Development of a SimpleProbe real-Time PCR Assay for rapid detection and identification of the US novel urethrotropic clade of Neisseria meningitidis ST-11 (US_NmUC).

Urethritis, or inflammation of the urethra, is one of the most common reasons men seek clinical care. Sexually transmitted pathogens including Neisseria gonorrhoeae are responsible for over half of the symptomatic urethritis cases in U.S. men. Recently, clinics in Indianapolis, Columbus, Atlanta, and other U.S. cities began to note increasing numbers of men presenting with urethritis and Gram-negative intracellular diplococci in their urethral smears who test negative for N. gonorrhoeae. Many of these discordant cases, which have periodically reached highs of more than 25% of presumed gonococcal cases in some sexually transmitted infection clinics in the U.S. Midwest, are infected with strains in a novel urethrotropic clade of Neisseria meningitidis ST-11 (US_NmUC). However, no cultivation-independent tests are available for the US_NmUC strains, and prior studies relied on microbial culture and genome sequencing to identify them. Here, we describe a PCR test that can identify the US_NmUC strains and distinguish them from commensal and invasive N. meningitidis strains as well as N. gonorrhoeae. Our SimpleProbe®-based real-time PCR assay targets a conserved nucleotide substitution in a horizontally acquired region of US_NmUC strain genomes. We applied the assay to 241 urine specimens whose microbial compositions had previously been determined by deep shotgun metagenomic sequencing. The assay detected the single US_NmUC positive case in this cohort, with no false positives. Overall, our simple and readily adaptable assay could facilitate investigation of the pathogenesis and epidemiology of the US_NmUC clade.

Optimizing bacterial DNA extraction in urine.

Urine is an acceptable, non-invasive sample for investigating the human urogenital microbiota and for the diagnosis of sexually transmitted infections. However, low quantities of bacterial DNA and PCR inhibitors in urine may prevent efficient PCR amplification for molecular detection of bacteria. Furthermore, cold temperatures used to preserve DNA and bacteria in urine can promote precipitation of crystals that interfere with DNA extraction. Saline, Dulbecco's Phosphate Buffered Saline, or Tris-EDTA buffer were added to urine from adult men to determine if crystal precipitation could be reversed without heating samples beyond ambient temperature. Total bacterial DNA concentrations and PCR inhibition were measured using quantitative PCR assays to compare DNA yields with and without buffer addition. Dissolution of crystals with Tris-EDTA prior to urine centrifugation was most effective in increasing bacterial DNA recovery and reducing PCR inhibition. DNA recovery using Tris-EDTA was further tested by spiking urine with DNA from bacterial isolates and median concentrations of Lactobacillus jensenii and Escherichia coli 16S rRNA gene copies were found to be higher in urine processed with Tris-EDTA. Maximizing bacterial DNA yield from urine may facilitate more accurate assessment of bacterial populations and increase detection of specific bacteria in the genital tract.

Sexually transmitted agents and their association with leucocytospermia in infertility clinic patients.

In this study, the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvumDNA were investigated using real-time multiplex PCR detection kit in the urine samples of 50 patients who presented to the infertility polyclinic. Patients were classified into two groups in accordance with the WHO leucocytospermia criteria as over 1 × 106 /ml (n = 25) and below 1 × 106 /ml (controls; n = 25). In addition, the semen sample results of the patients were evaluated. The mean leucocyte count in the leucocytospermia group was detected as 3.4 × 106 /ml. Agent positivity was found in 12 of 25 patients in the leucocytospermia group (U. parvum 10, U. urealyticum 3, M. hominis 3) and 9 of 25 patients in the control group (U. parvum 7, U. urealyticum 2, M. hominis 1). A chi-square test evaluation revealed no statistically significant difference between groups. (p = 0.390). The statistical evaluation using the Mann-Whitney U and chi-square tests revealed no statistically significant negative effect of agent positivity on semen analysis parameters in either group (p > 0.05). Although no significant difference was detected between the groups, this study provides data about the prevalence of asymptomatic sexually transmitted diseases in patients presenting to the infertility polyclinic.

Prevalence of M. genitalium and U. urealyticum in urine tested for C. trachomatis.

