What is the appropriate treatment for the management of rectal Chlamydia trachomatis in men and women?

Therapeutic Options for Chlamydia trachomatis Infection: Present and Future

Sexually transmitted infections (STIs), such as Chlamydia trachomatis (Ct) infection, have serious consequences for sexual and reproductive health worldwide. Ct is one of the most common sexually transmitted bacterial infections in the world, with approximately 129 million new cases per year. C. trachomatis is an obligate intracellular Gram-negative bacterium. The infection is usually asymptomatic, notwithstanding, it could also be associated with severe sequels and complications, such as chronic pain, infertility, and gynecologic cancers, and thus there is an urgent need to adequately treat these cases in a timely manner. Consequently, beyond its individual effects, the infection also impacts the economy of the countries where it is prevalent, generating a need to consider the hypothesis of implementing Chlamydia Screening Programs, a decision that, although it is expensive to execute, is a necessary investment that unequivocally will bring financial and social long-term advantages worldwide. To detect Ct infection, there are different methodologies available. Nucleic acid amplification tests, with their high sensitivity and specificity, are currently the first-line tests for the detection of Ct. When replaced by other detection methods, there are more false negative tests, leading to underreported cases and a subsequent underestimation of Ct infection's prevalence. Ct treatment is based on antibiotic prescription, which is highly associated with drug resistance. Therefore, currently, there have been efforts in line with the development of alternative strategies to effectively treat this infection, using a drug repurposing method, as well as a natural treatment approach. In addition, researchers have also made some progress in the Ct vaccine development over the years, despite the fact that it also necessitates more studies in order to finally establish a vaccination plan. In this review, we have focused on the therapeutic options for treating Ct infection, expert recommendations, and major difficulties, while also exploring the possible avenues through which to face this issue, with novel approaches beyond those proposed by the guidelines of Health Organizations.

In Vitro and In Vivo Activity of (Trifluoromethyl)pyridines as Anti-Chlamydia trachomatis Agents

Chlamydia trachomatis is the leading pathogen in sexually transmitted bacterial infections across the globe. The development of a selective treatment against this pathogen could be an attractive therapeutic option that will reduce the overuse of broad-spectrum antibiotics. Previously, we reported some sulfonylpyridine-based compounds that showed selectivity against C. trachomatis. Here, we describe a set of related compounds that display enhanced anti-chlamydial potency when compared to our early leads. We found that the active molecules are bactericidal and have no impact on Staphylococcus aureus or Escherichia coli strains. Importantly, the molecules were not toxic to mammalian cells. Furthermore, a combination of molecule 20 (the most active molecule) and azithromycin at subinhibitory concentrations acted synergistically to inhibit chlamydial growth. Molecule 20 also eradicated Chlamydia in a 3D infection model and accelerated the recovery of Chlamydia-infected mice. This work presents compounds that could be further developed to be used alone or in combination with existing treatment regimens against chlamydial infections.

Efficacy of doxycycline versus azithromycin for the treatment of rectal chlamydia: a systematic review and meta-analysis

BACKGROUND

Chlamydia trachomatis infection is the most common sexually transmitted infectious disease and carries a risk of complications. However, the optimal treatment for rectal chlamydial infection remains unclear.

OBJECTIVES

To compare the efficacy of doxycycline and azithromycin for the treatment of rectal chlamydia by undertaking a systematic review and meta-analysis of published data.

METHODS

We searched PubMed, EMBASE, Cochrane Library, Web of Science and clinicaltrials.gov databases from inception to 7 July 2021 for randomized controlled trials (RCTs) and observational studies that compared the efficacy of doxycycline and single-dose azithromycin on rectal chlamydia cure rates. Data were synthesized using a random-effects model, and subgroup analysis was conducted.

RESULTS

All included studies were conducted in developed countries. Two RCTs and nine observational studies, with a total of 2457 patients, were analysed. Doxycycline had a higher microbiological cure rate than azithromycin (risk ratio = 1.21; 95% CI = 1.15-1.28; P < 0.05). Pooled results from two RCTs also revealed a higher microbiological cure rate for doxycycline than azithromycin (risk ratio = 1.27; 95% CI = 1.20-1.35; P < 0.05). The results remained consistent in subgroups of different study designs, countries and sexes.

