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Borrelia burgdorferi was discovered to be the cause of Lyme disease in 1983, leading to seroassays. The 1994 serodiagnostic testing guidelines predated a full understanding of key B. burgdorferi antigens and have a number of shortcomings. These serologic tests cannot distinguish active infection, past infection, or reinfection. Reliable direct-detection methods for active B. burgdorferi infection have been lacking in the past but are needed and appear achievable. New approaches have effectively been applied to other emerging infections and show promise in direct detection of B. burgdorferi infections.

ObjectivesInfections due to Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are among the most common bacterial sexually transmitted infections worldwide, most of which are asymptomatic. Detection of infection using a variety of specimen types in symptomatic and asymptomatic subjects is important to effectively combat CT/NG infections. The performance of the cobas CT/NG v2.0 test was assessed for urogenital swabs, urine and cervical cytology samples collected in PreservCyt Solution from 5266 symptomatic and asymptomatic women (including 202 who were pregnant), and urine from 738 men.MethodsSensitivity and specificity were estimated compared with a patient infected status determined using two US Food and Drug Administration–cleared nucleic acid amplification tests.ResultsAmong 6004 participants, 487 CT (8.1%) and 159 NG (2.6%) infections were identified. Sensitivity estimates for CT for women ranged from 91.2% to 97.6% depending on specimen type, and the estimate for male urine specimens was 98.4%. Specificity for CT ranged from 99.2% to 99.7%. Sensitivity estimates for NG ranged from 95.6% to 100.0% for women, and the estimate for men was 100.0%. Specificity for NG ranged from 99.3% to 100.0%.ConclusionsThe cobas CT/NG v2.0 test performs well using urogenital swabs, urine and cervical samples collected in PreservCyt solution.

The cause of Lyme disease, Borrelia burgdorferi, was discovered in 1983. A 2-tiered testing protocol was established for serodiagnosis in 1994, involving an enzyme immunoassay (EIA) or indirect fluorescence antibody, followed (if reactive) by immunoglobulin M and immunoglobulin G Western immunoblots. These assays were prepared from whole-cell cultured B. burgdorferi, lacking key in vivo expressed antigens and expressing antigens that can bind non-Borrelia antibodies. Additional drawbacks, particular to the Western immunoblot component, include low sensitivity in early infection, technical complexity, and subjective interpretation when scored by visual examination. Nevertheless, 2-tiered testing with immunoblotting remains the benchmark for evaluation of new methods or approaches. Next-generation serologic assays, prepared with recombinant proteins or synthetic peptides, and alternative testing protocols, can now overcome or circumvent many of these past drawbacks. This article describes next-generation serodiagnostic testing for Lyme disease, focusing on methods that are currently available or near-at-hand.

Introduction: The ARIES® HSV 1&2 Assay is a new FDA cleared real-time PCR test for detection and differentiation of HSV-1 and HSV-2 DNA from cutaneous and mucocutaneous lesions. The test is performed on the ARIES® System, an automated sample to answer real-time PCR instrument that provides a closed system and simple workflow for performing molecular testing.Areas covered: This article reports the clinical performance of the ARIES® HSV 1&2 Assay assessed on 1963 prospectively collected specimens. Assay sensitivities were 91.1–95% (cutaneous) and 97–98.5% (mucocutaneous), and specificities were 88.8–94.2% (cutaneous) and 93.2–95.4% (mucocutaneous), as compared to the ELVIS® HSV test system.Expert commentary: Detection of HSV DNA by PCR is rapid and more sensitive than traditional culture and immunoassay methods and is being widely adopted in many laboratory settings. Sample to answer molecular platforms like ARIES® will enable routine and non-molecular labs to perform sensitive and rapid molecular t...

This multicenter study was designed to assess the accuracy and reproducibility of the Vitek MS v3.0 matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry system for identification of Mycobacterium and Nocardia species compared to DNA sequencing. A total of 963 clinical isolates representing 51 taxa were evaluated. In all, 663 isolates were correctly identified to the species level (69%), with another 231 (24%) correctly identified to the complex or group level. Fifty-five isolates (6%) could not be identified despite repeat testing. All of the tuberculous mycobacteria (45/45; 100%) and most of the nontuberculous mycobacteria (569/606; 94%) were correctly identified at least to the group or complex level. However, not all species or subspecies within the M. tuberculosis , M. abscessus , and M. avium complexes and within the M. fortuitum and M. mucogenicum groups could be differentiated. Among the 312 Nocardia isolates tested, 236 (76%) were correctly identified to the species level, with an additional 44 (14%) correctly identified to the complex level. Species within the N. nova and N. transvalensis complexes could not always be differentiated. Eleven percent of the isolates (103/963) underwent repeat testing in order to get a final result. Identification of a representative set of Mycobacterium and Nocardia species was highly reproducible, with 297 of 300 (99%) replicates correctly identified using multiple kit lots, instruments, analysts, and sites. These findings demonstrate that the system is robust and has utility for the routine identification of mycobacteria and Nocardia in clinical practice.

