Comparison of cobas 4800, m2000, Viper XTR, and Infinity 80 Automated Instruments When Processing Urine Specimens for the Diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae.

OBJECTIVES: North American and European advisory groups recommend testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) with nucleic acid amplification tests. Testing is often performed on automated instruments. The objectives of this study were to process urines for the diagnosis of CT and NG and to examine workflow procedures and outcomes. METHODS: While processing 1, 24, 48, 96, and 192 urine specimens on 3 batch-mode systems which use 96-well plates: cobas 4800, m2000, and Viper XTR and the random access cartridge testing GeneXpert Infinity 80, we measured assay performance, hands-on time for processing and maintenance, reagents and plastics consumption, time required to obtain results, and testing accuracy. RESULTS: The Infinity 80 required the least hands-on time for single specimens and smaller batches, whereas the Viper XTR and m2000 required the most hands-on time for all batch sizes. Cumulative daily, weekly, and monthly maintenance was highest for the Viper XTR and lowest for Infinity 80. All batch-mode instruments consumed large amounts of disposables. Time to results was shortest for the Infinity 80, and the Viper XTR provided the shortest time for the batch-mode instruments. All systems showed similar diagnostic accuracy. CONCLUSIONS: Because detection performances were similar, issues of hands-on time, maintenance, time to results, and consumables are important operational factors for the diagnosis and treatment of CT/NG infections.

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.

Comparison of Workflow, Maintenance, and Consumables in the GeneXpert Infinity 80 and Panther Instruments While Testing for Chlamydia trachomatis and Neisseria gonorrhoeae.

BACKGROUND: The 2015 Sexually Transmitted Diseases Treatment Guidelines from the Centers for Disease Control and Prevention recommend testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) using nucleic acid amplification tests, and prompt treatment of infected persons on site under direct observation. Faster time to results may enable treatment and management outcomes. METHODS: Workflow parameters for processing 1, 10, 48, 96, and 192 tests were determined in the GeneXpert Infinity 80 (Cepheid) and Panther (Hologic) instruments. RESULTS: In an Xpert CT/NG cartridge, the time to first results on the Infinity 80 was 1 hour 30 minutes for single or multiple tests and final results for 10, 48, 96, and 192 tests were available at 1 hour 37 minutes, 1 hour 54 minutes, 3 hour 17 minutes, and 5 hour 7 minutes, respectively. With the Aptima CT/GC assay on the Panther, the respective times were 3 hr 45 min for the first test result, and 3 hour 51 minutes, 4 hour 38 minutes, 5 hour 26 minutes, and 7 hour 4 minutes to final results. The Panther required more time for maintenance and consumed a greater variety of plastics and reagents but required less hands-on time when testing larger numbers of specimens. CONCLUSIONS: The Infinity 80 is a versatile instrument for continuous random access testing of small or large numbers of clinical specimens and may provide diagnostic results, in some settings, in time for treatment of CT and NG infections.

Ease, Comfort, and Performance of the HerSwab Vaginal Self-Sampling Device for the Detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

BACKGROUND: Many sexually transmitted diseases are asymptomatic in the lower genital tract and can cause upper tract complications if left untreated. Self-collected vaginal (SCV) swabs enable the accurate detection of many sexually transmitted infections and give women the option of collecting their own samples while providing them with privacy and convenience. METHODS: We compared SCV samples collected and transported dry using the HerSwab device to physician-collected vaginal (PCV) Aptima swabs for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), and measured patients' ease and comfort with self-collection. A total of 189 women aged 16 to 41 years were consented into the study and answered a standardized anonymized questionnaire regarding self-collection with the HerSwab device. RESULTS: Women reported self-collection with HerSwab to be easy (97.1%) and comfortable (88.3%). They preferred self-collection over physician collection (80.9%) and would consider using HerSwab for self-collection at home (79.7%). Samples of SCV and PCV showed an overall agreement of 94.7% (κ = 0.64) for CT and of 98.4% (κ = 0.56) for NG, and HerSwab collection detected 7 more positive patients than PCV collection. The overall prevalence of infection was 10.6% for CT and 2.6% for NG. CONCLUSION: HerSwab SCV samples are suitable for the diagnosis of CT and NG.