CONCLUSIONS

On the basis of our findings, we recommend doxycycline rather than azithromycin as a first-line treatment for rectal chlamydia in developed countries. More RCTs from developing countries are warranted.

Challenges in Treating Chlamydia trachomatis, Including Rectal Infections: Is It Time to Go Back to Doxycycline?

OBJECTIVE

To evaluate recent publications on efficacy of single-dose azithromycin and 7-day doxycycline when treating Chlamydia trachomatis.

DATA SOURCES

A literature search of MEDLINE, EMBASE, PubMed, and Cochrane library was conducted (1990 to June 13, 2021) using the terms: Chlamydia trachomatis, genital chlamydia, rectal chlamydia, extragenital chlamydia, azithromycin, doxycycline, and treatment guidelines. ClinicalTrials.gov was searched to identify ongoing trials.

STUDY SELECTION AND DATA EXTRACTION

English language studies, including controlled studies, retrospective analyses, systematic reviews, meta-analyses, and case reports, reporting microbiological or clinical outcomes in adolescents and adults were considered.

DATA SYNTHESIS

Systemic reviews and meta-analyses of randomized trials reported azithromycin efficacy of 96% to 97% in genital chlamydia. However, reports of treatment failure have emerged, especially among symptomatic males, with an increased risk of microbiological failure after azithromycin than doxycycline (relative risk = 2.45; 95% CI = 1.36-4.41). Retrospective analyses and prospective observational cohort studies reported lower efficacy range following azithromycin than doxycycline (74%-87% vs 92%-100%, respectively) in rectal chlamydia. First randomized controlled trial comparing azithromycin and doxycycline reported significantly higher microbiological cure following doxycycline, with absolute difference of 26% (95% CI = 16%-36%; P < 0.001). The proposed 2021 Centers for Disease Control and Prevention treatment guidelines designate doxycycline as the preferred agent for treatment at any site.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

A growing body of evidence for treatment failure following azithromycin, especially in rectal chlamydia supports updating current practice.

CONCLUSIONS

Doxycycline continues to achieve high efficacy in genital and rectal chlamydia. Clinicians should consider efficacy with convenience of dosing regimen, medication compliance, and sexual behavior risks when treating chlamydia infections.

Lymphogranuloma Venereum in a Public Health Service Hospital in Southern Spain: A Clinical and Epidemiologic Study

Lymphogranuloma venereum (LGV) is an emerging disease in men who have sex with men (MSM): the incidence was 1.15 cases per 100,000 population in Spain in 2017. Patients with LGV characteristically have severe proctitis that can cause abscesses, fistulas, and anal stenosis. Genital ulcers and inflammatory inguinal adenopathy may occasionally be present. The aim of this study was to describe a series of patients with LGV treated in a public health service hospital in Andalusia, Spain.

MATERIAL AND METHODS

Retrospective, observational description of a series of patients diagnosed with LGV. We gathered epidemiologic, clinical, microbiologic, and treatment data. Patients' sexual behaviors were also noted.

RESULTS

We found 17 cases of LGV diagnosed in MSM between October 2016 and May 2019. Twelve of the patients were also infected with the human immunodeficiency virus, and 13 had severe proctitis with ulcers in the anal canal and rectum. Four patients had genital or inguinal manifestations. The following high-risk sexual behaviors were on record: a high number of sexual partners, receptive anal sex with strangers and without a condom, seeking sexual partners online, participation in group sex, and sex with partners from outside Andalusia. Chlamydia trachomatis serovar L2 was identified in all cases, and the infection responded well to oral doxycycline. Two patients with the most characteristic form of LGV required longer treatment cycles. Three required surgery.

