Diagnosis of Chlamydia trachomatis infections in men and women by testing first-void urine by ligase chain reaction

Diagnosis of Chlamydia trachomatis genital infections in the era of genomic medicine

PURPOSE

Chlamydial genital infections constitute significant sexually transmitted infections worldwide. The often asymptomatic status of C. trachomatis (CT) infections leads to an increased burden on human reproductive health, especially in middle- and low-income settings. Early detection and management of these infections could play a decisive role in controlling this public health burden. The objective of this review is to provide an insight into the evolution of diagnostic methods for CT infections through the development of new molecular technologies, emphasizing on -omics' technologies and their significance as diagnostic tools both for effective patient management and control of disease transmission.

METHODS

Narrative review of the diagnostic methodologies of CT infections and the impact of the introduction of -omics' technologies on their diagnosis by review of the literature.

RESULTS

Various methodologies are discussed with respect to working principles, required specifications, advantages, and disadvantages. Implementing the most accurate methods in diagnosis is highlighted as the cornerstone in managing CT infections.

CONCLUSION

Diagnostics based on -omics' technologies are considered to be the most pertinent modalities in CT testing when compared to other available methods. There is a need to modify these effective and accurate diagnostic tools in order to render them more available and feasible in all settings, especially aiming on turning them to rapid point-of-care tests for effective patient management and disease control.

Urinary Meatal Swabbing Detects More Men Infected With Mycoplasma genitalium and Four Other Sexually Transmitted Infections Than First Catch Urine

Urinary meatal swabs compared with urine showed higher infection rates for Mycoplasma genitalium (15.3% vs 12.6%, P = 0.035), Chlamydia trachomatis (11.3% vs 9.3%, P = 0.039), Neisseria gonorrhoeae (1.4% vs 1.1%, P = 1.00), Trichomonas vaginalis (8.0% vs 1.7%, P < 0.001), and high-risk human papillomavirus (5.9% vs 3.4%, P = 0.078) respectively.

Advances in sampling and screening for chlamydia

Chlamydia is the most commonly diagnosed bacterial sexually transmitted infection in the developed world, with diagnosis rates continuing to increase each year. As chlamydia is largely asymptomatic, screening and treatment is the main way to detect cases and reduce transmission. Recent advances in self-collected specimens and laboratory tests has made chlamydia screening easier to implement as well as possible in nonclinical settings. This review will discuss new approaches to specimen collection and how these have expanded opportunities for reaching target populations for chlamydia screening. Furthermore, it will discuss how advanced molecular microbiological methods can be used with self-collected specimens to further our knowledge of the epidemiology of chlamydia and the dynamics of transmission.

Spolno Prenosljive Okužbe Z Bakterijo Chlamydia Trachomatis V Sloveniji / Sexually Transmitted Infections With The Bacteria Chlamydia Trachomatis In Slovenia

Namen:Namen prispevka je na osnovi sistematičnega pregleda objavljenih raziskav oceniti prevalenco genitalnihokužb z bakterijo Chlamydia trachomatis v Sloveniji.

Metode:Pregledana je bila literatura v dveh elektronskih podatkovnih zbirkah, in sicer v zbirki PubMed z uporabokombinacije ključnih besed »chlamydia« in »Slovenia« ter v zbirki Cobiss Slovenija s pomočjo ključnih besed»klamidija«, »chlamidia« in »chlamydia«. Vključene so raziskave, ki so bile v navedenih zbirkah vpisane do vključnokonca novembra 2011 in so vsebovale izsledke o pogostosti klamidijskih okužb med prebivalci Slovenije.

Rezultati:V obdobju od leta 1980 do vključno konca novembra 2011 je bilo objavljenih 18 raziskav, ki so ustrezaleiskalnim merilom. Večina raziskav je bila izvedena na različnih skupinah prebivalcev Slovenije in ne na verjetnostnihnacionalnih vzorcih. Klamidijska okužba je bila ugotovljena v 0-19% primerih. Pri preiskovancih z nekaterimi stanji,ki so lahko povezana z višjo prevalenco spolno prenosljivih okužb, je bila klamidijska okužba ugotovljena v 4,9-19%,pri tistih, ki takšnih stanj niso imeli opisanih, pa v 0-16,5%. Pet raziskav je bilo končanih po letu 2000 in pri teh jebila klamidijska okužba ugotovljena v 0-6,5%. Največ okuženih je med starimi 20 in 24 let.

Zaključki:Chlamydia trachomatis je pomembna povzročiteljica spolno prenosljivih okužb v Sloveniji. Večineklamidijskih okužb zaradi nizkih stopenj testiranja ne prepoznamo in tako zamujamo številne priložnosti za zdravljenjein preprečevanje kasnih posledic, predvsem za reproduktivno zdravje žensk

Characteristic male urine microbiomes associate with asymptomatic sexually transmitted infection

BACKGROUND

The microbiome of the male urogenital tract is poorly described but it has been suggested that bacterial colonization of the male urethra might impact risk of sexually transmitted infection (STI). Previous cultivation-dependent studies showed that a variety of non-pathogenic bacteria colonize the urethra but did not thoroughly characterize these microbiomes or establish links between the compositions of urethral microbiomes and STI.

METHODOLOGY/FINDINGS

Here, we used 16S rRNA PCR and sequencing to identify bacteria in urine specimens collected from men who lacked symptoms of urethral inflammation but who differed in status for STI. All of the urine samples contained multiple bacterial genera and many contained taxa that colonize the human vagina. Uncultivated bacteria associated with female genital tract pathology were abundant in specimens from men who had STI.

CONCLUSIONS

Urine microbiomes from men with STI were dominated by fastidious, anaerobic and uncultivated bacteria. The same taxa were rare in STI negative individuals. Our findings suggest that the composition of male urine microbiomes is related to STI.

Chlamydia in colposcopy clinics: to screen or not to screen?