BACKGROUND: Mycoplasma genitalium and Ureaplasma urealyticum cause sexually transmitted infections. While M. genitalium is an established aetiological agent, U. urealyticum is still controversial as a pathogen. Testing for these microbes is not yet widely available in Norway, and knowledge of their prevalence is limited. In this study we have investigated the prevalence of M. genitalium and U. urealyticum in a heterogeneous population from Vestfold and Telemark. MATERIAL AND METHOD: Urine samples (n = 4,665) received by the laboratory for testing for Chlamydia trachomatis in the period from February 2011 to January 2012 were subsequently tested for M. genitalium and U. urealyticum. Samples were analysed using an in-house PCR protocol. RESULTS: The prevalence of C. trachomatis, M. genitalium and U. urealyticum was 11.9%, 3.6% and 17.9% respectively. M. genitalium was found most frequently in women aged 20-24 years (5.1%), while the proportion of samples positive for U. urealyticum was greatest in persons aged 15-24 years (22.8%). INTERPRETATION: M. genitalium was highly prevalent in urine samples submitted for C. trachomatis testing. M. genitalium testing was requested for only a minority of the samples analysed, suggesting limited knowledge of this microbe. U. urealyticum was the most predominant microbe in the study, which may indicate that it is largely non-pathogenic.

Sensitive and rapid detection of Chlamydia trachomatis by recombinase polymerase amplification directly from urine samples.

Chlamydia trachomatis is the most common sexually transmitted human pathogen. Infection results in minimal to no symptoms in approximately two-thirds of women and therefore often goes undiagnosed. C. trachomatis infections are a major public health concern because of the potential severe long-term consequences, including an increased risk of ectopic pregnancy, chronic pelvic pain, and infertility. To date, several point-of-care tests have been developed for C. trachomatis diagnostics. Although many of them are fast and specific, they lack the required sensitivity for large-scale application. We describe a rapid and sensitive form of detection directly from urine samples. The assay uses recombinase polymerase amplification and has a minimum detection limit of 5 to 12 pathogens per test. Furthermore, it enables detection within 20 minutes directly from urine samples without DNA purification before the amplification reaction. Initial analysis of the assay from clinical patient samples had a specificity of 100% (95% CI, 92%-100%) and a sensitivity of 83% (95% CI, 51%-97%). The whole procedure is fairly simple and does not require specific machinery, making it potentially applicable in point-of-care settings.

Adolescent sexually transmitted infections and risk for subsequent HIV.

OBJECTIVES: We estimated the risk of HIV associated with sexually transmitted infection (STI) history during adolescence. METHODS: We retrospectively studied a cohort of adolescents (n = 75 273, born in 1985-1993) who participated in the Philadelphia High School STD Screening Program between 2003 and 2010. We matched the cohort to STI and HIV surveillance data sets and death certificates and performed Poisson regression to estimate the association between adolescent STI exposures and subsequent HIV diagnosis. RESULTS: Compared with individuals reporting no STIs during adolescence, adolescents with STIs had an increased risk for subsequent HIV infection (incidence rate ratio [IRR] for adolescent girls = 2.6; 95% confidence interval [CI] = 1.5, 4.7; IRR for adolescent boys = 2.3; 95% CI = 1.7, 3.1). Risk increased with number of STIs. The risk of subsequent HIV infection was more than 3 times as high among those with multiple gonococcal infections during adolescence as among those with none. CONCLUSIONS: Effective interventions that reduce adolescent STIs are needed to avert future STI and HIV acquisition. Focusing on adolescents with gonococcal infections or multiple STIs might have the greatest impact on future HIV risk.

[Experimental evaluation of the Sysmex UF-1000i for ruling out non-gonococcal urethritis]. / Utilizzo sperimentale di Sysmex UF-1000i nello screening di uretrite non gonococcica.

Acute nongonococcal urethritis (NGU) is one of the commonest sexually transmitted infections affecting men and women. The diagnosis of NGU has traditionally required microscopic evidence of urethritis. However, a significant proportion of patients with urethral symptoms do not have microscopic evidence of urethritis. The purpose of the present study was to evaluate the analytical performance of the UF1000i, a recently introduced fluorescence flow cytometer intended for urinalysis purposes which provides new analytical features that seem particularly suitable for microbiological diagnostics, for ruling out NGU or predicting the presence of infection. The Sysmex UF1000i is a flow cytometry analyzer capable of quantifying a lot of particles, including bacteria (BACT) and white blood cells (WBCs). To evaluate the analytical performance of the UF1000i as a method for ruling out NGU, we examined 200 urethral smear samples, collected in a new liquid transport medium (Copan), and compared the UF1000i results with standard culture/molecular and microscopic Gram stain results. With instrument cut-off values of 200 BACT x 10^6/L and 500 WBCs x 10^6/L, we obtained a sensitivity of 84%, a specificity of 82%, and a high negative predictive value (96%). Culture/molecular detection of pathogens remains the gold standard technique for the diagnosis of NGU. However, the Sysmex UF1000i is capable of improving the efficiency of NGU presumptive diagnosis, providing results in a few minutes, with a high negative predictive value and high values of sensitivity.

