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Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in pharyngeal and rectal specimens using the BD ProbeTec ET system, the Gen-Probe Aptima Combo 2 assay and culture
Abstract
This study compared the sensitivity and specificity of culture and two nucleic acid amplification tests (NAATs): the BD Probetec ET system (PT) and the Aptima Combo 2 (AC2) in detecting Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) in pharyngeal and rectal specimens.
Male subjects were prospectively recruited at an MSM clinic in Toronto, Canada. Pharyngeal and rectal specimens were obtained for GC and CT culture, PT and AC2. Urine was also obtained for PT. A true positive was defined as: (1) positive culture, (2) positive PT and AC2 at the same site or (3) a single positive NAAT and detection of the same organism by any method at another site.
248 subjects were recruited. The prevalence of pharyngeal GC was 8.1%, rectal GC 11.7%, pharyngeal CT 2.0% and rectal CT 7.7%. The sensitivity of culture for pharyngeal GC and CT was 0%; 41.4% for rectal GC and 21.1% for rectal CT. The sensitivity of PT for pharyngeal GC, rectal GC, pharyngeal CT and rectal CT was 95.0%, 93.1%, 80.0% and 94.7%, respectively. The sensitivity of AC2 was 95.0% for pharyngeal GC and 100% at all other sites. Specificity was consistently above 98%.
PT and AC2 detected GC and CT with superior sensitivity compared to culture. They detected 73 pharyngeal or rectal GC and CT infections compared to 16 by culture, using a rigorous gold standard. NAATs should be the method of choice for the detection of GC and CT in extragenital sites in men who have sex with men.
... This is of great concern as the only way to elucidate whether clinical failure is due to a strain with decreased susceptibility to ceftriaxone (the current recommended treatment worldwide) is by performing antimicrobial susceptibility testing (AST) on strains recovered by culture. Unfortunately, extragenital locations have been historically related to poor recovery rates, particularly in pharyngeal specimens, where recovery rates as low as 0% have been reported (Ota et al. 2009b). ...
... Neisseria gonorrhoeae culture sensitivity and recovery rate vary across the different studies, ranging from 15 to 90% in genital sites (Reichart et al. 1989;Benn et al. 2007;Harryman et al. 2012;Visser et al. 2020;Nash et al. 2021;Ratnappuli et al. 2021), 0-59% in pharynx (Young et al. 1997;Schachter et al. 2008;Ota et al. 2009b;Visser et al. 2020;Phillips et al. 2021), and 2-88% in rectum (Benn et al. 2007;Schachter et al. 2008;Ota et al. 2009b). These discrepancies probably reflect the inconsistent data between studies. ...
... Neisseria gonorrhoeae culture sensitivity and recovery rate vary across the different studies, ranging from 15 to 90% in genital sites (Reichart et al. 1989;Benn et al. 2007;Harryman et al. 2012;Visser et al. 2020;Nash et al. 2021;Ratnappuli et al. 2021), 0-59% in pharynx (Young et al. 1997;Schachter et al. 2008;Ota et al. 2009b;Visser et al. 2020;Phillips et al. 2021), and 2-88% in rectum (Benn et al. 2007;Schachter et al. 2008;Ota et al. 2009b). These discrepancies probably reflect the inconsistent data between studies. ...
Gonorrhoea infections are frequently diagnosed at extragenital locations in asymptomatic individuals and are historically related to poor recovery in culture, which hinders antimicrobial susceptibility testing. The aim of this study was to evaluate recovery rates of N. gonorrhoeae by culture among asymptomatic individuals who tested positive by nucleic acid amplification tests between 2018 and 2019 in Barcelona (Spain). In total, 10,396 individuals were tested for N. gonorrhoeae on first‐void urine, rectal, pharyngeal, and/or vaginal swabs depending on sexual behaviour. Overall infection prevalence was 5.5% (95% confidence interval [CI] 5.0 to 5.9%). Seven hundred and ten samples were positive corresponding to 567 individuals. The most common site of infection was the pharynx (71.3%), followed by rectum (23.1%) and genitals (4.7%) (p<0.0001). The N. gonorrhoeae recovery rate in culture, time from positive screening to culture specimen, and inoculation delay were calculated. Recovery rate was 21.7% in pharynx, 66.9% in rectum, and 37.0% in genitals (25.0% vagina, 71.4% urethra) (p<0.0001). Median culture collection time was 1 [0; 3] days, and median inoculation delay was 5.01 [4.99‐7.99] hours, with no impact on N. gonorrhoeae recovery, p=0.8367 and p=0.7670, respectively. Despite efforts towards optimizing pre‐analytical conditions, the N. gonorrhoeae recovery rate in asymptomatic individuals is unacceptably low (especially for pharynx), representing a problem for monitoring antimicrobial‐resistant infections.
... Published data support the fact that commercial nucleic acid amplification tests (NAATs) are more sensitive than culture for the diagnosis of N. gonorrhoeae and C. trachomatis infections across a range of specimen types and under varying conditions [4,5,9]. Even though culture is still regarded as the 'gold standard' for detection and diagnosis of N. gonorrhoeae from extra-genital sites [10,11], multiple studies have shown that it is in fact an insensitive diagnostic tool for detecting infections at such sites [7,12]. ...
... Regulatory approval from the US Food and Drug Administration (FDA) has been received for use of the following commercial NAATs for the detection of N. gonorrhoeae and C. trachomatis in urogenital specimens: Abbott RealTime m2000 CT/NG (Abbott Molecular Inc. Des Plaines, IL, USA), Amplicor and Cobas CT/NG test (Roche Molecular Diagnostics, Branchburg, NJ, USA), APTIMA (HOLOGIC®, San Diego, CA, USA), BD Pro-beTec ET and Qx (Becton Dickinson, Sparks, MD, USA) and Xpert® CT/ NG Assay (Cepheid, Sunnyvale, CA, USA) [2]. Extra-genital pharyngeal and ano-rectal swab specimens are not officially approved for use with the APTIMA Combo 2 assay, even though they have displayed acceptable performance characteristics in evaluations [2,9,15,16]. Each laboratory is required to perform their own validation and verification of data to support the results obtained from these sample sites according to the Clinical Laboratory Improvement Amendments (CLIA) regulatory requirements [15,20]. ...
... There are concerns regarding the specificity of NAATs when testing samples from sites colonised by other commensal Neisseria species [23]. These species are genetically closely related, and may result in false positive N. gonorrhoeae results [9,14,23]. The same has not been observed with the APTIMA Combo 2 or the APTIMA GC assays [9,17,19]. ...
Background
Extra-genital Neisseria gonorrhoeae and Chlamydia trachomatis infections are mostly asymptomatic, and important reservoir sites of infection as they often go undetected and may be more difficult to eradicate with recommended therapeutic regimens. Commercial nucleic acid amplification tests (NAATs) have not received regulatory approval for the detection of N. gonorrhoeae and C. trachomatis in extra-genital specimens. The HOLOGIC® APTIMA Combo2 assay for N. gonorrhoeae and C. trachomatis has performed well in evaluations using extra-genital specimens.
Methods
We assessed the performance of an in-house real-time duplex PCR assay for the detection of N. gonorrhoeae and C. trachomatis in urine and extra-genital specimens using the HOLOGIC® APTIMA assays as gold standard comparators. Urine, oropharyngeal and ano-rectal specimens were collected from each of 200 men-who-have-sex-with-men (MSM) between December 2011 and July 2012.
Results
For N. gonorrhoeae detection, the in-house PCR assay showed 98.5–100% correlation agreement with the APTIMA assays, depending on specimen type. Sensitivity for N. gonorrhoeae detection was 82.4% for ano-rectal specimens, 83.3% for oropharyngeal specimens, and 85.7% for urine; and specificity was 100% with all specimen types. The positive predictive value (PPV) for N. gonorrhoeae detection was 100% and the negative predictive value (NPV) varied with sample type, ranging from 98.5–99.5%. For C. trachomatis detection, correlation between the assays was 100% for all specimen types. The sensitivity, specificity, PPV and NPV of the in-house PCR assay was 100% for C. trachomatis detection, irrespective of specimen type.
Conclusion
The in-house duplex real-time PCR assay showed acceptable performance characteristics in comparison with the APTIMA® assays for the detection of extra-genital N. gonorrhoeae and C. trachomatis.
... No manufacturer of C. trachomatis NAATs has licensed extra-genital specimens for diagnosis. However, NAATs are the preferred test for all these specimens and some NAATs have been adequately validated for these specimens [IIa; B]. [112][113][114][115][116][117] Nevertheless, the sensitivity and specificity can be lower compared to urogenital specimens. 114,[118][119][120][121] Confirmation of the positive results with an independent assay may be appropriate [II]. ...
... However, NAATs are the preferred test for all these specimens and some NAATs have been adequately validated for these specimens [IIa; B]. [112][113][114][115][116][117] Nevertheless, the sensitivity and specificity can be lower compared to urogenital specimens. 114,[118][119][120][121] Confirmation of the positive results with an independent assay may be appropriate [II]. 114,118,119 Collecting pharyngeal and rectal specimens should always be considered in MSM, and in heterosexuals according to risk. ...
... 114,[118][119][120][121] Confirmation of the positive results with an independent assay may be appropriate [II]. 114,118,119 Collecting pharyngeal and rectal specimens should always be considered in MSM, and in heterosexuals according to risk. 117 With the increase (or persisting presence) of rectal LGV infections, especially in MSM, 34,122,123 it is recommended to identify LGV patients by testing all MSM who report receptive anal sex in the previous six months for anorectal C. trachomatis infection with a NAAT. ...
Chlamydia trachomatis infections, which most frequently are asymptomatic, are major public health concerns globally. The 2015 European C. trachomatis guideline provides: up-to-date guidance regarding broader indications for testing and treatment of C. trachomatis infections; a clearer recommendation of using exclusively-validated nucleic acid amplification tests for diagnosis; advice on (repeated) C. trachomatis testing; the recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection; and recommendations to identify, verify and report C. trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of C. trachomatis patients are crucial to control its spread. For detailed background, evidence base and discussions, see the background review for the present 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS. 2015).
... However, the primary data source for these estimates was the Health In Men (HIM) Study, which was conducted between 2001 and 2005 in Australia and relied on a combination of annual rectal testing plus participant self-report to estimate incidence of disease, with enrollment test results considered the cohort's prevalence [11]. Additionally, part of the HIM study was conducted prior to 2003 when culture was the primary testing technology, and after 2003, the study team employed a strand displacement assay (SDA) by BD Probe Tech, both of which are less sensitive than the Aptima [12]. In the HIM study, incidence of rectal gonorrhea was only 0.96 per 100 py and rectal chlamydia incidence was 2.75 infections per 100 py, both of which are less than 10% of the incidences that we observed using a more frequent testing interval. ...
... Most important, we used an RNA-based testing technology to detect and define infection. RNA-based NAATs are highly sensitive for gonorrhea and chlamydia diagnosis, especially compared with culture [12]. However, since they only detect nucleic acids, there can be false-positive results resulting from detection of nucleic acid in the absence of viable infection, leading to an overestimate of the true duration of infection. ...
Background
The duration of rectal gonococcal and chlamydial infection remains unknown. This basic epidemiologic parameter is needed to understand transmission dynamics.
Methods
We conducted a prospective, longitudinal, observational, cohort study of 140 men who have sex with men (MSM) at-risk of gonorrhea and chlamydia acquisition. For 48 weeks, enrolled men collected rectal swabs (Aptima multitest kit) at home and responded to an electronic survey about sexual behavior and health conditions weekly. Swabs remained untested until participants completed the study. We used Kaplan Meier estimates to determine the median duration of infection, censoring infections for treatment, loss-to-follow-up and end-of-study. We used Log-rank test to compare duration of infection by HIV status, history of infection with gonorrhea or chlamydia, and co-infection with the other pathogen.
Results
140 enrolled MSM contributed 70.5 person years of follow-up. Eighteen men had 20 incident rectal gonococcal infections, which persisted for 2 – 23 weeks; 30% were censored for treatment. The estimated median duration of rectal gonorrhea was 9 weeks (95% CI: 3-12 weeks). Twenty-four men experienced 32 rectal chlamydial infections, persisting between 2 to 42 weeks; 60% were censored. The estimated duration of rectal chlamydia was 13 weeks (95% CI: 6 weeks – undefined). There were no differences in the duration of rectal gonorrhea or chlamydia by HIV status, history of chlamydia/gonorrhea or co-infection.
Conclusions
On average, rectal gonorrhea and chlamydial infections last 2-3 months, though some infections some persist for 6-11 months. Further understanding into predictors of persistence are needed.
... Laboratories with sufficient resources and technical expertise have the capability to bring laboratory-developed tests or laboratory-modified assays onto their respective testing platforms 7 to assist their clinician and community partners in following CDC STI screening guidelines. One investigation of two commercial NAAT assays for off-label detection of STI agents from rectal sources 8 have advanced to the point where men can now be screened for these agents, with the assistance of laboratory-modified testing. 11,12 However, few reports have documented the prevalence of these agents in the young MSM and transgender women demographics. ...