The accuracy and robustness of the Vitek MS v3.0 matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) system was evaluated by identifying mycobacteria from automated liquid-medium systems using patient samples. This is the first report to demonstrate that proteins within the liquid medium, its supplements, and decontamination reagents for nonsterile patient samples do not generate misidentification or false-positive results by use of the Vitek MS v3.0 system. Prior to testing with patient samples, a seeded-culture study was conducted to challenge the accuracy of the Vitek MS system at identifying mycobacteria from liquid medium by mimicking a clinical workflow. Seventy-seven Mycobacterium strains representing 21 species, seeded in simulated sputum, were decontaminated, inoculated into BacT/Alert MP liquid culture medium, incubated until positivity, and identified using the Vitek MS system. A total of 383 liquid cultures were tested, of which 379 (99%) were identified correctly to the species/complex/group level, 4 (1%) gave a "no-identification" result, and no misidentifications were observed. Following the simulated-sputum study, a total of 73 smear-positive liquid-medium cultures detected using BD BBL MGIT and VersaTREK Myco liquid media were identified by the Vitek MS system. Sixty-four cultures (87.7%) were correctly identified to the species/complex/group level; 7 (9.6%) resulted in no identification; and 2 (2.7%) were misidentified at the species level. These results indicate that the Vitek MS v3.0 system is an accurate tool for routine diagnostics of Mycobacterium species isolated from liquid cultures.

Objectives Infections due to Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are among the most common bacterial sexually transmitted infections worldwide, most of which are asymptomatic. Detection of infection using a variety of specimen types in symptomatic and asymptomatic subjects is important to effectively combat CT/NG infections. The performance of the cobas CT/NG v2.0 test was assessed for urogenital swabs, urine and cervical cytology samples collected in PreservCyt Solution from 5266 symptomatic and asymptomatic women (including 202 who were pregnant), and urine from 738 men. Methods Sensitivity and specificity were estimated compared with a patient infected status determined using two US Food and Drug Administration–cleared nucleic acid amplification tests. Results Among 6004 participants, 487 CT (8.1%) and 159 NG (2.6%) infections were identified. Sensitivity estimates for CT for women ranged from 91.2% to 97.6% depending on specimen type, and the estimate for male urine specimens was 98.4%. Specificity for CT ranged from 99.2% to 99.7%. Sensitivity estimates for NG ranged from 95.6% to 100.0% for women, and the estimate for men was 100.0%. Specificity for NG ranged from 99.3% to 100.0%. Conclusions The cobas CT/NG v2.0 test performs well using urogenital swabs, urine and cervical samples collected in PreservCyt solution.

Introduction CDC recommends syphilis screening at least annually for sexually active MSM and screening every 3–6 months for MSM with risks such as multiple partners. Methods In collaboration with a large U.S. commercial laboratory, we identified men aged 15–60 years who had rectal chlamydia (CT) or gonorrhoea (GC) testing during September, 2013-Augest, 2015 as presumed MSM. We estimated: the frequency of testing (counting only tests≥3 months after a previous test); reactivity of nontreponemal tests (NTT) and treponemal tests (TT); and the association between CT/GC and the reactivity of syphilis NTT and TT. We also identified the number of the men with documented as primary, secondary, or early latent syphilis (PSELS) by ICD_9 codes. Results Of 52,771 MSM, 33.8% were aged 15–29 years, 89.6% had private insurance, 51.0% resided in South, and 74.8% had tests ordered by infectious disease specialists. 14.5% had no syphilis tests, 4.8% had TT only (38.2% were reactive), 63.0% had NTT only (2.0% were reactive), and 17.7% had both NTT and TT (8.3% neither were reactive and 86.4% both were reactive). Of 45,108 MSM who had syphilis tests, 1.1% had PSELS. Of 2,547 MSM who had TT only, the number of tests in the two years was one (57.1%), two (22.3%), and three (13.3%). Of 33,238 MSM who had NTT only, the number of tests was one (53.5%), two (23.3%), and three (11.1%). Of 9323 MSM who had both NTT and TT, the number of tests was one (30.4%), two (24.7%), three (17.8%), and four (12.8%). Of 11 870 men who had reactive TT, 51.8% had ≥two reactive TT. CT and GC were significantly higher in men with reactive vs. nonreactive NTT and TT: rectal CT (24.4% vs. 12.6%) or GC (19.8% vs. 9.9%); pharyngeal CT (5.4% vs. 2.9%) or GC (14.7% vs. 10.6%); urethral CT (7.6% vs. 5.7%) or GC (8.0% vs. 5.3%). Conclusion Syphilis testing was common among men who were tested for rectal CT or GC, but most were tested only once. Men with reactive syphilis tests were more likely to have GC or CT vs. men with nonreactive tests. Routine and timely syphilis testing should be prioritised.

