Urine Ligase Chain Reaction Research Articles

Expedited Partner Therapy for Adolescents Diagnosed with Chlamydia or Gonorrhea: A Position Paper of the Society for Adolescent Medicine

Expedited Partner Therapy for Adolescents Diagnosed with Chlamydia or Gonorrhea: A Position Paper of the Society for Adolescent Medicine

Spontaneous Resolution of Asymptomatic Chlamydia trachomatis in Pregnancy

We sought to estimate the rate of spontaneous resolution of asymptomatic Chlamydia trachomatis in pregnancy and to evaluate factors associated with its resolution. A cohort of women enrolled in a large multicenter randomized bacterial vaginosis antibiotic trial (metronidazole versus placebo) that, when randomly allocated, had asymptomatic C trachomatis diagnosed by urine ligase chain reaction (from frozen archival specimens) between 16(0/7) and 23(6/7) weeks were included. The urine ligase chain reaction is a highly accurate predictor of genital tract chlamydial infection. A follow-up ligase chain reaction was performed between 24(0/7) and 29(6/7) weeks. A total of 1,953 women were enrolled in the original antibiotic trial; 1,547 (79%) had ligase chain reaction performed both at randomization and follow-up. Women receiving antibiotics effective against Chlamydia between randomization and follow-up or having symptomatic Chlamydia infection were excluded (26 women). Of the 140 women (9%) who were diagnosed as positive via the initial ligase chain reaction assay, 61 (44%) had spontaneous resolution of Chlamydia by the follow-up ligase chain reaction assay. Factors associated with spontaneous resolution included older age (P = .02), more than 5 weeks from randomization to follow-up (P = .02), and a greater number of lifetime sexual partners (P = .02). Using a logistic regression model, maternal age and a greater-than-5-week follow-up interval remained significant; for every 5-year increase in maternal age, the odds of a positive result on the ligase chain reaction test at follow-up decreased by 40% (odds ratio 0.6; 95% confidence interval 0.4-0.9). Race, substance abuse, parity, and treatment with metronidazole were not associated with spontaneous resolution. Gram stain score and vaginal pH at randomization and follow-up also were not associated. The prevalence of asymptomatic C trachomatis in pregnancy was 9%; infection resolved spontaneously in almost half of these women. The association of older age and increasing time interval to spontaneous resolution of Chlamydia is consistent with a host immune-response mechanism.

Scrotal mass with fever and generalized lymphadenopathy in a young man secondary to Chlamydia trachomatis infection

A young man presented with systemic upset and generalised lymphadenopathy. Later, it transpired that he was under investigation for a scrotal mass. Investigations were carried out to ascertain the cause of his symptoms including lymph node biopsy. Because of the presence of a scrotal mass in a sexually active male, a urinary Chlamydia ligase chain reaction (LCR) test was carried out. The result was positive and he was treated with doxycycline for 2 weeks. His symptoms settled and further, the urinary LCR was negative. We propose that Chlamydia trachomatis infection caused his illness and that urine PCR or LCR tests for Chlamydia is a convenient and useful investigation in sexually active males with generalised lymphadenopathy and fever of unknown origin.

Limitations of Screening Tests for the Detection of Chlamydia trachomatis in Asymptomatic Adolescent and Young Adult Women

One hundred sexually active women aged 16 to 25 years who were being seen for a routine gynecologic examination were recruited to participate in this investigation of screening for chlamydial infection in asymptomatic patients. Before clinical examination, the women performed a self-collected screening technique using 2 Dacron swabs, which they inserted approximately 2 inches into their own vagina, swirled, and placed in a transport media for polymerase chain reaction (PCR). They also provided a urine specimen consisting of the first 30 mL of voided urine collected in a sterile container for PCR and ligase chain reaction (LCR). The clinician collected urethral, vaginal, and endocervical swabs, which were cultured and analyzed with PCR, LCR, and nucleic acid amplification tests. Results were available for 139 participants, who had a mean age of 19.1 years and a mean of 10 days since their last sexual encounter. Twenty-two women had a history of chlamydial infection and 8 had a history of other sexually transmitted disease. During clinical examination of these asymptomatic patients, 34% were found to have a vaginal discharge, and 22% had other cervical abnormalities (discharge, mucopus, lesions, friability, inflammation). Chlamydia trachomatis was diagnosed in 30 (22%) women. Among these women, there were 27 (21%) with true C. trachomatis. One hundred twenty-six study subjects had complete results from all 9 clinical tests. Test measures included urethral culture and PCR, self-collected vaginal PCR, clinician-collected vaginal PCR, endocervical culture, PCR, LCR, and urine PCR and LCR. Four patients were positive for all 9 tests, 8 had a single positive test (confirmed by nested PCR testing), and 15 had between 2 and 8 positive results. The characteristics of various tests and different collection sites are shown in Table 1. Both PCR and LCR yielded more positive results than culture. They were also more sensitive than culture, although some LCR had a lower specificity than either of the other tests. The positive and negative predictive values were high for all tests. When 2 tests were combined, urine LCR plus endocervical LCR proved the most sensitive but had a somewhat lower specificity than other combination strategies.