... Commercial RNA amplification was also 14.8% more sensitive than a second format of DNA amplification in detection of N. gonorrhoeae nucleic acid from rectal swab specimens. Ota et al. 8 reported 64.7% sensitivity of DNA amplification for detection of C. trachomatis nucleic acid from rectal swab specimens when compared to second-generation RNA amplification. Furthermore, RNA amplification was 30% more sensitive than a second format of DNA amplification testing in detection of C. trachomatis nucleic acid from rectal swab specimens. ...
Background:
This study's purposes were to characterize detection rates of several sexually transmitted infection (STI) agents and describe the effect additional specimen source and analyte screening has on STI detection within a cohort of young men who have sex with men and transgender women.
Methods:
Within a 16-month interval, 1966 encounters involved dual urine and rectal swab submissions assessed by commercial transcription-mediated amplification-based assays for Chlamydia trachomatis and Neisseria gonorrhoeae and by off-label transcription-mediated amplification-based Trichomonas vaginalis and Mycoplasma genitalium testing. Identification of STI carriers used algorithms involving Food and Drug Administration-cleared screening methods, laboratory-modified testing for extraurogenital C. trachomatis and N. gonorrhoeae, and laboratory-developed tests for T. vaginalis and M. genitalium.
Results:
Food and Drug Administration-indicated urine C. trachomatis and N. gonorrhoeae screening revealed 39 encounters (2.0%) yielding one or both agents. Via C. trachomatis and N. gonorrhoeae screening that included rectal swab analysis, 264 encounters (13.4%) yielded evidence of either (140 C. trachomatis, 88 N. gonorrhoeae) or both (36 participants) infections. Detection rates for C. trachomatis and N. gonorrhoeae were 1.4% and 0.6% for urine screening and 8.2% and 6.2% for rectal screening, respectively. Off-label screening identified 413 additional encounters with STI (5 T. vaginalis, 396 M. genitalium, 12 with both). Of these identifications, 82.1% were generated from analysis of rectal swabs (4 participants with T. vaginalis, 323 participants with M. genitalium, 12 with both). Overall detection rates of T. vaginalis (0.2% urine, 1.3% rectal) and M. genitalium (9.1% urine, 21.5% rectal) were variable.
Conclusions:
Additive analyte testing, including extraurogenital collections, contributes to comprehensive STI screening within a high-risk demographic.
... • The urethral or first-void urine TMA Combo test obtained high sensitivity for both C. trachomatis and N. gonorrhoea [15,26]. • The rectal NAAT (TMA and SDA) sensitivities (67--100%) were higher than those from cultures (35--49%) [22,23,30]. TMA had higher sensitivity compared to SDA. ...
... In MSM, NAAT using rectal selfcollected samples had a higher sensitivity compared to clinician-collected samples [22]. • The clinician-collected oropharyngeal NAAT (TMA and SDA) sensitivities (88-100%) were higher than sensitivities from cultures (55-100%) [23,30]. ...
Objectives
In the last 10 years, Belgium and countries of the European Economic Area and other high-income countries observed an increasing trend in syphilis diagnoses. Men who have sex with men (MSM) are the most affected population explained by high rates of unprotected sex, a greater number of sexual partners, and risk compensation as a result of pre-exposure prophylaxis use. The 2019 European Centre for Disease Prevention and Control (ECDC) technical report on syphilis proposed interventions such as enhanced screening of specific populations at risk. This guideline will address these issues.Methods: We performed a systematic review of the evidence for diagnosing and treating syphilis. Results: Based on the results, recommendations were formulated for primary health care professionals in Belgium. This syphilis guideline addresses prioritised testing, the sample and test for the diagnosis, the treatment of a person with syphilis including syphilis serology follow-up, and partner management.Conclusion: The identification and management of patients with syphilis will benefit from the application of this guideline.
... The composite reference standard was the ASIS, described above. The study was designed with a sample size of 2500 evaluable participants under the assumption that prevalence of NG infection in the rectum, NG infection in the pharynx, and CT in the rectum would each be greater than 7.5% in the population under evaluation [28][29][30][31][32][33][34][35]. That value provided at least an 80% probability of obtaining at least 174 participants with infection at each of those 3 anatomic sites. ...
... For the detection of NG, prior reported sensitivities were 84%-100% (pharyngeal) and 76%-100% (rectal), and specificities were 96%-100% (pharyngeal) and 95%-100% (rectal) [29-31, 34, 35, 41]. For the detection of CT, prior reported sensitivities were 100% for the pharyngeal site and 71%-100% for the rectal site, and specificities were >99% for the pharynx and 89%-100% for the rectum [28][29][30][31][32][33]42]. Differences are likely due to variation in the definition of the reference method used in each study. ...
Background:
Pharyngeal and rectal Neisseriagonorrhoeae and Chlamydiatrachomatis play important roles in infection and antibacterial resistance transmission, but no Food and Drug Administration-cleared assays for detection at these sites existed prior to this study. The objective was to estimate performance of assays to detect those infections in pharyngeal and rectal specimens to support regulatory submission.
Methods:
We performed a cross-sectional, single-visit study of adults seeking sexually transmitted infection testing at 9 clinics in 7 states. We collected pharyngeal and rectal swabs from participants. The primary outcome was positive and negative percent agreement for detection of N. gonorrhoeae and C. trachomatis for three investigational assays compared to a composite reference. Secondary outcomes included positivity as well as positive and negative predictive values and likelihood ratios. Subgroup analyses included outcomes by symptom status and sex.
Results:
2,598 participants (79% male) underwent testing. We observed N. gonorrhoeae positivity of 8.1% in the pharynx and 7.9% in the rectum and C.trachomatis positivity of 2.0% in the pharynx and 8.7% in the rectum. Positive percent agreement ranged from 84.8% to 96.5% for different anatomic site-infection combinations, while negative percent agreement was 98.8% to 99.6%.
Conclusions:
This study utilized a Master Protocol to generate diagnostic performance data for multiple assays from different manufacturers in a single study population, which ultimately supported first-in-class FDA clearance for extragenital assays. We observed very good positive percent agreement when compared to a composite reference method for the detection of both pharyngeal and rectal N. gonorrhoeae and C.trachomatis.
Registration:
ClinicalTrials.gov number NCT02870101.
... 8,9 Based on published values from a validation study in Ontario (performed by Public Health Ontario using the Hologic Aptima Combo 2 Assay), extragenital culture compared with NAAT was overall 37% sensitive, identifying 200 of 535 infections, with detection rates ranging from 13% (n = 21/159) for pharyngeal gonorrhea to 67% (n = 103/153) for rectal gonorrhea. 13,20,21 By comparison, the sensitivity for NAAT was 99.4% and 92.2% for pharyngeal and rectal chlamydia, and 100% for pharyngeal and rectal gonorrhea, respectively. The specifi cities were 99.9% for rectal and pharyngeal chlamydia, 98.25% for pharyngeal gonorrhea, and 99.0% for rectal gonorrhea. ...
... The specifi cities were 99.9% for rectal and pharyngeal chlamydia, 98.25% for pharyngeal gonorrhea, and 99.0% for rectal gonorrhea. 21 Based on these performance values, Public Health Ontario recommended extragenital NAATs only for patients deemed "high risk," defi ned as patients who are contacts of someone diagnosed with one of these two STIs, MSM, and sex trade workers and their clients. 14 The recommendation continued that patients not from these groups should have cultures done, although NAAT could be considered for low-risk patients based on clinical judgment and because of its higher sensitivity. ...
Chlamydia and gonorrhea are the most commonly diagnosed bacterial sexually transmitted infections (STIs), and both are increasing in incidence. Because these STIs are often asymptomatic and found at extragenital sites, such as the pharynx and rectum, it is important that clinicians know when and how to screen for them.
... Prevalence estimates vary depending on the population and site being screened [3]. In the adult MSM population, the prevalence of CT varies from 1.5-3.5% (pharyngeal) to 5-15% (rectal) while that of GC varies from 5-15% for both, pharyngeal and rectal infections [4][5][6]. Pharyngeal and rectal infections typically occur without concomitant urethral infection [7,8]. Moreover, these non-genital infections are found to have strong association with an increased risk of acquiring HIV infection. ...
... BD-Probe-Tec swabs and urine specimens were processed by the laboratory in accordance with the manufacturer's protocol (BD Probe-Tec™ ET System). The CDD laboratory validated the BD Probe-Tec (Strand Displacement method) assay on pharyngeal and rectal specimens in a manner consistent with recommendations from the CDC and the Association of Public Health Laboratories [6,16]. ...
... E xtraurogenital screening for agents of sexually transmitted infection (STI) has been advocated in a number of clinical and public health scenarios (1). Studies have reported increased rates of Chlamydia trachomatis and Neisseria gonorrhoeae detection from pharyngeal and rectal specimens via nucleic acid amplification testing compared to rates found with culture (2)(3)(4)(5)(6)(7). Moreover, differences in clinical and in vitro detection rates yielded by transcription-mediated amplification (TMA) versus DNA amplification modalities have been demonstrated (4)(5)(6)(7)(8)(9), likely owing to target capture-based removal of endogenous inhibitors (10,11). ...
... Studies have reported increased rates of Chlamydia trachomatis and Neisseria gonorrhoeae detection from pharyngeal and rectal specimens via nucleic acid amplification testing compared to rates found with culture (2)(3)(4)(5)(6)(7). Moreover, differences in clinical and in vitro detection rates yielded by transcription-mediated amplification (TMA) versus DNA amplification modalities have been demonstrated (4)(5)(6)(7)(8)(9), likely owing to target capture-based removal of endogenous inhibitors (10,11). Detection of Trichomonas vaginalis RNA from pharyngeal specimens (12) and Mycoplasma genitalium RNA from urine specimens (13) of male STI clinic attendees has recently been reported on the basis of commercial TMA assays. ...
Of 1493 male sexually-transmitted infection (STI) clinic encounters in a high-prevalence STI community, 8.7% revealed detection of Chlamydia trachomatis and 6.6% revealed detection of Neisseria gonorrhoeae . Additional Trichomonas vaginalis and Mycoplasma genitalium screening resulted in 17.4% and 23.9% of encounters positive for STI, respectively. STI agents were detected in 13.7% of urine specimens; addition of pharyngeal and rectal collections resulted in detection of STI agents in 19.0% and 23.9% of encounters, respectively. 101 (23.8%) encounters of identified STI involved sole detection of M. genitalium . Expansion of STI analyte panel (including M. genitalium ) and additional specimen source sampling within a comprehensive STI screening program increases identification of male STI carrier status.
... 18 Nucleic acid amplification tests (NAATs) provide highly sensitive and specific detection of NG and CT in all three susceptible anatomic sites. 19 Nevertheless, no manufacturer currently has a USA Food and Drug Administration approved product for pharyngeal or rectal specimen testing, despite its superiority to culture and recommended use by international guidelines. 6,[19][20][21] Currently in the USA, only laboratories that comply with the Clinical Laboratory Improvement Act and conduct a verification study may use NAATs for non-urethral testing. ...
... 19 Nevertheless, no manufacturer currently has a USA Food and Drug Administration approved product for pharyngeal or rectal specimen testing, despite its superiority to culture and recommended use by international guidelines. 6,[19][20][21] Currently in the USA, only laboratories that comply with the Clinical Laboratory Improvement Act and conduct a verification study may use NAATs for non-urethral testing. 22 Early detection of infection and appropriate medical therapy precludes further transmission of STIs (i.e. ...
The resurgence of sexually transmissible infections among men who have sex with men is a concern for sexual health. Traditional strategies have relied on the promotion of condom use, regular testing, treatment, and partner management. Future sexually transmissible infection control programs must combine current prevention methods with novel approaches that target the providers, patients, and mechanisms of health care delivery.
... The total culture rate for pharyngeal samples improved considerably from 2014 (from 1 to 28%), with significant improvement seen through bedside culture (26% v. 7.1% using standard culture). Our result is similar to other published studies [11,12]. ...
Background
Culture of Neisseria gonorrhoeae is essential for surveillance of complete antimicrobial susceptibility profiles. In 2014, the culture success rate of N. gonorrhoeae from samples taken at the clinic for sexually transmitted infections (STI clinic), Oslo University Hospital, Norway, was only 20%. The present study aimed to improve gonococcal culture rates using bedside inoculation of patient samples on gonococcal agar plates and incubation at the STI clinic.
Methods
This prospective quality improvement study was conducted by the STI clinic and the Department of Microbiology at Oslo University Hospital from May 2016 - October 2017. When culture of N. gonorrhoeae was clinically indicated, we introduced a parallel ‘bedside culture’ at the STI clinic and compared results with the standard culture at the microbiology department. Samples were taken from urethra, anorectum, pharynx and cervix. Culture rates were compared across symptomatic and asymptomatic anatomical sites.
