Community-based urine screening for Chlamydia trachomatis with a ligase chain reaction assay

Ligation-Based High-Performance Mimetic Enzyme Sensing Platform for Nucleic Acid Detection

G-quadruplex (G4)/hemin DNAzyme is a promising candidate to substitute horseradish peroxidase in biosensing systems, especially for the detection of nucleic acids. However, the relatively suboptimal catalytic capacity limits its potential applications. This makes it imperative to develop an ideal signal for the construction of highly sensitive biosensing platforms. Herein, we integrated a novel chimeric peptide-DNAzyme (CPDzyme) with the ligase chain reaction (LCR) for the cost-efficient and highly sensitive detection of nucleic acids. By employing microRNA (miRNA) and single-nucleotide polymorphism detection as the model, we designed a G4-forming sequence on the LCR probe with a terminally labeled amino group. Subsequently, asymmetric hemin with carboxylic arms allowed assembly with the LCR products and peptide to form CPDzyme, followed by the magnetic separation of the extraneous components and chemiluminescence detection. Compared with the conventional G4/hemin signaling-based method, the LCR-CPDzyme system demonstrated 3 orders of magnitude improved sensitivity, with accurate quantification of as low as 25 aM miRNA and differentiation of 0.1% of mutant DNA from the pool containing a large amount of wild-type DNA. The proposed LCR-CPDzyme strategy is a potentially powerful method for in vitro diagnostics and serves as a reference for the development of other ligation- or hybridization-based nucleic acid amplification assays.

Sexually Transmitted Diseases and Managed Care: An Inquiry and Review of Issues Affecting Service Delivery

To understand the potential role of managed care organizations (MCOs) in prevention and control of sexually transmitted diseases (STDs), we conducted a systematic review of articles on STDs and managed care and sought qualitative information from MCOs on STD-related activities. The review focused on prevention, risk assessment, patient education, counseling, screening, and costs of care, but revealed relatively few published articles. Barriers to STD service delivery included competing priorities, lack of time or supporting organizational structures, and differing mandates of health departments and MCOs. Facilitators included collaboration between health departments and MCOs, regulatory and performance incentives, buy-in from key stakeholders, availability of infrastructure to support data collection, and inclusion of chlamydia screening in the Health Employer Data and Information Set to monitor plan performance. Because of the shift of STD service delivery from the public to private sector, incentives need to maximize interest and cooperation of patients, clinicians, and MCOs in STD prevention.

Using urinary leucocyte esterase tests as an indicator of infection with gonorrhoea or chlamydia in asymptomatic males in a primary health care setting

To evaluate a leucocyte esterase test as a predictor of gonorrhoea or chlamydia in asymptomatic Aboriginal males at the Central Australian Aboriginal Congress Male Clinic (Ingkintja), first-void urine samples and clinical information were collected from consecutive asymptomatic males presenting to the Ingkintja in Alice Springs between March 2008 and December 2009. Urine was tested immediately with a leucocyte esterase test dipstick and then by polymerase chain reaction for gonorrhoea and chlamydia. Among the 292 specimens from asymptomatic males, 15.4% were positive for gonorrhoea or chlamydia. In this group, compared with polymerase chain reaction result for gonorrhoea or chlamydia, leucocyte esterase test alone and in combination with age ≤35 years showed sensitivities of 66.7% and 60%, specificities of 90.7% and 94.7%, positive predictive values of 56.6% and 67.5%, negative predictive values of 93.7% and 92.8% and the area under receiver operating characteristics curve values of 0.79 and 0.85, respectively. Leucocyte esterase tests can reasonably be used as a basis for immediate empirical treatment for gonorrhoea or chlamydia in asymptomatic central Australian Aboriginal men under 35 years of age.

Nucleic acid amplification testing in suspected child sexual abuse

The American Academy of Pediatrics recommends that site-specific cultures be obtained, when indicated, for sexually victimized children. Nucleic acid amplification testing is a highly sensitive and specific methodology for identifying sexually transmitted infections. Nucleic acid amplification tests are also less invasive than culture, and this may provide an efficacious alternative for children suspected of being sexually abused.

Relative efficiency of chlamydia screening in non-clinical settings in two California counties

We examined the relative efficiency of non-clinical sites to screen for chlamydia in youth and young adults. Chlamydia screening targeting youth (under 30 years of age) was performed at non-clinical sites in high-morbidity neighbourhoods of two California counties. Venues were subdivided into community outreach, schools, parenting centres and drug treatment/correctional facilities. Relative efficiency was estimated with multivariate Poisson regression using incidence of chlamydia per person-hours labour adjusting for strategy and county. Among the 1514 youths screened, the overall prevalence of chlamydia was 5.5%. By venue, the highest prevalence was in drug treatment/correction facilities at 11.1% followed by parenting centres at 6.3%, community outreach at 4.9% and schools at 4.6%. Drug treatment/correctional facilities were the most labour time efficient at 9.9 person-hours per chlamydia case. Schools and parenting centres had the lowest cost per screen at 0.9 person-hours per screen. Adjusted relative labour time efficiency (chlamydia cases per paid person-hour) was significantly higher in schools, 2.0 (95% confidence interval [CI] 1.0-4.2), parenting centres, 3.2 (95% CI 1.6-6.6) and drug treatment/correctional facilities, 2.9 (95% CI 1.0-7.8), compared with community outreach. In conclusion, parenting centres and drug treatment centres and correctional facilities are the most efficient venues for chlamydia screening.

Economic burden of sexually transmitted infections: incidence and direct medical cost of Chlamydia, gonorrhea, and syphilis among Illinois adolescents and young adults, 2005-2006

BACKGROUND

Local assessment of sexually transmitted infections (STI) magnitude and economic burden can aid in targeting resources and prevention programs.

METHODS

Reported cases of Chlamydia, gonorrhea, and primary and secondary syphilis (obtained from the Illinois Department of Public Health) were used to estimate the number of incident cases among persons aged 15 to 24 years, accounting for the proportion of undiagnosed and unreported cases, and sexually active population. STI costs were obtained from the published literature, and multiplied by the estimated incident cases of STIs in 2005 and 2006 to determine direct medical costs of incident infections. Incident rates per 100,000 population and costs in 2007 US dollars are estimated by age, gender, race, and county.

RESULTS

Chlamydia incidence and cost were estimated at 5030 infections per 100,000 population and $27,576,686 in 2005, and 5259 infections per 100,000 population and $28,779,734 in 2006. Gonorrhea incidence and cost were estimated at 1740 infections per 100,000 population and $7,698,135 in 2005, and 1704 infections per 100,000 population and $7,546,500 in 2006. Syphilis incidence and cost were estimated at 9.4 per 100,000 and $59,940 in 2005, and 10.4 per 100,000 population and $66,333 in 2006. Incidence and costs of all STIs were highest among women and blacks. Ten counties accounted for >80% of the estimated statewide morbidity and costs.