Molecular diagnostics is a key component of laboratory medicine. Here, the authors review key triggers of ever-increasing automation in nucleic acid amplification testing (NAAT) with a focus on specific automated Polymerase Chain Reaction (PCR) testing and platforms such as the recently launched cobas® 6800 and cobas® 8800 Systems. The benefits of such automation for different stakeholders including patients, clinicians, laboratory personnel, hospital administrators, payers, and manufacturers are described. Areas Covered: The authors describe how molecular diagnostics has achieved total laboratory automation over time, rivaling clinical chemistry to significantly improve testing efficiency. Finally, the authors discuss how advances in automation decrease the development time for new tests enabling clinicians to more readily provide test results. Expert Commentary: The advancements described enable complete diagnostic solutions whereby specific test results can be combined with relevant patient data sets to allow healthcare providers to deliver comprehensive clinical recommendations in multiple fields ranging from infectious disease to outbreak management and blood safety solutions.

A commercially available, nonamplified, nucleic acid probe-based test system (BD Affirm VPIII) was compared with nucleic acid amplification (NAA)-based assays for determining the etiology of vaginitis in a cohort of 323 symptomatic women. First, a semiquantitative, multiplexed PCR assay (BV-PCR) and the Affirm VPIII Gardnerella vaginalis test were compared with a unified bacterial-vaginosis (BV) reference standard incorporating both Nugent Gram stain scores and Amsel clinical criteria. In the evaluable population of 305 patients, BV-PCR was 96.9% (191/197) sensitive and 92.6% specific (100/108) for BV, while Affirm VPIII was 90.1% sensitive (179/197) and 67.6% specific (73/108). Second, a multiplexed PCR assay detecting Candida albicans and Candida glabrata (CAN-PCR) was compared with the Affirm VPIII Candida test using a reference standard for vulvovaginal candidiasis (VVC) of yeast culture plus exclusion of alternate vaginitis etiologies. In the population evaluated ( n = 102), CAN-PCR was 97.7% sensitive (42/43) and 93.2% specific (55/59) and Affirm VP III was 58.1% sensitive (25/43) and 100% specific (59/59) for VVC. Finally, the results of a commercial NAA test (GenProbe Aptima Trichomonas vaginalis assay; ATV) for T. vaginalis were compared with the Affirm VPIII Trichomonas vaginalis test. In the absence of an independent reference standard for trichomonal vaginitis (TV), a positive result in either assay was deemed to represent true infection. In the evaluable cohort of 388 patients, the sensitivity of ATV was 98.1% (53/54) versus 46.3% (25/54) for Affirm VPIII. The diagnostic accuracy of the combined NAA-based test construct was approximately 20 to 25% higher than that of the Affirm VPIII when modeled in populations with various prevalences of infectious vaginitis.

Background Centers for Disease Control and Prevention guidelines recommend at least annual rectal screening of men who have receptive anal intercourse for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT). Only limited national data are available on the prevalence of rectal GC and CT infection among US men. Methods In collaboration with a large US commercial laboratory, we estimated positivity of the first rectal GC and CT test ("index" test) in men aged 15-60 years tested between January 2013 and May 2015. We estimated the frequency and positivity of pharyngeal or urine specimens tested for GC and CT on the index date, and the frequency and positivity of repeat rectal testing or any follow-up testing at any anatomic site after the index date. Results Of 52 063 tested men aged 15-60 years, approximately 6.1% were positive for GC only, 8.3% for CT only, and 2.7% for both GC and CT on their index date. On that date, 86.5% had either urine or pharyngeal specimens collected, and 56.1% had both specimens collected. Pharyngeal GC infection was highly associated with rectal GC infection. Follow-up testing after 12 months ranged from 42.4% among uninfected men to 56.7% among infected men on the index date. Positivity was at least 5.7% in rectal GC, rectal CT, or pharyngeal GC at their last test. Conclusions This analysis of a large number of male rectal specimens tested for GC and CT suggest that routine testing and timely repeat rectal GC and CT testing should be prioritized among men who report receptive rectal sex.

