Laboratory Aspects of Screening Men for Chlamydia trachomatis in the New Millennium

Chlamydia trachomatis: From Urogenital Infections to the Pathway of Infertility

Chlamydia trachomatis (CT) is a major cause of sexually transmitted infections (STIs) worldwide, with significant implications for reproductive health. The bacterium's genome contains highly polymorphic regions, influencing both the type and severity of infections. These genetic variations, particularly those occurring in the major outer membrane protein (MOMP) gene, are critical for classifying the bacterium into distinct serovars and enable CT to adapt to diverse host environments, contributing to its immune evasion, persistence, and pathogenicity. Persistent or untreated urogenital infections can lead to chronic inflammation, tissue damage, and pelvic inflammatory disease, ultimately increasing the risk of ectopic pregnancy, spontaneous abortion, and infertility. This review consolidates current knowledge on the genetic diversity of CT, its potential role in modulating infection outcomes, and its immune evasion mechanisms. By integrating scientific evidence linking chlamydial infections to infertility, we underscore the urgent need for targeted research to address this critical public health challenge.

Using an agent-based sexual-network model to analyze the impact of mitigation efforts for controlling chlamydia

Chlamydia trachomatis (Ct) is the most reported sexually transmitted infection in the United States, with a major cause of infertility, pelvic inflammatory disease, and ectopic pregnancy among women. Despite decades of screening women for Ct, rates increase among young African Americans (AA). We create and analyze a heterosexual agent-based network model to help understand the spread of Ct. We calibrate the model parameters to agree with survey data showing Ct prevalence of 12% of the women and 10% of the men in the 15-25 year-old AA in New Orleans, Louisiana. Our model accounts for both long-term and casual partnerships. The network captures the assortative mixing of individuals by preserving the joint-degree distributions observed in the data. We compare the effectiveness of intervention strategies based on randomly screening men, notifying partners of infected people, which includes partner treatment, partner screening, and rescreening for infection. We compare the difference between treating partners of an infected person both with and without testing them. We observe that although increased Ct screening, rescreening, and treating most of the partners of infected people will reduce the prevalence, these mitigations alone are not sufficient to control the epidemic. The current practice is to treat the partners of an infected individual without first testing them for infection. The model predicts that if a sufficient number of the partners of all infected people are tested and treated, then there is a threshold condition where the epidemic can be mitigated. This threshold results from the expanded treatment network created by treating an individual's infected partners' partners. Although these conclusions can help design future Ct mitigation studies, we caution the reader that these conclusions are for the mathematical model, not the real world, and are contingent on the validity of the model assumptions.

Promoting safe sexual practices and sexual health maintenance in pediatric and young adult solid organ transplant recipients

The majority of Americans make their sexual debut during their adolescent years. Preventing pregnancy and STI during this period is vital to ensuring health and safety. As survival has improved after pediatric SOT, chronically immunosuppressed adolescents seek guidance in their medical home on matters of sexual health. Transplant practitioners often do not feel equipped to fully address these needs. This review serves as an introductory sexual preventive care resource for adolescent and young adult (AYA) SOT recipients. First, we review data on safety, efficacy, and use of contraceptive options currently available for transplant recipients with child-bearing potential. Then, we suggest a personalized sexual health discussion focusing on the diagnosis and prevention of STIs in adolescent and young adult transplant recipients. Finally, we present recommendations for STI screening of asymptomatic patients, use of index of suspicion and diagnostic testing in symptomatic patients, and opportunities to optimize STI prevention strategies. Data compiled from studies of adult SOT recipients, general population studies, and published guidelines are often extrapolated for use, as limited data exist in AYA SOT recipients. This informational dearth underscores the need for future research to better characterize the unique needs of AYA SOT recipients.

Clinician-collected urethra swab: A good alternative sample type using cobas 4800 system for Chlamydia trachomatis and Neisseria gonorrhoeae in men

Background

Nucleic acid amplification tests (NAATs) are being used increasing to detection of CT (Chlamydia trachomatis) and NG (Neisseria gonorrhoeae) infections for superior sensitivity and specificity than other tests. Male first‐void urine (FVU) sample is the optimal sample type for detection of CT and NG by NAATs. Although not being the recommended by NAATs, clinician‐collected urethra swab (CCUS) is perhaps a good alternative sample type compared with the FVU sample in men.