Evaluation and management of sexually transmitted infections in adolescent males presenting to a pediatric emergency department: is the chief complaint diagnostic?

OBJECTIVES: The objectives of the study were to (1) describe evaluation and treatment patterns for adolescent males presenting with a concern for sexually transmitted infection (STI) in a pediatric emergency department, (2) assess the rates of STIs in symptomatic males, and (3) determine the utility of urinalysis alone in predicting STIs in adolescent males. METHODS: A retrospective cohort study was conducted of all patients presenting to our pediatric emergency department from January 1, 2007, to December 31, 2007. Inclusion criteria included males, aged 15 to 21 years, with an STI or urinary chief complaint. Exclusion criteria were referrals from pediatricians, a previous history of urinary tract infection or preexisting urologic condition, or primary complaint of scrotal and/or testicular pain. RESULTS: A total of 270 patients were identified. Testing included urinalysis with microscopy (UA) (64%), urine culture (53%), Neisseria gonorrhoeae (GC), and Chlamydia trachomatis (CT) (93%), and Trichomonas vaginalis (5%). Sixty-four percent of males tested positive for either GC or CT, or both. Overall, 91% of patients were treated for CT and GC, 18% for T. vaginalis, and 5% for urinary tract infection. The sensitivity and specificity of a positive UA for presence of GC and/or CT were 86% and 82%, respectively, whereas the positive and negative predictive values were 89% and 77%, respectively. There were no positive urine cultures in the cohort. CONCLUSIONS: Sixty-four percent of patients were diagnosed with either GC or CT. Although UA is helpful in predicting STI, limited use is warranted, given the high prevalence of disease in this selected population. The urine culture does not appear to be a necessary adjunct in the management of these patients.

[Mycoplasma genitalium in men with non-gonococcal urethritis]. / Mycoplasma genitalium hos menn med urethritt.

BACKGROUND: C. trachomatis is the underlying cause of 20?-?50 % of sexually transmitted urethritis cases. Data from the last 10?-?15 years indicate that M. genitalium may be a cause, but the prevalence of M. genitalium in Norwegian patients has not previously been assessed or published. MATERIAL AND METHODS: Male patients at the Olafia Clinic in Oslo were examined for non-gonococcal urethritis. First void urine was collected and tested for presence of C. trachomatis and M. genitalium DNA by polymerase chain reaction (PCR). Presence of C. trachomatis or M. genitalium was correlated with microscopic signs of urethritis, quantified by counting polymorphonuclear leucocytes in urethral smears. RESULTS: Both C. trachomatis and M.gentialium were found more frequently in patients with microscopic signs of urethritis than in patients without (21.9 % vs 0.7 %, OR = 40, CI = 6?-?295; 8.7 % vs 0.7 %, OR = 14, CI = 1.8?-?102; respectively). The increase in prevalence correlated with the severity of urethritis, as assessed by the number of polymorphonuclear leucocytes present in urethral smears. INTERPRETATION: Data from Norwegian patients support earlier findings in other European populations, where M. genitalium is defined as a sexually transmitted infection that causes non-gonococcal urethritis in men.

[Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine samples of males and females by the strand displacement amplification (SDA) method].

Urine samples collected from 422 males and 53 females visiting a clinic in Kawasaki City who were suspected to have sexually transmitted infection were tested for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by BD ProbeTecET (SDA method). The detection rates of C. trachomatis by the SDA method and polymerase chain reaction (PCR) method (control) were as high as 98.1% for C. trachomatis, and as high as 99.4% for N. gonorrhoeae, and the concordance rate of detection of both bacterial species was high. The detection sensitivity and specificity of the SDA method were 90.6 and 99.3%, respectively for C. trachomatis and 98.7% and 100% for N. gonorrhoeae, when PCR was used as the standard method. There were no differences in these results between males and females. The number of patients showing a discrepancy of the results obtained between the SDA method and the PCR method was 9 for C. trachomatis and 1 for N. gonorrhoeae, but the results of redetermination by the SDA method tended to coincide with those of the PCR method. Urine samples tested by the SDA method were positive for N. gonorrhoeae even in patients in whom the culture of secretions from the male urethra was negative for N. gonorrhoeae. Based on these results, the BD ProbeTecET (SDA method) was confirmed to have the equivalent capability to the PCR method for the detection of C. trachomatis and N. gonorrhoeae in urine samples.