Canadian Public Health Laboratory Network laboratory guidelines for the use of point-of-care tests for the diagnosis of syphilis in Canada.

Syphilis point-of-care tests (POCT) are widely available in developing countries enabling early diagnosis, treatment and support. The majority of commercially available tests use treponemal antigens and the presence of antibodies does not distinguish between current and past infection, which may lead to unnecessary antibiotic use and stigmatization of having a current STI. In hard-to-reach populations, the benefits may outweigh the risks. Available studies show reasonable performance of POCT with median sensitivity of 86%, specificity of 99% and positive predictive values >80% when prevalence was >0.3%. Although no syphilis POCT are approved in Canada at this time, a single study in an outreach setting in Alberta showed limited benefit due to a high prevalence of previous infection but more studies are needed. Newer dual tests employing treponemal and nontreponemal antigens look promising.

Les tests au point de service (TPdS) de la syphilis sont largement répandus dans les pays en voie développement, ce qui favorise un diagnostic, un traitement et un soutien rapides. La majorité des tests offerts sur le marché font appel aux antigènes tréponémiques. Toutefois, la présence d'anticorps ne permet pas de distinguer une infection en cours d'une infection antérieure, ce qui peut entraîner l'utilisation inutile d'antibiotiques et une stigmatisation liée à l'ITS. Dans des populations difficiles à joindre, les avantages dépassent peut-être les risques. Selon les études existantes, les TPdS donnent des résultats raisonnables, à la sensibilité médiane de 86 %, à la spécificité de 99 % et aux valeurs prédictives positives de plus de 80 % lorsque la prévalence est supérieure à 0,3 %. Même si aucun TDdS de la syphilis n'est approuvé au Canada, une seule étude, réalisée dans un milieu communautaire en Alberta, en a démontré les avantages limités en raison de la forte prévalence d'infection antérieure, mais d'autres études s'imposent. De nouveaux doubles tests, faisant appel à des antigènes tréponémiques et non tréponémiques, semblent prometteurs.

Canadian Public Health Laboratory Network laboratory guidelines for the use of direct tests to detect syphilis in Canada.

Treponema pallidum subsp. pallidum and/or its nucleic acid can be detected by various methods such as microscopy, rabbit infectivity test or polymerase chain reaction (PCR) tests. The rabbit infectivity test for T. pallidum, although very sensitive, has been discontinued from most laboratories due to ethical issues related to the need for animal inoculation with live T. pallidum, the technically demanding procedure and long turnaround time for results, thus making it impractical for routine diagnostic use. Dark-field and phase-contrast microscopy are still useful at clinic- or hospital-based laboratories for near-bedside detection of T. pallidum in genital, skin or mucous lesions although their availability is decreasing. The lack of reliable and specific anti-T. pallidum antibodies and its inferior sensitivity to PCR may explain why the direct fluorescent antibody test for T. pallidum is not widely available for clinical use. Immunohistochemical staining for T. pallidum also depends on the availability of specific antibodies, and the method is only applicable for histopathological examination of biopsy and autopsy specimens necessitating an invasive specimen collection approach. With recent advances in molecular diagnostics, PCR is considered to be the most reliable, versatile and practical for laboratories to implement. In addition to being an objective and sensitive test for direct detection of Treponema pallidum subsp. pallidum DNA in skin and mucous membrane lesions, the resulting PCR amplicons from selected gene targets can be further characterized for antimicrobial (macrolide) susceptibility testing, strain typing and identification of T. pallidum subspecies.