The objective of the study was to assess the prevalence of Chlamydia trachomatis in our colposcopy clinic. A total of 337 consecutive patients newly referred to the colposcopy clinic between May and November 2003 were screened for chlamydia trachomatis. All our patients were referred by their GPs and none of the patients had had a recent chlamydia test performed. Four patients screened positive, overall giving a prevalence of 1.2% [95% CI 0.04-2.36%]. Three of those with positive results were in the 21 - 30 year age group (139 in the group, which equals 2.2% prevalence [95% CI 0 - 4.6%]). The fourth positive result was in the group over the age of 60. None of those screened in the other age groups was positive (< or =20, 31 - 40, 41 - 50, 51 - 60 years). Numbers screened in each of those groups were: 14, 115, 53 and 12, consecutively. Our study, though small in sample size, supports the view that the prevalence of chlamydia is not high in all colposcopy clinic attenders. Women younger than 30 years old are more likely to be infected than older women; hence opportunistic screening should target this age group. The prevalence rate may be low due to the enzyme linked immunosorbent assay giving a poor detection rate for chlamydia screening.

Performance of three nucleic acid amplification tests for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by use of self-collected vaginal swabs obtained via an Internet-based screening program

Use of self-obtained vaginal specimens processed by nucleic acid amplification tests (NAATs) has significantly increased the utilization of nontraditional locations for Chlamydia trachomatis and Neisseria gonorrhoeae screening programs. One important emerging source of such venues includes home-based self-sampling kits available via the Internet. The objective of our study was to evaluate the performance of three commercially available NAATs (Becton-Dickinson ProbeTec SDA, Gen-Probe Aptima Combo2 TMA, and Roche Amplicor PCR) for detection of C. trachomatis and N. gonorrhoeae in vaginal samples obtained via an Internet-based screening program. From July 2004 to August 2005, 500 self-collected vaginal swabs were tested for C. trachomatis and N. gonorrhoeae by using all three NAATs. Another 500 samples were collected between August 2005 and November 2007 and tested by ProbeTec and Combo2; PCR testing was discontinued due to low specificity for N. gonorrhoeae. All tests were conducted according to the manufacturers' procedures; the "gold standard" for an infected C. trachomatis or N. gonorrhoeae patient was defined as > or = 2 positive NAAT results. Of the first 500 swabs submitted, 46 were C. trachomatis infected (9.2%) and 5 were N. gonorrhoeae infected (1.0%), and 3 of these were coinfected (0.6%). All C. trachomatis and N. gonorrhoeae Combo2-positive/ProbeTec-negative samples were confirmed as true positives by an alternative NAAT. For C. trachomatis, ProbeTec, Combo2, and PCR had sensitivities of 82.6%, 100%, and 100%, with specificities of 100%, 100%, and 99.3%, respectively. For N. gonorrhoeae, ProbeTec, Combo2, and PCR had sensitivities of 80%, 100%, and 100%, with specificities of 100%, 100%, and 98.8%, respectively. Of the total 1,000 swabs submitted, 92 were C. trachomatis infected (9.2%) and 15 were N. gonorrhoeae infected (1.5%), and 7 of these were coinfected (0.7%). There were no ProbeTec-positive/Combo2-negative samples. For C. trachomatis, ProbeTec and Combo2 had sensitivities of 81.5% and 100%, with specificities of 100% and 100%, respectively. For N. gonorrhoeae, ProbeTec and Combo2 had sensitivities of 80% and 100%, with specificities of 100% and 100%, respectively. Overall, ProbeTec had 17 C. trachomatis false-negative results (1.7%) and 3 N. gonorrhoeae false-negative results (0.3%), while Combo2 had none. Our results were consistent with the sensitivities and specificities stated by the manufacturers. NAATs perform well for detection of chlamydia and gonorrhea with self-obtained vaginal swabs shipped in a dry state to a laboratory. For 1,000 self-collected vaginal swabs tested by NAATs, the sensitivities for C. trachomatis and N. gonorrhoeae for Combo2 were 100% and 100%, while they were 81.5% and 80%, respectively, for ProbeTec. For 500 PCR samples, the C. trachomatis sensitivity was 100% and the N. gonorrhoeae sensitivity was 100%, with specificities of 99.3% and 98.8%, respectively.

Nucleic-acid amplification testing of urine vs. patient complaint-driven evaluation

The present pilot study compared the ability of a conventional patient complaint-driven approach to that of nucleic-acid amplification testing (NAAT) of urine to identify those individuals among an adult, urban, Emergency Department (ED) population infected with Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV). Urine for NAAT was collected for testing after individuals had completed a questionnaire and before being seen by a physician. A total of 614 subjects were enrolled, and complete physical examinations were performed on 348 (56.6%) individuals, with women being significantly more likely to receive such an evaluation (odds ratio [OR] 3.09; 95% confidence interval [CI] 1.96-4.86); p < 0.001). A total of 153 (24.9%) of the study cohort tested positive for a least one sexually transmitted disease (STD), and only a reported history of STD (OR 1.74; 95% CI (1.18-2.57); p = 0.005) and a history of a new sexual partner in the last 3 months (OR 1.79; 95% CI 1.13-2.82); p = 0.012) were predictive of a positive STD test. NAAT of urine samples on patients who did not receive a complete physical examination resulted in a 33% (51/153) increase in diagnostic yield in this cohort of ED attendees.

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.

Chlamydia trachomatis load at matched anatomic sites: implications for screening strategies

Urethral and endocervical swabs and self-collected vaginal swabs (SCVSs) and urine specimens are all used as samples for diagnosis of urogenital infection with Chlamydia trachomatis. We have now determined chlamydial organism load in matched specimens from different anatomic sites and examined its relation to clinical signs and symptoms in men and women. Organism load was measured with assays based on the ligase chain reaction or real-time PCR analysis. The mean organism loads in 58 infected men were 1,200 and 821 elementary bodies (EBs) per 100 microl of sample for first-void urine (FVU) and urethral swabs, respectively (P>0.05). Organism load in FVU samples or urethral swabs was positively associated with symptoms (P<0.01) and clinical signs (P<0.01) in men. The mean organism loads in 73 infected women were 2,231, 773, 162, and 47 EBs/100 microl for endocervical swabs, SCVSs, urethral swabs, and FVU samples, respectively (P<0.001 for each comparison). Only the presence of multiple symptoms or clinical signs was associated with organism load in women. These results show that FVU is a suitable noninvasive sample type for men, given the fact that its chlamydial load did not differ significantly from that of urethral swabs. Given their higher organism load compared with FVU, SCVSs are the preferred noninvasive sample type for women.