CONCLUSIONS

When symptomatic proctitis is found in MSM who engage in high-risk sex, the LGV exudate should be sampled and the C trachomatis serovar identified. Genital ulcers or inguinal buboes are also highly suggestive of LGV. Clinical suspicion and early treatment are the keys to preventing complications and disease transmission.

Dissemination of Chlamydia from the reproductive tract to the gastro-intestinal tract occurs in stages and relies on Chlamydia transport by host cells

Chlamydia trachomatis is a Gram-negative bacterial pathogen and a major cause of sexually transmitted disease and preventable blindness. In women, infections with C. trachomatis may lead to pelvic inflammatory disease (PID), ectopic pregnancy, chronic pelvic pain, and infertility. In addition to infecting the female reproductive tract (FRT), Chlamydia spp. are routinely found in the gastro-intestinal (GI) tract of animals and humans and can be a reservoir for reinfection of the FRT. Whether Chlamydia disseminates from the FRT to the GI tract via internal routes remains unknown. Using mouse-specific C. muridarum as a model pathogen we show that Chlamydia disseminates from the FRT to the GI tract in a stepwise manner, by first infecting the FRT-draining iliac lymph nodes (ILNs), then the spleen, then the GI tract. Tissue CD11c⁺ DCs mediate the first step: FRT to ILN Chlamydia transport, which relies on CCR7:CCL21/CCL19 signaling. The second step, Chlamydia transport from ILN to the spleen, also relies on cell transport. However, this step is dependent on cell migration mediated by sphingosine 1-phosphate (S1P) signaling. Finally, spleen to GI tract Chlamydia spread is the third critical step, and is significantly hindered in splenectomized mice. Inhibition of Chlamydia dissemination significantly reduces or precludes the induction of Chlamydia-specific serum IgG antibodies, presence of which is correlated with FRT pathology in women. This study reveals important insights in context of Chlamydia spp. pathogenesis and will inform the development of therapeutic targets and vaccines to combat this pathogen.

Chlamydia trachomatis is a bacterial pathogen and a major cause of sexually transmitted disease and preventable blindness worldwide. In women, C. trachomatis may cause PID, ectopic pregnancy, chronic pelvic pain, and infertility. Chlamydia spp. are routinely found in the gastro-intestinal (GI) tract of humans and animals. However, whether and how Chlamydia spreads internally to the GI tract following the female reproductive tract (FRT) infection remains unknown. Using a mouse model of infection here we show that Chlamydia spreads to the GI tract in a stepwise manner, by first infecting the FRT-draining iliac lymph nodes (ILNs), then the spleen and the GI tract. Tissue DCs mediate the first step: FRT to ILN Chlamydia spread, which relies on CCR7:CCL21/CCL19 signaling. The second step, ILN to spleen spread, also relies on cell migration, and is dependent on sphingosine 1-phosphate (S1P) signaling. Finally, spleen to GI tract Chlamydia spread is the third critical step and is significantly hindered in splenectomized mice. Our study reveals important insight in context of Chlamydia pathogenesis. In addition, this work will inform the identification of therapeutic targets and development of vaccines against this pathogen.

Prevalence of gonorrhea and chlamydia in a community clinic for men who have sex with men in Lisbon, Portugal

Men who have sex with men (MSM) are at greater risk for sexually transmitted infections (STIs). Data on MSM chlamydia and gonorrhea prevalence estimates and associated risk factors are scarce. To our knowledge, this is the first study to describe the prevalence and the determinants of both chlamydia and gonorrhea infections in MSM in Portugal. We conducted a cross-sectional study using data from 1832 visits to CheckpointLX, a community-based center for screening blood-borne viruses and other STIs in MSM. Overall prevalence of chlamydia or gonorrhea in our sample was 16.05%, with 14.23% coinfection and 40.73% asymptomatic presentation among those testing positive. Anorectal infection was most common for chlamydia (67.26%), followed by urethral (24.78%) and oral (19.47%) infection. Oral infection was most common for gonorrhea (55.63%), followed by anal (51.25%) and urethral (17.50%) infection. In multivariate analyses, young age (U = 94684, p = 0.014), being foreign-born (χ² = 11.724, p = 0.003), reporting STI symptoms (χ² = 5.316, p = 0.021), inhaled drug use (χ² = 4.278, p = 0.039) and having a higher number of concurrent (χ² = 18.769, p < 0.001) or total (χ² = 5.988, p = 0.050) sexual partners were each associated with higher rates of chlamydia or gonorrhea infection. Young and migrant MSM are a vulnerable population to STIs, as are those who use inhaled drugs and those with a higher number of concurrent or total sexual partners. Although Portugal has no guidelines on chlamydia and gonorrhea screening, our results point toward a need for greater awareness about the importance of high-frequency screening for those at increased risk (i.e., every three to six months).

