Aptima Combo2 Assay Research Articles

Risk Compensation After Initiation of Daily Oral Pre-exposure Prophylaxis Among Sexual and Gender Minorities in Nigeria.

Pre-exposure prophylaxis (PrEP) use may be associated with risk compensation. We enrolled and provided PreP to sexual and gender minorities (SGM) in Abuja, Nigeria between April 2018 and May 2019. Behavioral information and samples for urogenital and anorectal Chlamydia trachomatis and Neisseria gonorrhoeae sexually transmitted infections (STIs) were collected at baseline. Blood samples for PrEP assay and self-reported adherence were collected at three-monthly follow-up visits. STIs were detected using Aptima Combo2 assay. We estimated the odds ratios (ORs) of PCR-diagnosed bacterial STIs and self-reported behavioral outcomes (condomless anal intercourse [CAI] and concurrent sexual relationships) with conditional logistic regression. Of 400 SGM who initiated PrEP, 206 were eligible for analysis, and had a median age of 24 years (IQR 22-27). In multivariable analysis, participants in the PrEP period had decreased odds of CAI (adjusted OR: 0.49, 95% CI 0.28, 0.84). PrEP use was not associated with risk compensation.

Chlamydia trachomatis Variants Escaping Detection in the Aptima Combo 2 Assay in the United States.

The Aptima Combo 2 (AC2) assay manufactured by Hologic, Inc., detects Neisseria gonorrhoeae and/or Chlamydia trachomatis (CT) in urogenital and extragenital specimens by targeting either a 16S rRNA (N. gonorrhoeae) or 23S rRNA (CT) region. In 2019, a mutation (C1515T) in the 23S rRNA region was reported to cause false-negative/equivocal results in specimens collected in Finland. Specimens containing this variant (Fl-nvCT) were also discovered internationally. Working with specimens submitted to a large commercial laboratory, we sought to determine if this variant was also present in the United States. A subset (n = 401) of specimens tested with the AC2 assay collected during a 5-week period in late 2019/early 2020 were evaluated using an updated AC2 assay. Although the FI-nvCT variant was not detected within this specimen panel, 2 CT variants containing 23S rRNA mutations (A1518G, G1526A) were identified. The updated AC2 assay targeting an additional region of the 23S rRNA detected both of these variants. A retrospective study of >18 million AC2 results tested between 2018 and 2019 did not display a decrease in CT positivity. Although we did not detect the Fl-nvCT variant among US specimens, we show evidence that the low occurrence of similar diagnostic-escape mutants can be detected with an updated AC2 assay using multiple 23S rRNA targets.

Can a Clean Catch Urine Sample Be Used to Diagnose Chlamydia and Gonorrhea in Adolescent Females?

PurposeClean catch urine samples may be an alternative specimen to test for chlamydia and gonorrhea infections. The aim of this study was to determine the sensitivity and specificity of clean urine for chlamydia and gonorrhea in women. MethodsThis was a noninferiority prospective cohort study of women aged 14–22 years requiring chlamydia and gonorrhea testing. Patients provided a vaginal swab (gold standard), clean urine (test sample), and dirty urine (usual care). All samples were analyzed using Hologic's Aptima Combo2 Assay, a second-generation nucleic acid amplification test. The sensitivity and specificity of the clean and dirty urine were calculated and compared. ResultsThree hundred and twenty-three females were included, mean age 17.0 ± 1.6 years. For chlamydia, 59 participants were positive by vaginal swab. The sensitivity of clean urine to diagnose chlamydia was 86.2% (95% CI: 74.8%–93.1%) and specificity was 98.8% (95% CI: 96.5%–99.8%). The sensitivity of dirty urine to diagnose chlamydia was 89.8% (95% CI: 79.2%–95.6%), and the specificity was 99.6% (95% CI 97.6%–100%). For gonorrhea, 18 participants were positive by vaginal swab. The sensitivity of clean urine to diagnose gonorrhea was 94.4% (95% CI: 72.4%–100%) and specificity was 99.7% (95% CI: 98.0%–100.0%). The sensitivity of dirty urine to diagnose gonorrhea was 100% (95% CI: 79.3%–100%) and specificity was 99.7% (95% CI: 98.0%–100%). Specificity of clean urine was noninferior compared with dirty urine for diagnosing chlamydia (p = .0004) and gonorrhea (p < .0001). ConclusionsClean urine samples may be an alternative option to diagnose chlamydia and gonorrhea in women.