Results
From 596 gonococcal-positive PCR samples, bedside culture had a significantly higher success rate of 57% compared to 41% with standard culture (p < 0.05). Overall, culture rate from symptomatic sites was 91% v. 45% from asymptomatic sites. The culture rates from different anatomical sites were as follows: urethra 93%, anorectum 64%, pharynx 28% and cervix 70%. Bedside culture significantly (p < 0.05) improved the culture rates for symptomatic urethral and asymptomatic pharyngeal samples.
Conclusions
Where feasible, bedside inoculation on gonococcal agar plates and incubation of samples from patients with gonorrhoea is recommended. This will improve the culture diagnostics and provide additional gonococcal isolates for antimicrobial resistance surveillance.
... Cultures for NG and CT have estimated sensitivities of 41% and 21%, respectively, and depend on the level of laboratory infrastructure [16,17]. ...
Introduction: Sexually transmitted infections (STIs) represent a major public health problem. Chlamydia trachomatis and Neisseria gonorrhoeae infections are often asymptomatic, thus leading to a high risk of transmission in subjects with risky behaviors. The objective of this study was to determine the prevalence of these 2 pathogens in an asymptomatic population. Methodology: A retrospective, cross-sectional, descriptive study was conducted in the medical biology laboratory of the Pasteur Institute of Dakar over a period of 23 months in asymptomatic patients who were seen as part of a travel check-up. A first-draft urine sample was collected and tested for C. trachomatis and N. gonorrhoeae by molecular biology techniques. Data entry and statistical analysis were performed by Excel 2010 and SPSS 2.0 respectively. Results: A total of 5012 patients were included and the overall prevalence of STIs related to these 2 pathogens was 3.8% (194/5012). The prevalences of C. trachomatis and N. gonorrhoeae were 2.7% (137/5012) and 1.0% (55/5012), respectively. The age group most affected was [20-29 years] with 58.4% (80/137; p=0.0001) for C. trachomatis and 45.5% (25/55; p=0.471) for N. gonorrhoeae. Co-infection with these two germs was observed in 0.3% (18; p=0.001) of patients. Conclusion: STIs with C. trachomatis and/or N. gonorrhoeae can be asymptomatic and continue the chain of transmission. Thus, for a better prevention of STIs due to these pathogens, it is important to screen, educate and sensitize the populations considered at risk.
... Although NAATs are highly sensitive, they are unable to discriminate nucleic acid originating from viable or nonviable bacteria. Indeed, up to 14% of rectal chlamydia may be false positives if the criterion of two positive NAAT results is used to define a true infection [30]. ...
Purpose of review:
Rectal chlamydia is a prevalent sexually transmissible infection in both men who have sex with men (MSM) and in women. Screening is recommended for MSM but remains controversial for women. The optimal treatment for rectal chlamydia is now conclusive but interpreting and managing positive results remains challenging. Infections among MSM are increasing and strategies are needed to reduce incident infections. This review summarizes recent developments for the screening and management of rectal chlamydia and its implications on reinfection.
Recent findings:
Reinfections in MSM may be occurring due to resumption of sex soon after treatment whereas repeat infections in women may occur due to autoinoculation in the absence of sex. Doxycycline is now first-line treatment but its role in chemoprophylaxis remains unclear. False positive results remain an issue, but the development of viability assays may prove useful in future to determine true infections.
Summary:
Doxycycline is the first-line treatment for rectal chlamydia and in women may prevent infections at the urogenital site. Viability assays can help to reduce antibiotic use once developed. The role of routine screening of rectal chlamydia in women remains unclear and this debate may soon include asymptomatic infections in MSM.
... Diagnostik: Der Nachweis von C. trachomatis sollte mittels NAAT(161,162) erfolgen. Therapie der ersten Wahl: Doxycyclin 2x100 mg p.o. pro Tag für 7 Tage. ...
Junge Mädchen haben in ihrer Gynäkologin/Gynäkologen ihren ganz speziellen Ansprechpartner. Doch wer kümmert sich eigentlich um die Jungen? Auch sie haben Sorgen und Nöte. Beim Thema Jungenmedizin herrscht bei vielen Ärztinnen und Ärzten Nachholbedarf.
... [3][4][5][6] Pharyngeal CT mostly remains asymptomatic 7 , and detection of pharyngeal CT fully depends on testing. Pharyngeal CT can be detected by nucleic acid amplification tests (NAAT) 8 and can be effectively treated with azithromycin or doxycycline. 9 Pharyngeal-only CT, that is without concurrent anogenital CT, is most important as they are not coincidentally treated with concurrent anogenital infections and might possibly contribute to ongoing transmission. ...
Pharyngeal Chlamydia trachomatis (CT) was diagnosed in 1.2% and pharyngeal-only CT in 0.5% of routinely universally tested men who have sex with men (MSM). In these 3-anatomic-site tested MSM, pharyngeal-only CT comprised 4.8% of all CT. The low positivity of pharyngeal-only CT indicates low public health impact of pharyngeal CT.
... 44 However, in women, urine samples have lower sensitivity than genital swabs for testing. 45 Moreover, NAATs are significantly more sensitive than culture for the detection of NG in pharyngeal and rectal samples, 46,47 being the tests of choice for screening for these kind of infections. However, these techniques are not approved for testing specimens from these locations. ...
Sexually transmitted infections (STIs) are one of the most frequent and universal Public Health problems. Health professionals should be aware of the possibility of STIs due to their high morbidity and the presence of sequelae. The delay in the diagnosis is one of the factors that justifies the difficulty to infections control. Diagnostic tests allow the introduction of aetiological treatment and also leads to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. In this review we have made an update of the main existing diagnostic methods for the more important STIs.
... Sin embargo, en las mujeres, las muestras de orina tendrán una menor sensibilidad que las muestras obtenidas con hisopos genitales45 . Además, las NAAT serán significativamente más sensibles que el cultivo para la detección de la NG en las muestras faríngeas y rectales[46][47] , por lo que son las pruebas de elección para el cribado de este tipo de infecciones. Sin embargo, estas técnicas no se han aprobado para el estudio de las muestras de estas localizaciones. ...
Resumen
Las infecciones de transmisión sexual (ITS) son uno de los problemas de salud pública más frecuentes y universales. Debido a que las ITS son responsables de una alta morbilidad, así como de secuelas graves, es muy importante que todos los profesionales de la salud las tengan en cuenta en el momento de valorar al paciente. La dificultad en el control de las ITS se debe principalmente al retraso diagnóstico. Las pruebas diagnósticas permiten realizar un manejo etiológico, así como facilitar un tratamiento más efectivo tanto de los pacientes sintomáticos como de los asintomáticos, y finalmente permitirán interrumpir de una forma más precoz la cadena epidemiológica de transmisión. En la presente revisión, se ha llevado a cabo una actualización acerca de los principales métodos diagnósticos existentes en las ITS más relevantes.
... Bacterial culture from conjunctival, rectal, and oropharyngeal samples require optimal growth conditions, are time consuming, and often frustrating, especially in the case of throat swabs. Vaginal swab specimens and urine are rarely successfully cultivated [23,25,26]. Gonococci are very demanding and fastidious pathogens. ...
The ideal laboratory test to detect Neisseria gonorrhoeae (Ng) should be sensitive, specific, easy to use, rapid, and affordable and should provide information about susceptibility to antimicrobial drugs. Currently, such a test is not available and presumably will not be in the near future. Thus, diagnosis of gonococcal infections presently includes application of different techniques to address these requirements. Microscopy may produce rapid results but lacks sensitivity in many cases (except symptomatic urogenital infections in males). Highest sensitivity to detect Ng was shown for nucleic acid amplification technologies (NAATs), which, however, are less specific than culture. In addition, comprehensive analysis of antibiotic resistance is accomplished only by in vitro antimicrobial susceptibility testing of cultured isolates. As a light at the end of the tunnel, new developments of molecular techniques and microfluidic systems represent promising opportunities to design point-of-care tests for rapid detection of Ng with high sensitivity and specificity, and there is reason to hope that such tests may also provide antimicrobial resistance data in the future.
... The cornerstone of public health control is the detection and treatment of these STDs, so as to prevent sequelae and limit disease transmission [5,6]. Even though gonococcal culture remains the "gold standard" to monitor developing resistance to current antibiotic treatments, published data support the fact that PCR is more sensitive than culture for the diagnosis of NG and CT infections [7,8]. ...
Background
Commercial kits performing Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) nucleic acid amplification tests (NAATs) for genital samples are recommended in association with culture, but the majority of real-time polymerase chain reaction (PCR) methods have not received regulatory approval for diagnostics in extra-genital sites. Since 2017, only the Hologic ® Aptima Combo2 assay has an in vitro diagnostic (IVD) certification from the European Medicine Evaluation Agency.
Methods
We assessed the Allplex™ STI-Essential Assay (EA) for the diagnosis of NG and CT in both genital and extra-genital sites. The performance of the extraction step was studied by means of a standard curve between the concentration of expected cultivable gonococci and the cycle threshold (C t ). Three later-generation NAATs were used as comparators, particularly to assess the specificity (Sp).
Results
A relation between the gonococcal concentration, expressed as colony-forming unit (CFU) per milliliter logarithm, and the C t was shown to be linear irrespective of the matrices (95% confidence interval [CI]). The detection limit was 10 CFU/mL, contrasting with the relatively poor sensitivity of culture due to inhibitory effects such as pH and the overgrowth of the commensal flora. NG molecular diagnostic is complex and the method comparisons showed some discrepancies when C t was above 34. We decided to include interpretative comments on our reports on the basis of the C t result. For CT, comparisons displayed a satisfactory agreement, and the detection limit was 50 copies/mL.
Conclusions
The Seegene Allplex™ STI-EA showed acceptable performance characteristics for the detection of genital and extra-genital NG and CT.
... In men, urethritis is the most frequent STI syndrome, with CT causing 15-40% of cases. Among MSM attending clinics in high-income countries, about 10% have CT detected in the rectum [8][9][10][11]. ...
Purpose of Review
To emphasize key gaps in knowledge impacting efforts to control single infection and co-infections with Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), the most common bacterial sexually transmitted infections (STIs) worldwide.
Recent Findings
Clinical and epidemiological studies describe gaps in understanding about female rectal CT infection, screening effectiveness, pelvic inflammatory disease, and influence of the microbiome. For NG, gaps in knowledge include factors increasing incidence in men who have sex with men, correlations between treatment and antibiotic resistance, the role of pharyngeal infection, and microbiome influence. CT/NG co-infections are poorly understood, and adequate models to explore pathophysiological consequences of co-infection urgently needed. The sole existing CT/NG co-infection mouse model showed that CT/NG interactions in vivo modulate host response and NG load/shedding—encouraging further consideration of this model and potential alternatives.
Summary
We stress key challenges in controlling these important STIs. Appropriate, quality-assured animal models are essential to improve understanding of the pathogenic interplay in CT/NG co-infections.
... Specimens submitted to the IDDL were tested with a target amplification nucleic acid probe on the Aptima Combo 2 (AC2) assay for C. trachomatis and N. gonorrhoeae (Hologic, Sunnyvale, CA) (7). The nucleic acid amplification test (NAAT) is the method of choice for detecting C. trachomatis and N. gonorrhoeae in clinical specimens, including those obtained from extragenital sites (13,14). Hologic's AC2 assay is U.S. Food and Drug Administration (FDA) approved for male urine and endocervical, vaginal, and urethral swabs (7). ...
Background:Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are the two most common causes of sexually transmitted disease in the US. Studies in adults, mostly in MSM, have shown that the prevalence of CT/GC infections is much higher in extragenital sources compared to urogenital sources. Similar large sample size data on the burden of CT/GC infections by anatomic site is lacking in children.
Methods: We retrospectively analyzed data from 655 patients tested for CT (887 specimens) and GC (890 specimens) at the Children's Hospital of Philadelphia. We restricted the analysis to include patients between 2 and 17 years of age that had all three sources (urine, oropharynx and rectum) collected at the same visit. The final dataset included specimens from all three sources from 148 and 154 patients for CT and GC, respectively. Specimens were tested for CT/GC using the Gen-Probe Aptima Combo 2 Assay.
Results: The burden of CT and GC infection was significantly higher in the 14-17-year age group (24.7%; p=0.041 and 25.8%; p= 0.001) compared to the 10-13 year (5.9%, 5.6%), 6-9 year (4.6%, 4.6%) and 2-5 year (8.3%, 0%) age groups, respectively. The positivity rate for CT was highest for rectal (16.2%) followed by urine (5.4%) and oropharyngeal (0.7%) sites. The positivity rate for GC was highest for rectal sites (10.4%), followed by oropharyngeal (9.7%) and urine (1.9%).
Conclusions: The source with highest diagnostic yield is rectum for CT and rectum and oropharynx for GC. Hence, extragenital screening is critical for the comprehensive detection of CT and GC in the pediatric population.
... The prevalence of this infection varies by anatomic sites (urethral, rectal, and oropharyngeal) [6] and the detection methods (gram's stain, standard culture, and molecular test (Nucleic Acid Amplification Tests; NAATs) [7]. The sensitivity of standard culture (the traditional gold standard) is greatly decreased at rectal and oropharyngeal sites [8][9]. This leads culture to an unacceptable first line diagnostic or confirmatory test for N. gonorrhoeae at extra-genital sites, and cases of gonorrhea may be missed. ...