CONCLUSIONS

Estimates of STI incidence and costs are conservative, yet represent a significant economic burden in Illinois. Focusing prevention efforts on locales with the highest STI rates may maximize effectiveness in terms of disease prevention and cost reduction.

Chlamydia trachomatis positivity rates among men tested in selected venues in the United States: a review of the recent literature

The cost-effectiveness of screening men for Chlamydia trachomatis depends in part on the prevalence of chlamydia in the screened population and the ease with which screening programs can be implemented. Screening in venues with high rates of chlamydia positivity among men may therefore be an important adjunct to chlamydia control. To evaluate the recent US literature on chlamydia positivity in chlamydia screening programs among asymptomatic men in nonsexually transmitted disease clinic settings, we reviewed published articles between 1995 and June 2007, using PubMed as the primary search tool. Articles were abstracted and positivity rates summarized by type of venue, race/ethnicity, age group, and US region. The overall median positivity rate was 5.1%. The highest rates were observed among men tested in juvenile (7.9%) and adult (6.8%) detention facilities, among blacks (6.7%), the 15 to 19 years old (6.1%) and 20 to 24 years old (6.5%) age groups, and among men screened in the southern United States (6.4%). Chlamydia rates among men are high in certain venues, particularly correctional settings, but also depend on the demographic composition of the target population and location. Programs considering male chlamydia screening programs should conduct pilot programs to assess chlamydia positivity as well as feasibility and cost in target venues.

Lensless high-resolution on-chip optofluidic microscopes for Caenorhabditis elegans and cell imaging

Low-cost and high-resolution on-chip microscopes are vital for reducing cost and improving efficiency for modern biomedicine and bioscience. Despite the needs, the conventional microscope design has proven difficult to miniaturize. Here, we report the implementation and application of two high-resolution (approximately 0.9 microm for the first and approximately 0.8 microm for the second), lensless, and fully on-chip microscopes based on the optofluidic microscopy (OFM) method. These systems abandon the conventional microscope design, which requires expensive lenses and large space to magnify images, and instead utilizes microfluidic flow to deliver specimens across array(s) of micrometer-size apertures defined on a metal-coated CMOS sensor to generate direct projection images. The first system utilizes a gravity-driven microfluidic flow for sample scanning and is suited for imaging elongate objects, such as Caenorhabditis elegans; and the second system employs an electrokinetic drive for flow control and is suited for imaging cells and other spherical/ellipsoidal objects. As a demonstration of the OFM for bioscience research, we show that the prototypes can be used to perform automated phenotype characterization of different Caenorhabditis elegans mutant strains, and to image spores and single cellular entities. The optofluidic microscope design, readily fabricable with existing semiconductor and microfluidic technologies, offers low-cost and highly compact imaging solutions. More functionalities, such as on-chip phase and fluorescence imaging, can also be readily adapted into OFM systems. We anticipate that the OFM can significantly address a range of biomedical and bioscience needs, and engender new microscope applications.

Should asymptomatic men be included in chlamydia screening programs? Cost-effectiveness of chlamydia screening among male and female entrants to a national job training program

OBJECTIVE

To compare the cost-effectiveness of various chlamydia screening strategies within a population of male and female youth entering a national job training program.

STUDY DESIGN

Cost-effectiveness analysis of various chlamydia screening strategies among a cohort of 4000 female and male New England job training students. Strategies for women include (a) no screening, (b) universal endocervical DNA probe screening, (c) universal urine based NAAT screening, and (d) universal endocervical NAAT screening. Strategies for men include (a) no screening, (b) selective urine NAAT screening of leukocyte esterase (LE)-positive urines, and (c) universal urine-based NAAT screening.

RESULTS

Universal endocervical NAAT screening of women and universal urine NAAT screening of men were the most effective and cost-effective strategies individually and in combination. Endocervical NAAT screening of women prevented 23 more cases of PID and saved $27,000 more than endocervical DNA probe screening. Likewise, universal urine NAAT screening of men prevented 21 more cases of PID in their female partners and saved $16,000 more than selective urine NAAT screening of LE positive men.

CONCLUSIONS

Use of a sensitive NAAT to screen both men and women for chlamydia upon entry to a National Job Training Program is cost-effective, cost-saving, and provides a public health opportunity to substantially reduce chlamydia infections among youth at risk for sexually transmitted diseases.

A new automated method for isolation of Chlamydia trachomatis from urine eliminates inhibition and increases robustness for NAAT systems

Chlamydia trachomatis is a leading cause of sexually transmitted infection. Diagnostic methods with easy non-invasive sample collection are important to increase testing and hence to reduce the spread of this infection. To enable more use of urine samples in C. trachomatis diagnostics, automation is an absolute requirement since obtaining high-quality DNA from urine specimens involves extensive processing. Here, we present a study in which a new automated sample preparation method, BUGS'n BEADS STI (BnB STI), was used up-front of the BDProbeTec ET end point analysis and compared with the full BDProbeTec ET method to analyze C. trachomatis in 1002 urine samples. The BnB STI system represents a new concept within magnetic sample preparation in which bacteria are first isolated from the sample material followed by purification of bacterial nucleic acid using the same magnetic particles. Similar sensitivity and specificity were obtained with both methods. None of the samples processed with BnB STI inhibited the BDProbeTec ET test whereas 1.8% showed inhibition when processed according to the manual BDProbeTect ET DNA preparation method. Moreover, the average MOTA scores obtained with the BnB STI system were 48% higher for all amplification controls and 57% higher for positive samples, compared to the manual sample preparation. Based on these results and the significant reduction in hands-on-time for urine sample processing, the automated BnB STI sample preparation method was implemented for routine analysis of C. trachomatis from urine samples.

Genital chlamydial infection among male attendees at a sexually transmitted disease clinic in urban Taiwan

OBJECTIVE

The aim of this study was to examine the epidemiology of genital Chlamydia trachomatis infection among male patients attending a sexually transmitted disease (STD) clinic in urban Taiwan.

METHODS

From July 2003 to June 2004, all male attendees at an STD clinic were invited to participate in this study. Attendees provided a first-void urine sample for examination for C. trachomatis using polymerase chain reaction (PCR) assay.

RESULTS

A total of 390 patients provided first-void urine specimens for testing for C. trachomatis. The overall prevalence of C. trachomatis was 17.7% (95% CI 16.3-19.1%). The age-specific prevalence was higher among patients aged under 20 years and lowest among those aged over 30 years. Approximately 40% of the infections were asymptomatic or subclinical. Younger age (aged <or= 30 years; adjusted odds ratio (AOR)=2.37, 95% confidence interval (CI)=1.31-4.34), inconsistent use of condoms (AOR=2.10, 95% CI=1.21-3.54), and being symptomatic at the time of testing (dysuria, urethral discharge, painful urination, urethral irritation/itching; AOR=2.05, 95% CI=1.16-3.40) were shown to be risk factors for C. trachomatis infection.