Characteristics of the m2000 automated sample preparation and multiplex real-time PCR system for detection of Chlamydia trachomatis and Neisseria gonorrhoeae

We evaluated a new real-time PCR-based prototype assay for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae developed by Abbott Molecular Inc. This assay is designed to be performed on an Abbott m2000 real-time instrument system, which consists of an m2000sp instrument for sample preparation and an m2000rt instrument for real-time PCR amplification and detection. The limit of detection of this prototype assay was determined to be 20 copies of target DNA for both C. trachomatis and N. gonorrhoeae, using serially diluted linearized plasmids. No cross-reactivity could be detected when 55 nongonococcal Neisseria isolates and 3 non-C. trachomatis Chlamydia isolates were tested at 1 million genome equivalents per reaction. Concordance with the Roche Amplicor, BDProbeTec ET, and Gen-Probe APTIMA Combo 2 tests was assessed using unlinked/deidentified surplus clinical specimens previously analyzed with these tests. For C. trachomatis, concordance for positive results ranged from 93.7% to 100%, while concordance for negative results ranged from 98.2% to 100%. For N. gonorrhoeae, concordance for positive and negative results ranged from 91.4% to 100% and 99.3% to 100%, respectively. A workflow analysis of the prototype assay was conducted to obtain information on throughput under laboratory conditions. At 48 samples/run, the time to first result for both C. trachomatis and N. gonorrhoeae was 4.5 h. A total of 135 patient specimens could be analyzed in 8.9 h, with 75 min of hands-on time. This study demonstrated the technical and clinical feasibility of the new Abbott real-time PCR C. trachomatis/N. gonorrhoeae assay.

APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae

The APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae have the greatest sensitivity of all the commercial nucleic acid amplification tests for the diagnosis of infections from noninvasive samples that may contain small amounts of nucleic acid. They have received extensive attention in male and female populations of varying prevalences of infection. Vulvovaginal swabs appear to be the specimen of choice (either self-collected or physician collected) in women and first-catch urine in men. Gen-Probe Inc. has created alternate amplification primers for confirmatory or initial single organism testing. With automation of the TIGRIS instrument, the assays should prove to be useful in high-volume laboratories.

High analytical sensitivity and low rates of inhibition may contribute to detection of Chlamydia trachomatis in significantly more women by the APTIMA Combo 2 assay

The clinical sensitivity of nucleic acid amplification tests may be determined by analytical sensitivity and inhibitors in patient samples. We established endpoints for detection of propagated Chlamydia trachomatis L2 434, diluted according to swab and urine protocols for APTIMA Combo 2 (AC2), ProbeTec ET (PT), and Amplicor (AMP) assays. AC2 was 1,000-fold more sensitive than PT and 10-fold more sensitive than AMP on mock swab specimens. For urine, AC2 analytical sensitivity was 100-fold greater than those of the other assays. Spiking an aliquot of each clinical-trial sample from 298 women demonstrated inhibition rates in first-void urine (FVU), cervical swabs (CS), and vaginal swabs (VS) of 12.1%, 12.8%, and 10.4% for AMP; 27.2%, 2%, and 2%, for PT; and 0.3%, 1.7%, and 1.3% for AC2. Inhibition of our C. trachomatis spike and the PT or AMP amplification controls from the manufacturers showed less than 50% correlation. Using an infected-patient reference standard (a specimen positive in at least two tests or a single test positive in two of three samples) in AC2, the VS identified 68/69 (98.6%) infected women compared to CS (89.9%) or FVU (81.2%). Significantly fewer women were identified by PT (65.2%, 63.8%, and 66.7%) or AMP (65.2%, 59.4%, and 56.5%) with the three specimens. By individual specimen type, AC2 confirmed virtually all PT- and AMP-positive specimens, but rates of AC2 confirmation by AMP or PT ranged from 62.9 to 80.3%. The AC2 test identified significantly more women infected with C. trachomatis (P = 0.001). Vaginal swabs appear to be the specimen of choice for screening.

Diagnosis of sexually transmitted infections (STI) using self-collected non-invasive specimens

Paramount in control of transmission of sexually transmitted infections (STIs) is their prompt recognition and appropriate treatment. In countries where definitive diagnoses are difficult, a 'syndromic approach' to management of STIs is recommended and practiced, yet many STIs have common symptoms or are asymptomatic and therefore go undetected and untreated. This is of particular concern with the recognition that HIV transmission is increased with co-existent STIs: the attributable risk for each STI varying with the prevalence within a particular population. Hence, HIV public health prevention approaches must include STI preventative strategies to be effective. Even then, microbiological screening is incorporated into STI control strategies; lack of access to appropriate services (especially in rural and remote areas), reluctance of at-risk populations to attend for treatment, fear of invasive genital examinations, and lower sensitivities of conventional diagnostic assays reduces the effectiveness of such programmes. Therefore, accurate, cost-effective, reliable diagnostic assays (preferably those which can be used in the field) are needed to impact on the incidence of the various STIs, as well as HIV. With the advent of molecular technologies, including target and signal amplification methods, diagnoses of STIs have been revolutionised and allow the use of non or minimally invasive sampling techniques, some of which are self-collected by the patient, e.g. first-void urine, cervico-vaginal lavage, low vaginal swabs, and tampons. Most studies evaluating such self-sampling with molecular diagnostic techniques have demonstrated an equivalent or superior detection of STIs as compared to conventional sampling and detection methods. These sampling methods can also be used to determine prevalence of STIs in various populations, but particularly those with difficult access to medical care. In this article, the utility of self-sampling collection devices for detection of various STIs, particularly in women, is reviewed as one step towards formulating appropriate strategies in control of STIs, and which are especially suited for remote areas.

Changes in the Etiology of Sexually Transmitted Diseases in Botswana between 1993 and 2002: Implications for the Clinical Management of Genital Ulcer Disease

BACKGROUND

In recent years, increasing evidence has accumulated that suggests the majority of cases of genital ulcer disease in sub-Saharan Africa are due to viral and not bacterial infections. Although many cross-sectional studies support such a trend, few serial cross-sectional data are available to show the evolution of genital ulcer disease over time.