BACKGROUND: In the United States, chlamydia screening has been recommended for all pregnant women by the Centers for Disease Control and Prevention (CDC) but only for pregnant women who are at increased risk by the US Preventive Services Task Force (USPSTF). Very limited evidence, such as age-specific chlamydia positivity in pregnant women, has been used to develop these recommendations. METHODS: We analyzed data from a large commercial laboratory corporation in the United States in 2013. At the first prenatal visit made by women aged 15 to 44 years for whom a chlamydia test was performed between June 2008 and July 2010, we estimated positivity of chlamydia by age, insurance coverage, geographic region, and test type. RESULTS: Of 601,001 pregnant women aged 15 to 44 years who had routine prenatal care, 62.9% had private insurance and 32.9% had Medicaid coverage, 60.3% resided in the South region, and 43.2% were aged 15 to 24 years, 26.8% were aged 25 to 29 years, and 19.1% were aged 30 to 34 years. Chlamydia positivity was 3.6% overall, and significantly decreased as age increased (15-19 years: 9.6 %; 20-24 years: 5.2%; 25-29 years: 1.8%; 30-34 years: 0.9%; and 35-44 years: 0.6%; P < 0.05). CONCLUSIONS: Our findings of higher positivity among younger pregnant women suggest that the yield is likely to be greater from screening younger pregnant women than from screening older pregnant women to identify chlamydia infection. The benefits of harmonizing CDC and USPSTF recommendations for pregnant women could be explored by reviewing age-specific positivity data and estimating the frequency of prenatal adverse health outcomes caused by chlamydia to develop consensus regarding the age limit for pregnant women who should be screened.

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.

Background Chlamydia is prevalent among young persons in the United States. Infected persons have a high prevalence of infection several months later, most likely from reinfection. Retesting of all men and women with a positive test is recommended 3 months after treatment. A test-of-cure is recommended for pregnant women 3-4 weeks after treatment. Methods We analyzed 2008-2010 chlamydia testing data from a large US laboratory to estimate test positivity by patient demographic characteristics and diagnoses, and patterns of repeat testing of men and nonpregnant women with a positive test and tests-of-cures of pregnant women with a positive test. Results During the study period, 7.0% of 0.40 million tests performed in men and 4.0% of 2.92 million tests performed in women were positive. Among young women, positivity rates were highest among those aged 15-19 years, ranging from 8.5% to 10.0%. Retesting rates of persons with a positive test were suboptimal, with 22.3% of men and 38.0% of nonpregnant women retested. Although 60.1% of pregnant women with a positive test were retested, only 22.0% received a test-of-cure within the 4-week recommended time frame. Repeat tests were positive in 15.9% of men, 14.2% of nonpregnant women, and 15.4% of pregnant women. Conclusions Analyses of laboratory testing data provided important insights into chlamydia testing, retesting, and positivity among a diverse US population of men and women. Too few persons were retested as recommended, and interventions are needed to increase both healthcare provider and patient adherence to recommendations for retesting men and women with positive tests.

Quantitative PCR assays were developed for 4 organisms reported previously to be useful positive indicators for the diagnosis of bacterial vaginosis (BV)— Atopobium vaginae , Bacterial Vaginosis-Associated Bacterium 2 (BVAB-2), Gardnerella vaginalis , and Megasphaera- 1—and a single organism ( Lactobacillus crispatus ) that has been implicated as a negative indicator for BV. Vaginal samples ( n = 169), classified as positive ( n = 108) or negative ( n = 61) for BV based on a combination of the Nugent Gram stain score and Amsel clinical criteria, were analyzed for the presence and quantity of each of the marker organisms, and the results were used to construct a semiquantitative, multiplex PCR assay for BV based on detection of 3 positive indicator organisms ( A. vaginae , BVAB-2, and Megasphaera -1) and classification of samples using a combinatorial scoring system. The prototype BV PCR assay was then used to analyze the 169-member developmental sample set and, in a prospective, blinded manner, an additional 227 BV-classified vaginal samples (110 BV-positive samples and 117 BV-negative samples). The BV PCR assay demonstrated a sensitivity of 96.7% (202/209), a specificity of 92.2% (153/166), a positive predictive value of 94.0%, and a negative predictive value of 95.6%, with 21 samples (5.3%) classified as indeterminate for BV. This assay provides a reproducible and objective means of evaluating critical components of the vaginal microflora in women with signs and symptoms of vaginitis and is comparable in diagnostic accuracy to the conventional gold standard for diagnosis of BV.