Recurrent/Intermittent Vaginal and Rectal Chlamydial Infection Following Treatment: A Prospective Cohort Study Among Female Sexually Transmitted Disease Clinic Patients

BACKGROUND

Rectal Chlamydia trachomatis (CT) is common among clinic-attending women, but little is known about clearance and health implications of rectal CT.

METHODS

At the municipal sexually transmitted disease clinic in Seattle, Washington, in 2017-2018, we enrolled women at high risk for urogenital CT into an 8-week prospective study. Women received standard CT treatment at enrollment. Women self-collected daily rectal and vaginal specimens for nucleic acid amplification tests (NAATs) and completed weekly sexual exposure diaries. We performed CT culture on the enrollment rectal specimen.

RESULTS

We enrolled 50 women; 13 (26%) tested positive for vaginal (n = 11) and/or rectal (n = 11) CT. Sixty percent of women with rectal CT per NAAT were also culture positive. Median time to CT clearance after azithromycin treatment was 8.0 days for vaginal CT and 7.0 days for rectal CT. Eight women with rectal CT at enrollment had at least 1 rectal CT-positive NAAT after clearance of the initial infection; none reported anal sex.

CONCLUSIONS

Most NAAT-positive rectal infections were culture positive, suggesting active infection. Time to NAAT clearance of rectal and genital tract CT was similar, and intermittent rectal CT positivity was common in the absence of anal sexual exposure. The cause of recurrent/intermittent rectal CT and the clinical implications of these infections require further study.

Community-Based, Point-of-Care Sexually Transmitted Infection Screening Among High-Risk Adolescents in Los Angeles and New Orleans: Protocol for a Mixed-Methods Study

Background

Sexually transmitted infection (STI) rates are increasing in the United States, with approximately half of new infections occurring among adolescents aged 15-24 years. Gay, bisexual, and transgender youth (GBTY), homeless youth, and youth with histories of drug use, mental health disorders, and incarceration are all at uniquely high risk for STIs. However, these adolescents often lack access to sexual health services.

Objective

This study aims to use point-of-care STI tests in community-based settings to screen for and treat STIs in adolescents.

Methods

We are recruiting 1500 HIV-uninfected youth and 220 HIV-infected youth from homeless shelters, GBTY organizations, and community health centers in Los Angeles, California and New Orleans, Louisiana. Study participants will receive STI screening every 4 months for 24 months. STI screening includes rapid HIV, syphilis, Chlamydia trachomatis, Neisseria gonorrhoeae, and Hepatitis C virus testing. Trained paraprofessionals will conduct all STI testing. When a participant screens positive for an STI, they are either linked to a partner medical clinic or provided with same-day antibiotic therapy and expedited partner therapy. We will monitor STI prevalence among study participants as well as point-of-care test performance, linkage to care, and treatment outcomes.

Results

The project was funded in 2016, and enrollment will be completed in 2019. Preliminary data analysis is currently underway.

Conclusions

As STI rates continue to rise, it is important to improve access to screening and treatment services, particularly for high-risk adolescents. In this study, we aim to evaluate the use of point-of-care STI diagnostic tests in community-based organizations. We hope to determine the prevalence of STIs among these adolescents and evaluate the acceptability and feasibility of community-based STI screening and treatment.

