Effect of nucleic acid amplification testing on detection of extragenital gonorrhea and chlamydial infections in men who have sex with men sexually transmitted disease clinic patients

Patterns of Extragenital Chlamydia and Gonorrhea in Women and Men Who Have Sex With Men Reporting a History of Receptive Anal Intercourse

BACKGROUND

Screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in men who have sex with men is risk based. Despite high frequencies of oral and receptive anal intercourse (RAI) among women, extragenital screening is not recommended.

METHODS

Women (n = 175) and men who have sex with men (n = 224) primarily recruited from a sexually transmitted infection clinic reporting a lifetime history of RAI completed a structured questionnaire and clinician-collected swab samples from the rectum, pharynx, vagina (women), and urine (men). CT and GC were detected using 2 commercial nucleic acid amplification tests (Aptima Combo 2; Hologic, Inc, Bedford, MA; Xpert CT/NG, Cepheid Innovation, Sunnyvale, CA).

RESULTS

The median age of the population was 26 years, 62% were white, and 88% were enrolled from a sexually transmitted disease clinic. Men were more likely than women to have GC (22.8% vs. 3.4%) and CT (21.9% vs. 12.6%). In men versus women, GC was detected in 16.5% versus 2.3% of pharyngeal swabs, 11.6% versus 2.3% of rectal swabs, and 5.4% versus 2.9% of urine samples or vaginal swabs. C. trachomatis was detected in 2.2% versus 1.7% of pharyngeal swabs, 17.4% versus 11.4% of rectal swabs, and 4.5% versus 10.3% for urogenital sites in men versus women. Overall 79.6% of CT and 76.5% of GC in men and 18.2% of CT and 16.7% of GC in women were detected only in the pharynx or rectum.

CONCLUSION

Reliance on urogenital screening alone misses most of GC and CT in men and more than 15% of infections in women reporting RAI.

New treatment options for infections caused by increasingly antimicrobial-resistant Neisseria gonorrhoeae

The emergence of high-level resistance to ceftriaxone is giving rise to serious concern about absence of effective treatment options to cure gonococcal infections. Increasing the dosage regimen can be applied to ceftriaxone and azithromycin, but the emergence of high-level resistance has already been reported. Spectinomycin is another active drug but has low efficacy in the treatment of pharyngeal gonorrhoea. Conventional antibiotics could be introduced for gonococcal treatment, but they have some limitations, such as the absence of clinical trials and breakpoint. Combining antibiotics is another promising method to cure patients and to prevent the emergence of resistance. The most important strategy to maintain the efficacy of antibiotics is rapid detection and dissemination control of novel resistant isolate.

Rectal Infection With Neisseria gonorrhoeae and Chlamydia trachomatis in Men in the United States

BACKGROUND

 Centers for Disease Control and Prevention guidelines recommend at least annual rectal screening of men who have receptive anal intercourse for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT). Only limited national data are available on the prevalence of rectal GC and CT infection among US men.

METHODS

 In collaboration with a large US commercial laboratory, we estimated positivity of the first rectal GC and CT test ("index" test) in men aged 15-60 years tested between January 2013 and May 2015. We estimated the frequency and positivity of pharyngeal or urine specimens tested for GC and CT on the index date, and the frequency and positivity of repeat rectal testing or any follow-up testing at any anatomic site after the index date.

RESULTS

 Of 52 063 tested men aged 15-60 years, approximately 6.1% were positive for GC only, 8.3% for CT only, and 2.7% for both GC and CT on their index date. On that date, 86.5% had either urine or pharyngeal specimens collected, and 56.1% had both specimens collected. Pharyngeal GC infection was highly associated with rectal GC infection. Follow-up testing after 12 months ranged from 42.4% among uninfected men to 56.7% among infected men on the index date. Positivity was at least 5.7% in rectal GC, rectal CT, or pharyngeal GC at their last test.

CONCLUSIONS

 This analysis of a large number of male rectal specimens tested for GC and CT suggest that routine testing and timely repeat rectal GC and CT testing should be prioritized among men who report receptive rectal sex.

Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature

In the United States, sexually transmitted diseases due to Chlamydia trachomatis and Neisseria gonorrhoeae continue to be a major public health burden. Screening of extragenital sites including the oropharynx and rectum is an emerging practice based on recent studies highlighting the prevalence of infection at these sites. We reviewed studies reporting the prevalence of extragenital infections in women, men who have sex with men (MSM), and men who have sex only with women (MSW), including distribution by anatomical site. Among women, prevalence was found to be 0.6–35.8% for rectal gonorrhea (median reported prevalence 1.9%), 0–29.6% for pharyngeal gonorrhea (median 2.1%), 2.0–77.3% for rectal chlamydia (median 8.7%), and 0.2–3.2% for pharyngeal chlamydia (median 1.7%). Among MSM, prevalence was found to be 0.2–24.0% for rectal gonorrhea (median 5.9%), 0.5–16.5% for pharyngeal gonorrhea (median 4.6%), 2.1–23.0% for rectal chlamydia (median 8.9%), and 0–3.6% for pharyngeal chlamydia (median 1.7%). Among MSW, the prevalence was found to be 0–5.7% for rectal gonorrhea (median 3.4%), 0.4–15.5% for pharyngeal gonorrhea (median 2.2%), 0–11.8% for rectal chlamydia (median 7.7%), and 0–22.0% for pharyngeal chlamydia (median 1.6%). Extragenital infections are often asymptomatic and found in the absence of reported risk behaviors, such as receptive anal and oral intercourse. We discuss current clinical recommendations and future directions for research.

Analysis of the sex ratio of reported gonorrhoea incidence in Shenzhen, China

OBJECTIVE

To assess the clinical process of gonorrhoea diagnosis and report in China, and to determine the difference of sex ratio between reported incidence based on reporting data and true diagnosis rate based on reference tests of gonorrhoea.

SETTING

A total of 26 dermatology and sexually transmitted disease (STD) departments, 34 obstetrics-gynaecology clinics and 28 urology outpatient clinics selected from 34 hospitals of Shenzhen regarded as our study sites.

PARTICIPANTS

A total of 2754 participants were recruited in this study, and 2534 participants completed the questionnaire survey and provided genital tract secretion specimens. There were 1106 male and 1428 female participants. Eligible participants were patients who presented for outpatient STD care at the selected clinics for the first time in October 2012 were at least 18 years old, and were able to give informed consent.

OUTCOME MEASURES

Untested rate, true-positive rate, false-negative rate and unreported rate of gonorrhoea, as well as reported gonorrhoea incidence sex ratio and true diagnosis sex ratio were calculated and used to describe the results.

RESULTS

2534 participants were enrolled in the study. The untested rate of gonorrhoea among females was significantly higher than that among males (female 88.1%, male 68.3%, p=0.001). The male-to-female sex ratios of untested rate, true-positive rate, false-negative rate and unreported rate were 1:1.3, 1.2:1, 1:1.6 and 1:1.4, respectively. The reported gonorrhoea incidence sex ratio of new diagnosed gonorrhoea was 19.8:1 (male vs female: 87/1106 vs 5/1420), while the true diagnosis sex ratio was 2.5:1 (male vs female: 161/1106 vs 84/1420). These data indicate that the sex ratio of reported gonorrhoea incidence has been overestimated by a factor of 7.9 (19.8/2.5).

CONCLUSIONS

We found the current reported gonorrhoea incidence and sex ratios to be inaccurate due to underestimations of gonorrhoea incidence, especially among women.

Sexually transmitted infections and pre-exposure prophylaxis: challenges and opportunities among men who have sex with men in the US

Pre-Exposure Prophylaxis (PrEP) has shown high efficacy in preventing human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) in several large clinical trials, and more recently in “real world” reports of clinical implementation and a PrEP demonstration project. Those studies also demonstrated high bacterial sexually transmitted infection (STI) incidence and raised the discussion of how PrEP may impact STI control efforts, especially in the setting of increasing Neisseria gonorrhoeae antimicrobial resistance and the increase in syphilis cases among MSM. Here, we discuss STIs as a driver of HIV transmission risk among MSM, and the potential opportunities and challenges for STI control afforded by expanded PrEP implementation among high-risk MSM.

Rapid identification of pathogens using molecular techniques

Real-time PCR is the traditional face of nucleic acid detection in the diagnostic microbiology laboratory and is now generally regarded as robust enough to be widely adopted. Methods based on nucleic acid detection of this type are bringing increased accuracy to diagnosis in areas where culture is difficult and/or expensive, and these methods are often effective partners to other rapid molecular diagnostic tools such as matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS). This change in practice has particularly affected the recognition of viruses and fastidious or antibiotic-exposed bacteria, but has been also shown to be effective in the recognition of troublesome or specialised phenotypes such as antiviral resistance and transmissible antibiotic resistance in the Enterobacteriaceae. Quantitation and high-intensity sequencing (of multiple whole genomes) has brought new opportunities as well as new challenges to the microbiology community. Diagnostic microbiologists currently training might be expected to deal less with the culture-based techniques of the last half-century than with the high-volume data and complex analyses of the next.