Introduction
Gonorrhea (GC) infection caused by Neisseria gonorrhoeae has been steadily increasing in Thailand over the last decade. Men who have sex with men (MSM) are at high risk for gonorrhea infection.
Materials and methods
In this study, we determined the prevalence of and risk factors associated with gonococcal infections by three anatomical sites among MSM. We have conducted a cross-sectional analysis of a sexually transmitted disease (STD), gonorrhea among MSM attending two STD clinics in Khon Kaen, Thailand. We included 358 MSM over 18 years of age. Data were collected using self-administered questionnaire. In each participant, an oropharyngeal, anorectal, and endourethral swab were tested with culture and nucleic acid amplification test (NAAT). However, 267 urine samples were tested by both methods. Factors associated with gonorrhea infections were assessed using univariate and multivariate logistic regression.
Results
One hundred and ninety-five out of 358 (54.47%) MSM tested were found to be positive for gonorrhea using a porA gene targeted NAAT by Real-time PCR with TaqMan probes, but there was no positive result by culture. The gonorrheal prevalence for male genital site, anal, and oropharyngeal, were 34.73% (95%CI 33.07, 45.08), 29.01% (95%CI 24.61, 34.33), and 27.93% (95%CI 23.35, 32.89), respectively, while 5.9% (21/355) were positive for gonococcal infection in all anatomic sites (oropharynx + anus + urethra) of one participant. Previous history of diagnosed STDs was a significant factor associated urethral gonorrhea (odds ratio = 3.52, 95%CI 1.87–6.66, P Value< 0.001). In addition, having more than one partner was increased urethral gonorrhea (adjusted odds ratio = 2.26, 95%CI 1.10–4.68, P Value = 0.026). 100% of condom use was found decreasing urethral infection (adjusted odds ratio = 0.39, 95%CI 0.15–0.99, P Value = 0.046).
Conclusions
The most common anatomic site of gonorrhea infection was male genital site, and the independent risk factors were having history of diagnosed STDs and having more than one partner in the past 3 months, but 100% condom use was a protective factor of this infection.
... Nucleic acid amplification tests (NAATs) have largely replaced culture in the detection of urethral gonorrhea and chlamydia. However, the Food and Drug Administration (FDA) has yet to approve NAATs for extragenital specimens despite multiple investigators demonstrating their superior sensitivity compared to culture in studies and their recommended use by the CDC [51][52][53][54]. Until FDA approval, only labs that demonstrate specifications defined by Clinical Laboratory Improvement Amendments may use NAATs as an aid in the clinical diagnosis of extragenital CT and NG infections. ...
Introduction: Syphilis continues to be a growing epidemic among men who have sex with men (MSM), particularly for those living with the human immunodeficiency virus (HIV). In 2016, MSM accounted for 80% of primary and secondary syphilis diagnoses in men in the United States; almost half of who were also HIV-infected. The synergistic relationship between HIV and syphilis has significant implications not only for HIV patient management, but also for sexually transmitted infection (STI) control among MSM.
Areas covered: We review the literature on STI screening and treatment barriers at the patient-, provider-, and health system-levels, and present strategies to incorporate STI prevention into HIV care settings.
Expert commentary: Integration of STI prevention into HIV care is paramount to stop the epidemic of not only syphilis, but also other curable STIs like gonorrhea and chlamydia. Although guidelines have been established for STI testing in HIV-infected MSM, screening rates continue to be lower than desired. Gonorrhea and chlamydia screening is below 50% in HIV-infected MSM; interventions that improve testing of those two infections must be implemented. For syphilis control, other additional strategies such as chemoprophylaxis should be considered given syphilis screening is above 50% in HIV-infected MSM.
... NAATs have been shown to be significantly more sensitive than culture in the detection of chlamydia and gonorrhoea, particularly in extra-genital sites (103)(104)(105)(106)(107)(108). Owing to cross-reactivity with nongonorrhoea Neisseria species, all NAAT tests for gonorrhoea from all sites should be confirmed with supplementary tests to improve specificity (109)(110)(111). ...
This guideline is intended for use in UK Genitourinary medicine clinics and sexual health services but is likely to be of relevance in all sexual health settings, including general practice and Contraception and Sexual Health (CASH) services, where men who have sex with men (MSM) seek sexual health care or where addressing the sexual health needs of MSM may have public health benefits. For the purposes of this document, MSM includes all gay, bisexual and all other males who have sex with other males and both cis and trans men. This document does not provide guidance on the treatment of particular conditions where this is covered in other British Association for Sexual Health and HIV (BASHH) Guidelines but outlines best practice in multiple aspects of the sexual health care of MSM. Where prevention of sexually transmitted infections including HIV can be addressed as an integral part of clinical care, this is consistent with the concept of combination prevention and is included. The document is designed primarily to provide guidance on the direct clinical care of MSM but also makes reference to the design and delivery of services with the aim of supporting clinicians and commissioners in providing effective services.
Methodology
This document was produced in accordance with the guidance set out in the BASHH CEG’s document ‘Framework for guideline development and assessment’ published in 2010 at http://www.bashh.org/guidelines and with reference to the Agree II instrument. Following the production of the updated framework in April 2015, the GRADE system for assessing evidence was adopted and the draft recommendations were regraded.
Search strategy (see also Appendix 1)
Ovid Medline 1946 to December 2014, Medline daily update, Embase 1974 to December 2014, Pubmed NeLH Guidelines Database, Cochrane library from 2000 to December 2014. Search language English only. The search for Section 3 was conducted on PubMed to December 2014. Priority was given to peer-reviewed papers published in scientific journals, although for many issues evidence includes conference abstracts listed on the Embase database. In addition, for ‘Identification of problematic recreational drug and alcohol use’ section and ‘Sexual problems and dysfunctions in MSM’ section, searches included PsycINFO.
Methods
Article titles and abstracts were reviewed and if relevant the full text article was obtained. Priority was given to randomised controlled trial and systematic review evidence, and recommendations made and graded on the basis of best available evidence.
Piloting and feedback
The first draft of the guideline was circulated to the writing group and to a small group of relevant experts, third sector partners and patient representatives who were invited to comment on the whole document and specifically on particular sections. The revised draft was reviewed by the CEG and then reviewed by the BASHH patient/public panel and posted on the BASHH website for public consultation. The final draft was piloted before publication.
Guideline update
The guidelines will be reviewed and revised in five years’ time, 2022.
... Culture detection of Neisseria gonorrhoeae has long been available for the detection of rectal or oropharyngeal gonococcal infection (1), but implementation of nucleic acid amplification testing (NAAT) for this pathogen has been reported to double its detection from rectal samples and increase its detection from pharyngeal samples 5-fold (2). Several studies using various platforms, including the Becton Dickinson Probetec ET, the Gen-Probe Aptima Combo2, and the Roche Cobas Amplicor PCR, have shown that NAAT for detection of Chlamydia trachomatis and N. gonorrhoeae in rectal and pharyngeal samples is more sensitive than culture (2,3,4,5,6,7). NAAT is less labor-intensive than culture and provides quick turnaround of results, leading to quicker treatment. ...
Nucleic acid amplification testing (NAAT) is the preferred method to detect Chlamydia trachomatis and Neisseria gonorrhoeae , but no commercial tests are cleared by the US Food and Drug Administration for use with extragenital swab samples. This study evaluated the performance of Gen-Probe Aptima® Combo2 assay (Aptima) and the Cepheid Xpert® CT/NG assay (Xpert) to detect C.trachomatis and N. gonorrhoeae in rectal and pharyngeal samples from 224 men and 175 women reporting a history of anal receptive sexual intercourse. Discordant results between the NAATs were repeated using the APTIMA CT or APTIMA GC assay, which target alternate primers, as the confirmatory tests. C. trachomatis was detected from 59 rectal swabs and 8 pharyngeal samples, with 97.7% and 99.5% agreement between the two test systems, respectively. For C. trachomatis , Xpert was 95% sensitive (95% CI, 86-99%) and Aptima was 92% sensitive (95% CI, 81-97%) from rectal swabs, while both systems were 100% sensitive from pharyngeal samples. N. gonorrhoeae was detected from 30 rectal and 40 pharyngeal samples, with 99.5% and 97.5% agreement between the two test systems. The sensitivity of Xpert for N. gonorrhoeae from rectal swabs was 100% (95% CI, 88-100%) versus 93% (95% CI, 78-99%) for Aptima. From pharyngeal swab samples Xpert was 98% sensitive (95% CI, 87-99.9%) versus 93% (95% CI, 80-98%) for Aptima. For C. trachomatis , neither system was >95% sensitive from the rectum, though both were >99.5% specific. For N. gonorrhoeae , Xpert had higher sensitivity than Aptima, but with more false positives from pharyngeal samples.
... При исследовании биологического материала из зева и конъюнктивы (из-за низкого содержания бактерий в этих образцах) как у детей, так и у взрослых методами выбора для диагностики также являются МАНК [21]. ...
Инфекция в гинекологии не утрачивает своей значимости, что в первую очередь предопределено повышением частоты воспалительных заболеваний гениталий и мочевыводящих путей, развитие которых обусловлено микробными агентами или, вернее, их множественными ассоциациями. В спектре этиологических факторов воспалительных заболеваний мочевыводящих и половых путей преобладают мультирезистентные возбудители, или L-формы бактерий (чаще всего хламидии, простейшие, грибы, вирусы), как правило, с измененными биологическими свойствами, преимущественно за счет распространенной в практическом здравоохранении полипрогмазии – необоснованного применения антибактериальных, гормональных препаратов, цитокинов и т.п. [1].
... The principal factors influencing the PPV are the prevalence of gonorrhoea in the population tested and variation in the specificity of available NAATs, particularly at non-genital sites. If the used diagnostic NAAT does not display a PPV exceeding 90%, positive samples are recommended to be subjected to confirmatory testing, i.e. repeated with a NAAT targeting another sequence [III; B]; [26][27][28] • NAATs are significantly more sensitive than culture for detecting pharyngeal and rectal infection [29][30][31][32][33][34][35] and are the test of choice for screening for rectal and pharyngeal gonococcal infection. However, commercially available NAATs are not licensed for testing specimens from these sites and they differ significantly in their specificity, 36,37 particularly at the pharynx due to the frequent presence of non-gonococcal Neisseria species. ...
... The majority of these infections would be missed when screening urine samples only [34,35], but require testing of appropriate oral and anal swabs to be diagnosed. Usually, commercial NAATs are not approved for testing non-genital sample types, but it has been shown in several studies that also in these specimens CT detection by NAATs is superior compared to culture or antigen tests [36][37][38][39]. Testing of specimens outside the approval of commercial tests requires evaluation of test performance characteristics according to quality assurance of microbiological diagnostics, such as CLIA (Clinical Laboratory Improvement Amendments). ...
The intracellular life style of chlamydia and the ability to cause persistent infections with low-grade replication requires tests with high analytical sensitivity to directly detect C. trachomatis (CT) in medical samples. Nucleic acid amplification tests (NAATs) are the most sensitive assays with a specificity similar to cell culture and are considered the method of choice for CT detection. In addition, NAATs can be performed on various clinical specimens that do not depend on specific transport and storage conditions, since NAATs do not require infectious bacteria. In the case of lower genital tract infections, first void urine and vaginal swabs are the recommended specimens for testing males and females, respectively. Infections of anorectal, oropharyngeal and ocular epithelia should also be tested by NAAT analysis of corresponding mucosal swabs. In particular, anorectal infections of men who have sex with men (MSM) should include evaluation of lymphogranuloma venereum (LGV) by identification of genotypes L1, L2 or L3. Detection of CT antigens by enzyme immunoassay (EIAs) or rapid diagnostic tests (RDTs) are unsuitable due to insufficient sensitivity and specificity. Recent PCR-based RDTs, however, are non-inferior to standard NAATs, and might be used at the point-of-care. Serology finds application in the diagnostic work-up of suspected chronic CT infection but is inappropriate to diagnose acute infections.
Sexually transmitted Chlamydia trachomatis infections remain common globally and most frequently are asymptomatic. The 2025 European C. trachomatis guideline provides up-to-date guidance regarding indications for testing and treatment of C. trachomatis infections. It includes advice on urogenital and extragenital C. trachomatis testing including the use of self-collected specimens; recommendation to use only validated NAATs for diagnosis; and recommendation to treat all C. trachomatis infections with doxycycline as first line in preference to single-dose azithromycin regimens. The absence of evidence and limited value of broad screening in asymptomatic populations for C. trachomatis infections is also discussed.
Objectives Sexually transmitted infections (STIs) have markedly increased over the last decade in Spain, calling for prevention and control innovative approaches. While there is evidence indicating the effectiveness of self-sampling for STI diagnosis, no kits for this purpose have been authorised in Spain.