Trial Registration

ClinicalTrials.gov NCT03134833; https://clinicaltrials.gov/ct2/show/NCT03134833

International Registered Report Identifier (IRRID)

DERR1-10.2196/10795

Lymphogranuloma venereum is on the rise in Belgium among HIV negative men who have sex with men: surveillance data from 2011 until the end of June 2017

Background

The number of cases of Lymphogranuloma venereum (LGV) is increasing in Europe. The described epidemic is mostly confined to HIV positive men who have sex with men (MSM). However, dissemination of LGV from HIV positive to HIV negative MSM could take place due to the implementation of pre-exposure prophylaxis (PrEP) and subsequent possible decrease in condom use. We describe here the LGV epidemiology in Belgium before the PrEP-era, starting from 2011 up to the end of the first half of 2017.

Methods

A descriptive analysis of the socio-demographic and clinical characteristics of all LGV cases was performed. Fisher’s exact test was used to compare symptomatic to asymptomatic patients. Logistic regression models were used to check for trends over time for: number of LGV cases, HIV status and symptoms.

Results

The number of LGV cases rose by a factor four, from 21 in 2011 to 88 in 2016, and regression models showed a positive trend estimate of 14% increase per half year (p < 0.001). LGV decreased among HIV positive cases (odds ratio (OR): 0.79, p < 0.001) and increased among HIV negative cases (OR: 1.27, p < 0.001). In addition, a rise in the number of asymptomatic LGV cases (6.7%) was observed (OR:1.39, p = 0.047). Asymptomatic cases were also less likely to be HIV (p = 0.046) or Hepatitis C positive (p = 0.027).

Conclusions

The rise of LGV in HIV negative MSM has now been documented. If we aim to halt the epidemic in HIV negative MSM, future public health strategies should include LGV testing of all Chlamydia trachomatis positive samples from MSM.

The efficacy of azithromycin and doxycycline treatment for rectal chlamydial infection: a retrospective cohort study in South Australia

BACKGROUND

There are ongoing concerns about treatment failure with azithromycin for the treatment of rectal chlamydia.

AIM

To investigate treatment efficacy of two treatments for rectal chlamydial infection.

METHODS

We performed a retrospective analysis of all patients diagnosed with rectal chlamydial infection between 2009 and 2015 in Adelaide, Australia. Patients were treated with either azithromycin (1 g single dose) or doxycycline (100 mg twice a day for 10 days) and returned for repeat testing 14-180 days after treatment commenced. Log-binomial models were used to estimate the relative risk (RR) of recurrent rectal chlamydia associated with the treatment with azithromycin versus doxycycline.

RESULTS

In men, rectal chlamydia prevalence was 6.7%, and in women, it was 8.1%. Of the 526 patients diagnosed with rectal chlamydial infections, 419 (79.7%), 93 (17.7%) and 14 (2.6%) patients were treated with doxycycline, azithromycin or other medication respectively. Of these patients, 173 (41.3%) of 419 doxycycline-treated patients and 31 (33.3%) of 93 azithromycin-treated patients were retested between 14 and 180 days after treatment commenced (P = 0.16). Among these patients, the repeat rectal chlamydia test was less commonly positive in those treated with doxycycline (5.8%; 95% confidence interval (CI) 0.03-0.10) compared with those treated with azithromycin (19.4%; 95% CI 0.09-0.36) and (P = 0.01). In the multivariate analysis, azithromycin-treated patients had a significantly higher risk of a positive test in the 14 and 180 days after treatment commenced (adjusted relative risk (aRR) 2.96, 95% CI 1.16-7.57).

CONCLUSION

The findings suggest that doxycycline may be more effective than azithromycin in treating rectal chlamydial infections.