Background review for the '2015 European guideline on the management of Chlamydia trachomatis infections'

SummaryChlamydia trachomatis infections are major public health concerns globally. Of particular grave concern is that the majority of persons with anogenital Chlamydia trachomatis infections are asymptomatic and accordingly not aware of their infection, and this silent infection can subsequently result in severe reproductive tract complications and sequelae. The current review paper provides all background, evidence base and discussions for the 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS 2015). Comprehensive information and recommendations are included regarding the diagnosis, treatment and prevention of anogenital, pharyngeal and conjunctival Chlamydia trachomatis infections in European countries. However, Chlamydia trachomatis also causes the eye infection trachoma, which is not a sexually transmitted infection. The 2015 European Chlamydia trachomatis guideline provides up-to-date guidance regarding broader indications for testing and treatment of Chlamydia trachomatis infections; clearer recommendation of using validated nucleic acid amplification tests only for diagnosis; advice on (repeated) Chlamydia trachomatis testing; recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection and recommendations to identify, verify and report Chlamydia trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of Chlamydia trachomatis patients are crucial to control its spread.

2015 European guideline on the management of Chlamydia trachomatis infections

Chlamydia trachomatis infections, which most frequently are asymptomatic, are major public health concerns globally. The 2015 European C. trachomatis guideline provides: up-to-date guidance regarding broader indications for testing and treatment of C. trachomatis infections; a clearer recommendation of using exclusively-validated nucleic acid amplification tests for diagnosis; advice on (repeated) C. trachomatis testing; the recommendation of increased testing to reduce the incidence of pelvic inflammatory disease and prevent exposure to infection; and recommendations to identify, verify and report C. trachomatis variants. Improvement of access to testing, test performance, diagnostics, antimicrobial treatment and follow-up of C. trachomatis patients are crucial to control its spread. For detailed background, evidence base and discussions, see the background review for the present 2015 European guideline on the management of Chlamydia trachomatis infections (Lanjouw E, et al. Int J STD AIDS. 2015).

Prevalence and characteristics of rectal chlamydia and gonorrhea cases among men who have sex with men after the introduction of nucleic acid amplification test screening at 2 Canadian sexually transmitted infection clinics

We sought to determine the prevalence of rectal chlamydia and gonorrhea after the introduction of nucleic acid amplification tests for screening in men reporting receptive anal intercourse. The rectal chlamydia prevalence was 14.1% (95% confidence interval, 11.9-16.3), and the gonorrhea prevalence was 5.9% (95% confidence interval, 4.4-7.3). Most cases were positive only from the rectum.

Screening for Asymptomatic Extragenital Gonorrhea and Chlamydia in Men Who Have Sex with Men: Significance, Recommendations, and Options for Overcoming Barriers to Testing

Men who have sex with men (MSM) have a disproportionately greater risk than other populations of acquiring Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC), the two most commonly reported notifiable diseases in the United States according to the Centers for Disease Control and Prevention (CDC). The presence of either of these diseases is a significant risk factor for the acquisition and transmission of human immunodeficiency virus (HIV). Recent studies have shown that significant rates of asymptomatic GC and CT infection are found at the extragenital oropharygeal and rectal sites in MSM, with or without concurrent urogenital infection. However, extragenital sites are not being routinely screened and, thus, many asymptomatic GC and CT infections at the oropharyngeal and rectal sites may go undiagnosed. This review will begin with the current evidence-based screening recommendations for extragenital GC and CT in MSM. This will be followed by recently reported extragenital GC and CT infection rates in asymptomatic MSM, and a discussion of the risks and potential implications of undiagnosed extragenital GC and CT infections. Finally, a discussion on the frequency of, and potential barriers to, screening will be presented with a summary of potential interventions for increasing screening frequency found in the literature. The scope of this review will focus primarily on U.S. recommendations, infection rates, and screening frequencies, with the inclusion of relevant international recommendations and studies for comparative and illustrative purposes.

Preparing for an era of untreatable gonorrhea

PURPOSE OF REVIEW

The proportion of Neisseria gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins (ESCs) has increased rapidly since 2006. Clinicians, researchers, and public health officials need to be prepared for the possibility of an era of untreatable gonorrhea. This review focuses on the evidence for current gonorrhea treatment recommendations, potential future treatment options, and other methods to control gonorrhea.

RECENT FINDINGS

In addition to an increase in isolates with decreased susceptibility to ESCs, there have been reported treatment failures to both cefixime and ceftriaxone. In response, some countries have increased the recommended cephalosporin dose, and most now recommend dual therapy with an ESC and azithromycin. The pharynx has been implicated as a site for acquiring resistance through transformation with commensal Neisseria species or induced resistance through subtherapeutic antimicrobial levels. Thus, appropriate screening of the pharynx and treatment with a regimen that eradicates gonorrhea from the pharynx is necessary. At present, several studies are evaluating various novel treatment regimens in preparation for an era of untreatable gonorrhea.

SUMMARY

Screening for asymptomatic infections, maintaining culture capacity to monitor antimicrobial resistance, treating with ceftriaxone and azithromycin, and ensuring that all sexual partners are treated are among the best strategies to control gonorrhea in the current clime.