METHODS

We surveyed the prevalence of sexually transmitted diseases (STDs) among patients with STD symptoms and women recruited from family planning clinics in 3 cities in Botswana in 2002 and compared our findings with those from a survey of a similar population conducted in 1993.

RESULTS

The observed proportion of cases of genital ulcer disease due to chancroid decreased from 25% in 1993 to 1% in 2002, whereas the proportion of ulcers due to herpes simplex virus increased from 23% in 1993 to 58% in 2002. Although the proportion of ulcers due to syphilis was similar for both surveys, the rate of positive serologic test results for syphilis among patients with genital ulcer disease decreased from 52% in 1993 to 5% in 2002. During this period, decreases in the prevalence of gonorrhea, syphilis-reactive serologic findings, chlamydial infection, and trichomoniasis were also detected among patients with STDs and women from family planning clinics. These changes remained significant after estimates were adjusted for the sensitivity and specificity of diagnostic tests.

CONCLUSIONS

Our findings suggest a decrease in the prevalence of bacterial STDs and trichomoniasis, a reduction in the proportion of ulcers due to bacterial causes, and an increase in the proportion of ulcers due to herpes simplex virus during the period 1993-2002. These changes should be taken into consideration when defining new guidelines for the syndromic management of genital ulcer disease.

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.

Comparison of strand displacement and ligase chain amplification for detection of Chlamydia trachomatis infection in urogenital specimens

Two amplification tests for the diagnosis of Chlamydia trachomatis infection, namely the ligase chain reaction (LCx) and the strand displacement assay (ProbeTec), were compared using samples from 1183 patients at sexually transmitted disease clinics. The overall prevalence of positive results was 8.0%, with agreement between the two assays of 98.8%. For endocervical, urethral and male urine samples, agreement was 99.3%, 99.4% and 97.7%, respectively. For ten discrepant samples, alternative amplification assays suggested that the LCx and ProbeTec assays gave erroneous results in six and four cases, respectively. Inhibition of amplification was observed with three (0.25%) urine specimens.

Can we evaluate population screening strategies in UK general practice? A pilot randomised controlled trial comparing postal and opportunistic screening for genital chlamydial infection

STUDY OBJECTIVE

To assess whether opportunistic and postal screening strategies for Chlamydia trachomatis can be compared with usual care in a randomised trial in general practice.

DESIGN

Feasibility study for a randomised controlled trial.

SETTING

Three West of Scotland general medical practices: one rural, one urban/deprived, and one urban/affluent.

PARTICIPANTS

600 women aged 16-30 years, 200 from each of three participating practices selected at random from a sample of West of Scotland practices that had expressed interest in the study. The women could opt out of the study. Those who did not were randomly assigned to one of three groups: postal screening, opportunistic screening, or usual care.

RESULTS

38% (85 of 221) of the approached practices expressed interest in the study. Data were collected successfully from the three participating practices. There were considerable workload implications for staff. Altogether 124 of the 600 women opted out of the study. During the four month study period, 55% (81 of 146) of the control group attended their practice but none was offered screening. Some 59% (80 of 136) women in the opportunistic group attended their practice of whom 55% (44 of 80) were offered screening. Of those, 64% (28 of 44) accepted, representing 21% of the opportunistic group. Forty eight per cent (59 of 124) of the postal group returned samples.

CONCLUSION

A randomised controlled trial comparing postal and opportunistic screening for chlamydial infection in general practice is feasible, although resource intensive. There may be problems with generalizing from screening trials in which patients may opt out from the offer of screening.

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.

The laboratory diagnosis of Chlamydia trachomatis infections

Lower genital tract infections with Chlamydia trachomatis are predominantly asymptomatic in men and women. Diagnostic technology has provided several approaches to the diagnosis of C trachomatis. Outside of cells, Chlamydia can die or degrade without optimal storage and transportation. Because some of the other assays perform better on certain specimen types, it is important for laboratories to recognize these differences and provide advice to physicians and nurses collecting patient specimens, with the objective of diagnosing lower genital tract infections to prevent transmission and upper tract damage. Most invasive specimens, such as cervical or urethral swabs, may be collected for culture, antigen or nucleic acid detection. Noninvasive samples such as first-void urine and vaginal swabs can be easily collected by the patient; these samples must be tested by more sensitive nucleic acid amplification tests. These newer investigative strategies should enable implementation of screening programs to identify and treat partners. Serology has not been particularly useful for the diagnosis of acute C trachomatis infections in adults. Presently, it appears that antibiotic-resistant C trachomatis is not a clinical problem. Laboratories providing C trachomatis diagnosis require participation in continuous quality improvement programs.

Gender Differences in Bacterial STIs in Canada

HEALTH ISSUE: The incidence of bacterial sexually transmitted infections (STIs) is rising in Canada. If these curable infections were prevented and treated, serious long-term sequelae including infertility, and associated treatment costs, could be dramatically reduced. STIs pose a greater risk to women than men in many ways, and further gender differences exist in screening and diagnosis. KEY FINDINGS: Reported incidence rates of chlamydia, gonorrhea, and infectious syphilis declined until 1997, when the trend began to reverse. The reported rate of chlamydia is much higher among women than men, whereas the reverse is true for gonorrhea and infectious syphilis. Increases in high-risk sexual behaviour among men who have sex with men were observed after the introduction of potent HIV suppressive therapy in 1996, but behavioural changes in women await further research. DATA GAPS AND RECOMMENDATIONS: STI surveillance in Canada needs improvement. Reported rates underestimate the true incidence. Gender-specific behavioural changes must be monitored to enhance responsiveness to groups at highest risk, and more research is needed on effective strategies to promote safer sexual practices. Geographic and ethnic disparities, gaps, and needs must be addressed. Urine screening for chlamydia should be more widely available for women as well as men, particularly among high-risk men in order to prevent re-infections in their partners. As women are more likely to present for health examinations (e.g. Pap tests), these screening opportunities must be utilized. Female-controlled methods of STI prevention, such as safer topical microbicides, are urgently needed.