Chlamydia and gonorrhea co-occurrence in a high school population.

Chlamydia and gonorrhea coinfection outside of healthcare facilities is less well known. To determine the co-occurrence of both sexually transmitted diseases (STDs) among high school students participating in a school-based screening and to assess the relevance of dual treatment recommendations in this population. During the 1998 to 1999 school year, 5,877 students attending an urban U.S. school district were screened for chlamydia and gonorrhea using urine ligase chain reaction assays. Overall, 451 students had chlamydia, 117 had gonorrhea, including 50 who had both STDs. The gonorrhea and chlamydia co-infections were 50/451 (11.1%) and 50/117 (42.7%), respectively. STD symptoms were reported by 16.0% of students having both infections, 7.7% of those having gonorrhea only, and 5.0% of students having chlamydia only (P = 0.01). The rates of coinfection in this population exceeded those that justify dual treatment in patient-care settings. Chlamydia and gonorrhea co-occurrence may be highly prevalent among certain populations not attending patient-care settings.

Limitations of screening tests for the detection of Chlamydia trachomatis in asymptomatic adolescent and young adult women

Objective The purpose of this study was to examine the performance of different test types, specimen sources, and collection methods for screening of genital Chlamydia trachomatis infection in young women. Study design Asymptomatic women aged 16 to 25 years collected their own vaginal swabs and a first-voided urine specimen; a clinician collected urethral, vaginal, and endocervical swabs for culture and nucleic acid amplification tests, polymerase chain reaction and ligase chain reaction. A positive culture, 2 positive nucleic acid amplification tests, or 1 positive nucleic acid amplification test confirmed by a separate nested polymerase chain reaction comprised the criterion standard to define a C trachomatis–infected woman. Results The prevalence of C trachomatis was 22% (30/139 women). All 9 test results were available for 126 participants (91%). Sensitivities were comparable for polymerase chain reaction and ligase chain reaction (52%-63%), except for urine polymerase chain reaction (44%), and were lower for culture (22%-37%); specificities were 99% to 100%, except for urine ligase chain reaction (91%). Positive predictive values were >93%, except for urine ligase chain reaction (65%); negative predictive values were 83% to 91%. Combining nucleic acid amplification test results from 2 different specimens improved sensitivities without compromising specificity. Conclusion When C trachomatis infection was defined by multiple tests from different specimen sources, the sensitivity of any 1 test from a single specimen source was lower than generally reported. The limitations of the use of a single test to identify C trachomatis infection should be considered when test type, specimen source, and collection method for screening young women is being determined.

Prevalence and high rate of asymptomatic infection of Chlamydia trachomatis in male college Reserve Officer Training Corps cadets.

Prevalence of Chlamydia trachomatis and risk factors for infection are not well described in male college students enrolled in the Reserved Officer Training Corps (ROTC). The goal was to determine prevalence of C. trachomatis infection, percentage of asymptomatic infections, and risk factors for infection in a population of male college ROTC students. We conducted a prevalence survey of C. trachomatis infection and risk factors using urine ligase chain reaction and questionnaire. Participants were 1443 ROTC male college cadets at Ft. Lewis, Washington, from June to July 2001. Prevalence of C. trachomatis infection was 31 of 1252 (2.48%); 93.6% of the infections were asymptomatic. Black race, exposure to a partner with a prior sexually transmitted disease, and self-reported symptoms were significant risk factors. The prominence of asymptomatic infection in a male population with comparatively low prevalence suggests that risk factor rather than clinically based screening could be beneficial in this population.

Duration of persistence of gonococcal DNA detected by ligase chain reaction in men and women following recommended therapy for uncomplicated gonorrhea.