Methods

Paired samples (FVU and CCUS) from one hundred male outpatients were simultaneously detected by urine pattern and swab pattern using cobas 4800 CT/NG assay on cobas 4800 system for the detection of CT and NG, respectively. And twenty‐one positive controls were also detected on cobas 4800 system.

Results

The CT/NG cycle thresholds (Ct) value of urine pattern is lower than that of swab pattern for the same positive samples (clinical samples and positive controls) on the cobas 4800 CT/NG assay. The final CT/NG results of two sample patterns from patients were highly consistent except for four discordant results.

Conclusion

CCUS is validated for a good alternative sample type for the CT/NG detection on the cobas 4800 system in this study.

Utilization of the Cepheid Xpert® CT/NG Sample Adequacy Control to Determine the Influence of the Urethral Swab on Cellular Content in Post-Swab versus Pre-Swab Urine

Chlamydia trachomatis/Neisseria gonorrhoeae assay performance in males is typically determined using post-swab urine, though pre-swab urine is used in practice. We collected swabs and urine from men and used the Cepheid Xpert® CT/NG sample adequacy control to determine the effect of swab collection on urine cellular content. No difference was observed.

Chronic Infection of the Prostate by Chlamydia muridarum Is Accompanied by Local Inflammation and Pelvic Pain Development

BACKGROUND

Chlamydia trachomatis urogenital infections are the leading cause of sexually transmitted bacterial infections. Although the prevalence of chlamydial infection is similar in men and women, current research is mainly focused on women, neglecting the study of male genital tract infections. We, therefore, investigated Chlamydia infection in the rodent male genital tract.

MATERIALS AND METHODS

Male NOD and C57BL/6 mice were inoculated in the meatus urethra with C. muridarum. Bacterial DNA, leukocyte infiltration of male genital tract tissues, pelvic pain, and Chlamydia-specific immune responses were analyzed at different time points.

RESULTS AND CONCLUSIONS

The inoculation of C. muridarum in the meatus urethra of male mice resulted in an ascending and widely disseminated infection of the male genital tract. C. muridarum remained longer and with the highest bacterial burdens in the prostate, thus showing a special tropism for this organ. Infection caused leukocyte infiltration, mainly composed by neutrophils, and also induced early pelvic pain development that rapidly dropped and resolved as the infection became chronic. Bacterial load and leukocyte infiltration was observed in all prostate lobes, although dorsolateral prostate was the most affected lobe. Interestingly, immune responses induced by both mice strains were characterized by the production of high levels of IL-10 during early stages of the infection, with highest and sustained levels observed in NOD mice, which showed to be less efficient in clearing the infection. Chronic infection of the prostate accompanied by local inflammation and pelvic pain development described herein have important implications for the improvement of the diagnosis and for the design of new efficient therapies. Prostate 77:517-529, 2017. © 2017 Wiley Periodicals, Inc.

Self-collected glans/meatal 'dry' swab specimen and NAAT technology detects Chlamydia trachomatis and Neisseria gonorrhoeae - implications for public policy changes

Increasing Chlamydia trachomatis (CT) rates and ever-present Neisseria gonorrhoeae (NG) infections in women have given rise in the past to consideration of male screening programs in order to address the silent male reservoir. Non-medical venues (e.g. home collection, restrooms or other private locations) may be viable venues to reach certain populations that in the past have not been accessed. Effortlessly collected, non-invasive, self-collected male specimens that are stable and easy to transport would enhance the success of male screening programs. We designed a head-to-head study to consider the effectiveness of non-invasive self-collected glans/meatal dry swab (SCS) specimens to detect CT and NG nucleic acid when compared to traditional clinician-collected swab (CCS) specimens and first-catch urine (FCU) specimens. A total of 284 male patients were included in the study. Specimens were processed using the Becton Dickinson ProbeTec ET system. The overall sensitivity of SCS was 91.1% with a specificity of 99.2%. There was an overall SCS agreement of 97.7% with CCS specimens and 90.4% with FCU specimens. Dry swab specimens are easy to collect, transport and test. Non-invasive dry self-collected glans/meatal swab specimens are a viable specimen choice.

The Ballseye programme: a mixed-methods programme of research in traditional sexual health and alternative community settings to improve the sexual health of men in the UK

Background

Sexually transmitted infection (STI) diagnoses are increasing and efforts to reduce transmission have failed. There are major uncertainties in the evidence base surrounding the delivery of STI care for men.