Performance of the MagNA pure LC robot for extraction of Chlamydia trachomatis and Neisseria gonorrhoeae DNA from urine and swab specimens

DNA from uncentrifuged urines (n = 195 and n = 202) and cervical swabs (n = 221 and n = 601) was extracted by the MagNA Pure LC robot and the Amplicor method to validate the robot's extraction for Chlamydia trachomatis and Neisseria gonorrhoeae testing by Roche PCR. The robot provided a highly sensitive and specific method of DNA extraction.

PCR-based diagnostics for infectious diseases: uses, limitations, and future applications in acute-care settings

Molecular diagnostics are revolutionising the clinical practice of infectious disease. Their effects will be significant in acute-care settings where timely and accurate diagnostic tools are critical for patient treatment decisions and outcomes. PCR is the most well-developed molecular technique up to now, and has a wide range of already fulfilled, and potential, clinical applications, including specific or broad-spectrum pathogen detection, evaluation of emerging novel infections, surveillance, early detection of biothreat agents, and antimicrobial resistance profiling. PCR-based methods may also be cost effective relative to traditional testing procedures. Further advancement of technology is needed to improve automation, optimise detection sensitivity and specificity, and expand the capacity to detect multiple targets simultaneously (multiplexing). This review provides an up-to-date look at the general principles, diagnostic value, and limitations of the most current PCR-based platforms as they evolve from bench to bedside.

Can the diagnosis of pelvic inflammatory disease be excluded without a bimanual examination?

Now that urine-based tests are available for detection of Chlamydia and gonorrhea, we sought to determine whether history alone could be used to exclude pelvic inflammatory disease (PID) and thus preclude a bimanual examination. The study design was a retrospective chart review. The study population included females aged 15-24 years diagnosed with PID. Outcome measures were documentation of screening symptoms (abdominal pain, dyspareunia, or abnormal vaginal bleeding) in the medical record. Our primary analysis was sensitivity of screening symptoms for identifying patients with PID. At least 1 of the 3 screening symptoms was reported by 93% of the PID group. If absence of all 3 screening symptoms were used as a screening instrument to exclude a bimanual examination, many women with lower genital tract symptoms could be evaluated noninvasively. However, this approach could result in delayed diagnosis of PID in a small number of patients. Before this strategy is adopted, a large prospective study is needed.

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.

Cost-Effectiveness Analysis of Screening Adolescent Males for Chlamydia On Admission to Detention

BACKGROUND

Chlamydia trachomatis infections can lead to serious and costly sequelae. Because chlamydia is most often asymptomatic, many infected youth do not seek testing. Entry to a detention system provides an opportunity to screen and treat many at-risk youth. GOAL The goal of this study was to determine the cost-effectiveness of screening male youth for chlamydia on entry to detention.

STUDY DESIGN

Incremental cost-effectiveness of 3 chlamydia screening strategies was compared for a hypothetical cohort of 4000 male youth per year: 1) universal chlamydia screening using a urine-based nucleic acid amplification test (NAAT), 2) selective NAAT screening of urine leukocyte esterase (LE)-positive urines, and 3) no screening. The model incorporated programmatic costs of screening and treatment and medical cost savings from sequelae prevented in infected males and female partners. The analysis was conducted from the healthcare system perspective.

RESULTS

Chlamydia prevalence in the sampled population of 594 was 4.8%, and the average number of female sexual partners/infected male was 1.6. Universal NAAT screening was the most cost-effective strategy, preventing 37 more cases of pelvic inflammatory disease (PID) and 3 more cases of epididymitis than selective screening and saving an additional 24,000 dollars. The analysis was sensitive to NAAT cost, LE sensitivity, rate of PID development, PID sequelae cost, and number of female partners. Universal screening remained the most cost saving for prevalence as low as 2.8% or higher.

CONCLUSIONS

Universal chlamydia screening of adolescent males on entry to detention was the most cost-effective strategy. Savings are primarily the result of the prevention of PID in recent and future partners of index males. Screening detained male youth using a urine-based NAAT provides a public health opportunity to significantly reduce chlamydia infections in youth at risk for sexually transmitted diseases.

Prevalence of Chlamydia trachomatis infections and specimen collection preference among women, using self-collected vaginal swabs in community settings

BACKGROUND

Chlamydia trachomatis is a common, often asymptomatic sexually transmitted infection.

GOAL

The goal was to estimate the prevalence and predictors of C. trachomatis among young women using self-collected vaginal swabs, and the preferences of women and physicians for self-testing.

STUDY DESIGN

A total of 514 attendees of university/college health clinics, adolescent birth control clinics, centers providing health services to homeless youth and adults (street health centers), a sexually transmitted diseases clinic, and family practices were tested by ligase chain reaction. Preference for self- versus provider-testing was examined.

RESULTS

Prevalence was 6.0% and was highest (18.2%) in the street health centers. In multivariate analysis, only recent contact with someone with C. trachomatis infection was significantly associated with infection (odds ratio, 7.1; 95% confidence interval, 2.5-20.0). Most women (54.2%; 256 of 472) preferred self-sampling compared with physician sampling (15.9%; 75 of 472). The majority of physicians (75.0%; 9 of 12) reported at the start and end of the study that they would use vaginal swab self-sampling if available.

CONCLUSIONS

Prevalence of infection in young women attending homeless youth organizations was high. Self-sampling was acceptable and could facilitate screening in high-risk women who do not regularly access health services.

Assessment of Chlamydia trachomatis infection of semen specimens by ligase chain reaction

Diagnostic potential of the Chlamydia trachomatis ligase chain reaction system (LCx) to assess the presence of C. trachomatis in urine and semen specimens was evaluated. Paired urine and semen specimens from 153 asymptomatic male partners of subfertile couples attending our Center for Reproductive Medicine were examined by LCx. As controls, 19 semen samples from four donors who were participating in the programme for artificial insemination were used. Of these, 12 samples had previously been shown to be C. trachomatis-positive by an in-house PCR. C. trachomatis was detected by LCx in seven of 153 (5 %) urine samples. None of the 153 semen samples tested positive by LCx. Also, none of the 12 C. trachomatis-containing control semen samples were positive by LCx. By in-house PCR, seven urine specimens and two of 153 (1 %) semen samples tested positive. The corresponding urine samples of these male partners were also C. trachomatis-positive, as well as the 12 C. trachomatis-containing samples from donors. In conclusion, LCx is not sensitive enough to assess the presence of C. trachomatis in semen specimens; therefore, this method is not recommended to routinely screen semen specimens from donors who participate in programmes for artificial insemination or male partners of subfertile couples for C. trachomatis.