Neisseria gonorrhoeae infection remains relatively common in the United States, representing a public health challenge. Ligase chain reaction (LCR) is both highly sensitive and specific for the detection of N. gonorrhoeae in urine and patient-obtained vaginal swab specimens. Because of the LCR test's exquisite sensitivity, it may potentially detect DNA from nonviable organisms following effective therapy, leading to false-positive test results and unnecessary additional treatment. The purpose of the present study was to determine the duration that gonococcal DNA is detectable by LCR following therapy for uncomplicated gonococcal infection. One hundred thirty men and women between the ages of 16 and 50 years presenting to a sexually transmitted disease clinic with urogenital gonorrhea were enrolled. After the standard history was taken and a genital examination was done, the patients were asked to submit either a urine specimen (men) or a urine specimen plus a self-obtained vaginal swab specimen (women) for N. gonorrhoeae testing by LCR at the initial visit and each day during the study period. At enrollment, patients were treated with single doses of ofloxacin, cefixime, or ceftriaxone. The median time to a negative urine LCR test result was 1 day for the men (mean, 1.6 +/- 0.14 days) and 2 days for the women (mean, 1.7 +/- 0.19 days). Among the women the clearance time was significantly longer for vaginal specimens (mean, 2.8 +/- 0.30 days) than for urine specimens (mean, 1.7 +/- 0.11 days). Irrespective of patient gender and specimen type, gonococcal DNA can be expected to be absent from urogenital specimens within 2 weeks following successful therapy.

The Prevalence of Asymptomatic Chlamydia trachomatis in Military Dependent Adolescents

Chlamydia trachomatis infection is common among sexually active populations and often asymptomatic. Infection is associated with complications, including pelvic inflammatory disease and infertility. Using a noninvasive urine ligase chain reaction assay, we determined the prevalence of asymptomatic C. trachomatis infection among sexually active military dependent adolescents and young adults attending clinics at military facilities in San Antonio. The overall prevalence rate was 14%, higher than that reported in many high-risk settings, including sexually transmitted disease clinics. Gender-specific rates were 15% for females and 11% for males. Given a clear cost benefit to screening and treating at-risk populations, we conclude that screening of all sexually active military dependents, both male and female, using this noninvasive test should be performed routinely.

The Prevalence of Asymptomatic Chlamydia trachomatis in Military Dependent Adolescents

Chlamydia trachomatis infection is common among sexually active populations and often asymptomatic. Infection is associated with complications, including pelvic inflammatory disease and infertility. Using a noninvasive urine ligase chain reaction assay, we determined the prevalence of asymptomatic C. trachomatis infection among sexually active military dependent adolescents and young adults attending clinics at military facilities in San Antonio. The overall prevalence rate was 14%, higher than that reported in many high-risk settings, including sexually transmitted disease clinics. Gender-specific rates were 15% for females and 11% for males. Given a clear cost benefit to screening and treating at-risk populations, we conclude that screening of all sexually active military dependents, both male and female, using this noninvasive test should be performed routinely.

Mass media as a population-level intervention tool for Chlamydia trachomatis screening: report of a pilot study.

To determine the feasibility and affect of mass media use in a population-level intervention for chlamydia screening promotion. A population-level chlamydia intervention protocol was field tested. The intervention, targeting 15-25-year-old individuals, was designed to: (a) increase awareness of personal risk for chlamydial infection; (b) facilitate dissemination of chlamydia knowledge by use of a telephone hot line; and (c) promote care-seeking behavior (report for a chlamydia screening program). The intervention activities included: (a) mail outreach, (b) a television and radio campaign, (c) a prerecorded Check-It-Out chlamydia hot line, (d) a staffed chlamydia Options information line, and (e) a free confidential urine ligase chain reaction (LCR) test for chlamydia. Mass mailings were scheduled at intervals, starting two-weeks before the beginning of the television advertisement. The 30-second television advertisement was aired on local television stations 130 times in a 6-week period. The outcome measures were quantity and characteristics of incoming calls to the automated hot line and staffed chlamydia information phone line in response to the chlamydia campaign, and response to the urine screening program. Descriptive and bivariate analyses were used to evaluate the outcomes. The hot line was called 642 times during the monitoring period (November 1, 1999 to March 8, 2000), the majority (92%) during the 6 weeks of television advertisement, with an average of 99 calls per week, compared with an average of 9 calls per week after the commercial ended. Each bulk mailing was accompanied by a boost in the incoming hot line calls. The research staff triaged 133 calls to the "Options" phone line, 81% in the 6 weeks of the TV ad. The mean age of the 133 callers was 23.9 +/- 7.7 years (range 14-49 years). A majority called for screening information; 67% of callers were females and 84% of female callers were under age 26 years. Five percent of callers identified themselves as a parent of a teenager. The majority credited the TV ad as their source of the hot line number. Thirty-one individuals reported for a confidential chlamydia screening, 27 of 31 (87%) during the 6 weeks of TV advertising. No negative responses regarding the chlamydia campaign were encountered. This report describes strategies used to implement and measure the effectiveness of a mass media campaign and demonstrates evidence that mass media is effective in delivering STD intervention messages to young people.