Methods A prospective single-blind cross-sectional study carried out between November and December 2022 in an STI clinic in Madrid, Spain, to determine the validity, feasibility and acceptability of self-sampling kits used by non-healthcare professionals from vagina, pharynx, rectum and urethra to diagnose Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). Self-samples were compared with samples collected by healthcare professional (HC samples) and analysed by PCR. Frequency of CT and NG diagnosis by sample type was compared using McNemar’s test for paired data. Sensitivity and specificity of self-samples for CT and NG diagnosis were also calculated.
Results 306 self-samples from 51 participants were analysed. 80% were men with median age of 33 (IQR: 28–38) years. Self-samples and HC samples showed no significant statistical differences in CT and NG diagnosis. Self-samples had a sensitivity of 81% for CT and 93% for NG, with a specificity of 97% for CT and 95% for NG. More than 90% of participants had no difficulty understanding the kit instructions and 71% expressed high levels of satisfaction with the self-sampling kit.
Conclusion Self-sampling kits for CT and NG diagnosis can be safely and effectively used by non-healthcare professionals in Spain. National strategies for STI prevention and control should prioritise self-sampling strategies.
Background: Neisseria gonorrhoeae is one of the most important causative organisms in causing sexually transmitted infections. The clinical presentation of gonorrhoea mimics the symptoms of other sexually transmitted infections, and a proper diagnosis of the same is therefore crucial in patient management. The current study intended to compare different in-house molecular methods: that is, conventional PCR, real-time PCR, and LAMP assay for detection of N. gonorrhoeae. Methods: A total of 163 samples were collected from 145 patients who presented with urethral and vaginal discharge. Collected samples were processed for culture on GC agar base, and three different molecular diagnostic tests (conventional PCR, real-time PCR, and LAMP assay) were performed simultaneously on all the samples. Results: Culture of N. gonorrhoeae was positive in 17 out of 21 (80.9%) swab samples. With culture as the gold standard method, conventional and real-time PCR had a sensitivity of 94.1%, whereas the sensitivity of the LAMP assay was found to be 88.2%. All three methods had a specificity of 100%. In addition to swab samples, evaluation of urine samples by different molecular methods yielded a good concordance with a kappa value of 0.85 by conventional PCR and real-time PCR showing a perfect level of agreement, while the LAMP assay was found to have a substantial level of agreement. Conclusion: LAMP assay had a comparable diagnostic accuracy to other molecular methods for the detection of N. gonorrhoeae and can be used as a point-of-care test in resource-limited settings.
Gonorrhea is the second most common bacterial sexually transmitted infection in the United States. Rates are increasing, and multiple challenges compound management, including worsening antimicrobial resistance. New therapeutics, enhanced screening and partner notification, and treatment through point-of-care testing and expedited partner therapy, as well as primary prevention efforts provide opportunities for success in combating these trends.
Introduction
Isolating oropharyngeal Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) from oral wash specimens (OWSs) is uncommon. Therefore, we evaluated the performance of the Abbott RealTime CT/NG assay and the Cobas 4800 CT/NG assay in detecting NG and CT in OWSs.
Methods
This multicenter prospective study included 457 patients from 14 medical facilities suspected of having untreated male urethritis or female cervicitis from November 2014 to December 2015. OWSs were collected and tested using the Abbott and Cobas assays. Finally, the discordant results were confirmed using the APTIMA Combo 2 transcription-mediated amplification assay and retested using each assay.
Results
The sensitivity and specificity of the Abbott assay were 100% and 97.2% for NG and 87.5% and 100% for CT, respectively, and of the Cobas assay were 100% and 98.8% for NG and 93.8% and 99.8% for CT, respectively. Both assays had high negative but low positive predictive values for oropharyngeal NG (Abbott assay: 65.7%, Cobas assay: 82.1%). Based on the definition of “true positive,” the prevalence of oropharyngeal NG and CT were 5.0% and 3.5%, respectively.
Conclusions
The Abbott and Cobas assays using OWSs had high sensitivity and specificity, which can help diagnose oropharyngeal NG and CT. We consider that if a positive result is obtained, the patient should be treated because the negative predictive values were high. However, limited data are available on oropharyngeal NG and CT detection, and further studies are needed to clarify the role of oropharyngeal sexually transmitted infections.
Background
Pharyngeal Chlamydia trachomatis in women might contribute to autoinoculation and transmission to sexual partners. Data for effectiveness of different testing practices for pharyngeal C trachomatis are scarce. We therefore aimed to assess the prevalence of pharyngeal C trachomatis, determinants, and effectiveness of different testing practices in women.
Methods
We did a retrospective cohort study, in which surveillance data for all women visiting sexually transmitted infection clinics in all regions in the Netherlands between Jan 1, 2008, and Dec 31, 2017, were used. We collected consultation-level data and individual-level data from 2016 onwards for sociodemographic characteristics, sexual behaviour in the past 6 months, self-reported symptoms, and STI diagnoses. The primary outcome was the positivity rate of pharyngeal C trachomatis infection compared between routine universal testing (>85% tested pharyngeally per clinic year), selective testing (5–85% tested pharyngeally per clinic year), and incidental testing (<5% pharyngeally tested per clinic year). We calculated the number of missed infections by extrapolating the positivity rate assessed by routine universal testing to all selectively tested women. We used multivariable generalised estimating equations logistic regression analyses to assess independent risk factors for pharyngeal C trachomatis and used the assessed risk factors as testing indicators for comparing alternative testing scenarios.
Findings
Between Jan 1, 2008, and Dec 31, 2017, a total of 550 615 consultations with at least one C trachomatis test was recorded, of which 541 945 (98·4%) consultations (including repeat visits) were included in this analysis. Pharyngeal C trachomatis positivity was lower in the routine universal testing group than in the selective testing group (1081 [2·4%; 95% CI 2·2–2·5] of 45 774 vs 3473 [2·9%; 2·8–3·0] of 121 262; p<0·0001). The positivity rate was also higher among consultations done in the incidental testing group (44 [4·1%; 95% CI 3·1–5·5] of 1073; p<0·0001) than in the routine universal testing group. Based on extrapolation, selective testing would have hypothetically missed 64·4% (95% CI 63·5–65·3; 6363 of 9879) of the estimated total of C trachomatis infections. The proportion of pharyngeal-only C trachomatis was comparable between routinely universally tested women (22·9%) and selectively tested women (20·4%), resulting in a difference of 2·5% (95% CI −0·3 to 5·3; p=0·07). When using risk factors for pharyngeal C trachomatis as testing indicators, 15 484 (79·6%) of 19 459 women would be tested to detect 398 (80·6%) of 494 infections.
Interpretation
No optimal testing scenario was available for pharyngeal C trachomatis, in which only a selection of high-risk women needs to be tested to find most pharyngeal C trachomatis infections. The relative low prevalence of pharyngeal-only C trachomatis (0·5%) and probably limited clinical and public health effect do not provide support for routine universal testing.
Funding
Public Health Service South Limburg.
Background:
Neisseria gonorrhoeae culture is required for antimicrobial susceptibility testing (AST), but recovering isolates from clinical specimens is challenging. While many variables influence culture recovery, studies evaluating the impact of culture specimen collection timing and patient symptom status are limited. This study analyzed urogenital and extragenital culture recovery data from CDC's Strengthening US Response to Resistant Gonorrhea (SURRG) program, a multi-site project, which enhances local N. gonorrhoeae culture and AST capacity.
Methods:
Eight SURRG jurisdictions collected gonococcal cultures from patients with N. gonorrhoeae-positive nucleic acid amplification tests (NAATs) attending STD and community clinics. Matched NAAT and culture specimens from the same anatomic site were collected, and culture recovery was assessed. Time between NAAT and culture specimen collection was categorized as, same day, 1-7 days, 8-14 days, or ≥ 15 days and patient symptoms were matched to the anatomic site where culture specimens were collected.
Results:
From 2018-2019, among persons with N. gonorrhoeae-positive NAAT, urethral infections resulted in the highest culture recovery (5927/6515 = 91.0%), followed by endocervical, (222/363 = 61.2%), vaginal (63/133 = 47.4%) rectal (1117/2805 = 39.8%), and pharyngeal (1019/3678 = 27.7%) infections. Culture recovery was highest when specimens were collected on the same day as NAAT specimens and significantly decreased after 7 days. Symptoms were significantly associated with culture recovery at urethral (p = <0.0001) and rectal (p = <0.0001) sites of infection but not endocervical, vaginal, or pharyngeal sites.
Conclusions:
Culture specimen collection timing and patient symptomatic status can impact culture recovery. These findings can guide decisions about culture collection protocols to maximize culture recovery and strengthen detection of antimicrobial resistant infections.
Gonorrhea is a sexually transmitted disease with a high morbidity burden. Despite having
guidelines for its treatment, the incidence of the disease follows an increasing trend worldwide. This is mainly due to the appearance of antibiotic-resistant strains, inefficient diagnostic methods and poor sexual education. Without an effective vaccine available, the key priorities for the control of the disease include sexual education, contact notification, epidemiological surveillance, diagnosis and effective antibiotic treatment. This Special Issue focuses on some of these important issues such as the molecular mechanisms of the disease, diagnostic tests and different treatment strategies to combat gonorrhea.
Gonorrhoea is a major public health concern globally. Increasing incidence and sporadic ceftriaxone-resistant cases, including treatment failures, are growing concerns. The 2020 European gonorrhoea guideline provides up-to-date evidence-based guidance regarding the diagnosis and treatment of gonorrhoea. The updates and recommendations emphasize significantly increasing gonorrhoea incidence; broad indications for increased testing with validated and quality-assured nucleic acid amplification tests (NAATs) and culture; dual antimicrobial therapy including high-dose ceftriaxone and azithromycin (ceftriaxone 1 g plus azithromycin 2 g) OR ceftriaxone 1 g monotherapy (ONLY in well-controlled settings, see guideline for details) for uncomplicated gonorrhoea when the antimicrobial susceptibility is unknown; recommendation of test of cure (TOC) in all gonorrhoea cases to ensure eradication of infection and identify resistance; and enhanced surveillance of treatment failures when recommended treatment regimens have been used. Improvements in access to appropriate testing, test performance, diagnostics, antimicrobial susceptibility surveillance and treatment, and follow-up of gonorrhoea patients are essential in controlling gonorrhoea and to mitigate the emergence and/or spread of ceftriaxone resistance and multidrug-resistant and extensively drug-resistant gonorrhoea. This review provides the detailed background, evidence base and discussions, for the 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults (Unemo M, et al. Int J STD AIDS. 2020).
Gonorrhoea is a major public health concern globally. Increasing incidence and sporadic ceftriaxone-resistant cases, including treatment failures, are growing concerns. The 2020 European gonorrhoea guideline provides up-to-date evidence-based guidance regarding the diagnosis and treatment of gonorrhoea. The updates and recommendations emphasize significantly increasing gonorrhoea incidence; broad indications for increased testing with validated and quality-assured nucleic acid amplification tests and culture; dual antimicrobial therapy including high-dose ceftriaxone and azithromycin (ceftriaxone 1 g plus azithromycin 2 g) OR ceftriaxone 1 g monotherapy (ONLY in well-controlled settings, see guideline for details) for uncomplicated gonorrhoea when the antimicrobial susceptibility is unknown; recommendation of test of cure (TOC) in all gonorrhoea cases to ensure eradication of infection and identify resistance; and enhanced surveillance of treatment failures when recommended treatment regimens have been used. Improvements in access to appropriate testing, test performance, diagnostics, antimicrobial susceptibility surveillance and treatment, and follow-up of gonorrhoea patients are essential in controlling gonorrhoea and to mitigate the emergence and/or spread of ceftriaxone resistance and multidrug-resistant and extensively drug-resistant gonorrhoea. For detailed background, evidence base and discussions, see the background review for the present 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults (Unemo M, et al. Int J STD AIDS. 2020).
Objectives
Gonorrhoea continues to be a public health concern in Belgium with pharyngeal and rectal infections increasing in persons with high-risk sexual behaviour. Belgian health care practitioners rely on international guidance when managing gonorrhoea resulting in non-adapted suboptimal care for the Belgian patient. This guideline will rectify this situation.
Methods
This guideline was developed following an evidence-based approach and involving a guideline development group (GDG). Research questions were prioritised by the GDG and researchers conducted a systematic review of the evidence that was assessed using GRADE approach.
Results
The guideline offers recommendations for gonorrhoea diagnosis, treatment and management for primary care professionals in Belgium and applies a risk group approach. This approach aims for improved identification of at-risk persons and targeted testing of at-risk groups; it includes behavioural questioning when deciding on diagnostic sampling and provides clear advice on treatment. The guideline defines when to add surveillance testing for antibiotic resistance, and what consists of good follow-up.
Results
A concerted application of this guideline by all stakeholders in Belgium may result in improving the diagnosis of infections and eventually addressing the emerging multi-drug resistance.
Background:
Nucleic acid amplification testing (NAAT) is the preferred method to detect Chlamydia trachomatis and Neisseria gonorrhoeae, but information regarding performance of currently available assays is needed. This study evaluated the performance of the Aptima Combo 2, GeneXpert, cobas4800, and ProbeTec Q (CTQ/GCQ) to detect chlamydia and gonorrhea in pharyngeal, rectal, and urine specimen.