Sustained high prevalence of Chlamydia trachomatis infections in female army recruits

BACKGROUND

Chlamydia trachomatis infections are prevalent among young sexually active females, have serious sequelae, and are mostly asymptomatic. Screening and treatment of infected females has been demonstrated to prevent sequelae such as pelvic inflammatory disease.

GOAL

To assess prevalence and risk factors for chlamydia infection in US Army female recruits, whether these changed over time, and to examine variables contributing to any observed patterns.

STUDY DESIGN

Prevalence study of 23,010 non-healthcare-seeking female Army recruits enrolled in a chlamydia screening program at Fort Jackson, SC, from January 1996 through June 1999. Each of the 4-year cohorts was examined separately for prevalence and risk factors.

MAIN OUTCOME MEASURES

Urine-based testing for C trachomatis by ligase chain reaction was used to determine prevalence, and questionnaires were used to collect demographic and risk information. State home of record for each recruit was transformed into Public Health reporting region: West, Midwest, South, Northeast, and Territories.

RESULTS

Prevalence for all years was 9.51%, but a progressive increase from 8.51% to 9.92% occurred over the course of study (P=0.018). The proportion of individuals reporting specific risk factors during the 90 days preceding the study generally decreased over time. In a regression model, significant risk factors for infection included black race, age 25 years or younger, home-of-record from the South, being screened during years 3 and 4 of the study, more than one sex partner, a new sex partner, and history of any sexually transmitted disease. Condom use was protective. In another model controlling for age and home-of-record from the South, being screened in years 2, 3, and 4 of the study were significantly predictive for being chlamydia positive.

CONCLUSION

A high and slightly increasing prevalence of C trachomatis infection was observed among young females entering the military over 4 consecutive years. Young age, black race, home-of-record from the South, more than one sex partner, a new sex partner, condom use, and a history of having a sexually transmitted disease were correlates of chlamydia infection. Sustained high rates of C trachomatis infection in this population provide clear justification for a chlamydia control program for young women entering the Army consisting of screening at entry on the basis of age and possibly home-of-record together with continued periodic rescreening.

SUMMARY

A study of 23,010 female Army recruits demonstrated that a high prevalence of C trachomatis was sustained during 4 years of observation. Year of study, young age, and being from the South were significant predictors of infection.

Clinical management of chlamydia and gonorrhea infection in a county teaching emergency department--concerns in overtreatment, undertreatment, and follow-up treatment success

To date, several studies have examined overtreatment or undertreatment of Neisseria gonorrheae, Chlamydia trachomatis, or both in women. However, no study has looked at both subpopulations together, along with eventual treatment of disease-positive patients who were not empirically treated. This study is unique, for it looks at all of these subpopulations to assess overall efficacy of management of these diseases in women. A 1-year prospective, descriptive study was performed in a teaching county hospital Emergency Department (ED). There were 1260 women receiving a pelvic examination and routine GEN-PROBE testing for gonorrhea and chlamydia who were studied. The main outcome measures were the proportion of women disease positive and initially not treated (undertreated), the proportion of women disease negative who were initially treated (overtreated), as well as the follow-up treatment rate for those undertreated. Finally, the subpopulation of women disease positive and not empirically treated was examined in detail. Of 1260 GEN-PROBE-tested women, 81 (6.4%, 95% CI 1.1-11.7%) were disease positive and 31/81 (38.3%, 95% CI 21.2-55.4%) of these women were undertreated. Furthermore, 20/31 (64.5%, 95% CI 43.5-85.5%) women did not return for follow-up treatment. The billable health care dollars of routine GENPROBE testing per woman (n = 11/1260, 0.9%) returning for treatment as a result of the test was $4762.80 US dollars. Four hundred twenty-six (33.8%) of the 1260 women were empirically treated on the initial visit. Of these 426 initially treated women, 376 (88.3%, 95% CI 85.1-91.5%) were GEN-PROBE negative for disease (overtreated). The billable health care dollars of this overtreatment was $12,449.51 US dollars. This study demonstrates that health care providers are substantially overtreating women who are gonorrhea and chlamydia negative. This generates moral, ethical, health care, and financial concerns. Additionally, one-third of disease-positive women are not treated on initial visit and the majority of undertreated patients are not returning for subsequent treatment. This study provides support for investigating improved methods in the management of chlamydia and gonorrhea in women.

The impact of switching to polymerase chain reaction for the diagnosis of Chlamydia trachomatis infections in women

BACKGROUND

We noted a marked increase in Chlamydia trachomatis (CT) infections in the Capital Health Region of NS coincident with substitution of a PCR for an enzyme immunoassay (EIA). We reviewed our experience to determine the cost of switching and the impact on the number of new infections diagnosed.

METHODS

Information on the number of EIA and PCR tests performed on women was retrieved from an abstracted laboratory information database. We examined records of testing performed between April 1998 and December 2001. Prior to June 2001, all genital swabs were tested using the MicroTrak, II Chlamydia EIA and confirmed by direct fluorescence examination. After July 2001, genital swabs were tested using the COBAS AMPLICOR C. trachomatis test.

RESULTS

During the study period, 62,288 EIA tests were performed on specimens submitted; 2,061 (3.33%) were positive. In the six months when testing was performed by the PCR method, 9,559 PCR tests were performed, 463 (4.84%) were positive; 46% increase. In the three years before PCR testing was implemented, an average of 1,626 specimens were submitted monthly. An average of 54 tests were positive (3.3%). The cost for each positive detected by PCR was 208 dollars Cdn and 226 dollars by EIA.

CONCLUSIONS

The switch to PCR for the diagnosis of CT produced a marked increase in the number of chlamydia infections diagnosed. The recent increase in the number of reported CT cases in Canada may be due in large part to more sensitive tests. Surprisingly, the cost of each positive test by PCR was 18 dollars Cdn less than that of the EIA.

