testing for STIs, vaginal swabs are the sample of choice and first-void urine should be avoided. Designating (self-sampled) vaginal swabs as a consensus sample type enables harmonization of STI testing and extension of testing to large numbers of unscreened females.     

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by strand displacement amplification and relevance of the amplification control for use with vaginal swab specimens

Vaginal swab specimens may be preferable to cervical swab or urine specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae because of the ease of specimen collection and transport. The purpose of this study was to evaluate whether vaginal swab specimens are equivalent to cervical swab specimens for the detection of N. gonorrhoeae and C. trachomatis by the Becton Dickinson strand displacement amplification assay (SDA) with the BDProbeTec ET instrument and then to evaluate the use of the amplification control in a clinical research setting. In the first phase, vaginal and cervical swab specimens were obtained from 455 symptomatic women aged 18 to 40 attending primary health care and sexually transmitted disease clinics. Thirty-nine specimens (8.6%) had true-positive results for N. gonorrhoeae and 37 specimens (8.1%) had true-positive results for C. trachomatis. The sensitivity of SDA was superior to that of culture for the detection of N. gonorrhoeae with vaginal swab specimens and equivalent to that of the Roche PCR for the detection of C. trachomatis with cervical swab specimens. In the second phase of the study, 1,411 consecutively collected vaginal swab specimens were evaluated, with 357 (25.3%) specimens giving indeterminate readings on the basis of the result for the amplification control. The prevalences of sexually transmitted pathogens in vaginal swab specimens with and without use of the amplification control were 6.0 and 5.8%, respectively, for C. trachomatis and 3.1 and 3.0%, respectively, for N. gonorrhoeae. Although, vaginal swab specimens were equivalent to cervical swab specimens for the detection of N. gonorrhoeae and C. trachomatis by SDA with respect to sensitivity, one in four vaginal swab specimens yielded an indeterminate result when the amplification control was used. The amplification control has limited value for use with vaginal swab specimens.     

Direct Detection of Mycobacterium tuberculosis in Clinical Specimens Using Nucleic Acid Amplification Tests

Tuberculosis continues to be a significant cause of morbidity and mortality worldwide. Rapid detection of Mycobacterium tuberculosis directly in clinical specimens using nucleic acid amplification tests enables infected patients to be placed on appropriate therapy much sooner than when results of conventional culture methods are used. The availability of rapid results also facilitates infection control measures to interrupt transmission of tuberculosis in healthcare settings. The era of commercially available molecular diagnostics for detection of M. tuberculosis began 25 years ago and now encompasses multiple assays that can detect organisms in the M. tuberculosis complex. Several assays also detect chromosomal mutations associated with antimicrobial resistance to further refine therapeutic strategies early in the course of disease. NAATs have revolutionized the diagnosis of TB across the globe and have become the standard of care in many high-burden developing countries.     

Evaluation of rectal swab use for the determination of enteric pathogens: a prospective study of diarrhoea in adults

ObjectivesA stool sample is the sample of choice for microbiological testing of enteric pathogens causing diarrhoea, but a rectal swab can be a more practical alternative. A prospective observational study was performed to evaluate the diagnostic performance of flocked rectal swab specimens using the syndromic molecular approach to determine the aetiology of diarrhoea in adults.MethodsWe compared the performance of rectal swabs with stool samples as the reference standard in determining viral, bacterial and protozoal pathogens using real-time multiplex PCR as well as standard stool culture. Paired samples of stool and rectal swab specimens were collected from 304 adult patients with diarrhoea, presented at the Department of Infectious Diseases, University Medical Centre Ljubljana, between June 2016 and August 2017.ResultsOverall sensitivity of rectal swab samples in the syndromic molecular approach was 83.2% (95% CI 77.2%–88.1%). Pathogen group-specific analysis of rectal swabs showed sensitivity of 65.6% (95% CI 52.7%–77.1%) for viruses and 57.1% (95% CI 28.9%–82.3%) for parasites. For bacteria, sensitivity was 86.5% (95% CI 79.5%–91.8%) when PCR was performed and 61.4% (95% CI 52.4%–69.9%) when culture for bacteria was performed. Mean threshold cycle (Ct) values for most pathogens were higher in rectal swab specimens than in stool specimens.ConclusionsOur results indicate that rectal swabs can be used in the diagnosis of diarrhoea in adults when stool specimens are not available or when rapid aetiological determination is needed. However, rectal swabs should be analysed using a molecular approach. The mean Ct value for most pathogens is higher in rectal swab specimens than in stool specimens.     