Methods:
Adult male patients seen at an urban HIV clinic in Birmingham, Alabama who reported sex with men (MSM) and no antibiotic use in the past 30 days were enrolled between November 2014 and December 2016. Following a baseline survey, rectal and initial void urine specimens were self-collected. A composite infection standard was used, where one assay was compared to three others to determine sensitivity and specificity estimates for rectal and urine samples. Two pharyngeal samples were clinician-collected for chlamydia and gonorrhea testing and both had to be positive in order to be considered a true positive.
Results:
Among the 181 men enrolled into the study, 15.5% and 7.2% had at least one positive chlamydia and gonorrhea result at any site, respectively. Among all four assays, chlamydia sensitivity rates ranged from 82% to 96% among rectal samples. Rectal gonorrhea sensitivity estimates ranged from 67% to 99%. The GCQ assay was less sensitive in detecting rectal gonorrhea compared to the other assays (p=0.02).
Conclusion:
More than 80% of chlamydia and gonorrhea infections would have been missed with urine-only screening, highlighting the importance in using NAATs to detect chlamydia and gonorrhea infections among MSM.
Gonorrhea is a sexually transmitted disease caused by the obligate human pathogen Neisseria gonorrhoeae. This Gram‐negative diplococcus is highly infective due to its virulence factors: pili, Por proteins, Opa proteins, Rmp proteins, lipooligosaccharides and IgA protease. The most common form of presentation in men is acute anterior urethritis, while gonococcal infection in women does not have specific symptoms. More than 106 million new cases of gonorrhea are estimated to occur yearly worldwide. The highest incidence areas include Africa and the Western Pacific regions. Gonorrhea is primarily transmitted from an infected individual by direct human‐to‐human contact between the mucosal membranes of the urogenital tract, anal canal and the oropharynx, usually during sexual activities. Ever since sulphonamides were introduced to treat gonorrhea in the 1930s, gonococci have continuously shown an extraordinary ability to develop resistance to any antimicrobial introduced for treatment. Treatment is currently given empirically, without performing antimicrobial susceptibility tests. However, the increasing issue of drug‐resistant gonococci has lead the scientific community to focus research in new drugs and alternative treatments, having obtained encouraging results. The diagnosis of gonorrhea is established by identification of N. gonorrhoeae in genital, rectal, pharyngeal or ocular secretions. N. gonorrhoeae can be detected by culture or nucleic acid amplification tests and, in some cases, Gram staining. Seeing as all attempts to develop a vaccine against gonococci have been unsuccessful, prevention and control of the disease relies completely on early diagnosis, accurate treatment and public health education.
A series of novel immobilized platinum catalysts was prepared by loading Pt onto silica particles modified with polycarboxylic acid groups such as diethylenetriaminepentaacetic acid (DTPA), nitrolotriacetic acid (NTA) and succinic acid (SA). The three modified heterogeneous Pt catalysts were characterized using infrared spectroscopy (IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and atomic absorption spectroscopy (AAS). The residual H2PtCl6 solutions were characterized using ultraviolet spectroscopy (UV). The polycarboxylic acid-functionalized silica supported Pt catalysts were used to catalyze alkene hydrosilylation and 1-hexene was chosen as a model alkene. The data indicated that the catalytic performance was strongly dependent on the properties of the polycarboxylic acid group bonded to the silica particles. Among them, DTPA-functionalized silica supported Pt (SiO2-DTPA-Pt) showed the best catalytic activity and reusability. Furthermore, some hydrosilylation reactions between other linear alkenes (1-heptene, 1-octene, 1-decene, 1-do-decene, 1-tetra-decene, 1-hexa-decene, 1-octa-decene, styrene or cis-hex-2-ene), or ring type alkenes (norbornene) with methyldichlorosilane could be catalyzed in the presence of these three Pt catalysts. Their high activities were more than 90%, and their selectivities were more than 99%, which were apparently better than homogeneous Pt catalysts. In addition, reactions with cyclohexene were also successfully catalyzed by the Pt catalysts. These results indicate that the polycarboxylic acid-functionalized silica gel supported Pt catalysts have potential value in industrial hydrosilylation reactions.
Introduction:
Pharyngeal Neisseria gonorrhoeae infections are mostly asymptomatic, yet sustain ongoing gonococcal transmission. We assessed the proportion of pharyngeal gonorrhea that spontaneously clears and identified determinants of clearance.
Methods:
At the sexually transmitted infections clinic Amsterdam, at-risk females and men who have sex with men were routinely screened for pharyngeal N. gonorrhoeae using an RNA-based nucleic acid amplification test (NAAT; Aptima Combo 2®).We retrospectively examined medical records of pharyngeal gonorrhea patients (January 2012-August 2015). We included patients who returned for antibiotic treatment and had a new sample taken for NAAT prior to treatment. Spontaneous clearance was defined as a negative NAAT at the follow-up visit.
Results:
During the study period, 1,266 cases with a pharyngeal gonorrhea were not treated at the first consultation and returned for a follow-up visit. Median time between the first consultation and follow-up [interquartile range] was 10 [7-14] days. Spontaneous clearance was found in 139 cases (11.0%) and was associated with age ≥45 years (vs 16-24 years) (adjusted odds ratio [aOR]=2.02 [95%CI 1.09-3.75]), and with time from the first consultation to follow-up (aOR=1.08 [1.06-1.10], per extra day).
Conclusion:
Eleven percent of pharyngeal gonorrhea cases cleared spontaneously. Spontaneous clearance of pharyngeal gonorrhea was more often seen among older patients.
Objectives
The objective of this study was to examine the associations between clinicians’ self-reported sampling technique and the detection rate of gonorrhoea at the oropharynx and anorectum using a highly sensitive nucleic acid amplification test (NAAT).
Methods
We analysed oropharyngeal and anorectal gonorrhoea swab results among men who have sex with men attending the Melbourne Sexual Health Centre (MSHC) between March 2015 and December 2016. Swabs were tested by NAAT using the Aptima Combo 2 transcription-mediated amplification assay due to its high sensitivity. Clinicians at MSHC were invited to complete a questionnaire on sampling techniques in November 2016. Univariable generalised estimating equations (GEE) logistic regressions were performed to determine the association between gonorrhoea detection rates and clinicians’ sampling technique. Patients’ epidemiological risk factors were included in the multivariable GEE logistic model.
Results
A total of 2605 oropharyngeal gonorrhoea and 2392 anorectal gonorrhoea swab results were analysed. There was no significant difference in the detection rates of gonorrhoea between the 23 clinicians at the oropharynx (range 3.6%–16.9%, median 8.2%, P=0.302) or and anorectum (range 2.4%–17.3%, median 10.5%, P=0.177). Variations in clinicians’ self-reported sampling technique were not associated with oropharyngeal or anorectal gonorrhoea detection rates after adjusting for patients’ epidemiological risk factors.
Conclusions
This study shows that differences in clinicians’ self-reported sampling technique did not result in measurable differences in the detection rate for oropharyngeal or anorectal gonorrhoea when using NAAT.
Objectives
Screening of men who have sex with men (MSM) for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) requires sampling from anorectal and pharyngeal sites in addition to urogenital sampling. Due to the cost of testing multiple anatomical sites individually testing of pooled specimens has potential merit. The Cepheid GeneXpert CT/NG assay (GeneXpert), which also has potential for point-of-care nucleic acid testing in the sexual health clinic, has not been assessed for pooled specimen testing.
Methods
We prospectively compared GeneXpert testing of pooled pharyngeal and rectal swabs with urine samples to standard of care testing of individual specimens from 107 participants using the Roche cobas 4800 CT/NG assay (cobas) for CT and NG in high-risk MSM attending an inner city sexual health clinic.
Results
We found testing of pooled pharyngeal, rectal and urine samples by the GeneXpert to have 100% agreement for NG and 94% overall agreement for CT when compared with individual specimen testing by cobas. For CT testing, 14 cases were detected for both tests, 4for cobas only, 2 for GeneXpert only and 89 participants were negative for both tests.
Conclusions
Pooled specimen CT and NG testing by the GeneXpert was accurate when compared with single specimen testing and has potential for screening MSM for CT and NG. The role of pooled specimen testing with the GeneXpert as a point-of-care nucleic acid test in MSM requires further investigation.
We sought to confirm the results of 81 rectal specimens positive for Chlamydia trachomatis by the APTIMA Combo 2 assay among patients with concurrently collected negative genitourinary specimens. A total of 79 (97.5%) samples were confirmed by the APTIMA single target assay and/or sequencing of the C. trachomatis ompA gene.
Background:
Current literature comparing the prevalence rates of curable sexually transmitted infections (STIs) in pregnant women in various global regions is limited. As a result, antenatal screening practices for curable STIs in pregnant women, specifically Treponema pallidum (syphilis), Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), and Trichomonas vaginalis (TV) vary around the world, differing by country and particular STI.
Methods:
We conducted a systematic review of publications on STI prevalence among pregnant women in 30 different low- and middle-income countries. We searched PubMed for studies reporting prevalence of syphilis, CT, NG, and TV in pregnant women. English language studies published between January 1, 2010, and March 1, 2015, were included. The adjusted mean STI prevalence by region was calculated via multivariable linear regression adjusting for health care setting, women's mean age, study sample size, and sensitivity of diagnostic test.
Results:
We identified 75 studies that met inclusion criteria, providing 116 point prevalence estimates for curable STIs among 3,489,621 pregnant women. Adjusted mean prevalence for NG ranged from 1.2% (95% confidence interval [CI], 1.0-1.3) in Latin America to 4.6% (95% CI, 4.0-5.2) in Southern Africa; syphilis prevalence ranged from 1.1% (95% CI, 0.5-1.6) in Asia to 6.5% (95% CI, 4.7-6.3) in Southern Africa; CT ranged from 0.8% (95% CI, 0.4-1.1) in Asia to 11.2% (95% CI, 6.0-16.4) in Latin America; and TV ranged from 3.9% (95% CI, 2.2-5.6) in Latin America to 24.6% (95% CI, 17.9-31.4) in Southern Africa.
Conclusions:
Although we observed a wide variation in STI burden in pregnancy after adjusting for age, test, and health care setting, further valid comparison may depend on adjustment for access to care and screening practices.
To determine whether Chlamydia trachomatis urogenital infections persist or relapse after antimicrobial therapy by serial measurement of chlamydial-specific DNA using the polymerase chain reaction (PCR), cell cultures, and serological studies.
Prospective evaluation of an inception cohort.
University student health clinic.
Twenty women with culture-proven and PCR-proven C trachomatis urogenital infections.
Incidence of persistent infection as determined by PCR, culture, and serial measurement of local and systemic antibody to C trachomatis for 5 months after doxycycline therapy.
Prior to therapy, C trachomatis was isolated in cell culture from the cervix in 19 of 20 women, from the urethra in 13 women, and from the rectum in 13 women. All culture-positive specimens were also PCR-positive. Immediately after completion of antimicrobial therapy, all women had negative cell cultures for chlamydia. Ten of 20 culture-negative cervical specimens and two culture-negative urethral specimens had chlamydial DNA present immediately after treatment. In addition, three women had detectable DNA from cervical specimens 1 week after treatment. The presence of cervicitis (P = .01), high inclusion counts (P = .004), and serological evidence of recent infection (P = .0004) were each significantly associated with PCR positivity after treatment. All 384 subsequent cervical, rectal, and urethral specimens collected over 5 months were negative by both PCR and culture with the exception of one woman who was reinfected. Serum immunoglobulin M (IgM) titers, geometric mean serum immunoglobulin G (IgG) titers, and prevalence of local antibody to chlamydia progressively declined after treatment.
Standard antimicrobial therapy is effective in the long-term microbiologic eradication of uncomplicated C trachomatis urogenital infections. The presence of chlamydial DNA after antimicrobial therapy is of short duration and reflects excretion of nonviable organisms rather than persistent infection.
The fully automated COBAS AMPLICOR CT/NG and semiautomated AMPLICOR CT/NG tests were evaluated in a multicenter trial for the ability to detect Chlamydia trachomatis infections. Test performance compared to that of culture was evaluated for 2,236 matched endocervical swab and urine specimens obtained from women and for 1,940 matched urethral swab and urine specimens obtained from men. Culture-negative, PCR-positive specimens that tested positive in a direct fluorescent-antibody test or in a confirmatory PCR test for an alternative target sequence were resolved as true positives. The overall prevalences of chlamydia were 2.4% in women and 7.2% in men. The COBAS AMPLICOR and AMPLICOR formats yielded concordant results for 98.1% of the specimens. With the infected patient as the reference standard, the resolved sensitivities of COBAS AMPLICOR were 89.7% for endocervical swab specimens, 89.2% for female urine specimens, 88.6% for male urethral swab specimens, and 90.3% for male urine specimens. When results were analyzed as if only a single test had been performed on a single specimen type, the resolved sensitivity was always higher. The resolved specificities of PCR were 99.4% for endocervical swab specimens, 99.0% for female urine specimens, 98.7% for male urethral swab specimens, and 98.4% for male urine specimens. The internal control revealed that 2.4% of the specimens were inhibitory when initially tested. Nevertheless, valid results were obtained for 98.6% of the specimens because 59.1% of the inhibitory specimens were not inhibitory when a second aliquot was tested. The COBAS AMPLICOR and AMPLICOR CT/NG tests for C. trachomatis exhibited equally high sensitivity and specificity with both urogenital swab and urine specimens and thus are well suited for screening for C. trachomatis infection.