CONCLUSIONS

The prevalence of untreated asymptomatic chlamydial infection is high in young adults in Taipei. Young Taiwanese men attending STD clinics should be screened routinely for chlamydial infection.

Chlamydial infection among patients attending STD and genitourinary clinics in Taiwan

Background

The main objective of this study is to examine the epidemiology of Chlamydia trachomatis (CT) infection amongst patients (473 men, 180 women) seen two hospitals in Taiwan.

Methods

Between July 2004 and June 2005, a total of 653 patients provided first-void urine samples for examination of CT using PCR assay.

Results

The overall prevalence of CT infection was 18.4% (95% confidence interval [CI] 17.3–19.5). Prevalence for men and women were 16.7 % (95% CI 15.3–18.0%) and 22.8% (95% CI 17.5–28.1%), respectively. Age group-specific prevalence was 25.7% (95% CI 22.5–28.9%) in < 20 year olds, 23.5% (95% CI 20.3–26.7%) in 20–24 year olds, 22.3% (95% CI 18.9–25.7%) in 25–30 year olds, and 11.5% (95% CI 10.3–12.7%) in > 30 year olds. Independent risk factors for chlamydial infection included younger age (aged ≤ 30 years) (adjusted odds ratio [AOR] = 2.44; 95% CI 1.52–3.84; p < 0.001), inconsistent condom use (AOR = 2.01; 95% CI 1.32–3.06; p < 0.001), being symptomatic (dysuria, urethral discharge) at the time of testing (AOR = 1.84; 95% CI 1.21–2.80; p < 0.001), and having N. gonorrhoeae infection (AOR = 3.82; 95% CI 2.20–6.58; p < 0.001).

Conclusion

Genital chlamydial infection is an important sexually transmitted disease in Taiwan. Young Taiwanese persons attending a STD clinic should be screened for CT infection and counselled on condom use.

A randomized trial of strategies to increase chlamydia screening in young women

OBJECTIVE

Despite the recommendations of numerous clinical practice guidelines, testing of at-risk women for Chlamydia trachomatis infection remains low. We evaluated an intervention to increase guideline-recommended chlamydia screening.

METHOD

In a two-by-two factorial design randomized trial conducted in 2001-2002, 23 primary care clinics at Group Health Cooperative in Washington State were randomized to either control (standard) or intervention (enhanced) guideline implementation arms. Clinic-level intervention strategies included use of clinic-based opinion leaders, individual measurement and feedback, and exam room reminders. A second patient-level intervention, a chart prompt to screen for chlamydia, was delivered in a random sample of 3509 women. The outcome measure was post-intervention chlamydia testing rates among sexually active women ages 14-25.

RESULTS

The clinic-level intervention did not significantly affect overall chlamydia testing (odds ratio (OR) = 1.08, 95% confidence interval (CI) 0.92-1.26, P = 0.31). However, testing rates increased significantly among women making preventive care visits (OR, Pap test visit = 1.23, 95% CI, 1.01-1.51, P = 0.04; OR, physical exam visit = 1.22, 95% CI 1.06-1.42, P = 0.009, intervention vs. control clinics). The chart prompt intervention had no significant effect (OR = 1.08, 95% CI 0.94-1.23, P = 0.27).

CONCLUSIONS

Interventions to improve guideline-recommended chlamydia testing increased testing among women making preventive care visits. Additional organizational change and/or patient activation strategies may improve plan-wide testing, particularly among asymptomatic women.

School-Based Screening for Chlamydia Trachomatis and Neisseria Gonorrhoeae Among Philadelphia Public High School Students

CONTEXT

The prevalence of sexually transmitted diseases among adolescents is high. Innovative screening and treatment programs need evaluation.

OBJECTIVES

The objectives of this study were to identify, treat, and describe the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infections among Philadelphia public high school students.

DESIGN

We analyzed cross-sectional data from the first year of an annual program offering education, screening, and treatment for CT and GC. For the school year analyzed, screening took place between January 2003 and June 2003.

RESULTS

In the first year, 19,394 students aged 12-20 years were voluntarily tested; 1,052 students were identified with GC, CT, or both; 1,051 received treatment. Prevalence of CT among females (95% confidence interval [CI] = 8.1) was 3.3 times higher than among males (95% CI = 2.5%). Attending disciplinary schools and residing in high reported morbidity areas were also related to higher prevalence of CT and GC.

CONCLUSIONS

A high prevalence of CT infections was identified among Philadelphia public high school students. This program demonstrated the effectiveness of a school-based screening program to identify and treat these infections.

Studying adolescence

Young people in their teens constitute the largest age group in the world, in a special stage recognized across the globe as the link in the life cycle between childhood and adulthood. Longitudinal studies in both developed and developing countries and better measurements of adolescent behavior are producing new insights. The physical and psychosocial changes that occur during puberty make manifest generational and early-childhood risks to development, in the form of individual differences in aspects such as growth, educational attainment, self-esteem, peer influences, and closeness to family. They also anticipate threats to adult health and well-being. Multidisciplinary approaches, especially links between the biological and the social sciences, as well as studies of socioeconomic and cultural diversity and determinants of positive outcomes, are needed to advance knowledge about this stage of development.

[Screening of sexually transmitted diseases in clinical and non-clinical settings in Salvador, Bahia, Brazil]

The objectives were to study: (1) acceptance of STD screening in non-clinical settings for asymptomatic individuals; (2) risk factors and STD prevalence among individuals in non-clinical and clinical settings; and (3) non-clinical screening of asymptomatic populations as a feasible method for STD control. We recruited 139 males and 486 females between 18 and 30 years of age from a family planning clinic, schools, and community centers in low-income neighborhoods. We asked about STD symptoms and STD/HIV risk behaviors and tested the individuals for gonorrhea, Chlamydia, syphilis, and HIV. Except for HIV, women recruited directly from the community had higher STD rates than those who came in for care at the clinic. Screening in non-clinical settings in Brazil is feasible and has a high yield among young adults in low-income communities. Infected participants would likely never have otherwise sought care or been tested or treated. STD control efforts could be implemented in any site that can reach populations at risk and become a routine procedure in health care settings where people report for problems unrelated to STDs.

Chlamydia trachomatis infection in Sydney women

BACKGROUND

In Australia, reported rates of Chlamydia trachomatis infection have been rising progressively since the mid-1990s. Opportunistic testing of sexually active young women attending clinical services for other reasons has already been implemented in a number of other countries.

AIMS

To help guide chlamydia testing of women, this study aimed to establish factors predictive of chlamydial infection in an Australian clinical setting.

METHODS

Women attending a sexual health service in Sydney who tested positive for C. trachomatis by polymerase chain reaction and who did not have any concurrent urogenital infections (n = 170) were compared with chlamydia-negative controls (n = 170). Factors independently associated with chlamydia were determined using logistic regression.