Sulfated polysaccharides block chlamydia infectionin vitro,but do not protect mice from vaginal inoculation

There is considerable interest in developing a vaginal product that women could use to protect themselves from sexually transmitted pathogens, including chlamydia. It has been suggested that sulfated polysaccharides would be effective in a prophylactic product because they have been shown to block infection of cultured cells by sexually transmitted pathogens, including chlamydia. In order to comparein vitrofindings with animals, we placed sulfated polysaccharides into the vaginae of mice prior to inoculation with chlamydia. The surfactant nonoxynol 9 (N9) was used as a positive control as it has been previously shown to protect mice from infection by chlamydia. In this study, N9 also protected the mice from infection. However, sulfated polysaccharides which had been shown to be efficaciousin vitrodid not block infection.     

Performance of Three Nucleic Acid Amplification Tests for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Use of Self-Collected Vaginal Swabs Obtained via an Internet-Based Screening Program

Use of self-obtained vaginal specimens processed by nucleic acid amplification tests (NAATs) has significantly increased the utilization of nontraditional locations for Chlamydia trachomatis and Neisseria gonorrhoeae screening programs. One important emerging source of such venues includes home-based self-sampling kits available via the Internet. The objective of our study was to evaluate the performance of three commercially available NAATs (Becton-Dickinson ProbeTec SDA, Gen-Probe Aptima Combo2 TMA, and Roche Amplicor PCR) for detection of C. trachomatis and N. gonorrhoeae in vaginal samples obtained via an Internet-based screening program. From July 2004 to August 2005, 500 self-collected vaginal swabs were tested for C. trachomatis and N. gonorrhoeae by using all three NAATs. Another 500 samples were collected between August 2005 and November 2007 and tested by ProbeTec and Combo2; PCR testing was discontinued due to low specificity for N. gonorrhoeae. All tests were conducted according to the manufacturers'' procedures; the “gold standard” for an infected C. trachomatis or N. gonorrhoeae patient was defined as ≥2 positive NAAT results. Of the first 500 swabs submitted, 46 were C. trachomatis infected (9.2%) and 5 were N. gonorrhoeae infected (1.0%), and 3 of these were coinfected (0.6%). All C. trachomatis and N. gonorrhoeae Combo2-positive/ProbeTec-negative samples were confirmed as true positives by an alternative NAAT. For C. trachomatis, ProbeTec, Combo2, and PCR had sensitivities of 82.6%, 100%, and 100%, with specificities of 100%, 100%, and 99.3%, respectively. For N. gonorrhoeae, ProbeTec, Combo2, and PCR had sensitivities of 80%, 100%, and 100%, with specificities of 100%, 100%, and 98.8%, respectively. Of the total 1,000 swabs submitted, 92 were C. trachomatis infected (9.2%) and 15 were N. gonorrhoeae infected (1.5%), and 7 of these were coinfected (0.7%). There were no ProbeTec-positive/Combo2-negative samples. For C. trachomatis, ProbeTec and Combo2 had sensitivities of 81.5% and 100%, with specificities of 100% and 100%, respectively. For N. gonorrhoeae, ProbeTec and Combo2 had sensitivities of 80% and 100%, with specificities of 100% and 100%, respectively. Overall, ProbeTec had 17 C. trachomatis false-negative results (1.7%) and 3 N. gonorrhoeae false-negative results (0.3%), while Combo2 had none. Our results were consistent with the sensitivities and specificities stated by the manufacturers. NAATs perform well for detection of chlamydia and gonorrhea with self-obtained vaginal swabs shipped in a dry state to a laboratory. For 1,000 self-collected vaginal swabs tested by NAATs, the sensitivities for C. trachomatis and N. gonorrhoeae for Combo2 were 100% and 100%, while they were 81.5% and 80%, respectively, for ProbeTec. For 500 PCR samples, the C. trachomatis sensitivity was 100% and the N. gonorrhoeae sensitivity was 100%, with specificities of 99.3% and 98.8%, respectively.Each year, an estimated 3 million Chlamydia trachomatis infections occur in the United States, with over 1 million reported in 2006 surveillance reports (2). In these same reports, 358,366 cases of Neisseria gonorrhoeae infection were reported to occur in the United States (2). Since many sexually transmitted infections (STIs) are asymptomatic, especially chlamydial infections, traditional approaches to clinic-based diagnosis of STIs omit a whole segment of the population that would not ordinarily get tested. Prior to the emergence of nucleic acid amplification tests (NAATs), symptomatic persons or contacts of infected patients would be the only persons seeking care for STIs, usually at a sexually transmitted disease clinic or family planning clinic.Through the use of noninvasive urogenital samples, it is now possible to use alternative venues for screening programs outside the clinic where a clinician is not required to obtain the specimens. Utilization of self-obtained specimens for C. trachomatis and N. gonorrhoeae testing, which employ the highly sensitive and specific NAATs, has enhanced the use of noninvasive urogenital samples (9, 17). Studies have reported that self-collected vaginal specimens are acceptable and can be successfully used to diagnose STIs, especially chlamydia and gonorrhea, when they are used with NAATs (3, 14, 17, 18, 26). This can eliminate the necessity for a clinician-performed pelvic examination for women for sample collection and may represent cost savings when a woman does not require a Pap test or have symptoms (1).Expansion of alternative venues in which chlamydia testing can be performed may even be taken to Internet recruitment for home collection of vaginal swabs for mailing to a laboratory for testing (11, 13). This alternative venue may be popular among adolescents who search the Internet for health care information and information regarding STIs (20). The Internet is also used by people seeking sex partners, and these users appear to be at greater risk for STIs (22). Internet use statistics are staggering; the Pew American Life Project reports that 168 million people are on the Internet per day (http://www.pewinternet.org/reports.asp). Internet use is estimated at 83% of those aged 18 to 29 years, the prime age range in which STIs are most prevalent (http://www.pewinternet.org/reports.asp).We have successfully used an Internet-based recruitment method for home collection of self-obtained vaginal swabs for chlamydia testing (11). While such samples collected at home are not yet FDA cleared, self-obtained vaginal swabs collected in a clinic are FDA cleared for one type of NAAT (26). We therefore decided to compare the performances of the three commercially available NAATs for C. trachomatis and N. gonorrhoeae testing with vaginal samples obtained at home through an Internet screening program and mailed in a dry state (10, 17, 29) to the laboratory for testing.     