In 264 genitourinary medicine clinic attenders reporting recent fellatio, the prevalence of pharyngeal Chlamydia trachomatis determined by an expanded standard including cell culture and two in-house PCR tests was 1.5% in 194 women and zero in 70 men. The ligase chain reaction (Abbott LCx) had a specificity of 99.2% and a positive predictive value of 60%.
The fully automated COBAS AMPLICOR CT/NG and semiautomated AMPLICOR CT/NG tests were evaluated in a multicenter trial for their ability to detect Neisseria gonorrhoeae infections. Test performance compared to that of culturing was evaluated for 2,192 matched endocervical swab and urine specimens obtained from women and for 1, 981 matched urethral swab and urine specimens obtained from men. Culture-negative, PCR-positive specimens that tested positive in a confirmatory PCR test for an alternative target sequence within the N. gonorrhoeae 16S rRNA gene were considered to be true positives. The overall prevalences of gonorrhea were 6.6% in women and 20.1% in men. The COBAS AMPLICOR and AMPLICOR formats yielded concordant results for 98.8% of the specimens and exhibited virtually identical sensitivities and specificities. The results that follow are for the COBAS AMPLICOR format. With the infected patient as the reference standard, the resolved sensitivities of PCR were 92.4% for endocervical swab specimens and 64.8% for female urine specimens. There were no significant differences in these rates between women with and without symptoms. Among symptomatic men, COBAS AMPLICOR sensitivities were 94.1% for urine and 98.1% for urethral swabs; for asymptomatic men, the results were 42.3 and 73.1%, respectively. In comparison, the sensitivities of culturing were 84.8% for endocervical specimens, 92.7% for symptomatic male urethral specimens, and only 46.2% for urethral specimens obtained from asymptomatic men. When PCR results were analyzed as if only a single test had been performed on a single specimen type, the resolved sensitivity was always higher. The resolved specificities of PCR were 99.5% for endocervical swab specimens, 99.8% for female urine specimens, 98.9% for male urethral swab specimens, and 99.9% for male urine specimens. The internal control revealed that 2.1% of specimens were inhibitory when initially tested. Nevertheless, valid results were obtained for 99.2% of specimens because 60.0% of the inhibitory specimens were not inhibitory when a second aliquot was tested. The COBAS AMPLICOR CT/NG test for N. gonorrhoeae exhibited high sensitivity and specificity with urethral swab and urine specimens from men and endocervical swab specimens from women and thus is well suited for diagnosing and screening for N. gonorrhoeae infection.
The performance of the Becton Dickinson BDProbe Tec ET SystemChlamydia trachomatis and Neisseria gonorrhoeaeAmplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109
men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology
clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those
from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture
transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results.
Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent
difference in the results. Without the AC result, sensitivity for C. trachomatis and N. gonorrhoeae were 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatis and N. gonorrhoeae sensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified
DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to
chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based
assays for these organisms.
We compared ligase chain reaction (LCR) assay with standard culture for the detection of pharyngeal Neisseria gonorrhoeae infection in men who have sex with men (MSM) presenting at a sexually transmitted diseases clinic in San Francisco. Pharyngeal
specimens were obtained from 200 MSM who reported performing fellatio during the previous 2 weeks. Confirmatory testing of
discrepant specimens was conducted using N. gonorrhoeae pilin proteins. Prevalence of pharyngeal N. gonorrhoeae was 6% by culture or 11% by LCR. The sensitivity and specificity of LCR were 94.7% and 97.8%, respectively, compared with
values of 47.4% and 100% for culture. Prevalence of pharyngeal N. gonorrhoeae infection, as determined by DNA amplification testing, was higher than that suggested by traditional culture. Results support
the use of DNA amplification testing in the oropharynx. The high prevalence of pharyngeal N. gonorrhoeae infection among MSM suggests that routine screening should be considered in efforts to reduce the burden of gonorrhea in
this population.
The greater sensitivity of nucleic acid amplification tests (NAATs) for Chlamydia trachomatis and Neisseria gonorrhoeae permits the use of urine and other noninvasive specimens, which can increase the reach and decrease the costs of public health
screening programs aimed at controlling these infections. This study evaluated the performance of the APTIMA Combo 2 assay,
a multiplex assay based on the transcription-mediated amplification reaction, for the simultaneous detection of both pathogens
in endocervical swab and urine specimens from females. Combo 2 assay results were compared with patient infected status, which
were available by using other commercial NAATs. Sensitivity and specificity for C. trachomatis were 94.2 and 97.6%, respectively, in swabs and 94.7 and 98.9%, respectively, in first-catch urine (FCU). Sensitivity and
specificity for N. gonorrhoeae were 99.2 and 98.7%, respectively, in swabs and 91.3 and 99.3%, respectively, in FCU. The assay reliably detected both infections
in coinfected patients. The Combo 2 assay can be recommended for use with endocervical swab and urine specimens from females,
especially for screening tests for asymptomatic women in sexually transmitted disease surveillance programs. This Food and
Drug Administration-cleared assay can be a useful tool in efforts to reduce the prevalence and incidence of C. trachomatis and N. gonorrhoeae infections in sexually active women and to prevent their costly and serious sequelae.
The intragenus specificities of five molecular diagnostic methods for Neisseria gonorrhoeae were determined. Three assays were considered suboptimal. Molecular detection of N. gonorrhoeae from sites where other Neisseria spp. commonly occur or from any site in low-prevalence settings should be confirmed by a test targeting a different genetic
locus.
Screening guidelines for men who have sex with men (MSM) recommend testing of extragenital sites (pharyngeal and rectal) for
gonorrhoea and chlamydia. Testing of specimens from these sites is not validated by most commercial nucleic amplification
tests, such as the COBAS Amplicor assay. To investigate the utility of the COBAS Amplicor assay for detection of Chlamydia trachomatis in extragenital specimens, this study developed and evaluated confirmatory tests using the omp1 gene as an alternative target for amplification by PCR. Of anal and throat swabs collected from men in male-only saunas,
52 swabs that tested C. trachomatis positive by COBAS Amplicor and 30 swabs that tested as negative were included for confirmatory omp1 PCR testing. A total of 49 (94%) COBAS Amplicor-positive samples were confirmed by the omp1 PCR. A substantial proportion of specimens were confirmed by using a nested omp1 PCR (27%). Not confirmed by any omp1 PCR were three anal swabs (6%). It is most probable that these samples contained lower bacterial levels that were near or
below the detection level of the omp1 PCR assays. The findings of this study support the confident reporting of C. trachomatis detected by COBAS Amplicor in extragenital specimens and support the utility of this assay as a screening test for MSM.
A clinical evaluation was conducted in six North American centers to determine the ability of APTIMA CT (ACT) and APTIMA GC
(AGC) nucleic acid amplification assays to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections in 1,322 men by testing their urethral swabs and first-catch urine (FCU). The results obtained with ACT and AGC
assays were compared to an infected patient status determined by testing the specimens with the APTIMA Combo 2 and the BD
ProbeTec energy transfer multiplex assays. Symptoms did not influence the values. Positive and negative agreements of the
ACT and AGC assays for individual specimens were high, with each comparator assay ranging between 94.3 and 100% for positives
and 93.9 and 99.4% for negatives. The ACT and AGC assays performed on noninvasive specimens such as FCU effectively identified
C. trachomatis or N. gonorrhoeae infections in symptomatic and asymptomatic men and should be suitable for screening male populations.
We evaluated three CDC-suggested approaches for confirming positive nucleic acid amplification tests (NAATs) for Chlamydia trachomatis: (i) repeat the original test on the original specimen, (ii) retest the original specimen with a different test, and (iii)
perform a different test on a duplicate specimen. For approach 1, specimens (genital swabs or first-catch urine [FCU]) initially
positive by the Abbott LCx Probe System Chlamydia trachomatis Assay (LCx; Abbott Laboratories), the APTIMA Combo 2 Assay (AC2; Gen-Probe Inc.), the Amplicor CT/NG Assay (PCR; Roche Diagnostics
Corp.), or the BD ProbeTec ET System C. trachomatis amplified-DNA assay (SDA; Becton Dickinson Diagnostic Systems) were retested by the same NAAT. In several evaluations, multiple
efforts were made to confirm the original positive result. For approach 2, specimens initially positive by SDA and the Hybrid
Capture 2 CT-ID DNA Test (HC2; Digene Corp.) were retested by different NAATs (SDA, PCR, AC2, and the APTIMA assay for C. trachomatis [ACT]). For approach 3, duplicate male urethral or cervical swabs were tested by SDA or by both AC2 and ACT. FCU specimens
were tested by all three tests. We found that 84 to 98% of SDA, LCx, PCR, and AC2 positive results were confirmed by a repeat
test and that 89 to 99% of SDA and AC2 and 93% of HC2 positive results were confirmed by different NAATs, but that some NAATs
cannot be used to confirm other NAATs. The use of repeat testing did not confirm 11% of C. trachomatis SDA positive results that could be confirmed by more extensive testing. Doing more testing confirms more positive results;
>90% of all positive NAATs could be confirmed.
To examine the geographical variations in HIV prevalence (diagnosed and undiagnosed), use of sexual health services, sexually transmitted infections and sexual behaviour in a community sample of men who have sex with men in three cities in England, specifically London, Brighton and Manchester.
Cross-sectional surveys of men visiting gay community venues in three large cities in England. Men self-completed a questionnaire and provided an anonymous oral fluid sample for HIV antibody testing.
HIV prevalence ranged from 8.6% to 13.7% in the three cities. Over one-third of HIV infection remained undiagnosed in all sites despite 69% of HIV-positive men reporting attending a genitourinary medicine clinic in the last year. Similar and high levels of risk behaviour were reported in all three cities. 18% of HIV-negative men and 37% of HIV-positive men reported unprotected anal intercourse with more than one partner in the last year. 20% of negative men and 41% of positive men reported an STI in the last year.
Across all cities, despite widespread availability of anti-retroviral treatment and national policy to promote HIV testing, many HIV infections remain undiagnosed. Data from this community sample demonstrate high levels of risk behaviour and STI incidence, especially among those who are HIV positive. Renewed efforts are needed to increase diagnosis and to reduce risk behaviour to stem the continuing transmission of HIV.
We evaluated three of the CDC approaches for confirming Neisseria gonorrhoeae (gonococcus [GC])-positive nucleic acid amplification test (NAAT) results: (i) repeating the original test on the original specimen, (ii) testing the original specimen with a different test, and (iii) performing a different test on a duplicate specimen collected at the same visit. For the first approach, clinical specimens were initially tested by Aptima Combo 2 (AC2) (Gen-Probe Inc., San Diego, CA), ProbeTec (strand displacement amplification [SDA]) (Becton Dickinson Co., Sparks, MD), and Amplicor (PCR) (Roche Molecular Systems, Branchburg, NJ). The original GC-positive specimens were then retested by the same NAAT for confirmation. For the second approach, specimens initially positive by AC2, SDA, or PCR were retested by different NAATs (SDA, PCR, AC2, and Aptima Neisseria gonorrhoeae assay [AGC]; Gen-Probe Inc.). For the third approach, duplicate urethral swabs and first-catch urine (FCU) samples from men and duplicate cervical swabs and FCU samples from women were each tested by SDA, AC2, and AGC in parallel. We found that 89 to 96% of samples positive by SDA, PCR, and AC2 were confirmed by repeat testing and that 85 to 98% of SDA, PCR, and AC2 results were confirmed by using different NAATs on the original specimen. For FCU samples from men, any NAAT can be used for confirmation. However, for all other specimen types, some NAATs cannot be used to confirm positive results from other NAATs. Thus, a single repeat test appears to be a reliable method for confirmation, but by doing more extensive testing, an additional 5% were confirmed. With >90% of all GC-positive NAATs being confirmed, our results show that confirmatory testing is not warranted for these genital specimens.
Several nucleic acid amplification tests (NAATs) are US Food and Drug Administration-cleared for detecting urogenital Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infection, but they have not been adequately evaluated for the relatively common oropharyngeal or rectal CT and GC infections in men who have sex with men (MSM).
Multiple swabs were collected from the oropharynx and rectum of MSM attending a city sexually transmitted disease clinic. The specimens were tested by standard culture and the following NAATs: Roche's Amplicor (PCR), Becton Dickinson's ProbeTec (SDA), and Gen-Probe's APTIMA Combo 2 (AC2) for the detection of CT and GC. Confirmatory testing of specimens with discrepant results was done by NAATs using alternate primers.