Diverses méthodes, telles que la microscopie, le test d'infectivité du lapin et la réaction en chaîne de la polymérase (PCR), permettent de déceler le Treponema pallidum sous-espèce pallidum et/ou son acide nucléique. Même s'il est très sensible, le test d'infectivité du lapin n'est plus utilisé dans la plupart des laboratoires pour déceler le T. pallidum. En effet, des raisons éthiques liées à la nécessité d'inoculer le T. pallidum vivant à l'animal, l'intervention exigeante sur le plan technique et la longue attente avant d'obtenir les résultats le rendent peu pratique pour un usage diagnostique régulier. Dans les laboratoires des cliniques ou des hôpitaux, la microscopie à fond noir et la microscopie à contraste de phase contribuent toujours à déceler le T. pallidum dans les lésions génitales, cutanées ou muqueuses près du chevet du patient, mais elles sont de moins en moins offertes. Le test d'immunofluorescence directe est peu utilisé pour diagnostiquer le T. pallidum en milieu clinique, peut-être en raison de l'absence d'anticorps anti-T. pallidum fiables et spécifiques et de sa faible sensibilité par rapport au PCR. La coloration immunohistochimique du T. pallidum dépend également de la présence d'anticorps spécifiques, et la méthode est applicable seulement à l'examen histopathologique des prélèvements invasifs de biopsies et d'autopsies. Étant donné les progrès récents des diagnostics moléculaires, la PCR est considérée comme le test le plus fiable, le plus polyvalent et le plus pratique à utiliser en laboratoire. Le PCR est objectif et spécifique pour la détection directe de l'ADN du Treponema pallidum sous-espèce pallidum dans les lésions de la peau et des muqueuses ; ses amplicons provenant de cibles géniques précises peuvent être caractérisés en vue de tests de susceptibilité antimicrobienne (aux macrolides), du typage des souches et du dépistage des sousespèces de T. pallidum.

Canadian Public Health Laboratory Network laboratory guidelines for the diagnosis of neurosyphilis in Canada.

Neurosyphilis refers to infection of the central nervous system by Treponema pallidum, which may occur at any stage. Neurosyphilis has been categorized in many ways including early and late, asymptomatic versus symptomatic and infectious versus non-infectious. Late neurosyphilis primarily affects the central nervous system parenchyma, and occurs beyond early latent syphilis, years to decades after the initial infection. Associated clinical syndromes include general paresis, tabes dorsalis, vision loss, hearing loss and psychiatric manifestations. Unique algorithms are recommended for HIV-infected and HIV-uninfected patients, as immunocompromised patients may present with serologic and cerebrospinal fluid findings that are different from immunocompetent hosts. Antibody assays include a VDRL assay and the FTA-Abs, while polymerase chain reaction for T. pallidum can be used as direct detection assays for some specimens. This chapter reviews guidelines for specimen types and sample collection, and identifies two possible algorithms for use with immunocompromised and immunocompetent hosts using currently available tests in Canada, along with a review of treatment response and laboratory testing follow-up.

La neurosyphilis désigne l'infection du système nerveux central par le Treponema pallidum à tout stade de la maladie. Elle est classée de diverses façons, y compris précoce ou tardive, asymptomatique ou symptomatique, infectieuse ou non infectieuse. La neurosyphilis tardive touche principalement le parenchyme du système nerveux central et se manifeste après une syphilis latente précoce, des années ou même des décennies après l'infection initiale. Des syndromes cliniques s'y associent, y compris la parésie générale, le tabes dorsalis, la perte d'acuité visuelle et auditive et les manifestations psychiatriques. Des algorithmes différents sont recommandés pour les patients infectés ou non infectés par le VIH, car les manifestations sérologiques et céphalorachidiennes des patients immunodéprimés peuvent différer de celles des patients immunocompétents. Les tests de détection des anticorps incluent le VDRL et le FTA-Abs, tandis que pour certains prélèvements, la réaction en chaîne de la polymérase peut servir de test de détection du T. pallidum. Ce chapitre traite des directives sur les types de prélèvement et leur collecte et présente deux algorithmes qui peuvent être utilisés auprès des hôtes immunodéprimés et immunocompétents à l'aide des tests offerts au Canada. Il contient également une analyse de la réponse thérapeutique et du suivi des tests de laboratoire.