A chlamydia prevalence survey of young women living in Melbourne, Victoria.

BACKGROUND: To estimate the population-based chlamydia prevalence among women aged 18 to 35 years living in Melbourne, Victoria, and to assess the feasibility of using mailed urine specimens to test women. METHODS: A simple random sample of 11,001 households in Melbourne was selected from the telephone directory. Participants completed telephone interviews and provided urine specimens through the mail for chlamydia testing. Urines were tested using polymerase chain reaction. RESULTS: 11,001 households were contacted, with 1532 households identified as including eligible women; telephone interviews were completed, with 979 women giving a response rate of 64%. Six hundred and fifty-seven women provided a urine specimen with a response rate of 43%. Among sexually active women aged 18-24 years, the chlamydia prevalence was 3.7% (95% CI: 1.2%, 8.4%) and 0.2% (95% CI: 0.0%, 1.1%) among 25-35 year olds. Chlamydia prevalence increased significantly with an increasing number of male sexual partners. CONCLUSIONS: This is the first study of its kind in Australia and shows that chlamydia prevalence increases with an increasing number of male sexual partners in the last 12 months. Mailed urine specimens are feasible for conducting population-based chlamydia-prevalence surveys but it is difficult to obtain high response rates with this methodology. Public health resources should now be directed towards investigating how to reach young women at increased risk of infection, ensuring that they are tested for chlamydia.

Acceptability of self-taken vaginal swabs and first-catch urine samples for the diagnosis of urogenital Chlamydia trachomatis and Neisseria gonorrhoeae with an amplified DNA assay in young women attending a public health sexually transmitted disease clinic.

OBJECTIVES: Public health efforts are needed to encourage young women to get tested for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). GOAL: To assess the acceptability and feasibility of 2 noninvasive diagnostic approaches. STUDY DESIGN: Participants of this cross-sectional survey were 413 young women (age 16-35) who underwent STD testing by self-taken vaginal swab (SVS) and a first-catch urine sample (FCU) by nucleic acid amplification test (BDProbTec) and filled out a questionnaire. RESULTS: CT and GC were diagnosed in 10.9% (45/413) and 1.5% (6/413). Eleven percent of the participants who never previously had an STD examination (68%) tested STD positive. SVS and FCU were almost uniformly reported as easy to perform and preferred above gynecologic examination. CONCLUSIONS: Using SVS combined with FCU can be an important enhancing tool in public health approaches. Acceptability among potential patients is high, enabling the noninvasive detection of STDs that would otherwise remain undetected and untreated.

Home STI testing: the adolescent female's opinion.

PURPOSE: To assess sexually active adolescent females' attitudes of home tests for sexually transmitted infections. METHODS: This study represents a follow-up to a study on adolescent attitudes toward different sampling methods for STI testing. In the initial study participants completed a pre-examination health survey, provided first void urine (FVU) and self-collected vaginal swab samples followed by a pelvic examination with STI screening by endocervical swabs. Participants' attitudes about the three collection techniques were assessed at the end of the visit. For the current study, this same group of ethnically diverse adolescents (13-20-years-old) was contacted by telephone 9 months after their initial clinic visit to re-assess their attitudes about the three specimen collection techniques and to evaluate their attitudes regarding the use of home STI testing. Friedman tests of mean ranks evaluated teens' rankings of STI sampling methods and multivariate regression analysis was used to identify predictors of home test preference. RESULTS: Home urine testing was the first choice for STI screening followed by the FVU, self-obtained vaginal swab and endocervical swab collected in a clinical setting. FVU was preferred to self-collected vaginal swabs (p = .01). Adolescents who worried about having an STI were more likely to favor home urine testing (OR 5.5, p = .01). Only 22% would seek any STI screening if asymptomatic. CONCLUSIONS: Because young women preferred home STI testing, this may be an additional option, as the foundation for such testing kits has progressed. Adolescent preferences may be heavily influenced by the pelvic examination experience. Because of the largely asymptomatic nature of CT infections, multiple screening options (clinical and home-based) need to be available to increase access to care.