RESULTS

Although they were present in only a minority of infected women, symptoms of dysuria [adjusted odds ratio (AOR) = 3.2 (95% CI: 1.2-9.1), P = 0.03] and postcoital bleeding [AOR = 2.7 (95% CI: 1.0-7.1), P < 0.05] were each independently associated with chlamydia. Symptoms of vaginal discharge (P = 0.3), abdominal pain (P = 0.2), or intermenstrual bleeding (P = 0.1) did not help to discriminate between infected and uninfected women. The following factors were independently associated with chlamydia: younger age (P = 0.003); being overseas-born [AOR = 2.3 (95% CI: 1.3-4.0), P = 0.005]; sex with a partner from overseas [AOR = 2.0 (95% CI: 1.3-12.3), P = 0.01]; and sex with a partner known or suspected to be chlamydia-infected [AOR = 7.4 (95% CI: 3.6-15.0), P < 0.001].

CONCLUSIONS

Chlamydia testing is clinically indicated in sexually active young women with dysuria, postcoital bleeding or contact with a suspected chlamydia-infected partner. Consideration should be given to enhanced screening programs for travelling and migrant men and women in Australian cities.

Chlamydia trachomatis infection in the family planning clinical setting across New South Wales

Background: Following a small pilot study in 2003, a study was set up to determine the prevalence of genital Chlamydia trachomatis infection in young women presenting to Family Planning NSW centres across New South Wales and to evaluate the characteristics of those infected. Methods: A cross-sectional survey of 621 consecutive women aged from 16 to 24 years was carried out over a 3-month period in 2004 at five Family Planning NSW centres. Urine samples were tested for C. trachomatis using the polymerase chain reaction (PCR) method. Women with a positive result were reviewed and treated. Results: Of 925 eligible clients, 621 (67%) were recruited to the study. Chlamydia trachomatis was detected in 35 of the 621 recruits (5.6%, 95% CI 3.8–7.4). The prevalence at the Hunter centre was significantly higher than the combined prevalence at the other four participating centres (9.7% compared with 3.9%; P = 0.008). Two characteristics were identified as independent predictors of infection in this study: ‘reporting a recent change of partner in the past three months’ (crude odds ratio (OR) 3.33, 95% CI 1.67–6.64) and ‘reporting three or more partners in the past year’ (crude OR 3.69, 95% CI 1.83–7.46). Reported condom use, a history of one or more sexually transmissible infections and current combined oral contraceptive pill use were not associated with infection in this study. Conclusions: The prevalence of C. trachomatis infection is sufficiently high to support targeted testing of 16–24-year-old women in the Family Planning NSW setting and informs the development of a national screening strategy.

Modelling the impact of opportunistic screening on the sequelae and public healthcare costs of infection with Chlamydia trachomatis in Australian women

OBJECTIVES

To describe the health outcomes and public healthcare costs of a single screening for Chlamydia trachomatis in Australian women aged 15-34 years.

METHODS

A decision analytic model was used to determine the epidemiological estimates of prevalence and costs of C. trachomatis infection and its diagnosis, treatment and sequelae.

RESULTS

We estimate that in any female population in Australia, with a Chlamydia prevalence rate of 5.7% or higher, a single screening examination for Chlamydia is cost saving for the public healthcare system.

CONCLUSIONS

We found that opportunistic screening of high-risk populations is likely to be cost saving to the public healthcare system, although there is not sufficient evidence to support periodic population screening. As our model uses conservative epidemiological and public healthcare cost estimates, the health and financial impacts of C. trachomatis used in the model may be an underestimate of the true costs of infection.

Nucleic acid amplification tests for gonorrhea and chlamydia: practice and applications

Nucleic acid amplification tests (NAATs), which are highly sensitive and specific, have provided the ability to use alternative sam-ple types for the diagnosis of sexually transmitted infections (STIs). Self-collected genital specimens, such as urine or even vaginal swabs, can now be accurately used to diagnose gonorrhea or chlamydia infections. In many cases, use of these sample types can decrease the necessity for a clinician to perform a pelvic examination on women or to collect a urethral swab from men, thus extending the diagnostic capability for detecting these infections to nonclinic screening venues. As most chlamydia infections and many gonorrhea infections are asymptomatic, the use of NAATs for self-collected samples greatly increases the types and numbers of patients that can be screened outside of clinic settings. Self-sampling also allows clinicians to easily screen patients in the clinic for STIs who are not presenting for pelvic or urogenital examinations. The application of NAATs to self-collected specimens has the potential to augment public health programs designed to control the epidemic of STIs in the community.

Innovative Approaches to the Prevention and Control of Bacterial Sexually Transmitted Infections

Bacterial STI continues to be a major problem in developed nations. Research and evolving standards of public health practice are cause for optimism and concern. Innovations in case-finding and treatment, particularly the application of NAATs to test for chlamydial infection in nonclinical settings, are successes that merit more widespread application. EPT, selective STI screening in men, and rescreening are all promising, but are not yet in widespread use and may face significant operational barriers. To date, public health efforts to alter sexual behavior, at least through specific interventions, are more discouraging. Although some behavioral interventions have been effective, none has been widely instituted. Moreover, the likelihood that existing behavioral interventions will be widely applied seems remote. Future research efforts in this area will need to focus less on proof-of-concept efficacy trials and more on developing and testing sustainable, cost-effective interventions that focus on those at greatest risk and that can be scaled-up within the existing public health infrastructure.

Chlamydia trachomatis and Neisseria gonorrhoeae prevalence and coinfection in adolescents entering selected US juvenile detention centers, 1997-2002

BACKGROUND

Juvenile detention centers offer public health practitioners an opportunity to gain access to large numbers of adolescents at risk for chlamydia and gonorrhea.

GOAL

To describe the prevalence and coinfection of chlamydia and gonorrhea among adolescents in 14 US juvenile detention centers from 1997 to 2002.

STUDY

We calculated the prevalence of chlamydia and gonorrhea in males and females, stratified by race/ethnicity, age group, and site. We also calculated the proportion of adolescents with chlamydia that were coinfected with gonorrhea and the proportion of those with gonorrhea that were coinfected with chlamydia.

RESULTS

The prevalence of chlamydia was 15.6% in 33,619 females and 5.9% in 98,296 males; gonorrhea prevalence was 5.1% in females and 1.3% in males. Of females with gonorrhea, 54% were coinfected with chlamydia, and 51% of males with gonorrhea were coinfected with chlamydia.

CONCLUSIONS

Chlamydia and gonorrhea prevalence was very high in females in all project sites. In males, chlamydia prevalence was high in some areas; however, gonorrhea prevalence was substantially lower. These prevalence data justify screening for chlamydia and gonorrhea among female adolescents in juvenile detention centers nationally.

Performance of urine leukocyte esterase in asymptomatic male youth: another look with nucleic acid amplification testing as the gold standard for Chlamydia detection

PURPOSE

To re-evaluate the sensitivity and specificity of leukocyte esterase (LE) for screening adolescent and young adult males for Chlamydia trachomatis using a nucleic acid amplification test (NAAT) as the gold standard.