Background: The Roche cobasCT/NG test (c4800), performed on the cobas 4800 system, is a new diagnostic assay using an automated workstation to isolate nucleic acids from clinical specimens and a real-time instrument for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). This study compared the perfor- mance characteristics of the c4800 with the Becton Dickinson Pro- beTec™ CT/GC Q x assay (Q x ) and Gen-ProbeAptima Combo 2 (AC2) assay for the detection of CT and NG in male urine using patient-infected-status (PIS). Methods: Urine and urethral swabs were obtained from men attend- ing STD, family planning, or OB/GYN clinics from 11 geographically distinct locations. Aliquot order was randomized for urine specimens between AC2, c4800, and Q x . Urethral swabs were randomized be- tween AC2 and Q x . Urethral swabs were only used to define PIS and were not tested on the c4800. A participant was considered infected if the 2 comparator assays with different molecular targets had positive results from either sample type. Results: A total of 790 men were screened, with 768 evaluable for CT and NG. Symptoms were reported in 296 (38.5%) participants. For urine, the overall sensitivity and specificity of the c4800 assay for CT were 97.6% and 99.5%, respectively, when compared with PIS. Sen- sitivity and specificity for NG were 100% and 99.7%, respectively. Conclusions: The c4800 has excellent sensitivity and specificity for male urine specimens when compared with PIS. Assay performance was similar in symptomatic and asymptomatic men and was equivalent to nucleic acid amplification tests that are currently on the market.

The next-generation amplification test for Chlamydia trachomatis and 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 P values, >0.05), and the fully automated system provides high laboratory efficiency.

Background US guidelines recommend at least annual rectal chlamydia and gonorrhoea screening in men who have receptive anal intercourse. Data on rectal infection with chlamydia and gonorrhoea in men at the US national level are limited. Methods In an ongoing collaboration with LabCorp, a large commercial laboratory corporation with a substantial share of the US market, we estimated rectal chlamydia and gonorrhoea positivity in male rectal specimens tested in 2014. Rectal specimens have unique test codes that are consistent among all LabCorp laboratories. LabCorp had previously validated rectal specimens in collaborative studies. Results Of 38,411 rectal specimens for chlamydia or gonorrhoea, 96.8% (37,170) from 28,945 men aged 15–60 years were tested for both chlamydia and gonorrhoea with nucleic acid amplification tests (NAAT). Of these men, 90.0% had private insurance and 5.0% had Medicaid; 15.4% were aged 15–24 years, 36.4% 25–34 years, and 22.5% 35–44 years. Of these 37,170 specimens, 11.0% were positive for chlamydia, 8.3% gonorrhoea, and 2.4% both. Chlamydia and gonorrhoea positivity varied significantly (p 44 years, respectively). Of these specimens, 71.6% were collected by infectious disease doctors, 9.4% internists, 6.7% family doctors, and 2.6% public health providers. Conclusions This study represents the largest analysis of rectal testing for chlamydial and gonococcal infection in the US Almost all men who receive rectal testing are tested for both chlamydia and gonorrhoea; most rectal testing is performed by infectious disease doctors. NAATs are not FDA cleared for rectal specimens, but many clinical laboratories have validated NAATs under CLIA guidelines and can perform rectal testing. The LabCorp dataset might be the best available source for estimating male rectal infection with chlamydia and gonorrhoea.