Screening positive urine pregnancy tests for sexually transmitted diseases expedites the treatment of infected adolescent gravidas.

OBJECTIVE: To test the utility of screening the urine samples used to diagnose pregnancies at urban teen clinics for Chlamydia trachomatis and Neisseria gonorrhoeae by polymerase chain reaction (PCR). We hypothesized that urine screening would increase the proportion of teenagers treated for these two sexually transmitted diseases (STDs) before they initiated pregnancy-related care. DESIGN: A randomly selected subset of the urine samples used to diagnose 212 teen pregnancies were tested for C. trachomatis and N. gonorrhoeae by PCR. Endocervical testing was at the providers' discretion. Bivariate analyses were used to compare the teenagers randomized to the urine screening group (n = 102) and the non-screening group (n = 110). RESULTS: Of the 102 urine PCR tests, 14 (13.7%) were positive. Endocervical swabs were obtained in 31 (14.6%) of the 212 teenagers and five (16.1%) were positive. Since pelvic examinations were performed so infrequently, the net endocervical swab detection rate was significantly lower than the urine-based detection rate (1.8% compared to 13.7%; p = 0.001). Only one infected teenager was untreated when she initiated pregnancy-related care. Thus, the treatment rate was more than six times higher when urine samples were screened (12.7% compared to 1.8%; p = 0.003). CONCLUSIONS: Screening the urine samples used to diagnose teen pregnancies for two common STDs is a simple, non-invasive procedure that is acceptable to providers and patients, and significantly increases the number of teenagers who are treated for genital infection before they initiate pregnancy-related care.

Chlamydia and gonorrhea screening in San Francisco high schools.

BACKGROUND: Previous school-based studies in cities with a high prevalence of chlamydia found a substantial prevalence of chlamydial infection among students. GOAL: The goal was to determine the feasibility and acceptability of chlamydia and gonorrhea screening in San Francisco high schools. STUDY DESIGN: Sexually transmitted disease (STD) education and screening were conducted at four high schools. Students provided basic demographic information and urine specimens for chlamydia and gonorrhea ligase chain reaction testing. RESULTS: Among 283 asymptomatic females screened, 3.9% had chlamydia and 0.7% had gonorrhea. The prevalence of chlamydia was 1.5% among females <16 years of age and 4.6% among females >or=16 years of age. Only 0.8% of asymptomatic males (3/381) had chlamydia, and none had gonorrhea. CONCLUSION: STD screening was both feasible and acceptable in San Francisco high schools. STD screening in high schools should be prioritized as follows: (1) chlamydia screening over gonorrhea screening, (2) female screening over male screening, and (3) screening of older students (juniors and seniors) over screening of younger students.

Sexual transmission and reinfection of group B streptococci between spouses.

OBJECTIVE: To study how GBS infection takes place between pregnant GBS-carriers and their husbands. METHODS: Pregnant women in whom GBS infections could be detected during 26 to 30 weeks of pregnancy and their husbands were studied during the two periods of August 1994 through May 1995 (Period A, 243 couples) and June through September 1997 (Period B, 141 couples). A urine sample was collected from a husband in the same morning when the vagina of his wife was tested for GBS. GBS were also classified according to their serotypes in 34 couples during Period A and B. RESULTS: In the two periods, GBS was detected in 18.1 and 19.3% of the wive's vaginal cultures, and in 19.1 and 17.0% of husbands' urinary cultures, respectively. There were no significant differences of the rate of GBS detection between the spouses, and also between the two trials. A high possibility of GBS infection was found in a couple when either of the spouses was possible to GBS. The serotypes of 31 of the 34 couples (91.2%) were identical. CONCLUSION: It is suggested that GBS can be sexually transmitted, and cause reinfection between spouses in spite of antepartum medication.

Use of ligase chain reaction and polymerase chain reaction on urine specimens to detect Chlamydia trachomatis infections in a sexually transmitted diseases clinic in Singapore.