Performance assessment of the Allplex™ STI Essential real-time PCR assay for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis infections in genital and extra-genital sites

Abstract 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 (Ct). 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 Ct 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 Ct was above 34. We decided to include interpretative comments on our reports on the basis of the Ct 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.

Comparison of an in-house real-time duplex PCR assay with commercial HOLOGIC\xae APTIMA assays for the detection of Neisseria gonorrhoeae and Chlamydia trachomatis in urine and extra-genital specimens

BackgroundExtra-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.MethodsWe 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.ResultsFor 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.ConclusionThe 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.

Comparison of the Cepheid GeneXpert CT/NG assay to the Hologic Aptima Combo2 assay for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in self-collected rectal swabs

Self-collected rectal-swabs were tested for CT and NG on GeneXpert CT/NG as compared to APTIMA Combo2. Of 448 rectal-swabs, 22 were positive for CT; 7 for NG on both assays; two were discordant. Sensitivity and specificity of GeneXpert was 95.5% and 99.7% for chlamydia, respectively; for gonorrhea both were 100%.

Asymptomatic and symptomatic urethral gonorrhoea in men who have sex with men attending a sexual health service

ObjectivesGuidelines regarding whether men who have sex with men (MSM) without symptoms of urethritis should be screened for urethral gonorrhoea differ between countries. We examined the rate of asymptomatic urethral gonorrhoea in MSM using sensitive nucleic acid amplification testing. MethodsThis study was conducted on consecutive MSM attending the Melbourne Sexual Health Centre between July 2015 and May 2016 for sexually transmitted infections screening. Gonorrhoea testing with the Aptima Combo 2 (AC2) assay was performed on all urine specimens obtained from MSM, whether symptoms of urethritis were present or not. Men were classified as having: typical discharge if they reported symptoms suggesting purulent discharge; other symptoms if they reported other symptoms of urethritis; and no symptoms if they reported no urethral symptoms. ResultsDuring the study period, there were 7941 clinic visits by 5947 individual MSM with 7090 urine specimens obtained from 5497 individual MSM tested with the AC2 assay. Urethral gonorrhoea was detected in 242 urine specimens from 228 individual MSM. The majority (189/242, 78%, 95% CI 73–83) reported typical discharge, 27/242 (11%, 95% CI 8–16) reported other urethral symptoms, and 26/242 (11%, 95% CI 7–15) reported no symptoms on the day of presentation and testing. Among men with urethral gonorrhoea, the proportions with concurrent pharyngeal or rectal gonorrhoea were 32% (134/210) and 64% (74/235), respectively. The mean interval between last reported sexual contact and onset of typical urethral discharge, where present, was 3.9 days. ConclusionThe findings from our study lend support to guidelines that recommend screening asymptomatic MSM for urethral gonorrhoea.

Prevalence and Clinical Significance of Mycoplasma genitalium in Gynecologic Patients

Objective: Mycoplasma genitalium has been recognized as a cause of male urethritis, and there is now evidence suggesting it causes cervicitis and pelvic inflammatory disease (PID) in women. Methods: Prevalence, risk factors and co-infections with other sexually transmitted pathogens were collected in a cross-sectional study looking at 400 women at the gynecologic clinics of a university medical center in the United States. Bacterial vaginosis and trichomoniasis were diagnosed using Amsel’s criteria, gram stain and trichomonas culture respectively. Cervicitis and PID were clinically diagnosed. After testing for Chlamydia trachomatis and Neisseria gonorrhoeae, the residual cervical swab transport medium (Gen-Probe/Hologic®) was stored at -70°C. Stored samples were later analyzed for M. genitalium by a research use only transcription-mediated amplification assay using procedures similar to those established for APTIMA Combo2 assay for C. trachomatis and N. gonorrhoeae (Gen-Probe/Hologic®). Results: The overall prevalence of infection with C. trachomatis, N. gonorrhoeae, T. vaginalis and M. genitalium was found to be 7.8%, 1.8%, 10.43% and 8.9%, respectively. Prevalence of M. genitalium was comparable to that of C. trachomatis and greater than the prevalence of N. gonorrhoeae. Univariate analysis of M. genitalium status showed that participants with lower condom use had an increased probability of M. genitalium (p=0.037). Conclusion: Prevalence of M. genitalium was comparable to C. trachomatis in our study, but more research is needed to clarify pathogenicity.