Aim

To improve the sexual health of young men in the UK by determining optimal strategies for STI testing and care

Objectives

To develop an evidence-based clinical algorithm for STI testing in asymptomatic men; model mathematically the epidemiological and economic impact of removing microscopy from routine STI testing in asymptomatic men; conduct a pilot randomised controlled trial (RCT) of accelerated partner therapy (APT; new models of partner notification to rapidly treat male sex partners of people with STIs) in primary care; explore the acceptability of diverse venues for STI screening in men; and determine optimal models for the delivery of screening.

Design

Systematic review of the clinical consequences of asymptomatic non-chlamydial, non-gonococcal urethritis (NCNGU); case–control study of factors associated with NCNGU; mathematical modelling of the epidemiological and economic impact of removing microscopy from asymptomatic screening and cost-effectiveness analysis; pilot RCT of APT for male sex partners of women diagnosed withChlamydia trachomatisinfection in primary care; stratified random probability sample survey of UK young men; qualitative study of men’s views on accessing STI testing; SPORTSMART pilot cluster RCT of two STI screening interventions in amateur football clubs; and anonymous questionnaire survey of STI risk and previous testing behaviour in men in football clubs.

Settings

General population, genitourinary medicine clinic attenders, general practice and community contraception and sexual health clinic attenders and amateur football clubs.

Participants

Men and women.

Interventions

Partner notification interventions: APTHotline [telephone assessment of partner(s)] and APTPharmacy [community pharmacist assessment of partner(s)]. SPORTSMART interventions: football captain-led and health adviser-led promotion of urine-based STI screening.

Main outcome measures

For the APT pilot RCT, the primary outcome, determined for each contactable partner, was whether or not they were considered to have been treated within 6 weeks of index diagnosis. For the SPORTSMART pilot RCT, the primary outcome was the proportion of eligible men accepting screening.

Results

Non-chlamydial, non-gonococcal urethritis is not associated with significant clinical consequences for men or their sexual partners but study quality is poor (systematic review). Men with symptomatic and asymptomatic NCNGU and healthy men share similar demographic, behavioural and clinical variables (case–control study). Removal of urethral microscopy from routine asymptomatic screening is likely to lead to a small rise in pelvic inflammatory disease (PID) but could save > £5M over 20 years (mathematical modelling and health economics analysis). In the APT pilot RCT the proportion of partners treated by the APTHotline [39/111 (35%)], APTPharmacy [46/100 (46%)] and standard patient referral [46/102 (45%)] did not meet national standards but exceeded previously reported outcomes in community settings. Men’s reported willingness to access self-sampling kits for STIs and human immunodeficiency virus infection was high. Traditional health-care settings were preferred but sports venues were acceptable to half of men who played sport (random probability sample survey). Men appear to prefer a ‘straightforward’ approach to STI screening, accessible as part of their daily activities (qualitative study). Uptake of STI screening in the SPORTSMART RCT was high, irrespective of arm [captain led 28/56 (50%); health-care professional led 31/46 (67%); poster only 31/51 (61%)], and costs were similar. Men were at risk of STIs but previous testing was common.

Conclusions

Men find traditional health-care settings the most acceptable places to access STI screening. Self-sampling kits in football clubs could widen access to screening and offer a public health impact for men with limited local sexual health services. Available evidence does not support an association between asymptomatic NCNGU and significant adverse clinical outcomes for men or their sexual partners but the literature is of poor quality. Similarities in characteristics of men with and without NCNGU precluded development of a meaningful clinical algorithm to guide STI testing in asymptomatic men. The mathematical modelling and cost-effectiveness analysis of removing all asymptomatic urethral microscopy screening suggests that this would result in a small rise in adverse outcomes such as PID but that it would be highly cost-effective. APT appears to improve outcomes of partner notification in community settings but outcomes still fail to meet national standards. Priorities for future work include improving understanding of men’s collective behaviours and how these can be harnessed to improve health outcomes; exploring barriers to and facilitators of opportunistic STI screening for men attending general practice, with development of evidence-based interventions to increase the offer and uptake of screening; further development of APT for community settings; and studies to improve knowledge of factors specific to screening men who have sex with men (MSM) and, in particular, how, with the different epidemiology of STIs in MSM and the current narrow focus on chlamydia, this could negatively impact MSM’s sexual health.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Influence of storage time on DNA of Chlamydia trachomatis, Ureaplasma urealyticum, and Neisseria gonorrhoeae for accurate detection by quantitative real-time polymerase chain reaction