Impact of urine collection order on the ability of assays to identify Chlamydia trachomatis infections in men

BACKGROUND

Noninvasive urine samples have been used to diagnose Chlamydia trachomatis infections, with the assumption that the first-void urine (FVU), defined as the first 20 to 30 ml at any micturition, would be the optimal collection. We compared testing technologies on first, second, and third volumes for diagnosis.

GOAL

The goal was to test in nonculture assays three sequential volumes of urine from men also undergoing urethral swabbing for C trachomatis culture specimens.

STUDY DESIGN

A total of 237 men attending an STD clinic (C trachomatis prevalence, 11%) collected three containers of urine (each containing 20-30 mL) for testing in four nonculture assays. A urethral swab specimen was tested in cell culture.

RESULTS

The numbers of men positive by testing of FVU with nucleic acid amplification (LCx chlamydia), nucleic acid hybridization (PACE 2), enzyme immunoassay (Chlamydiazyme), and a leukocyte esterase dipstick were 26, 7, 14, and 11, respectively; urethral culture identified 6 of the infected men. Comparative testing of all voids from the 26 men positive by the FVU assays demonstrated a reduction of LCx-positives. Non-amplified-test positivity declined precipitously in subsequent voids, approaching zero in the third void. The presence of symptoms and time of last void up to 8 hours had little effect on the number of positives detected by LCx of FVU.

CONCLUSION

Amplified testing of FVU was most effective for diagnosing infection in these men.

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.

Female prisoners' preferences of collection methods for testing for Chlamydia trachomatis and Neisseria gonorrhoeae infection

BACKGROUND

There is an increasing reliance on noninvasive techniques to collect specimens for the detection of sexually transmitted infections. The acceptability of these methods among the general population has been explored, but little is known about their acceptability among women confined in prison.

GOAL

The goal was to compare female prisoners' preferences for collection of specimens (self-collected vaginal swab specimens, urine collection, or pelvic examination) for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

STUDY DESIGN

A cross-section of inmates in a large federal prison provided urine samples and self-collected vaginal swab specimens. Women then completed a questionnaire regarding the ease of each method and their preferences for future specimen collection.

RESULTS

A total of 535 women between the ages of 18 and 52 years (median = 33) participated in the study. More than half of the participants (57%) reported no difference between urine and swab in terms of ease of collection. Approximately 30% of participants said they would prefer to give a swab specimen in the future rather than collect urine (21%), but nearly half of the women expressed no preference for one method over the other. Most participants (60%) expressed a preference for providing a self-collected swab specimen rather than having a pelvic examination (23%), but nearly 17% expressed a preference for one over the other.

CONCLUSION

The study population of female federal prisoners expressed no aversion to the self-collection of either vaginal swab or urine specimens for STD testing. A majority of participants expressed a preference for noninvasive techniques rather than a pelvic examination.

Parallel observation of four methods for screening women under 25 years of age for genital infection with Chlamydia trachomatis

OBJECTIVES

To compare four methods of screening women for Chlamydia trachomatis in an obstetrics and gynaecology department.

STUDY DESIGN

A total of 303 healthy women under 25 years were recruited from antenatal, induced abortion, and family planning clinics. Each underwent parallel testing of endocervical specimens by enzyme immunoassay (EIA) and ligase chain reaction (LCR), vulval swabs by LCR, and urine by LCR. Outcome measures included sensitivity, specificity, acceptability of each method, and the influence of pregnancy.

RESULTS

Overall prevalence (95% CI) was 9.9% (6.8-14%). All methods had a high rate of detection (75-100%), not affected by pregnancy. Urine was most acceptable, followed by vulval swabbing.

CONCLUSIONS

Opportunistic screening of women under 25 years attending obstetric and gynaecology affiliated clinics found high rates of C. trachomatis infection. Both urine and vulval swab methods were highly sensitive, acceptable, and not affected by pregnancy status. Due to pragmatic issues surrounding the urine method, screening by vulval swabs deserves wider recognition.

Opportunistic screening for genital chlamydial infection. II: prevalence among healthcare attenders, outcome, and evaluation of positive cases

OBJECTIVES

To determine the prevalence and treatment outcomes among young women screened opportunistically for genital Chlamydia trachomatis and to evaluate the impact of screening in those participating.

DESIGN

An opportunistic screening programme (1 September 1999 to 31 August 2000) using urine samples, tested by ligase chain reaction (LCR). In-depth interviews were used for programme evaluation.

SETTING

Screening was offered in two health authorities at general practice, family planning, genitourinary medicine (GUM), adolescent sexual health, termination of pregnancy clinics and women's services in hospitals (antenatal, colposcopy, gynaecology and infertility clinics). Main participants: Sexually active women (16-24 years) attending for any reason.

MAIN OUTCOME MEASURES

Screening data: prevalence of infection by age and healthcare setting; proportion of positive patients attending for treatment. Evaluation data: participants' attitudes and views towards screening and follow up.

RESULTS

In total, 16 930 women (16-24 years) were screened. Prevalence was higher in younger women (16-20) than those aged 21-24 years and was highly variable at different healthcare settings (range 3.4%-17.6%). Prevalence was approximately 9% in general practice. The role of the project health advisers in managing results and coordinating treatment of positive individuals was essential; the vast majority of all positives were known to be treated. Women felt that screening was beneficial. Improving awareness and education about sexually transmitted infections is required to alleviate negative reactions associated with testing positive for infection.

CONCLUSIONS

Prevalence of infection outside GUM clinics is substantial and opportunistic screening using urine samples is an acceptable method of reaching individuals with infection who do not normally present at specialist clinics.

Identification of symptoms that indicate a pelvic examination is necessary to exclude PID in adolescent women

BACKGROUND

Diagnosis of chlamydia, gonorrhea, and vaginitis is now possible in adolescents using urine testing and vaginal swabs obtained by care provider or patient. However, a complete pelvic examination is necessary to diagnose pelvic inflammatory disease (PID). It is thus important to identify patients who might have pelvic inflammatory disease to assure complete gynecologic assessment of genitourinary symptoms.

PURPOSE

To determine whether adolescent patients with pelvic inflammatory disease report predictable symptoms during the medical interview and to determine what proportion of patients diagnosed with PID report at least one predictor symptom.

DESIGN

Observational study.