METHODS

This study was conducted at two Massachusetts Department of Youth Services sites and one Job Corps site. Recently admitted asymptomatic sexually active male youth aged 14 to 25 years (mean 16.6 years) were recruited between January 2001 and July 2003 (N = 1008). Participants provided first part voided urine specimens for testing with LE and Chlamydia NAAT. The sensitivity, specificity, and positive and negative predictive value of urine LE for identification of Chlamydia infection were determined using NAAT as the gold standard.

RESULTS

Fifty-seven (5.7%) participants were infected with Chlamydia as defined by a positive NAAT. Defining trace + as the LE cut point resulted in sensitivity and specificity of 57.9% and 78.3%, respectively. Defining 1+ as the cut point resulted in sensitivity and specificity of 47.4% and 96.1%, respectively.

CONCLUSIONS

Urine leukocyte esterase is a moderately sensitive method to screen for Chlamydia. Nevertheless, a substantial proportion of infections are not detected with LE screening. When feasible, urine NAAT provides a much more sensitive and equally noninvasive method of detecting Chlamydia. However, if LE is used as an initial screen followed by NAAT confirmation of LE positive samples, we recommend using trace LE as the cut point for positive results.

Impact of patient characteristics on performance of nucleic acid amplification tests and DNA probe for detection of Chlamydia trachomatis in women with genital infections

The performance of nucleic acid amplified tests (NAAT) for Chlamydia trachomatis at the cervix and in urine was examined in 3,551 women, and the impacts of clinical findings (age, endocervical and urethral inflammation, menses, and gonococcal coinfection) were assessed. Ligase chain reaction (LCR) and first-generation uniplex PCR were studied relative to an unamplified DNA probe (PACE2) and to an expanded, independent diagnostic reference standard. Relative to the expanded standard, cervical or urine LCR was generally the most sensitive test in most subgroups. Increased detection by NAAT of cervical C. trachomatis over PACE2 was highest among women without mucopurulent endocervical discharge versus those with (relative increase in positivity with cervical LCR, 46%) and among women > or =20 years old versus younger women (relative increase in positivity with cervical LCR, 45%). The sensitivity of cervical PCR was highest when mucopurulent endocervical discharge was present (84%) and highest for cervical LCR when cervical gonococcal coinfection was detected (91%). Urethral inflammation was associated with higher sensitivities of urine LCR (86 compared to 70% when inflammation was absent) and PCR (82 compared to 62% when inflammation was absent). Menses had no effect on test performance. The effects of patient characteristics on test specificities were less pronounced and were closely related to observed sensitivities. These findings support expanded use of NAAT for screening and diagnosis of C. trachomatis in diverse clinical populations of women.

Urine nucleic acid amplification tests for the diagnosis of sexually transmitted infections in clinical practice

PURPOSE OF REVIEW

With the advent of highly sensitive and specific nucleic acid amplification assays, this report will demonstrate that self-collected genital specimens, such as urine or even vaginal swabs can be accurately used to diagnose sexually transmitted infections.

RECENT FINDINGS

Use of self collected samples can eliminate the necessity of a clinician to perform a pelvic examination for women or collect a urethral swab for men, thus extending the diagnostic capability for sexually transmitted infections to non-clinic screening venues. As many sexually transmitted infections are asymptomatic, this ability to use self-sampling greatly increases the numbers of patients that can be screened, and has the potential to augment public health programs designed to control the epidemic of sexually transmitted infections in the community. Patient collected samples are highly acceptable, highly accurate, and are becoming widely used. Self-sampling also allows clinicians to easily screen patients in the clinic, who are not presenting for pelvic or urogenital examinations, for sexually transmitted infections.

SUMMARY

Highly accurate molecular tests and easily obtained self-collected urogenital samples represent the ideal combination for obtaining the public health goal of decreasing the sexually transmitted infection epidemic among sexually active persons in the United States today.

Prevalence of Chlamydia trachomatis Infection Among Men Screened in 4 U.S. Cities

OBJECTIVE

The objective of this study was to measure the prevalence of Chlamydia trachomatis (CT) infection among men in clinical and nonclinical settings across the United States.

GOAL

The goal of this study was to obtain data to inform recommendations regarding male CT screening.

STUDY

The authors conducted a cross-sectional study of CT prevalence among adolescent and adult men in 4 U.S. cities (Baltimore, Denver, San Francisco, and Seattle). CT was detected using urine-based testing, and prevalence was calculated for first testing event.

RESULTS

Over 23,000 men were tested for CT over a 3 1/2-year period. The majority (96%) were asymptomatic. Overall, prevalence was 7% and varied significantly between cities (range: Seattle, 1%; Baltimore, 12%), by age (peak prevalence at age 20-24 years, 9%), and between venues where CT testing was offered.

CONCLUSIONS

At 7%, the prevalence of CT is moderately high among men opportunistically tested in nonclinical and clinical settings.

Sexually transmitted infections, blood-borne viruses and risk behaviour in an Australian senior high school population—the SHLiRP study

Objectives: To determine the feasibility and acceptability of screening for sexually transmitted infections and blood-borne viruses and to study the profile of sexual activity and other risk behaviours in a senior high school population. Methods: In this descriptive study we provided sexual health education and screening to students from two senior high schools in the Australian Capital Territory. We collected behavioural data using a self-administered questionnaire. Urines and swabs were tested for Chlamydia trachomatis (Ct), Neisseria gonorrhoea (Ng), Trichomonas vaginalis (Tv) and human papilloma virus (HPV). Blood specimens were tested for hepatitis B and C, HIV, herpes simplex viruses (HSV-1 and HSV-2) and syphilis. Results: A total of 795 students participated (31% of the enrolled population; female to male ratio 60 : 40) and 67.0% were sexually active. Of 795 students, 644 (81.0%) were screened. Rates of infection were Ct 1.1% (95% CI: 0.4–2.6), HPV 11.7% (95% CI: 7.4–17.3), HSV-1 32.5% (95% CI: 28.9–36.3), HSV-2 2.4% (95% CI: 1.3–3.9), hepatitis B surface antigen 0.3% (95% CI: 0.04–1.1) and hepatitis C antibodies 0.7% (95% CI: 0.07–1.6). Only 22.3% (95% CI: 19.3–25.7) of students had immunity to hepatitis B. There were no cases of HIV, gonorrhoea, trichomoniasis or syphilis. Of the sexually active students, 49.2% (95% CI: 38.9–59.2%) reported never or only sometimes using condoms, 41.5% (95% CI: 32.2–52.3%) reported unsafe drinking, 33.3% (95% CI: 23.9–43.1%) were smokers and 1.9% (95% CI: 0.2–7.0%) reported injecting drug use. Conclusions: Rates of STI and blood-borne viruses and immunity to hepatitis B were low in this population, but unsafe sex and other risk behaviours were common. We have demonstrated that STI screening, including serological testing, was well accepted in a senior high school population.