The shipment and storage conditions of clinical samples pose a major challenge to the detection accuracy of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Ureaplasma urealyticum (UU) when using quantitative real-time polymerase chain reaction (qRT-PCR). The aim of the present study was to explore the influence of storage time at 4°C on the DNA of these pathogens and its effect on their detection by qRT-PCR. CT, NG, and UU positive genital swabs from 70 patients were collected, and DNA of all samples were extracted and divided into eight aliquots. One aliquot was immediately analyzed with qRT-PCR to assess the initial pathogen load, whereas the remaining samples were stored at 4°C and analyzed after 1, 2, 3, 7, 14, 21, and 28 days. No significant differences in CT, NG, and UU DNA loads were observed between baseline (day 0) and the subsequent time points (days 1, 2, 3, 7, 14, 21, and 28) in any of the 70 samples. Although a slight increase in DNA levels was observed at day 28 compared to day 0, paired sample t-test results revealed no significant differences between the mean DNA levels at different time points following storage at 4°C (all P>0.05). Overall, the CT, UU, and NG DNA loads from all genital swab samples were stable at 4°C over a 28-day period.

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

BACKGROUND

Self-obtained penile-meatal swabs and urine specimens have been used for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) for outreach screening in men.

OBJECTIVE

To compare the sensitivity of self-collected male penile-meatal swabs and urine for the detection of CT, NG and TV.

METHODS

Matching penile-meatal swabs and urines were collected at home after recruitment to the study; via the internet programme, http://www.iwantthekit.org. The instructions directed the participant to place the tip of a Copan flocked swab at the meatal opening of the urethra to collect the penile-meatal sample. Two ml of urine was collected after the swab onto a Copan sponge-on-a-shaft collection device. Both swab and urine were placed into individual Aptima transport media tubes and mailed to the laboratory for testing. All specimens were tested for CT and NG using the GenProbe Aptima Combo2 Assay and for TV using GenProbe Aptima Analyte Specific Reagents with TV oligonucleotides.

RESULTS

Of 634 men, 86 (13.6%) were positive for CT, 9 (1.4%) were positive for NG and 56 (9.3%) positive for TV. For CT, swab sensitivity was 81/86 (94.2%), and urine sensitivity was 66/86 (76.7%). For NG, swab sensitivity was 9/9 (100%) and urine sensitivity was 8/9 (88.9%). For TV, swab sensitivity was 45/56 (80.4%) and urine sensitivity was 22/56 (39.3%).

CONCLUSIONS

Self-obtained penile-meatal swabs provided for the detection of more CT, NG and TV, than urine specimens.

Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Tests for Chlamydia trachomatis and Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being ≥ 99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being ≥ 99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts.

A randomized trial of home versus clinic-based sexually transmitted disease screening among men

BACKGROUND

Preventing sexually transmitted diseases (STD) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) remains a public health challenge. The U.S. Preventive Services Task Force suggests STD screening among men will likely lead to a decrease in infection rates of women. However, innovative approaches are necessary to increase the traditionally low rates of male screening. The purpose of this study is to compare the acceptability and effectiveness of home-based versus clinic-based urine screening for CT and GC in men.

METHODS

We conducted a randomized clinical trial of 200 men aged 18 to 45 years who reside in St. Louis, MO. Men were enrolled via telephone and randomly assigned to receive a free urine CT/GC screening kit either in-person at the research clinic or to have it mailed to the participant's preferred address. Participants completed questionnaires at baseline and 10 to 12 weeks postenrollment. The primary outcome was whether STD screening was completed.

RESULTS

Sixty percent (120/200) completed STD screening. Men assigned to home-based screening were 60% more likely to complete screening compared with clinic-based screening (72% vs. 48%, RRadj = 1.6, 95% CI = 1.3, 2.00). We identified 4 cases of CT or GC in the home-based group compared with 3 cases of CT in the clinic group. Men who completed screening were significantly more likely to be white, younger, and college educated.

CONCLUSIONS

Home-based screening for CT and GC among men is more acceptable than clinic-based screening and resulted in higher rates of screening completion. Incorporating home-based methods as adjuncts to traditional STD screening options shows promise in improving STD screening rates in men.

Male rat genital tract infection with Chlamydia muridarum has no significant consequence on male fertility

PURPOSE

Chlamydia trachomatis infection of the male genital tract was proposed to alter male fertility. We studied the putative consequences of chlamydial male genital tract infection on semen quality and male fertility in an experimental rat model of infection.