Low Prevalence of Chlamydia trachomatis by Urinary Ligase Chain Reaction in Women Patients in the Emergency Department

Recent studies suggest that women with acute urethral syndrome or abdominal pain, presenting to emergency departments (EDs), have a high prevalence of Chlamydia trachomatis. Objectives: To estimate the prevalence of C. trachomatis in women presenting to an ED and to see whether those with dysuria or abdominal pain have a higher prevalence of C. trachomatis. Methods: The authors conducted a prospective cross‐sectional study of C. trachomatis in the urine of women aged 18 to 50 years who had a urinalysis performed at a university/county ED from February through May 1998. Urine specimens were labeled for the presence of symptoms and analyzed for C. trachomatis by ligase chain reaction (LCR). Polymerase chain reaction (PCR) testing of cervical swabs for C. trachomatis was done for usual clinical indications. Difference in proportions of positive LCR tests among patients was tested with Fisher's exact test. Agreement between PCR and LCR was measured using Cohen's kappa statistic. Results: Of 397 women whose urine was tested, 280 had symptoms of dysuria, abdominal pain, or both, and 117 had no symptoms. The overall prevalence of C. trachomatis by LCR was 3.8% (95% CI = 2.1% to 6.2%); and the combined PCR—LCR prevalence was 4.3% (95% CI = 2.5% to 6.8%). The presence of symptoms was not associated with a positive LCR test for C. trachomatis (p = 0.26, power = 0.8, alpha = 0.05, difference 3% vs. 12%). In the 172 patients who had both a PCR cervical swab and urine LCR, agreement was excellent (kappa = 0.67, 95% CI = 0.45 to 0.90). Conclusions: This ED had a surprisingly low prevalence of C. trachomatis. Women with symptoms were not more likely to test positive than those without.

Low prevalence of Chlamydia trachomatis by urinary ligase chain reaction in women patients in the emergency department.

Recent studies suggest that women with acute urethral syndrome or abdominal pain, presenting to emergency departments (EDs), have a high prevalence of Chlamydia trachomatis. To estimate the prevalence of C. trachomatis in women presenting to an ED and to see whether those with dysuria or abdominal pain have a higher prevalence of C. trachomatis. The authors conducted a prospective cross-sectional study of C. trachomatis in the urine of women aged 18 to 50 years who had a urinalysis performed at a university/county ED from February through May 1998. Urine specimens were labeled for the presence of symptoms and analyzed for C. trachomatis by ligase chain reaction (LCR). Polymerase chain reaction (PCR) testing of cervical swabs for C. trachomatis was done for usual clinical indications. Difference in proportions of positive LCR tests among patients was tested with Fisher's exact test. Agreement between PCR and LCR was measured using Cohen's kappa statistic. Of 397 women whose urine was tested, 280 had symptoms of dysuria, abdominal pain, or both, and 117 had no symptoms. The overall prevalence of C. trachomatis by LCR was 3.8% (95% CI = 2.1% to 6.2%); and the combined PCR-LCR prevalence was 4.3% (95% CI = 2.5% to 6.8%). The presence of symptoms was not associated with a positive LCR test for C. trachomatis (p = 0.26, power = 0.8, alpha = 0.05, difference 3% vs. 12%). In the 172 patients who had both a PCR cervical swab and urine LCR, agreement was excellent (kappa = 0.67, 95% CI = 0.45 to 0.90). This ED had a surprisingly low prevalence of C. trachomatis. Women with symptoms were not more likely to test positive than those without.

Screening women in jails for chlamydial and gonococcal infection using urine tests: feasibility, acceptability, prevalence, and treatment rates.