Background US guidelines recommend chlamydia screening for all sexually active young women, HIV-infected persons, and men who have sex with men (MSM). Several types of chlamydia tests are available, including nucleic amplification tests (NAATs), DNA probe, and culture. Different assays have different sensitivity and specificity, and sensitivity and specificity also varies by specimen type. Because reported chlamydia trends could be impacted by shifts in the proportion of tests and specimen types used by providers and laboratories, it is important to monitor changes in test usage to help interpret reported trends in morbidity. We examined chlamydia testing data from one of the two largest commercial laboratories in the USA Methods Among chlamydia tests performed from June 2008—to July 2010 by this laboratory, we assessed the frequency of test types used by year, sex, specimen type, and positivity of these tests. Results During these 2 years, 2.9 million specimens were tested for chlamydia. Among those tested, 86% were women. Tests performed were: 77% NAATs, 23% DNA probes, and 0.3% cultures. Between year 1 and 2, NAATs increased from 73% to 80% of all tests, and DNA probes decreased from 27% to 19%. Test type varied by sex; 88% of tests among men were NAATs compared to 75% among women. The top specimen types among women tested by NAAT were: 45% cervical, 35% urine and 18% vaginal. Chlamydia positivity varied by test type: 5.1% NAAT, 1.4% DNA probe, and 2.3% culture. Conclusions NAATs were the most frequently used chlamydia test and their use increased over the evaluation period, creating a smaller market for other tests. Although vaginal swabs are the most sensitive specimen for testing women by NAAT, currently they are the least common specimen type used for testing. This may reflect the delayed introduction (FDA clearance) of the vaginal swab compared to other collection devices. Stocking the wide assortment of collection devices required for testing different specimens in different populations might also be a barrier for providers. Because these data are from one of the largest U.S. laboratories, with representation by insurance type and geography of the U.S. population, they can be useful for monitoring testing trends. Laboratory testing data also might be a valuable adjunct for national surveillance of chlamydia positivity trends that would not be dependent on provider or health department reporting nor small sample size from national surveys.

Background Guidelines recommend chlamydia screening of sexually active young women. Screening rates have increased over the past 10 years, but remain low. Current data used to monitor chlamydia testing trends and positivity rates have limitations, for example, national surveys provide representative data but are cross sectional and use small sample sizes, so longitudinal and subgroup analyses are not possible. To monitor trends more effectively, we solicited chlamydia testing data from commercial laboratories to obtain a representative sample of the US market. Methods Demographic characteristics of persons tested, their geographic location, assay types, specimen sources, and test positivity by sex, age, and insurance type were assessed for all chlamydia testing performed by this laboratory corporation during June 2008–July 2010. Results The dataset contained 3.26 million specimen records. Among those tested, 86.2% were women, 41.0% were aged 15–24 years, 73.5% had commercial insurance, 21.8% had Medicaid insurance, and 56.6% resided in the South. The most frequently used type of chlamydia test was a nucleic acid amplification test (77.5%). Among women, 59.7% of specimens were cervical, 21.1% vaginal, and 18.8% urine. Overall, 4.0% of tests were positive. Positivity rates were highest in persons aged 15–19 years, and higher in men than women for all age groups. Rates also were higher in women with Medicaid insurance than women with private insurance. Conclusions Systematically collected laboratory data can fill a critical gap in monitoring US chlamydia testing and positivity trends. These data are more representative of the US population by geographic distribution and insurance type than other data sources. The analysis of laboratory testing data might be useful for national surveillance that would not be dependent on provider or health department reporting. Our findings underscore the importance of screening young women for chlamydia, especially adolescents in whom screening rates are low. Men had higher positivity rates probably because they sought treatment for symptoms or were referred by an infected partner. Further analysis is needed to assess if testing of persons older than 25 years was according to guidelines, such as pregnant women, at-risk persons, or symptomatic persons.

Background Trichomonas vaginalis (TV) is a sexually transmitted organism associated with vaginitis, cervicitis, urethritis, low birth weight, preterm delivery, pelvic inflammatory disease and HIV transmission and acquisition. Nucleic acid amplification testing improves the sensitivity for detection of pathogens. The performance of the BD ProbeTec™ TV Qx (TVQ) Amplified DNA Assay and the Gen-Probe Aptima TV assay were compared to patient infected status (PIS) established by the InPouch TV culture and wet mount for the detection of trichomonas in women. Methods Participants with symptoms of trichomonas or presenting for routine visit were enrolled from seven geographically diverse centres. First void urine, a patient collected vaginal swab, and three clinician-collected vaginal swabs were obtained from each participant. Urine was aliquoted into BD neat and UPT tubes as well as an Aptima UTT tube. The first two clinician-collected vaginal swabs were randomised for wet mount and InPouch TV culture. The third was used for the Aptima TV assay. Results There were a total of 1034 compliant participants with evaluable PIS. Specimen and instrument level exclusions resulted in 830 compliant vaginal result sets and 733 neat, UPT and UTT urine result sets for evaluation. For vaginal specimens, the sensitivity (specificity) of the TVQ Assay and the Aptima TV Assay compared to PIS were 98.3% (99%) and 100% (98.3%), respectively. For BD neat and UPT urine specimens, the sensitivity (specificity) of the TVQ Assay compared to PIS were 95.5% (98.7%) and 94.6% (98.6%). For the Aptima UTT urine specimen, the sensitivity and specificity of the Aptima TV Assay compared to PIS were 97.3% and 98.7%. Conclusion The BD ProbeTec™ Trichomonas vaginalis Q x Amplified DNA Assay on the BD Viper™ System in extracted mode demonstrated excellent performance characteristics that were comparable to the only commercially available nucleic acid amplification assay for the detection of Trichomonas vaginalis.