MATERIALS AND METHODS

We used 36 male and 40 female Wistar rats. Male genital infection was created by inoculating Chlamydia muridarum in the meatal urethra. The presence of C. muridarum was evaluated by polymerase chain reaction in semen and male genital tract organs early (15 days) and late (80 days) after infection. Sperm quality parameters were assayed in seminal and epididymal sperm from sham infected and infected rats. Mating studies with sexually mature females were performed and fertility parameters were assayed, including potency, fecundity and fertility indexes, fetal size, and pre-implantation and post-implantation embryo loss.

RESULTS

Male rats showed ascending, disseminated infection 15 days after infection. Bacteria persisted in the prostate and seminal vesicles 80 days after infection. C. muridarum was detected in semen in most rats regardless of acute or chronic infection. Seminal or epididymal sperm quality did not differ in infected and sham infected rats 15 or 80 days after infection. Sperm apoptosis was also minimal in infected rats. No differences were observed in fertility parameters between infected and sham infected rats.

CONCLUSIONS

C. muridarum infects the rat male genital tract and persists mainly in the prostate. Although C. muridarum was detected in semen during acute and chronic infection, no alterations in sperm quality were observed. C. muridarum infection does not impair male fertility.

Is asymptomatic non-chlamydial non-gonococcal urethritis associated with significant clinical consequences in men and their sexual partners: a systematic review

Opinions are divided on whether to screen asymptomatic men for non-chlamydial non-gonococcal urethritis (NCNGU). We systematically reviewed the literature to determine whether male asymptomatic NCNGU is associated with significant clinical outcomes for men and/or their sexual partners. We searched electronic databases and reference lists from retrieved articles and reviews. No studies reporting clinical outcomes in men with asymptomatic NCNGU were identified. Two eligible studies report rates of sexually transmitted infections (STIs) in female partners of men with asymptomatic NCNGU; Chlamydia trachomatis was detected in 2.4% and 8.3% of these women. The evidence available is insufficient in quality and breadth to enable us to conclude whether asymptomatic NCNGU is associated with significant health consequences for men or their sexual partners; however, clinical consequences of asymptomatic NCNGU are poorly investigated. Clinicians should be aware of the limitations of the evidence on which current screening guidelines for asymptomatic men are based.

2010 European guideline for the management of Chlamydia trachomatis infections

This guideline aims to provide comprehensive information regarding the management of infections caused by Chlamydia trachomatis in European countries. The recommendations contain important information for physicians and laboratory staff working with sexually transmitted infections (STIs) and/or STI-related issues. Individual European countries may be required to make minor national adjustments to this guideline as some of the tests or specific local data may not be accessible, or because of specific laws.

First report of performance of the Versant CT/GC DNA 1.0 assay (kPCR) for detection of Chlamydia trachomatis and Neisseria gonorrhoeae

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

Performance of the Abbott RealTime CT/NG for detection of Chlamydia trachomatis and Neisseria gonorrhoeae

A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.

Questioning the value of screening for gonorrhoea in symptomless heterosexual men

These two papers discuss whether gonorrhoea screening of asymptomatic heterosexual men with no contact history should continue in UK genitourinary medicine clinics. Currently, most clinics routinely test all attenders. This requires an estimated 330,000 tests annually to detect 915 positives (1 in 361). The benefits to these patients are uncertain but the costs are huge and could fund currently unprovided services such as oral contraceptive provision or HIV testing before terminations of pregnancy. However stopping testing would deny individuals the reassurance they seek, prevent early detection of outbreaks and fail to detect carriers who go on to cause morbidity in their partners. On this view, the availability of non-invasive tests should be used to widen screening.

Genital Chlamydia trachomatis infections

Chlamydia trachomatis infections affect young, sexually active persons. Risk factors include multiple partners and failure to use condoms. The incidence of infection has increased in the past 10 years. Untreated C. trachomatis infections are responsible for a large proportion of salpingitis, ectopic pregnancy, infertility and, to a lesser extent, epididymitis. Screening is a possible intervention to control the infection, which is often asymptomatic. The emergence of lymphogranuloma venereum proctitis in men who have sex with men, in Europe, and of a variant with a deletion in the cryptic plasmid, in Sweden, are new features of C. trachomatis infections in the last years. A diagnosis is best made by using nucleic acid amplification tests, because they perform well and do not require invasive procedures for specimen collection. Single-dose therapy has been a significant development for treatment of an uncomplicated infection of the patient and his or her sexual partner.

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.