Can We Use Antibodies to Chlamydia trachomatis as a Surveillance Tool for National Trachoma Control Programs? Results from a District Survey.

BackgroundTrachoma is targeted for elimination by 2020. World Health Organization advises districts to undertake surveillance when follicular trachoma (TF) <5% in children 1–9 years and mass antibiotic administration has ceased. There is a question if other tools could be used for surveillance as well. We report data from a test for antibodies to C. trachomatis antigen pgp3 as a possible tool.MethodologyWe randomly sampled 30 hamlets in Kilosa district, Tanzania, and randomly selected 50 children ages 1–9 per hamlet. The tarsal conjunctivae were graded for trachoma (TF), tested for C. trachomatis infection (Aptima Combo2 assay: Hologic, San Diego, CA), and a dried blood spot processed for antibodies to C. trachomatis pgp3 using a multiplex bead assay on a Luminex 100 platform.Principal findingsThe prevalence of trachoma (TF) was 0.4%, well below the <5% indicator for re-starting a program. Infection was also low, 1.1%. Of the 30 hamlets, 22 had neither infection nor TF. Antibody positivity overall was low, 7.5% and increased with age from 5.2% in 1–3 year olds, to 9.3% in 7–9 year olds (p = 0.015). In 16 of the 30 hamlets, no children ages 1–3 years had antibodies to pgp3.ConclusionsThe antibody status of the 1–3 year olds indicates low cumulative exposure to infection during the surveillance period. Four years post MDA, there is no evidence for re-emergence of follicular trachoma.

006.5 Periodic presumptive treatment for vaginal infections may reduce chlamydia and gonorrhoea incidence: a secondary analysis from the preventing vaginal infections trial

Background Women with bacterial vaginosis (BV) are at increased risk for sexually transmitted infections (STI), including Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). Among women participating in a randomised trial of periodic presumptive treatment to reduce vaginal infections, we assessed the intervention effect on incident CT and GC infections. Methods Non pregnant, HIV-uninfected women aged 18–45 from the US and Kenya were randomised to receive intravaginal metronidazole 750 mg plus miconazole 200 mg or matching placebo for 5 consecutive nights each month for 12 months. Genital specimens were collected every other month. Baseline specimens were tested for CT/GC during the trial and follow-up specimens were tested after trial completion using the Aptima Combo-2 assay. Baseline STIs were treated according to local guidelines. Poisson regression models were used to assess the intervention effect on the outcomes separately and as a combined endpoint. Results Of 234 women enrolled, 221 (94%) had specimens available for analysis (intervention n = 110; placebo n = 111). Baseline CT and GC prevalence was 7% (n = 16) and 1% (n = 3), respectively, and similar by arm. Among 205 CT- participants, there were 21 incident CT infections during 179.6 person-years (CT incidence = 11.7/100 person-years), with lower CT incidence in the intervention arm versus placebo (7.8/100 person-years versus 15.6/100 person-years; incidence rate ratio [IRR] = 0.50, 95% CI 0.20–1.23). Among 218 GC- participants, GC incidence was 7.2/100 person-years (14 infections during 93.3 person-years) and also lower in the intervention arm (5.2/100 person-years versus 9.3/100 person-years; IRR = 0.56, 95% CI 0.19–1.67). Results were consistent when CT/GC was assessed as combined endpoint (IRR = 0.57; 95% CI 0.27–1.19). Conclusions This intervention, which significantly reduced BV over 12 months, may also reduce women’s STI acquisition risk. The small sample size in this secondary analysis precluded detection of significant associations, but generated point estimates for reductions in STIs that could inform the planning of future STI prevention trials Disclosure of interest statement R. S. M. has received honoraria for invited lectures and consulting as well as donated study product for this trial from Embil Pharmaceutical Company. R. S. M. currently receives research funding from Hologic/Gen-Probe. J. E. B. received honoraria from Symbiomix, Inc for consulting and donated reagents from Hologic/Gen-Probe. J. S. has received consultancy payments from Akesis, Hologic, Symbiomix, and Starpharma, and has grants/pending grants from Akesis, BD Diagnostic, Hologic, Cepheid, Quidel, Symbiomix, Starpharma, and Viamet. All other authors declare that they do not have a commercial or other association that might pose a conflict of interest.

Evaluation of the new AmpliSens multiplex real-time PCR assay for simultaneous detection of Neisseriagonorrhoeae, Chlamydiatrachomatis, Mycoplasmagenitalium, and Trichomonasvaginalis.