Self-collected swabs of the urinary meatus diagnose more Chlamydia trachomatis and Neisseria gonorrhoeae infections than first catch urine from men.

OBJECTIVES: To compare first catch urine (FCU) and self-collected urinary meatal swabs for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) using the APTIMA Combo 2 assay. METHODS: A total of 511 young men from a high risk street youth clinic were studied. Group A (n=293) collected a FCU and a meatal APTIMA swab followed by Group B (n=218) who collected a FCU and two meatal samples using an APTIMA swab and a flocked swab. Order of sample collection was alternated. Individuals in Group B rated collection as easy, difficult or neither, then expressed a preference for sampling and swab type. All subjects performed meatal self-collection in the presence of a study monitor. RESULTS: The combined CT prevalence was 7.8% and 2.7% for NG where 80% of the men were without symptoms. Meatal swabbing identified 35 cases of CT and 14 cases of NG compared to 33 and 11 for FCU. Flocked and APTIMA swabs were equally effective in detecting more cases. The majority of men found self-collection of meatal swabs and urine to be easy. Although 63% preferred urine sampling, 60% of those who preferred swabbing selected the flocked swab. CONCLUSIONS: Collection of meatal swabs could serve as an alternative to urethral swabbing and FCU for the detection of CT and NG.

The laboratory diagnosis of Chlamydia trachomatis infections.

Lower genital tract infections with Chlamydia trachomatis are predominantly asymptomatic in men and women. Diagnostic technology has provided several approaches to the diagnosis of C trachomatis. Outside of cells, Chlamydia can die or degrade without optimal storage and transportation. Because some of the other assays perform better on certain specimen types, it is important for laboratories to recognize these differences and provide advice to physicians and nurses collecting patient specimens, with the objective of diagnosing lower genital tract infections to prevent transmission and upper tract damage. Most invasive specimens, such as cervical or urethral swabs, may be collected for culture, antigen or nucleic acid detection. Noninvasive samples such as first-void urine and vaginal swabs can be easily collected by the patient; these samples must be tested by more sensitive nucleic acid amplification tests. These newer investigative strategies should enable implementation of screening programs to identify and treat partners. Serology has not been particularly useful for the diagnosis of acute C trachomatis infections in adults. Presently, it appears that antibiotic-resistant C trachomatis is not a clinical problem. Laboratories providing C trachomatis diagnosis require participation in continuous quality improvement programs.

The evaluation of diagnostic tests for sexually transmitted infections.

Diagnostic tests should receive method- and use-effectiveness evaluations. Method-effectiveness evaluations determine sensitivity, specificity and predictive values for new tests. Use-effectiveness evaluations determine how practical or convenient a new test will be in a specific setting and may not be performed in a formal way in North American laboratories. To perform a clinical method evaluation of diagnostic tests, a good relationship between laboratory and clinical personnel is essential. Studies are usually conducted separately on populations of men and women, and should include sampling from different prevalence groups. Test performance comparisons may be made on a single specimen type or on more than one specimen from the same patient, which allows for the expansion of a reference standard and includes the ability of a particular assay, performed on a specimen type to diagnose an infected individual. The following components of the evaluation should be standardized and carefully followed: specimen identification; collection; transportation; processing; quality control; reading; proficiency testing; confirmatory testing; discordant analysis - sensitivity, specificity and predictive value calculations; and record keeping. Methods are available to determine whether sample results are true or false positives or negatives. Use-effectiveness evaluations might determine the stability or durability of supplies and equipment; the logistics of shipping, receiving and storing supplies; the clarity and completeness of test instructions; the time and effort required to process and read results; the subjectivity factors in interpretation and reporting; and the costs. These determinations are usually more apparent for commercial assays than for homemade tests.

APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae.

The APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae have the greatest sensitivity of all the commercial nucleic acid amplification tests for the diagnosis of infections from noninvasive samples that may contain small amounts of nucleic acid. They have received extensive attention in male and female populations of varying prevalences of infection. Vulvovaginal swabs appear to be the specimen of choice (either self-collected or physician collected) in women and first-catch urine in men. Gen-Probe Inc. has created alternate amplification primers for confirmatory or initial single organism testing. With automation of the TIGRIS instrument, the assays should prove to be useful in high-volume laboratories.

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.

Prevalence of Chlamydia trachomatis infections and specimen collection preference among women, using self-collected vaginal swabs in community settings.

BACKGROUND: Chlamydia trachomatis is a common, often asymptomatic sexually transmitted infection. GOAL: The goal was to estimate the prevalence and predictors of C. trachomatis among young women using self-collected vaginal swabs, and the preferences of women and physicians for self-testing. STUDY DESIGN: A total of 514 attendees of university/college health clinics, adolescent birth control clinics, centers providing health services to homeless youth and adults (street health centers), a sexually transmitted diseases clinic, and family practices were tested by ligase chain reaction. Preference for self- versus provider-testing was examined. RESULTS: Prevalence was 6.0% and was highest (18.2%) in the street health centers. In multivariate analysis, only recent contact with someone with C. trachomatis infection was significantly associated with infection (odds ratio, 7.1; 95% confidence interval, 2.5-20.0). Most women (54.2%; 256 of 472) preferred self-sampling compared with physician sampling (15.9%; 75 of 472). The majority of physicians (75.0%; 9 of 12) reported at the start and end of the study that they would use vaginal swab self-sampling if available. CONCLUSIONS: Prevalence of infection in young women attending homeless youth organizations was high. Self-sampling was acceptable and could facilitate screening in high-risk women who do not regularly access health services.

Vaginal swabs are appropriate specimens for diagnosis of genital tract infection with Chlamydia trachomatis.

Because self-collected vaginal swabs (VS) are potentially very useful for screening asymptomatic women for Chlamydia trachomatis infection, a multicenter study evaluated that specimen with nucleic acid amplification tests (NAATs). The objective was to determine whether VS are equal to Food and Drug Administration (FDA)-cleared specimens (cervical swabs and first-catch urines [FCU]) for diagnosing genital chlamydial infection. All NAATs then commercially available (October 1996 to October 1999) were used (ligase chain reaction [LCx Probe System; Abbott Laboratories, Abbott Park, Ill.]; PCR [Amplicor; Roche Molecular Systems, Branchburg, N.J.]; and transcription-mediated amplification, [Amplified CT Assay; Gen-Probe Inc., San Diego, Calif.]). NAATs were performed on FCU, urethral, cervical, self- and clinician-collected VS. Sensitivity was compared to isolation using cervical and urethral swabs. Agreement of NAAT results between VS and cervical swabs or FCU was calculated. Specimens from 2,517 15- to 25-year-old asymptomatic women attending clinics at nine different centers were evaluated. Results with self- and clinician-collected VS were equivalent and were at least as good as results with FCU and cervical swabs. Across all sites, summary specificities for all specimens were >99%. Among culture-positive women, NAAT sensitivity with VS (93%) was as high as or higher than NAAT sensitivity with cervical swabs (91%) or FCU (80.6%) or culture of cervical swabs (83.5%). VS are appropriate specimens for diagnosing chlamydial genital tract infection by NAATs. That patients can efficiently collect them offers important benefits for screening programs. It would be beneficial for public health programs if the NAAT manufacturers sought FDA clearance for this specimen.