Prevalence and Risk Behaviors for Chlamydial Infection in a Population-Based Study of Female Adolescents in Brazil

BACKGROUND

Adolescents are vulnerable to sexually transmitted infections (STIs) and unplanned pregnancy. Prevention measures and assistance are of significant public health importance in this population.

OBJECTIVE

The objective of this study was to identify demographic, behavioral, and clinical factors for STIs and to determine the prevalence of Chlamydia trachomatis infection (CT) among female adolescents in Vitória, Brazil.

METHODS

We performed a cross-sectional study among female adolescents (15-19 years) served by the Health Family Program. Participants were screened for CT and Neisseria gonorrhoeae (GC) using ligase chain reaction applied to urine and answered a face-to-face questionnaire to assess demographic, behavioral, and clinical factors. All participants and their parents signed the informed consent.

RESULTS

Four hundred sixty-four young women were sampled. The prevalence of CT was 8.9% (95% confidence interval [CI], 6.5-11.9%) overall. Among sexually active women, CT and gonorrhea prevalence were 12.2 (95% CI, 9.4-17.0%) and 1.9% (95% CI, 1.1-2.7%), respectively. Previously diagnosed STI was reported by 12.8%. Women who reported regular condom use and having condoms at home were significantly less likely to have CT, and having never purchased condoms was significantly associated with a positive CT result.

CONCLUSION

A high prevalence of CT was found in this population, and behavioral risk was high despite readily available STI prevention information. Women who reported positive condom use behaviors were less likely to have CT. These results demonstrate the need for ongoing STI prevention activities, including STI screening and continued successful risk reduction activities such as condom use to further decrease CT and other STI among adolescents.

Cost-effectiveness of universal screening for chlamydia and gonorrhea in US jails

Universal screening for the sexually transmitted diseases (STDs) of chlamydia and gonorrhea on intake in jails has been proposed as the most effective strategy to decrease morbidity in inmates and to reduce transmission risk in communities after release. Most inmates come from a population that is at elevated risk for STDs and has limited access to health care. However, limited resources and competing priorities force decision makers to consider the cost of screening programs in comparison to other needs. The costs and cost-effectiveness of universal screening in correctional settings have not been documented. We estimated the incremental cost-effectiveness of universal urine-based screening for chlamydia and gonorrhea among inmates on intake in US jails compared to the commonly used practice of presumptive treatment of symptomatic inmates without laboratory testing. Decision analysis models were developed to estimate the cost-effectiveness of screening alternatives and were applied to hypothetical cohorts of male and female inmates. For women, universal screening for chlamydia only was cost-saving to the health care system, averting more health care costs than were incurred in screening and treatment. However, for men universal chlamydia screening cost $4,856 more per case treated than presumptive treatment. Universal screening for both chlamydia and gonorrhea infection cost the health care system $3,690 more per case of pelvic inflammatory disease averted for women and $650 more per case of infection treated for men compared to universal screening for chlamydia only. Jails with a high prevalence of chlamydia and gonorrhea represent an operationally feasible and cost-effective setting to universally test and treat women at high risk for STDs and with limited access to care elsewhere.

Chlamydia screening of youth and young adults in non-clinical settings throughout California

BACKGROUND

Urine-based chlamydia tests enable screening in non-clinical settings.

GOAL

The goal of this study was to determine the prevalence of chlamydia infection among high-risk youth and young adults in non-clinical settings.

DESIGN

County sexually transmitted disease (STD) programs implemented chlamydia screening projects in non-clinical settings using nucleic acid amplification tests. Demographic and access to care data were collected.

RESULTS

Overall, 16,279 female and male youth were screened for chlamydia in 24 counties throughout California. The 158 screening venues included 32 educational, 32 correctional, and 94 community-based settings. Chlamydia infection rates varied significantly by gender, age, and venue type. Among females, the highest prevalence was found in jail settings (14.6%), juvenile detention (13.0%), and alternative schools (10.0%). Among males, the highest prevalence was found in jail (7.9%) and juvenile detention (5.8%). Venue types that serve populations with poor access to care and high rates of infection were identified.

CONCLUSIONS

Screening projects in non-clinical settings identify high-risk youth in need of STD care, improve access to STD screening and education, and foster local collaborations.

Developments in the screening for Chlamydia trachomatis: a review

Many studies have evaluated selective screening criteria for women in various settings. Most have concluded and all guidelines recommend that all women aged < 25 be screened yearly for C. trachomatis infection. Behavioral criteria, such as the number of sex partners, new or more than one sex partners, and previous infection, also can serve as criteria for screening women aged > 25. Because re-infection rates are high and occur within a few months, complications may be reduced further if partners are treated and women rescreened 4 to 6 months after initial infection. Revised recommendations for C. trachomatis screening programs have stated that more frequent screening may be considered among women < 20 and those with recent infection. Screening in nontraditional settings and careful evaluation of local prevalence and risk factor information should be encouraged. Private providers and emergency room providers should discuss screening recommendations and adopt a C. trachomatis screening policy for the population they serve. The HEDIS measure should serve to encourage at least annual screening of 15- to 25-year-old sexually active females through providers linked to managed care organizations. In general, high yields (ie, percentage of tests that are positive) in nontraditional settings and enhanced feasibility and acceptability of urine-based tests may encourage further innovative approaches to reach and screen populations at risk. Several issues remain to be addressed to increase the effectiveness of screening efforts. If more sensitive amplification tests are used widely, more infected persons will be identified and treated, and transmission patterns may change, particularly if partner treatment also occurs. Current screening criteria should continue to be re-evaluated. An important issue that affects testing methods includes the possible need for confirmation testing when using NAATs if the prevalence of C. trachomatis is less than 2%. If the sensitivity of an NAAT is 85% and specificity is 99%, in a hypothetical population of 10,000 with a prevalence of 2%, the positive predictive value is 170/268 (63%). A second important issue affecting testing methods and feasibility of using NAATs for screening large numbers of individuals is the pooling of urine specimens, which has been evaluated in several studies and found to be very effective for reducing costs. A research issue for pooling is the determination of the most cost-effective prevalence levels for pooling. An additional research question is in which populations should a NAAT be used for detection of C. trachomatis and N. gonorrhoeae. There are no recommendations for the routine screening of men because of the paucity of data showing that this strategy can reduce sequelae. The CDC is conducting a multisite study to examine the feasibility, acceptability, and usefulness of screening of asymptomatic men. There are a few studies have determining cost-effective prevalence threshold levels, particularly with NAATs. A recently developed decision analysis model by CDC designed to maximize the effectiveness of screening strategies for C. trachomatis infections may be useful for decision makers. It is intended to serve as an easy and flexible tool to determine cost effectiveness at a local level and takes into account positivity rates and test performance characteristics (SOCRATES). It is unclear if recurrent infection is caused by true re-infection by the same or a different partner or recurrence of initial infection. Recurrence may be caused by persistence of C. trachomatis or antibiotic resistance. This distinction is of scientific interest because the appropriate intervention differs (eg, identification of risk factors for the former and microbiologic investigations for the latter). Effective partner management and retesting are critical to reducing sequelae of C. trachomatis infection. Screening for C. trachomatis infection remains an essential component of C. trachomatis control. It is cost effective, most infections are asymptomatic, and symptom-based health care seeking and testing identify few of those infected. The likelihood that opportunities for screening are missed is high particularly in non-STD clinic settings. Local studies using NAATs to determine C. trachomatis prevalence and risk factors are helpful to health care providers so they can make evidence-based decisions on who to screen. The use of nontraditional, non-clinic-based test settings should be explored further. We have focused on summarizing the medical evidence regarding recommendations for screening for C. trachomatis. High-risk populations for C. trachomatis infection may overlap with populations for other STDs, and comprehensive STD prevention programs that involve a range of STD service providers are needed to successfully reduce the STD-related health burden in the population.