Women entering jails are at high risk for sexually transmitted diseases; however, screening for chlamydial and gonococcal infection is not routinely performed in most jails. New urine tests have made it easier to screen for these infections in nonclinical settings. The feasibility and acceptability of urine-based screening for women entering jails and the prevalence of and treatment rates for chlamydial and gonococcal infections were determined. Women entering jails in Chicago, Illinois; Birmingham, Alabama; and Baltimore, Maryland, who signed consent forms were tested for chlamydial and gonococcal infection by means of the urine ligase chain reaction assay. Those testing positive were treated in jail; health department staff members attempted to contact those already released. Most women who were approached agreed to be tested (range, 87-98%, depending on city), and most of these women provided a specimen (range, 92-100%). Among 5364 women aged 16 to 75 years who were tested, the prevalence of chlamydial and gonococcal infections was high, especially among those <25 years of age (range, 15.3-21.5% for chlamydial infection and 8.2-9.2% for gonorrhea, depending on city). The majority of women testing positive were treated in jail or outside of jail (61-85%). Screening women in jails for chlamydial and gonococcal infection with urine tests is feasible, is acceptable to most women, and leads to detection and treatment of many infections. Routine screening should reduce medical complications in this population and should prevent transmission in the community, given that many women are soon released.

Cost-effectiveness of five strategies for gonorrhea and chlamydia control among female and male emergency department patients.

Previous studies have shown screening for gonorrhea and chlamydia to be cost-effective for limiting the sequelae of infection and the associated costs of management. To evaluate the cost-effectiveness of enhanced screening for gonorrhea and chlamydia in an emergency department (ED) setting. Five strategies were compared with use of decision analysis for theoretical cohorts of 10,000 female and 10,000 male ED patients aged 18 years to 31 years: standard ED practice, three enhanced screening strategies, and mass treatment. Main outcome measures were untreated gonorrhea or chlamydia cases and their sequelae, transmission to a partner, congenital outcomes, and cost to prevent a case. This analysis, from the perspective of the healthcare sector, included medical case costs expressed in US dollars (1999), discounted at an annual rate of 3%. Mass treatment was the most cost-effective strategy among women and men. Of the screening strategies for women, universal screening combined with standard practice was the most cost-effective; it was used for treating 499 more cases of gonorrhea and chlamydia than was standard practice, saving $95.70 per case treated. Standard ED practice remained the most cost-effective strategy for men under a variety of circumstances. The authors recommend urine ligase chain reaction screening for gonorrhea and chlamydia in women aged 18 years to 31 years in the ED, in conjunction with standard ED practice, to decrease the occurrence of the sequelae and costs associated with infection.

Features of Chlamydia trachomatis and Neisseria gonorrhoeae infection in male Army recruits.

Non-health care-seeking male United States Army recruits were tested for Chlamydia trachomatis (n=2245) and Neisseria gonorrhoeae (n=884), using a urine ligase chain reaction test to determine prevalence and potential risk factors for infection. The prevalence of chlamydial infection was 5.3%. Black race, a new sex partner, a history of trichomonas, and the presence of symptoms were associated with chlamydial infection. The prevalence of N. gonorrhoeae infection was 0.6%. Only a reported history of or positive test for C. trachomatis was associated with gonorrheal infection. Of those testing positive for chlamydia, 14% reported symptoms versus 40% of those with gonorrhea. Younger age was not a predictor of either infection, as has been shown for women. A substantial number of male army recruits are infected with C. trachomatis, but few are infected with N. gonorrhoeae. Screening on the basis of symptoms alone would miss the majority of both infections.

Correlation between urine and cervical specimens for the detection of cervical Chlamydia trachomatis and Neisseria gonorrhoeae using ligase chain reaction in a cohort of HIV infected and uninfected adolescents.