Comparison of DRY and WET vaginal swabs with cervical specimens in Roche Cobas 4800 HPV and Abbott RealTime High Risk HPV tests

BackgroundSelf-collected vaginal swab samples have been proposed as an alternative specimen collection method for human papillomavirus (HPV) DNA detection.ObjectivesTwo vaginal swabs (a cone-shaped flocked swab (DRY) and a L-shape FLOQSwab with 2 mL eNAT transport medium (WET)) were compared to standard cervical samples for HPV DNA testing. Additionally, they were also compared by using Roche Cobas 4800 HPV (Roche_HPV) and Abbott Real-time High Risk HPV (Abbott_HPV) tests.Study designNinety-six women were prospectively enrolled from the National Cancer Center in Korea between June and August 2015. WET and DRY vaginal swabs and cervical specimens were collected. Roche_HPV and Abbott_HPV tests were performed. The Roche_HPV test on cervical specimens was used as reference.ResultsThe observed agreements (kappa) of Roche_HPV and Abbott_HPV between WET and DRY swabs were 89.6% (0.790, 95% confidence interval (95% CI): 0.667–0.913) and 91.7% (0.833, 95%CI: 0.723–0.943), respectively. No statistical difference was observed between WET and DRY swabs (p > 0.05 for all comparisons). For HPV16/18, the sensitivity/specificity of Roche_HPV on the DRY and WET samples presented 93.8%/96.3% and 87.5%/97.5%, respectively. For other High Risk HPV (hrHPV), the sensitivity/specificity of Roche_HPV on the DRY and WET swabs presented 91.9%/91.5% and 97.3%/98.3, respectively. The sensitivity/specificity of the Abbott_HPV on the DRY and WET swabs were 93.8%/98.8%, 87.5%/98.8% for HPV16/18, and 91.9%/93.2%, 100.0%/93.2% for other hrHPV, respectively.ConclusionsHPV tests performed similarly when using vaginal DRY and WET swab samples. Using DRY and WET swabs to collect vaginal specimens could be an alternative to collecting cervical samples for HPV DNA testing.