Genital Chlamydia trachomatis infection in Australia: epidemiology and clinical implications

Over the last decade, notification rates for genital Chlamydia trachomatis infection in Australia have been rising progressively. While chlamydia is common and possibly increasing in the general population, heterosexual adolescents, indigenous Australians in remote settings, and homosexually active men are at particular risk of infection. Few studies are available on the extent of morbidity from chlamydia-associated diseases. Australia urgently needs a national strategy to control chlamydia, with widespread, selective screening as a key component. As general practitioners have an important role to play, we proffer guidelines for selective testing in primary care.

Testing for Chlamydial and Gonorrheal Infections Outside of Clinic Settings

BACKGROUND

Nucleic acid amplification tests (NAATs) provide new technology that makes it feasible to initiate testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infection outside of clinic settings.

METHODS

We summarized the English-language literature describing chlamydial or gonorrheal testing with self-collection of urine or vaginal specimens outside of clinic settings in developed countries published between January 1995 and August 2002.

RESULTS

Testing for CT or GC infection has been initiated in school, community, and home settings. Purposes include screening of asymptomatic populations, improving quality of clinic-based health care, and research. Challenges include defining and reaching target populations, overcoming logistic issues, developing communication and counseling strategies, and determining whether alternative testing strategies are effectively reducing infection rates.

CONCLUSIONS

The use of NAATs to detect CT and GC infection outside of clinic settings will undoubtedly continue. Future research should focus on how to best use this technology to reduce rates of infection.

Prevalence and High Rate of Asymptomatic Infection of Chlamydia trachomatis in Male College Reserve Officer Training Corps Cadets

BACKGROUND

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).

GOAL

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.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Community-based screening and treatment for STDs: results from a mobile clinic initiative

BACKGROUND

The persistence of syphilis and other bacterial sexually transmitted diseases (STDs) in many areas of the United States suggests that innovative approaches to controlling these diseases are needed.

GOAL

To evaluate the feasibility, acceptability, and yield of mobile community-based STD screening and treatment services in high STD incidence areas.

STUDY DESIGN

Free, voluntary, confidential screening and treatment for STDs were conducted in high STD incidence neighborhoods of Baton Rouge, Louisiana, using a 32-foot mobile van. Demographic and behavioral data were obtained from participants. Participants were screened for syphilis, chlamydia, and gonorrhea and were also offered HIV testing. Community attitudes toward the screening program were assessed with street-intercept surveys conducted two weeks after screening events.

RESULTS

From March 1997 to August 2000, 256 community-based screening events were held. During this period, 3110 blood samples were collected for syphilis testing, of which 37 (1.2%) new cases of syphilis were identified. Of the 2807 blood samples collected for HIV testing, 70 (2.5%) were positive. Of 2229 urine samples, 185 (8.3%) tested positive for Chlamydia trachomatis and 108 (4.9%) positive for Neisseria gonorrhoeae. Of 389 street-intercept surveys, 97% of respondents thought that neighborhood STD testing was a "good" or "very good" idea.

CONCLUSION

Mobile community-based STD screening and treatment are feasible, identify high positivity of STDs, and are accepted by the community as an innovative approach to STD control.

Missed opportunities for sexually transmitted diseases, human immunodeficiency virus, and pregnancy prevention services during adolescent health supervision visits

OBJECTIVE

To describe prevention counseling on pregnancy and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV), received by sexually experienced youth in the primary care setting and to test associations between recent sexual risk behaviors and preventive counseling.

METHODS

Using data from the 1999 Youth Risk Behavior Surveillance survey, a nationally representative survey (N = 15 349) of high school students, we analyzed responses to questions about sexual experience, time since last preventive health care visit, and discussion of STD, HIV, or pregnancy prevention with a doctor or nurse during their last preventive health care visit. Logistic regression was used to test associations; students' demographic characteristics were controlled.

RESULTS

More than half of the US high school students surveyed reported a preventive health care visit in the 12 months preceding the survey: 60.4% (95% confidence interval [CI]: 57.2%-63.6%) of female students and 57.5% (95% CI: 53.9%-61.1%) of male students. For female students, sexual experience was positively associated with a preventive health care visit (odds ratio [OR]: 1.3; 95% CI: 1.1-1.6), but for male students, sexual experience had a negative effect (OR: 0.8; 95% CI: 0.7-0.9). Of the students who reported a preventive health care visit in the 12 months preceding the survey, 42.8% (95% CI: 38.6%-47.1%) of female students and 26.4% (95% CI: 22.7%-30.2%) of male students reported having discussed STD, HIV, or pregnancy prevention at those visits. Sexual experience was associated with a higher likelihood of engaging in a dialogue about sexual health once a student entered the health care system: female students (OR: 3.8; 95% CI: 3.0-4.9) and male students (OR: 1.9; 95% CI: 1.3-2.7).

CONCLUSION

Primary care providers miss opportunities to provide STD, HIV, and pregnancy prevention counseling to high-risk youth.

Current Issues in Screening for Chlamydia trachomatis

During the past several years, research related to screening for Chlamydia trachomatis has flourished, with new diagnostic tests, new methods for specimen collection, and new prevalence data in different populations. Public health endorsements for screening are now more specific than ever, yet several important clinical and laboratory questions remain, including questions concerning who to screen and how often to screen. Additional important research is addressing issues related to assay validity, efficacy of screening in different populations, and feasibility of screening on the level of the individual patient and the level of the community and health care system. This article discusses major research findings related to chlamydial screening from the past several years and suggests areas in which additional research is needed.

Asymptomatic sexually transmitted diseases: the case for screening

BACKGROUND

The United States has the highest prevalence of sexually transmitted diseases in the developed world. Control strategies should address the most frequent reasons why curable sexually transmitted diseases are not treated.