Background The Roche cobas 4800 (cobas) is a new diagnostic assay that utilises an automated workstation to isolate nucleic acids from clinical specimens and a real time instrument for the detection of C trachomatis (CT) and N gonorrhoeae (NG). The objective of this study was to compare the performance characteristics of the cobas to the BD Viper (Viper) and GenProbe Aptima Combo 2 (AC2) assays for the detection of CT and NG using a patient infected standard (PIS). Methods Specimens were obtained from women attending STD, family planning, or OB/GYN clinics from 12 geographically distinct locations. Urine and vaginal swabs were obtained from each participant as were endocervical (data not shown) and liquid based cytology samples (data not shown). Women were randomised to either self-obtained (SOV) or clinician-obtained (COV) vaginal swab collection. Four sites performed testing by AC2, cobas, and Viper for urine and by cobas for vaginal swabs. A patient was considered infected if at least two of the assays with different molecular targets gave positive results from cervical or urine samples. Results Overall CT sensitivity ranged from 91.9% to 93.9% and specificity ranged from 99.7% to 99.8% for all sample types. Overall GC sensitivity ranged from 97.0% to 100% and specificity from 99.9% to 100% see Abstract P3-S1.33 table 1. Conclusions The cobas assay has excellent sensitivity and specificity when compared to PIS. There was no difference in performance between the SOV and COV specimens or between the vaginal and urine specimens. Self-obtained vaginal swabs provide opportunities for increased efficiency within the clinical settings. The assay is easy to perform, automated, and can be completed in

Background Women treated for chlamydia have a high prevalence of infection several months later, likely caused by reinfection from an untreated or new infected sex partner. To prevent potential adverse outcomes of chlamydia, US guidelines recommend repeat testing 3 months after treatment, regardless of partner treatment. If retesting at 3 months is not possible, women should be retested at their next clinical encounter within 12 months. A chlamydia test-of-cure is also recommended for all infected pregnant women 3–4 weeks after treatment. We assessed adherence to retesting guidelines using data from a US laboratory corporation that has a large share of the US market. Methods Among tests performed from June 2008 to May 2010, we estimated the percentage of women who were retested ≥3 weeks later by test result, age and pregnancy status. We also estimated the positivity rate among repeat chlamydia tests and the mean time between an initial test and the first repeat test. We assumed that for each woman in the database all chlamydia tests during the study period were performed by this laboratory corporation. Results Among 2.90 million chlamydia tests performed in 1.77 million women, 4.0% (114 963) were positive. Among the 1.77 million women with tests, 1.34 million (75.7%) had only a single test and 0.43 million (24.3%) had at least one repeat test. If an initial test was positive, 48.6% were retested compared to 23.5% if the initial test was negative (p Conclusions These data from a large laboratory corporation provide insight into chlamydia testing practices among women in the USA, and suggest suboptimal adherence to retesting recommendations for both pregnant and nonpregnant women. These data can be useful to monitor the effectiveness of interventions to improve follow-up testing of women with chlamydia.