(a) To examine the concordance between ligase chain reaction (LCR) results from urine and cervical samples for Chlamydia trachomatis and Neisseria gonorrhoeae in HIV infected and uninfected adolescent women, and (b) to examine factors that may influence the concordance of LCR results in this population. Baseline specimens from 269 of 334 female subjects enrolled in a longitudinal study of HIV infection in adolescents were analyzed for C. trachomatis and N. gonorrhoeae using ligase chain reaction (LCR) assays in a central laboratory. Concordance was measured using kappa coefficient with permutation analyses to calculate the difference between HIV status groups. Discordant LCR results were examined for the co-infection with the other microorganism, bacterial vaginosis, or Trichomonas vaginalis. The prevalence of C. trachomatis detected by LCR in the HIV infected and uninfected groups was 19.3% and 12.2%, respectively (p = .16); the prevalence of N. gonorrhoeae was 7.0% and 2.4%, respectively (p = .16). Urine LCR assay sensitivity to detect cervical C. trachomatis infection was 86% (95% CI: 68%-96%) in the HIV infected group and 100% (95% CI: 69%-100%) in the HIV uninfected group. Urine LCR assay sensitivity to detect cervical N. gonorrhoeae infection was 92% (95% CI: 62%-100%) in the HIV infected group. There were only 2 N. gonorrhoeae infections in the HIV uninfected group, and both were urine LCR positive. Differences in sensitivity between HIV infected and HIV uninfected subjects were not statistically significant. Coinfection with N. gonorrhoeae, bacterial vaginosis or Trichomonas vaginalis was not associated with the concordance of urine and cervical LCR results. The relatively high sensitivity of urine LCR testing overall suggests that urine screening may be reasonable for sexually active adolescent females with or without HIV infection in situations in which urine screening may be more acceptable than pelvic examinations.

Screening females in juvenile detention for chlamydial cervicitis: A cost-minimization analysis

PURPOSE: To compare the costs of different strategies of testing and treating chlamydia cervicitis in adolescent females in the juvenile justice system.METHODS: Using a decision analytic model, we compared 5 strategies: 1) do nothing; 2) treat everyone with a single 1 gm dose of azithromycin; 3) screen for current symptoms or history of a sexually transmitted disease (SH) and treat those who have a positive screen; 4) screen with urine ligase chain reaction (LCR) and treat those who have a positive test; 5) screen with cervical LCR and treat those who have a positive test. Chlamydia prevalence and SH screen test characteristics were determined from a cohort study conducted at a juvenile detention center. Treatment and testing costs were taken from the cost accounting system at an urban teaching facility. LCR test characteristics, treatment efficacy, and complication (pelvic inflammatory disease, infertility, chronic pelvic pain, and ectopic pregnancy) rates and costs were derived from the literature. Future costs were discounted at a 3% annual rate in the base case.RESULTS: In this cohort (241 females, 59.8% African American, 40% Caucasian, mean age 14.8 years) with a prevalence of chlamydia of 16.8%, empiric treatment (Strategy 2) was the least expensive strategy, but screening with urine LCR (Strategy 4) was only minimally more expensive (see table). Although changes in a number of variables affected the total costs, only changes in chlamydia prevalence and the pelvic inflammatory disease rate would render strategies other than 2 or 4 to be preferred. For example, if the prevalence of chlamydia were between 0 and 3.5%, then doing nothing (Strategy 1) would be the least expensive strategy; between 3.5% and 5.6%, SH (Strategy 3) would be least expensive; between 5.6% and 16.4%, urine LCR (Strategy 4) would be least expensive; and if the prevalence of chlamydia were greater than 16.4%, then empiric therapy (Strategy 2) would be least expensive.CONCLUSION: In a detained adolescent female population, empiric treatment for chlamydia cervicitis or treatment based on urine LCR results are nearly equivalent in cost and are less costly than other strategies.

Opportunistic Urine Ligase Chain Reaction Screening for Sexually Transmitted Diseases in Adolescents Seeking Care in an Urban Emergency Department

Opportunistic Urine Ligase Chain Reaction Screening for Sexually Transmitted Diseases in Adolescents Seeking Care in an Urban Emergency Department

Unsuspected gonorrhea and chlamydia in patients of an urban adult emergency department: a critical population for STD control intervention.

Urban emergency departments (EDs) providing services to patients at high risk for sexually transmitted infection may be logical sites for intervention. To determine the prevalence of gonorrhea (GC) and chlamydia (CT) in an adult ED patient population, and to assess risk factors for infection. Cross-sectional study of patients aged 18 to 44 in an urban ED, seeking care of any medical nature. Main outcome was positive for GC or CT by urine ligase chain reaction assay. Test results for GC and/or CT were positive in 13.6% of 434 18 to 31 year-olds and in 1.8% of 221 32 to 44 year-olds. Of 63 infected individuals identified by the study, 15 (23.8%) were treated at the ED visit. Age < or =31 detected 88% of infections. Among 18- to 31-year-old patients, predictive risk factors by multivariate analysis included age <25, >1 sex partner in the past 90 days, and a history of sexually transmitted disease. This study identified a high prevalence of GC and CT in patients seeking ED services. Many of these infections were clinically unsuspected. These data demonstrate that the ED is a high-risk setting and may be an appropriate site for routine GC and CT screening in 18- to 31-year-old patients.