This study was done to assess the specificity and sensitivity of the DNA amplification assays of ligase chain reaction (LCR) and polymerase chain reaction (PCR) on urine specimens to detect Chlamydia trachomatis infections in both male and female patients seen at a sexually transmitted diseases (STD) clinic in Singapore, compared with other diagnostic methods currently in use. A total of 100 patients were selected; 50 male patients diagnosed with non-gonococcal urethritis based on symptoms and a positive Gram-stained urethral smear and 50 female asymptomatic sex workers were assessed. Automated assays using LCR and PCR were used, and compared to enzyme immunoassays, chlamydial cell cultures and PCR of urethral and endocervical swab specimens. In male patients, LCR and PCR of urine specimens had sensitivities of 100%, compared to 87.0% for PCR of urethral swab specimen, 82.6% for enzyme immunoassay (EIA) and 91.3% for cell cultures. In female patients, LCR and PCR of urine samples achieved sensitivities of 77.8% and 88.9% respectively, compared with 55.6% for PCR of endocervical swab specimens, 22.2% for EIA and 66.7% for cell cultures. LCR and PCR of urine samples provided higher sensitivity compared to cell cultures, EIA and PCR of urethral and endocervical swab specimens. The use of LCR and PCR on urine as a non-invasive means of detecting chlamydial infections is viable, and may have a role to play in population-based screening programmes.

False-negative results of a ligase chain reaction assay to detect Chlamydia trachomatis due to inhibitors in urine.

The aim of this study was to assess the presence of inhibitors in urine specimens causing false-negative results in a commercial Chlamydia trachomatis gap-filling ligase chain reaction (Gap-LCR) assay. On testing of urine samples by the Gap-LCR assay and urethral swab specimens by cell culture, 73 (19%) Chlamydia trachomatis positive subjects were detected among 382 men attending a clinic for sexually transmitted diseases. In 56 subjects, the agent was detected in both the urine and the urethral samples, while 309 subjects were negative in both tests. In seven subjects urine samples were Gap-LCR positive (confirmed by a different Gap-LCR assay), but the corresponding urethral swab samples were cell culture-negative. In another ten subjects the urethral swab samples were cell culture positive, but their urine samples were Gap-LCR negative. Subsequent re-analysis of the urine samples including the addition of external Chlamydia trachomatis DNA indicated full or partial inhibition in nine of the cell culture-positive Gap-LCR negative subjects. When urine preparations were freeze-thawed and diluted prior to testing, Chlamydia trachomatis was detected in six of the ten initially Gap-LCR-negative samples. Gap-LCR inhibitors were present in at least nine (12%) of the 73 urine preparations from the Chlamydia trachomatis positive individuals. Identification of samples containing Gap-LCR inhibitors and subsequent processing to reduce the inhibition increased the sensitivity of the test from 86% to 95%.

Evaluation of three immunoassays for detection of Chlamydia trachomatis in urine specimens from asymptomatic males.

The performances of three commercially available immunoassays (Chlamydiazyme/Antibody Blocking Assay [Abbott Diagnostics, Abbott Park, Ill.], IDEIA [Analytab Products, Plainview, N.Y.], and Microtrak EIA [Syva Co. Palo Alto, Calif.]) were evaluated for the detection of Chlamydia trachomatis in urine specimens from asymptomatic males. Assay results were compared with direct specimen immunofluorescence (DFA) analysis of urine sediment (Syva Microtrak; Syva Co.), which was chosen as the study confirmation assay. An overall Chlamydia prevalence of 7% (24 of 340) was found in our study population, with peak incidences occurring in the adolescent (8 of 93 specimens) and young adult (11 of 146 specimens) age groups. Sensitivity and specificity data among the Chlamydiazyme, IDEIA, and Microtrak enzyme immunoassays (EIAs) were determined to be 79.1 and 99%, 91.7 and 98%, and 95.8 and 99%, respectively. The Microtrak EIA and IDEIA products demonstrated sensitivities and specificities equal to or greater than those claimed for urine specimens. The diagnostic accuracies of these assays on asymptomatic subjects, along with the ease of this collection method, suggest a role for these products as screening tools. The sensitivity of the Chlamydiazyme assay was lower than that claimed previously in symptomatic patients, with 5 of 24 positive specimens demonstrating false-negative results. In those cases, centrifugation of the original immunoassay aliquot material and then DFA examination confirmed specimen positivity. Urine immunoassay screening in combination with DFA confirmation (which was chosen because it has antibody epitopic specificity different from that of the primary assay) provides a high degree of diagnostic precision. The use of noninvasive collection methods could result in greater testing compliance among asymptomatic males and, subsequently, could reduce the incidences of both symptomatic and silent chlamydial infections.