SETTINGS

Hospital-based adolescent clinic and Job Corps health service.

PATIENTS

A convenience sample (n = 193) of adolescent and young adult women who had a pelvic examination performed to evaluate a wide range of genitourinary symptoms.

MAIN OUTCOME MEASURE

Clinical diagnosis of pelvic inflammatory disease.

ANALYSIS

Sensitivity, specificity, and positive and negative predictive value of predictor symptoms for identifying patients given a diagnosis of pelvic inflammatory disease.

RESULTS

Twenty (10.4%) patients received a clinical diagnosis of PID. Lower abdominal pain was the most common symptom (90.0%) reported by these patients. All of the patients with PID reported either lower abdominal pain or dyspareunia in the medical history compared with 97 (56.1%) of those without PID. The presence of lower abdominal pain and/or dyspareunia in the clinical history yielded a sensitivity of 100%, specificity of 44%, and positive and negative predictive value of 17% and 100%, respectively, for identifying patients given a diagnosis of PID.

CONCLUSION

This study identified two symptoms reported in the medical history (lower abdominal pain and dyspareunia) that were associated with a clinical diagnosis of pelvic inflammatory disease. If lack of these two symptoms was used as a criterion for omitting a pelvic examination, more than one third of the patients in this study could have been evaluated for cervical and vaginal infections with urine and directly obtained vaginal swabs. Although some of these patients might have required a pelvic examination to exclude other causes of abnormal vaginal bleeding, at least 30% of the total sample could have been evaluated without a speculum and bimanual examination. If further studies support these findings, patients with symptoms suggestive of uncomplicated genitourinary infection (e.g., vaginal discharge, vaginal pruritus, or dysuria) who deny lower abdominal pain and dyspareunia can be evaluated with urine and vaginal samples in place of a speculum and bimanual examination.

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.

Pregnant adolescents at risk: sexual behaviors and sexually transmitted disease prevalence

OBJECTIVE

The purpose of this study was to determine the level of high-risk sexual behaviors and the prevalence of chlamydia and gonorrhea among pregnant adolescents.

STUDY DESIGN

These analyses used data from 203 pregnant and 209 nonpregnant adolescents who were recruited from public health clinics. Data sources included interviewer-administered questionnaires, ligase chain reaction tests for chlamydia/gonorrhea in the third trimester of pregnancy, and state health department reports of chlamydia/gonorrhea. Statistical analyses included logistic regression.

RESULTS

Pregnant adolescents were significantly more likely to have not used condoms during sexual intercourse in the past 30 days compared with nonpregnant adolescents, although other sexual risk behaviors were reduced. Nineteen percent of pregnant adolescents had chlamydia or gonorrhea diagnosed during the pregnancy.

CONCLUSION

Pregnant adolescents have high levels of sexually transmitted diseases during pregnancy, and many adolescents use condoms inconsistently. Prenatal care providers may be in a unique position to decrease sexually transmitted diseases among pregnant adolescents by encouraging the reduction of risk behaviors and aggressively screening for sexually transmitted diseases as part of routine prenatal care.

The accuracy and efficacy of screening tests for Chlamydia trachomatis: a systematic review

Screening women for lower genital tract infection with Chlamydia trachomatis is important in the prevention of pelvic inflammatory disease, ectopic pregnancy and infertility. This systematic review aims to state clearly which of the available diagnostic tests for the detection of C. trachomatis would be most effective in terms of clinical effectiveness. The review included all studies published from 1990 onward that evaluated diagnostic tests in asymptomatic, young, sexually active populations. Medline and Embase were searched electronically and key journals were hand-searched. Further studies were identified through the Internet and contact with experts in the field. All studies were reviewed by two reviewers and were scored by Irwig's assessment criteria. Additional quality assessment criteria included a documented sexual history and recording of previous chlamydial infection. The reviews were subjected to meta-analysis and meta-regression. The 30 studies that were included examined three types of DNA-based test--ligase chain reaction (LCR), PCR and gene probe--as well as enzyme immuno-assay (EIA). The results showed that while specificities were high, sensitivities varied widely across the tests and were also dependent on the specimen tested. Pooled sensitivities for LCR, PCR, gene probe and EIA on urine were 96.5%, 85.6%, 92% and 38%, respectively, while on cervical swabs the corresponding sensitivities of PCR, gene probe and EIA were 88.6%, 84% and 65%. Meta-analysis demonstrated that DNA amplification techniques performed best for both urine and swabs in low prevalence populations. We conclude that nucleic acid amplification tests used on non-invasive samples such as urine are more effective at detecting asymptomatic chlamydial infection than conventional tests, but there are few data to relate a positive result with clinical outcome.

Self-collected vaginal swabs for the detection of multiple sexually transmitted infections in adolescent girls

OBJECTIVE

To evaluate the use of self-collected vaginal swabs to test for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis, and to describe the acceptability of this technique to adolescents.

DESIGN

Comparison of a new protocol for sexually transmitted infection (STI) testing with the current standard of care, using the same subjects. Survey of attitudes regarding the self-collection technique.

SETTING

A juvenile correctional facility in western Pennsylvania.

PARTICIPANTS

Convenience sample of 133 detainees, 12-17 years of age.

INTERVENTION

Girls were invited to undergo STI screening using a self-collected vaginal swab. Polymerase chain reaction was used to test this specimen for each of the above three infections. Pelvic exams and endocervical testing were performed at the discretion of the physician performing the intake physical, independent of the study.

MAIN OUTCOME MEASURES

The number of infections diagnosed using the self-testing protocol, compared to the number diagnosed using standard practices; acceptability of the self-collection technique.

RESULTS

Twenty-four percent of sexually active subjects had one or more infections diagnosed by self-testing: 11.3% had C. trachomatis, 8.5% had N. gonorrhoeae, and 11.7% had T. vaginalis. Only 30% of subjects with infections had pelvic exams while detained; therefore 70% of girls with infections would have been missed in the absence of the self-testing option. The self-collection technique was acceptable to 95% of subjects.

CONCLUSIONS

STI testing using self-collected vaginal specimens is highly acceptable to adolescent girls, and can dramatically increase the detection rate for these three treatable infections when pelvic exams are not performed.