In this study, we performed an evaluation of the new CE-marked multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay compared to APTIMA tests, i.e., APTIMA COMBO 2assay, APTIMA Trichomonasvaginalis assay (FDA-approved), and two different APTIMA Mycoplasmagenitalium assays (research use only; one of them only used for discrepancy analysis). Vaginal swabs (n=209) and first-void urine (FVU) specimens from females (n=498) and males (n=554), consecutive attendees (n=1261) at a dermatovenerological clinic in Sweden, were examined. The sensitivity of the AmpliSens PCR assay for detection of C.trachomatis (6.3% prevalence), M.genitalium (5.7% prevalence), N.gonorrhoeae (0.3% prevalence), and T.vaginalis (0.08% prevalence) was 97.5% (95% confidence interval (CI): 91.2-99.6%), 81.9% (95% CI: 70.7-89.7%), 100% (95% CI: 40.2-100%) and 100% (95% CI: 16.5-100%), respectively. The specificity of the AmpliSens PCR assay was 100% (95% CI: 99.6-100%) for all agents. The analytical sensitivity and specificity for N.gonorrhoeae detection was excellent, i.e., 55 international gonococcal strains detected and 135 isolates of 13 non-gonococcal Neisseria species were negative. In conclusion, the multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay demonstrated high sensitivity and excellent specificity for the detection of C.trachomatis, N.gonorrhoeae, and T.vaginalis, and excellent specificity but suboptimal sensitivity for M.genitalium detection.

P2.132 Pharyngeal and Conjunctival Chlamydia Trachomatis Infections: Chicken or Egg?

BackgroundChlamydial inclusion conjunctivitis caused by genital serovars of Chlamydia trachomatis (CT) is well-recognised, and usually thought to result from auto-inoculation from genital CT infection or direct sexual contact. In this...

O18.6 Persistence of PharyngealChlamydia TrachomatisFor 1–2 Weeks is Common Among Clients at the Amsterdam STI Clinic

BackgroundPharyngealChlamydia trachomatis(PCt) must persist to contribute to ongoing transmission. We examined the prevalence, persistence and determinants of PCt among STI clinic clients.MethodsAll men having sex with men (MSM) and women with a high risk profile were screened for anogenital and pharyngeal Ct with the APTIMACombo2 assay. After one week, clients with PCt were recalled for treatment, a follow-up pharyngeal swab and a questionnaire. Clients who used antibiotics since first visit were excluded from the analysis.ResultsBetween January 2011 and July 2012, we detected 148 PCt in MSM (13,111 visits; prevalence 1.1%) and 160 PCt in women (6,915 visits; 2.3%). In both groups, PCt was associated with being notified for STI, concurrent urogenital Ct and &gt; 10 partners, but not with pharyngeal symptoms. Women reporting sex work had a lower risk, while women with pharyngeal gonorrhoea and MSM with anorectal Ct had a higher risk for PCt. 53% of MSM and 32% of women with PCt had no concurrent anogenitial Ct.Of 43 (29%) MSM and 55 (34%) women, follow-up swabs and questionnaire data were available. The median time between both visits was 10 days. PCt persisted in 27 (63%) MSM and in 35 (64%) women. In both groups 50% had unprotected active oral sex between first and second visit, but this did not affect persistence.Among MSM no determinants for persistence were detected; among women being notified for STI, younger age and urogenital Ct were significantly associated with persistence in univariate analysis.Among clients (n = 16) whose second visit was more than 3 weeks after the first visit, 11 (69%) had PCt at second visit.DiscussionThe prevalence of PCt is low among STI clinic clients, but persistence is common. Therefore, the pharynx is a potential reservoir for ongoing Ct transmission.