Background To compare the performance characteristics of the BD ProbeTecTM HSV1 Qx Assay* on the BD ViperTM System in Extracted Mode to viral culture and a well-characterised molecular assay for the detection of HSV1. External anogenital lesions were sampled with two different collection devices: a universal viral transport (UVT) kit and a BD Qx swab (QS) kit*. Methods Eleven geographically diverse clinical centers participated in the study, with nine of the sites enrolling participants. The UVT was collected first followed by the QS specimen. A portion of each UVT specimen was transferred to a Qx Diluent tube (diluted UVT) and a cryovial. The remainder of the UVT in the original tube was frozen at −70°C and sent to one of two sites for HSV viral culture using the ELVIS®HSV ID and D3 Typing Test System (Diagnostic Hybrids, Inc). The diluted UVT and QS specimens were shipped to one of three sites for HSV testing on the BD Viper. The UVT aliquot in the cryovial was stored at −70°C and shipped to the University of Washington for PCR testing for HSV. Results Subjects (n=508) were enrolled from February to August of 2010 with 312 UVT and 308 QS samples available for comparison to ELVIS culture, and 506 and 502 samples, respectively, for comparison to the PCR assay. Samples positive for HSV2 by viral culture did not have results for HSV1 per the ELVIS package insert and were excluded from further analysis. The sensitivity and specificity of the BD HSV1 Qx Assay as compared to ELVIS culture and the positive (PPA) and negative per cent agreement (NPA) of the assay compared to the HSV PCR assays were determined for both specimen types see Abstract P3-S2.03 table 1. Conclusions The BD HSV1 Qx Assay on the BD Viper System had excellent agreement with viral culture and the lab developed PCR assay, which is currently recognised as one of the best available tests for the detection of HSV1. A commercially available molecular-based assay for the detection of HSV would not only improve detection and reduce turn-around time on results, but may also obviate the need for stringent transport conditions required for HSV culture. *Product not for sale, for investigational use only in the US.

Background US guidelines recommend annual Chlamydia screening of the rectum and urethra among men who have sex with men (MSM) with sexual exposure at these anatomic sites. Routine pharyngeal chlamydia screening is not recommended. About 6% of US males have a history of sex with men. The prevalence of rectal chlamydia has consistently been high among MSM with a history of receptive anal sex. One study indicated that up to 53% of chlamydial infections would be missed and not treated if only urethral testing was performed among MSM. We examined data from a large commercial laboratory corporation with a substantial share of the US market and testing available across all 50 states, that also offers rectal and pharyngeal testing with nucleic acid amplification tests (NAAT), to estimate the frequency and positivity of specimens collected from men by anatomic site for chlamydia testing. Methods Data for all Chlamydia testing methods was obtained by a large commercial laboratory between June 2008 and July 2010. The data set was then queried to obtain testing performed on males and analysed for anatomic site, test type, test result and age. Urethral and urine specimens were assumed to be testing for urethral infections. Results Chlamydia testing was performed on 227 188 specimens from men: 98.2% urethral, 1.3% rectal, and 0.5% pharyngeal. The age distribution of those tested was: 2.4% 44 years. Chlamydia positivity varied by anatomic site (8.7% rectal, 6.9% urethral, and 3.5% pharyngeal), and by age (2.5% 44 years). Of 2918 rectal specimens, 17.8% were tested by culture and 75.5% by NAAT, compared to 93.5% of urethral specimens tested by NAAT. Conclusions Given the sexual practices of men in the US, it appears that only a small proportion of MSM are appropriately screened for rectal Chlamydia. Lack of FDA clearance for these specimen sources may contribute to the small proportion of MSM being screened for rectal Chlamydia. Interventions to increase rectal chlamydial testing among MSM are needed. Because data from this corporation represents a large proportion of testing in the US, it could be used to monitor changes in chlamydia testing practice among men in the future.

Cell extracts prepared by osmotic lysis of protoplasts were analyzed by sucrose gradient sedimentation. In the absence of detergents, ribosomal precursor particles were found in a gradient fraction which sedimented faster than mature 50S subunits and in two other fractions coincident with mature 50S and 30S ribosomal subunits. Phospholipid, an indicator of membrane, was shown to be associated with only the fastest-sedimenting ribosomal precursor particle fraction. After the extracts were treated with detergents, all phospholipid was found at the top of the gradients. Brij 58, Triton X-100, and Nonidet P-40 did not cause a change in the sedimentation values of precursors; however, the detergents deoxycholate or LOC (Amway Corp.) disrupted the fastest-sedimenting precursor and converted the ribosomal precursor subunits which sedimented at the 50S and 30S positions to five different classes of more slowly sedimenting particles. Earlier reports on the in vivo assembly of ribosomal subunits have shown that several stages of ribosomal precursor subunits exist, and, in the presence of the detergents deoxycholate and LOC, which had been used to prepare cell extracts, the precursors sedimented more slowly. Our data are consistent with the hypothesis that those detergents selectively modify the structure of ribosomal precursors and lend further support to the hypothesis that the in vivo ribosomal precursor subunits have 50S and 30S sedimentation values. In addition, these data support the idea that the ribosomal precursor particles found in the fast-sedimenting fraction may constitute a unique precursor fraction.