Laboratory Aspects of Screening Men for Chlamydia trachomatis in the New Millennium

Gaydos, Charlotte A.; Ferrero, D; Papp, John R.

doi:10.1097/olq.0b013e31816d1f6d

Cited by 40 publications

(32 citation statements)

References 69 publications

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“…For C. trachomatis and N. gonorrhoeae, there was no statistical difference in test sensitivity for men or women for any sample type when participants were stratified based on symptoms. Although C. trachomatis sensitivity for urine, as the recommended sample of choice for testing men, was slightly lower for symptomatic men (96.1%) than for asymptomatic men (100%), the difference was not statistically significant (2,14). For females, although N. gonorrhoeae sensitivity for female urine was slightly lower for asymptomatic women (91.7%) than for symptomatic women (100%), the difference was not statistically significant.…”

Section: Discussionmentioning

confidence: 64%

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

et al. 2013

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Tests for Chlamydia trachomatis and Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being >99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being >99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts. Chlamydia trachomatis and Neisseria gonorrhoeae are the agents of the two most prevalent bacterial sexually transmitted infections (STIs) reported to the Centers for Disease Control and Prevention (CDC), accounting for Ͼ1.6 million reported infections in the United States in 2010 (1). The CDC estimates that STIs 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 aged 16 to 25 years. Further, since coinfections are common, most diagnostic test platforms assay for both organisms. Nucleic acid amplification tests (NAATs) are now recommended by the CDC (2) as the tests of choice; however, current NAATs are classified as being of high or moderate complexity and might take 1 to 2 days for results to become available. New assays and new platforms that provide results at the time of patient visits are urgently needed, since many patients do not return for their results when laboratory-based tests that require several days for their results are performed (3, 4).The Cepheid GeneXpert CT/NG (Xpert) assay is a rapid (Ͻ2 h to results) NAAT assay that can be performed in on-site laboratories. The assay detects the DNA of C. trachomatis and N. gonorrhoeae from endocervical, vaginal, and urine specimens of females, as well as from urine specimens of males, from both symptomatic and asymptomatic individuals. The Xpert test is performed using a modular cartridge-based platform for testing each specimen by nucleic acid amplification, and it can process from 1 to 96 specimens in Ͻ2 h with easy-to-use cartridges that minimize processing steps and contamination. This study compares the clinical performance (as measured by sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV]) of the Xpert assay to the patient infection status (PIS)...

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Section: Discussionmentioning

confidence: 64%

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

et al. 2013

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“…Anche la positività a M. genitalium, che è del 1.75%, è in accordo con quanto riportato in letteratura (5,34,36,39,43). L'inserimento in routine dell'estrazione automatica del DNA con o senza pretrattamento del campione ha permesso ai "nuovi" test NAATs di essere impiegati anche in campioni alternativi al tampone cervicale o uretrale quali liquido spermatico e soprattutto urine, matrice biologica di elezione per lo screening soprattutto nell'uomo (11,17). Numerosi sono infatti gli studi condotti sulla tipologia di matrici su cui ricercare i diversi patogeni e la maggior parte riguardano la ricerca di C. trachomatis sulle urine (16).…”

Section: Discussioneunclassified

“…Ad esempio, nei maschi, si osserva una positività a C. trachomatis del 23.58% nel tampone uretrale, comparabile con la positività riscontrata nel liquido seminale (17.3%), mentre la positività nelle urine è solo del 5.56% (tabella 4). Questo dato non supporta i numerosi lavori in letteratura che riportano le urine come la matrice più indicata per effettuare gli screening nei maschi con una sensibilità dell'85-95% (11,17). Inoltre, nello studio MST2, tutta la messa a punto della fase di prelievo ed estrazione è stata settata confrontando la cellularità/prelievo utilizzando la quantificazione di un gene umano mediante Real-Time PCR.…”

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Frequency of sexually transmitted diseases and main methodological implications

et al. 2013

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INTRODUZIONELe infezioni sessualmente trasmesse (MST) hanno un'incidenza di circa 340 milioni di nuovi casi ogni anno (48); se non trattate, molte di esse possono produrre infezioni con gravi complicanze, quali infertilità, aborti precoci e malattie neonatali di grado severo (18,24). I costi socio-economici di queste infezioni e delle loro complicanze sono elevati; lo screening per la prevenzione primaria del cancro della cervice e gli interventi per il trattamento e follow-up delle neoplasie cervicali intraepiteliali di grado lieve (CIN 1), moderato (CIN 2) e grave (CIN 3), il trattamento dell'infertilità, la cura della cecità e delle infezioni polmonari nei neonati, rappresentano una larga porzione dei costi sanitari complessivi. Quantificare l'incidenza e la distribuzione di questi patogeni nella popolazione, mediante l'investimento in opportune strategie di controllo e prevenzione, è importante per ridurre la morbilità e la mortalità correlata a questo tipo di infezioni con ricadute, sicuramente, in termini di qualità di vita per i pazienti ma anche in termini di spesa sanitaria più complessa da calcolare. Numerosi sono i test di amplificazione degli acidi nucleici (NAATs) in Real-Time polymerase chain reaction (RT-PCR) per la rivelazione di Chlamydia trachomatis e Neisseria gonorrhoeae (11,23,32,45) mentre poco implementati quelli per la rilevazione di Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum e Ureaplasma parvum, nonostante numerosi studi abbiano dimostrato una maggiore sensibilità delle metodiche 2,28,41,44). Diversi sono i laboratori che stanno implementando la diagnostica molecolare e impiegano le metodiche colturali solo quando è necessario l'antibiogramma. Praticamente inesistenti i test di diagnostica quantitativa in RT-PCR che hanno un'importanza nel follow-up del trattamento. Per la diagnostica del Papillomavirus umano ad alto rischio oncogeno (HR-HPV), numerose sono invece le metodiche NAATs per la rilevazione e la genotipizzazione basate sull'amplificazione del DNA virale delle

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“…This increase in detection of positive infections from screening assays must not be overlooked in assessing the utility of outreach screening programs. When NAATs were first introduced, it was shown that they could be used to test first-catch urine (FCU) specimens from men and that the performance profiles were very similar to those seen with urethral swabs (5), and now, FCU is considered the specimen of choice for testing men for chlamydia (12). Shortly after, FCU specimens from females, when tested by NAATs, were shown to have performance profiles similar to those reported for endocervical swab specimens (4).…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2009

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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 ProbeTecpositive/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.

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Laboratory Aspects of Screening Men for Chlamydia trachomatis in the New Millennium

Abstract: Screening more men with NAAT assays may provide the possibility of reducing the overall burden of chlamydia in both men and women.

Cited by 40 publications

References 69 publications

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Frequency of sexually transmitted diseases and main methodological implications

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

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