METHODS

We approached 1,631 persons ages 18-29 in various sites and offered them screening for gonorrhea and chlamydial infection and surveys regarding past genitourinary symptoms. For those with past symptoms we abstracted medical records or conducted additional interviews. From these data we estimated the total number of persons who had gonorrhea or chlamydial infections in the previous year, the proportion treated, and the primary reasons for nontreatment.

RESULTS

The prevalence of gonorrhea was 2.3% and that of chlamydial infection was 10.1%. We estimate that 45 and 77% of all cases of gonorrhea and chlamydial infection, respectively, were never symptomatic and that 86 and 95% of untreated cases of gonorrhea and chlamydial infection, respectively, were untreated because they were never symptomatic. The remaining 14 and 5% of untreated cases of gonorrhea and chlamydia, respectively, were not treated because persons did not receive medical care for symptoms.

CONCLUSIONS

The primary reason that gonorrhea and chlamydial infections are untreated is that infected persons never have symptoms. The most effective method to control these sexually transmitted diseases is routine screening at high-volume sites.

Drug use patterns and infection with sexually transmissible agents among young adults in a high-risk neighbourhood in New York City

AIMS

To determine relationships between drug use "hardness" (defined in increasing order of hardness as no drug use, marijuana use, non-injected heroin or cocaine use, crack smoking and injection drug use) and prevalences of several sexually transmissible infections among young adults in a high-risk neighbourhood. Drug users, particularly injection drug users and crack smokers, may be a core group for some sexually transmitted infections.

DESIGN

Cross-sectional survey and assays of young adults from (a) a household probability sample and (b) a targeted sample of youth who have used injected drugs, crack, other cocaine or heroin.

SETTING

Bushwick, an impoverished New York City minority neighbourhood with major drug markets.

PARTICIPANTS

A total of 363 18-24-year-olds from a household probability sample; 165 Bushwick 18-24-year-olds who have used injected drugs, crack, other cocaine or heroin.

MEASUREMENTS

Drug use by self-report; serum- and urine-based assays for HIV, hepatitis B and C, syphilis, gonorrhoea, chlamydia and herpes simplex (type 2).

FINDINGS

Household-sample prevalences: HIV, hepatitis C and syphilis, 1%; gonorrhoea 3%; chlamydia 5%; past or present hepatitis B infection 8%; herpes simplex (type 2) 18%. In combined household and targeted samples, hepatitis C and HIV were concentrated among drug injectors. Herpes simplex (type 2), syphilis and hepatitis B increased among women with "hardest drug ever used".

CONCLUSIONS

Using "harder" drugs is associated with some but not all of these infections. Prevention efforts should help youth avoid unsafe sex and higher-risk drugs.

The clinical and economic consequences of screening young men for genital chlamydial infection

BACKGROUND

Wide-scale application of urine-based screening of asymptomatic men for chlamydial infection has not been thoroughly assessed.

GOAL

The goal was to compare clinical and economic consequences of three strategies: (1). no screening, (2). screening with ligase chain reaction (LCR) assay of urine, and (3). prescreening urine with a leukocyte esterase test (LE) and confirming positives with LCR.

STUDY DESIGN

We used a decision analytic model.

RESULTS

At a chlamydia prevalence of 5%, the no screening cost was US dollars 7.44 per man screened, resulting in 522 cases of pelvic inflammatory disease (PID) per 100000 men. LE-LCR was most cost-effective, preventing 242 cases of PID over no screening at an additional cost of US dollars 29.14 per male screened. The LCR strategy prevented 104 more cases of PID than LE-LCR but cost US dollars 22.62 more per male screened. For this to be more efficient than LE-LCR, the LCR assay cost needed to decline to <or=US dollars 18.

CONCLUSION

At a chlamydia prevalence of 5%, LE-LCR is the most efficient use of resources. If LCR cost decreases or chlamydia prevalence increases, the LCR strategy is favored.

Surveillance of Chlamydia trachomatis and Neisseria gonorrhoeae infections in women in detention in Baltimore, Maryland

BACKGROUND

In conjunction with a program to expand syphilis and HIV infection services, women were also offered screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) during intake at the Baltimore Women's Detention Center.

GOAL

The goal was to assess the effectiveness of a routine screening program for CT and GC in women in a detention setting. The association among infection, race, and area of residence was also explored.

STUDY DESIGN

CT and GC prevalences were determined and analyzed by demographic data, including zipcode, for 1,858 women enrolled over a 48-week period. Informed consent was obtained, and infections were detected with use of urine samples tested by ligase chain reaction.

RESULTS

Overall, the population had prevalence rates of 5.9% (109/1,858) and 3.4% (63/1,858) for CT and GC respectively. Among whites, CT and GC prevalences were 9.0% (29/323) and 8.7% (28/323), respectively. Among African Americans the prevalence rates were 5.1% (77/1,510) and 2.3% (34/1,510) for CT and GC, respectively. White women <25 years of age were associated with the highest CT and GC prevalences, at 20.0% (13/65) and 13.9% (9/65), respectively. African American women <25 years of age also were associated with the highest CT and GC prevalences, at 13.9% (24/173) and 5.8% (10/173), respectively. Multivariate analysis of risk factors and demographic data indicated that ages <25 years and 25 to 34 years, white race, and certain zipcodes of residence were risk factors for infection.

CONCLUSION

This study illustrated that urine-based screening for CT and GC is feasible in detention settings and can be productive in high-prevalence areas. Geographic analysis demonstrated no definitive relationship among race, infection, and area of residence, although it did demonstrate clustering of infected individuals and could be useful in future interventions. These findings demonstrated the need for implementing screening programs for sexually transmitted infections in detention centers.

Chlamydia trachomatis infection in asymptomatic men

BACKGROUND

The epidemiology of Chlamydia trachomatis infection in men is not well defined, especially among those who are asymptomatic or show no signs of infection. Established C. trachomatis screening programs for women have demonstrated the benefit of routine screening in reducing prevalence over time, but the yield and benefit of screening asymptomatic men are unclear.

METHODS

Cross-sectional study of C. trachomatis prevalence and associated risk factors among men tested at sexually transmitted disease (STD) clinics in Alaska, Idaho, Oregon, and Washington. We analyzed data from 43,094 men universally tested from 1997 to 1999 at 103 STD clinics, and assessed age-specific prevalence of infection, controlling for signs of infection (urethritis diagnosed by clinician) and report of sexual contact to a person with an STD (defined as "contact").

RESULTS

Overall prevalence of C. trachomatis was 10.3%. Age-specific prevalence was highest among men aged 18 to 19 years and lowest among those aged >29 years, regardless of signs of infection upon examination or contact to a person with an STD. If these factors and age <25 years had been used to direct C. trachomatis testing at STD clinics, 59% of men would have been tested and 91% of positives would have been detected.

CONCLUSIONS

Using either the presence of clinical signs or report of a sex partner with an STD in combination with selective screening of all men aged <25 years detects the majority of infections and, in our population, would have considerably reduced the number of negative tests performed.