Mycoplasma genitalium: prevalence in men presenting with urethritis to a South Australian public sexual health clinic

This study aimed to determine the prevalence of Mycoplasma genitalium infection among male patients with dysuria and/or urethral discharge. An analysis of the clinical, demographic and microbiological factors associated with M. genitalium infection was also conducted. From May 2007 to June 2011, men presenting to the clinic with self-reported symptoms of dysuria and/or urethral discharge were identified and underwent urethral swab, which was microscopically assessed for objective non-gonococcal urethritis. A first-void urine sample was tested for Chlamydia trachomatis and Neisseria gonorrhoeae using the Aptima Combo-2 assay. A portion of the urine sample was sent for polymerase chain reaction analysis for M. genitalium. One thousand, one hundred and eighty-two men with dysuria and/or urethral discharge were tested for M. genitalium. Of those, 96 men (8.1%) were positive for M. genitalium. Men identifying as solely MSM (men who have sex with men) constituted 16.3% (n = 193) of the sample. Their infection rate was 3.1% (n = 6). The infection rate for heterosexual and bisexual men was 9.1%. For all men, the M. genitalium co-infection rate was 14.6% (n = 14) with C. trachomatis and 3.1% (n = 3) with N. gonorrhoeae. Factors associated with M. genitalium infection were analysed by univariate analysis. We determined that five investigated predictors were significantly associated with M. genitalium infection, urethral discharge, non-gonococcal urethritis on Gram stain of urethral smears, identification as heterosexual or bisexual, and absence of co-infection with C. trachomatis or N. gonorrhoeae. In Adelaide, M. genitalium is an important sexually transmitted infection among men with dysuria and/or urethral discharge, and is primarily an infection of heterosexual and bisexual men.

Assessment of self taken swabs versus clinician taken swab cultures for diagnosing gonorrhoea in women: single centre, diagnostic accuracy study

Objective To compare gonorrhoea detection by self taken vulvovaginal swabs (tested with nucleic acid amplification tests) with the culture of urethral and endocervical samples taken by clinicians.Design Prospective study of...

Assessment of best single sample for finding chlamydia in women with and without symptoms: a diagnostic test study

Objective To compare vulvovaginal swabs with endocervical swabs as optimal diagnostic sample for detection of Chlamydia trachomatis infection.Design A diagnostic test study.Setting An urban sexual health centre.Participants 3973 women aged...

Comparison of self-obtained penile-meatal swabs to urine for the detection of C. trachomatis, N. gonorrhoeae and T. vaginalis

BackgroundSelf-obtained penile-meatal swabs and urine specimens have been used for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) for outreach screening in men.ObjectiveTo compare the sensitivity of self-collected...

P76 Equivocal Aptima Combo 2 results: what do they mean in clinical practice?

BackgroundMolecular diagnostic tests have become standard of care for detection of gonococcal (GC) and chlamydial (CT) infections. The Aptima Combo 2 (AC2) test is widely used and is highly sensitive...

P1-S2.67 Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae among college students who attended the Johns Hopkins University Health and Wellness Center from 2009 to 2010

BackgroundThe Centers for Disease Control and Prevention (CDC) recommends that sexually active women 25 years or younger be tested yearly for Chlamydia trachomatis. An ongoing screening program among college students...

First Report of Performance of the Versant CT/GC DNA 1.0 Assay (kPCR) for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

We evaluated the analytical, work flow, and clinical performance of the Versant CT/GC DNA 1.0 assay (Versant CT/GC assay, where "CT" represents Chlamydia trachomatis and "GC" represents Neisseria gonorrhoeae). The assay simultaneously detects Chlamydia trachomatis and Neisseria gonorrhoeae in swab and first-catch urine (FCU) specimens. The limit of detection (LoD) was determined to be 342 copies/ml for C. trachomatis and 137 copies/ml for GC. The Versant CT/GC assay detected 15 C. trachomatis serovars and 46 GC strains. The Versant CT/GC assay demonstrated no cross-reactivity with 136 potentially cross-reacting organisms. Clinical concordance of the Versant CT/GC assay to the Aptima Combo 2 (AC2) assay from Gen-Probe was demonstrated using 1,129 patient specimens, including 589 urine and 540 swab specimens. Discrepant specimens were subjected to DNA sequencing to identify the presence of amplified targets and to identify false-positive and false-negative results. Overall percent agreement was greater than 98%. Positive and negative percent agreements for detection of C. trachomatis were 94.4% and 99.1%, respectively, in urine specimens and 95.8% and 99.8%, respectively, in swab specimens. Positive percent agreement for the detection of N. gonorrhoeae was 100% in both urine and swab specimens, and negative percent agreements were 99.6% and 99% in urine and swab specimens, respectively. In conclusion, the performance of the Versant CT/GC assay was comparable to that of the AC2 assay. The Versant CT/GC assay can be recommended for the detection of C. trachomatis and N. gonorrhoeae in swab and urine specimens of symptomatic and asymptomatic individuals.