Evaluation of self-collected glans and rectal swabs from men who have sex with men for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by use of nucleic acid amplification tests

Self-collected glans and rectal swab specimens from men who have sex with men (MSM) may be appropriate, convenient specimens for testing. We evaluated the use of self-collected swabs for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by a transcription-mediated amplification test (AC2; Aptima Combo 2; Gen-Probe Inc.) and a strand displacement amplification test (SDA; ProbeTec; Becton Dickinson Co.) in MSM seen at the city sexually transmitted disease clinic in San Francisco, CA. For the glans swab specimen, subjects enrolled early in the study rolled a Dacron swab across the meatus three times (method 1). A slightly more invasive procedure was performed later in the study: the subjects inserted the swab 1/4 in. into the urethra, rotated the swab, and then withdrew the swab (method 2). MSM self-collected a rectal swab specimen and also provided first-catch urine (FCU). Additional rectal swab samples were then obtained by the clinician. For the detection of C. trachomatis and N. gonorrhoeae, all swabs were evaluated by AC2 and SDA, FCU was tested by AC2, and the clinician-collected rectal swabs were cultured. A rectal true-positive (TP) result was defined as a culture-positive result for C. trachomatis or N. gonorrhoeae, two or more positive nucleic acid amplification test (NAAT) results, or a single NAAT-positive result confirmed by an alternate amplification method (the Aptima C. trachomatis or N. gonorrhoeae test). A glans TP result was defined as a positive result for FCU, positive results for both glans specimens (one tested by AC2 and one tested by SDA), or a positive result for a single glans specimen confirmed by an alternate amplification method. The prevalence rates of C. trachomatis and N. gonorrhoeae by testing of FCU were 6.8% (60/882 specimens) and 12.2% (108/882 specimens), respectively. Mixed results were obtained with the glans swab: N. gonorrhoeae detection by AC2 and SDA (method 1) had the best performance (sensitivities, >92%) with samples from a population with a higher prevalence of infection, but their performance for the detection of C. trachomatis was poor and varied by collection method (sensitivities, 56 to 68%). The prevalence rates of C. trachomatis and N. gonorrhoeae in the rectum were 7.3% (66/907 specimens) and 9.4% (83/882 specimens), respectively. The sensitivities of the tests with self-collected and clinician-collected rectal swab specimens were comparable (for C. trachomatis, 41% and 44%, respectively, by SDA and 82% and 71%, respectively, by AC2; for N. gonorrhoeae, 77% and 68%, respectively, by SDA and 84% and 78%, respectively, by AC2). AC2 and SDA were far superior to culture for the detection of C. trachomatis and N. gonorrhoeae in the rectum, with both tests detecting at least twice as many infections. While we found self-collected rectal swabs from MSM to be valid specimens for testing, the sensitivities of the tests with glans swab specimens were disappointing except for those from patients with symptomatic N. gonorrhoeae infections. Self-collected glans swab specimens may not be appropriate for the detection of C. trachomatis or for the detection of N. gonorrhoeae in low-risk or asymptomatic patients by AC2 and SDA, and we would not recommend their use on the basis of our results. Further studies are needed.

The cost-effectiveness of screening men for Chlamydia trachomatis: a review of the literature

BACKGROUND

An important consideration in determining whether to implement or continue a program to screen men for chlamydia is its cost-effectiveness. A review of the literature on the cost-effectiveness of screening men for chlamydia could potentially provide guidance.

METHODS

An Ovid Medline search was conducted for articles published between 1990 and July 2007 using terms for cost, chlamydia, and male. This search returned 175 articles; 25 were retained after eliminating those not relevant to cost-effectiveness studies of male chlamydia screening. We added 4 articles that were in-press or are published in this issue, for a total of 29. These articles were examined for common themes and their results summarized.

RESULTS

The reviewed studies examined both proactive and opportunistic screening and included screening of risk groups and of the general population. Some older studies included enzyme immunoassays; more recent studies featured nucleic acid amplification assays. Six studies used dynamic transmission models. Fourteen studies analyzed male and female chlamydia screening interventions. Several contained sufficient data to examine the cost-effectiveness of male screening compared with female screening. Male screening was preferred to expanded female screening in 1 study. In other studies, combined male and female screening programs were cost-saving.

CONCLUSIONS

Studies comparing chlamydia screening in men with chlamydia screening in women may be the most useful for guidance to programs. The studies which compare the 2 generally have found that screening men from the general population is not preferred to screening women from the general population, although 1 study found that screening of men from risk groups can be cost-effective compared with screening women from the general population.