A total of 1110 MSM were enrolled. Based on initial findings on 205 MSM, PCR had a 78.9% GC specificity with oropharyngeal swabs. Thus, we discontinued PCR testing for the rest of the study. For oropharyngeal GC (89 infections detected), sensitivities were 41% for culture, 72% for SDA, and 84% for AC2. For rectal GC (88 infections detected), sensitivities were 43% for culture, 78% for SDA and 93% for AC2. For oropharyngeal CT (9 infections detected), sensitivities were 44% for culture, 67% for SDA, and 100% for AC2. For rectal CT (68 infections detected), sensitivities were 27% for culture, 63% for SDA, and 93% for AC2. Specificities of SDA and AC2 were > or =99.4% for both organisms and anatomical sites.
AC2 and SDA were far superior to culture for the detection of CT or GC from the oropharynx and rectum with AC2 detecting twice as many infections as culture. Further analyses with larger pharyngeal samples are needed, but clearly NAATs can improve our ability to diagnose rectal and oropharyngeal infection with CT or GC in MSM.
In addition to the urogenital tract, Neisseria gonorrhoeae infects extragenital sites such as the pharynx and anorectal canal. Culture and a ligase chain reaction (LCR)-based assay were compared for their performance for the diagnosis of N. gonorrhoeae infection with specimens from various urogenital and extragenital sites of 200 men and 125 women. The sensitivity and specificity of the LCR assay with male urethral swabs were both 100%, compared to values of 95.9 and 100%, respectively, for culture of urethral swabs or 98.0 and 100%, respectively, for LCR with first-void urine (FVU). For women, LCR with FVU showed the highest sensitivity (94.7%), and culture of urethral samples showed the lowest sensitivity (63.2%) (P < 0.05). In a selected subgroup of 47 men and 22 women at increased risk, the rates of pharyngeal infection were 15 and 18%, respectively, and those of anorectal infection were 13 and 45%, respectively. The sensitivity of LCR was greater than that of culture for both pharyngeal and anorectal specimens. Thus, the overall performance of LCR testing with swabs or FVU was better than that of culture for the diagnosis of genital or extragenital gonorrhea.
To investigate, by use of the Amplicor PCR in a routine setting, the recovery rate of Chlamydia trachomatis in ano-rectal and pharyngeal swab samples obtained from males and females attending an STD clinic in relation to sexual practices, symptoms, and signs.
Data regarding sexual practices, and symptoms and signs related to the rectum and pharynx, were obtained from 196 females and 208 males, including 31 homosexuals and eight bisexuals. Swab samples were obtained from the urethra, rectum, and pharynx from all the patients. An additional endocervical swab sample was obtained from the females.
All samples were analysed by the Amplicor PCR (Roche).
Rudolph Bergh's Hospital, a clinic for sexually transmitted diseases situated in the centre of Copenhagen, Denmark.
The overall prevalence of urogenital C trachomatis infection was 9.2% (37/404). The specificity of the Amplicor PCR was 100% for both ano-rectal and pharyngeal swab samples. In females three (13%) of the 23 infections were detected only by testing an ano-rectal or throat swab sample. In homosexual males two (67%) of three infections were detected only by the anorectal swab sample. Ano-rectal intercourse without use of condom was reported by 44% of females and by 52% of homosexual males. Fellatio without condom use was reported by 91% of females, and 80% of heterosexual males practised cunnilingus. Pharyngeal infection, however, occurred only in females, and the presence of pharyngeal symptoms or signs seemed predictive for pharyngeal C trachomatis infection, for which the time of incubation or colonisation exceeded 3 months. The presence of ano-rectal signs or symptoms was not predictive for an ano-rectal C trachomatis infection.
The Amplicor PCR can be used on ano-rectal and pharyngeal swab samples. Ano-rectal swab samples should be obtained in females and homosexual males at high risk of being infected. Pharyngeal samples should be taken in females at high risk of being infected, especially when pharyngeal signs or symptoms are present.
We evaluated four commercial transport systems with a standardized inoculum of clinical isolates of N. gonorrhoeae (NG), and assessed survival after holding for up to 48 hours at both ambient and refrigeration temperatures. Suspensions of clinical isolates of NG were standardized and adsorbed onto four transport swab types: Culturette EZ (Becton Dickinson [BD], Cockeysville, MD, USA); Cultureswab (Difco Laboratories, Detroit, MI, USA); Venturi Transystem (Copan Italia, Bovezzo, Italy); and a recently modified Starswab (Starplex Scientific, Etobicoke, ON). Swabs were plated to chocolate agar at 0, 6, 24, and 48 hours, and colonies counted. Each swab type was tested in quadruplicate with each NG strain for all time and temperature variables. There was a marked reduction in NG CFUs after only 6 hours incubation with each of the swabs tested. Survival was best using Venturi Transystem and Cultureswab transports (colony counts were reduced to 15.3% and 13.0%, respectively, at 6 hours) when compared with the Culturette EZ and Starswab (colony counts were reduced to 2.2% and 4.3%, respectively, at 6 hours). After the 24-hour holding period, 94% of the cultures from the Venturi Transystem were positive, 82% from the Cultureswab, 24% from the Starswab; and 17% from the Culturette EZ. After 48 hours, recovery dropped to 72%, 43%, 14%, and 0.04%, respectively. All of the systems tested had at least an 80% decrease in recovered colonies after only 6 hours. Further studies are required to determine how poor transport conditions influence the number of positive cultures and what the public health implications are. Of the swabs tested, Cultureswab and Venturi Transystem were most acceptable.
The Roche Cobas Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae polymerase chain reaction (PCR) assay can simultaneously detect both C. trachomatis and N. gonorrhoeae, and has been cleared by United States Food and Drug Administration (FDA) for the testing of endocervical and urethral swabs and urine specimens. The Amplicor N. gonorrhoeae PCR target sequence is known to be present in some strains of commensal Neisseria species, including N. cinerea and N. subflava, necessitating the use of a second PCR assay to confirm positive results. This study analyses the performance of the assay on 7,007 unselected specimens submitted to the laboratory for the PCR diagnosis of N. gonorrhoeae and C. trachomatis; compares the PCR assay with culture for the detection of N. gonorrhoeae; examines the performance of the assay with specimens from different body sites; and briefly compares two confirmatory PCR assays. Confirmation rates for an initial Amplicor N. gonorrhoeae positive result varied widely by specimen type, ranging from 86.2 per cent for penile/urethral swabs to 5.6 per cent for oropharyngeal swabs, indicating all positive Amplicor N. gonorrhoeae results should be confirmed by a second method to maintain adequate specificity. Overall there was 98.1 per cent agreement between the confirmed PCR assay and culture, with confirmed PCR showing a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 81.7 per cent, 99.5 per cent, 92.7 per cent and 98.5 per cent respectively, compared with N. gonorrhoeae culture. When confirmed C. trachomatis/N. gonorrhoeae PCR assay performance was analysed against culture using only FDA-cleared specimens (553 penile/ urethral swabs, urines and cervical/vaginal swabs), sensitivity, specificity, PPV and NPV and percent agreement were 96.7 per cent, 99.8 per cent, 98.9 per cent, 99.4 per cent and 99.3 per cent respectively. No significant differences were found between the two confirmatory PCR assays used during the study period. Limitations of Amplicor for the detection of N. gonorrhoeae and the appropriate use of combined C. trachomatis/N. gonorrhoeae PCR in a routine diagnostic setting are discussed.
To compare a nucleic acid amplification test (ligase chain reaction) with culture for detecting rectal and pharyngeal gonorrhoea in men who have sex with men (MSM).
Duplicate rectal and throat swabs from MSM attending a genitourinary medicine clinic were collected for culture on modified New York City medium and detection of gonococcal nucleic acid by the Abbott ligase chain reaction (LCR) utilising probes based on opa 1 gene sequences. LCR positive culture negative specimens were tested by a second LCR utilising probes based on pilin gene sequences. Patients with rectal and/or pharyngeal cultures yielding Gram negative diplococci confirmed as Neisseria gonorrhoeae by biochemical and immunological methods were diagnosed with rectal and/or pharyngeal gonorrhoea. The criteria for diagnosing rectal and pharyngeal infection by LCR included a positive opa LCR with a positive culture from the same site or, in the case of a negative culture, a positive opa LCR and a positive pilin LCR.
Duplicate rectal samples were obtained from 227 MSM. The results of LCR and culture were concordant in 219 samples (96.5%). The prevalence of rectal gonorrhoea by LCR and culture was 7.0% (16/227) and 4.0% (9/227), respectively. Duplicate throat samples were obtained from 251 MSM. The results of LCR and culture were concordant in 230 (91.6%) cases. The prevalence of pharyngeal gonorrhoea by LCR and culture was 12.7% (32/251) and 6.0% (15/251), respectively. The specificity of LCR was 99.5% (210/211) for rectal and 98.2% (215/219) for pharyngeal specimens.
The high prevalence and asymptomatic nature of pharyngeal and rectal gonococcal infection suggests that routine screening for infection at these sites by a nucleic acid amplification test method such as LCR should be considered as part of the overall strategy to control gonorrhoea in MSM.
Little is known about the prevalence of rectal chlamydial infection amongst men who have sex with men (MSM). Previous studies using culture methods reported this to be between 4-6%. The emergence of nucleic acid amplification tests has significantly increased the sensitivity and specificity for chlamydial detection, making it possible to estimate the prevalence of rectal infection more accurately.
A prospective cross sectional study involving 443 MSM who were screened for sexually transmitted infections (STIs) between May 1999 and January 2002. Rectal swabs for chlamydiae were obtained in addition to specimens for routine STI screening. Rectal chlamydiae were detected by ligase chain reaction (LCR) utilizing the Abbott LCX Amplicor with confirmation by COBASE amplicor for the majority of cases. Those with rectal chlamydial infection were treated with azithromycin. The characteristics of men with rectal chlamydial infection were compared with those who were not infected at this site.
Rectal chlamydia was detected in 32 (7.2%) of 443 patients. Those with rectal chlamydial infection were more likely to have rectal symptoms (12/32) or having a partner with confirmed chlamydial (2/32) or gonococcal (3/32) urethritis than those MSM without rectal chlamydial infection. They were also more likely to have a history of receptive anal sex (25/32) in the previous three months compared to those MSM without rectal chlamydial infection (263/411). The most common symptoms of patients with rectal chlamydial infection were pruritus ani and peri-anal pain. Eight (25%) of those with rectal chlamydial infection were known to be HIV seropositive.
Rectal chlamydial infection is common amongst MSM and is effectively diagnosed by LCR. The test should be included in the routine STI screening offered to MSM.
A Neisseria gonorrhoeae LightCycler (NGpapLC) assay targeting the porA pseudogene was compared with bacterial culture for detection of N. gonorrhoeae in 636 clinical specimens (216 cervical, 185 urethral, 196 throat, and 39 rectal swab specimens). The specificity of the NGpapLC assay was further investigated by testing a bacterial reference panel comprising several Neisseria species. Overall, 19 (3.0%) specimens were positive and 613 (96.4%) specimens were negative by both methods. Four (0.6%) specimens were positive by the NGpapLC assay only. For the cervical and urethral swabs, the NGpapLC provided 100% sensitivity and 100% specificity compared with bacterial culture. Following discrepant analysis, the clinical sensitivity and specificity of the NGpapLC for throat and rectal swabs was also 100%. For the bacterial panel, only N. gonorrhoeae isolates provided positive results. The results show the NGpapLC assay is suitable for use on a range of clinical specimens and could improve detection of pharyngeal N. gonorrhoeae.
The Centers for Disease Control and Prevention developed screening and diagnostic testing guidelines for chlamydia and gonorrhea at urethral, rectal, and pharyngeal sites for men who have sex with men (MSM). However, in most clinical settings, rectal chlamydial testing is not performed for MSM, and primarily sexually transmitted disease (STD) clinics alone perform routine rectal and pharyngeal gonorrhea screening for asymptomatic men.
We evaluated the prevalence of rectal, urethral, and pharyngeal chlamydial and gonococcal infections among MSM seen at the municipal STD clinic and the gay men's community health center. We also determined the proportion of asymptomatic rectal infections, described the patterns of single and multiple anatomic sites of infection, and evaluated the proportion of chlamydial infections that would be missed and not treated if MSM were not routinely tested for chlamydia. We tested specimens using previously validated nucleic acid amplification tests (NAATs).
The prevalence of infection varied by anatomic site (chlamydia: rectal, 7.9%; urethral, 5.2%; and pharyngeal, 1.4%; for gonorrhea, rectal, 6.9%; urethral, 6.0%; and pharyngeal, 9.2%). Approximately 85% of rectal infections were asymptomatic supporting the need for routine screening. Because 53% of chlamydial infections and 64% of gonococcal infections were at nonurethral sites, these infections would be missed and not treated if only urethral screening was performed. In addition, >70% of chlamydial infections would be missed and not treated if MSM were tested only for gonorrhea.
Because these infections enhance both HIV transmission and susceptibility, clinical settings serving MSM should evaluate the prevalence of chlamydial and gonococcal infections by anatomic site using validated NAATs.
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.
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.
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.
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.