Efficacy of Genital Chlamidiae Trachomatis Treatment in Women of Reproductive Age

Cervicitis is inflammation of the cervix, and the causes of such inflammation may include infection from certain sexually transmitted diseases (STDs), injury to the cervix from a foreign body inserted into the vagina (for example, birth control devices such as a cervical cap or diaphragm), or cervical cancer, whose course can be subacute or chronic. Our research aimed to test the efficacy of the proposed treatment protocol for chlamydia trachomatis distal genital infections in reproductive women. This single-centre, randomized, quasi-experimental prospective study was conducted among 40 women with diagnosed Chlamydia Trachomatis (CT) cervical infections who were diagnosed and treated at the Clinic of Obstetrics and Gynaecology in the Clinical Center Kragujevac in Serbia from December 2014 to January 2015. Patients were divided into two groups according to the treatment method: the tetracycline group (n=20), with doxiciclyn (Dovicin®) given at a dose of 100 mg twice per day for 10 days and 100 mg per day for the next 10 days, and the macrolides group (n=20), with azithromycin (Hemomycin®) at a dose of 1000 mg per day, divided into four doses or a single dose per day. Treatment with doxycycline proved to be statistically more effective compared to treatment with azithromycin. Our results confirm that the outcome of infections caused by C. trachomatis depends solely on the applied therapy and management, but extensive prospective studies in a female cohort that includes more parameters, such as potential age related, dose-dependent and adherence variability, are necessary to determine and confirm the best choice for treatment of CT cervicitis.

Biological and Behavioral Factors Associated With Positive Chlamydia Retests

BACKGROUND

Repeat chlamydia detection after treatment is common, and there is concern that treatment failure may be a cause.

METHODS

Within a randomized trial, we established a prospective cohort of 600 participants with anogenital chlamydia diagnoses (200 each of women, heterosexual men, and men who have sex with men [MSM]). Participants were invited for repeat testing at 3 months and to complete a behavioral survey at 4 months. Positive samples were analyzed for organism DNA load and genovar. We estimated repeat chlamydia positivity, reinfection and treatment failure rates, and investigated the biological and behavioral factors associated with a repeat positive test.

RESULTS

A total of 290 participants (100 women, 89 heterosexual men, 101 MSM) were retested at 1 to 4 months, with 43 repeat positives, including 26 classed as reinfection and 9 as treatment failures. Comparing MSM with heterosexual men and women combined, repeat positivity was higher (20.8% vs 11.6%, P = 0.04), and treatment failure was higher (6.9% vs 1.1%, P = 0.01), but there was no difference in reinfection rates (11.9% vs 7.4%, P = 0.21). Among MSM, the odds of repeat positivity increased by 90% with each additional log organism load in the original specimen (baseline) (adjusted odds ratio, 1.9; 95% confidence interval, 1.1-3.2). Among heterosexuals, the odds of repeat positivity decreased by 10% with each additional week delay in being retested for chlamydia (adjusted odds ratio, 0.9; 95% confidence interval, 0.8-0.9).

CONCLUSIONS

Positive retests were more common among MSM than heterosexuals. Treatment failure was more common in MSM with rectal chlamydia, reinforcing concerns about azithromycin treatment failure.

The growing epidemic of sexually transmitted infections in adolescents: a neglected population

PURPOSE OF REVIEW

Sexually transmitted infection (STI) incidence is on the rise in the United States. The increase is especially pronounced in adolescents (15-24 years of age). Despite making up only a quarter of the population, adolescents account for approximately half of new STIs in the United States every year. This review summarizes recent developments in the field of STIs, excluding HIV, in adolescents.

RECENT FINDINGS

In this review, we examine the epidemiology, screening, management, and prevention of STIs in adolescents. STI rates in adolescents have been rising since 2014, with young women and MSM at particularly high risk. Barriers to STI screening for adolescents include confidentiality concerns and lack of access to health services. Prevention through STI vaccines represents a promising way to combat the epidemic.

SUMMARY

STIs are a growing concern for adolescents. Routine screening and management are of critical importance. Furthermore, prevention efforts such as human papillomavirus vaccination should be prioritized. Much of the current literature on STIs does not address the unique nature of STIs in adolescents, and additional research into effective prevention and treatment strategies of STIs in adolescents is urgently needed.

Adolescent Sexuality: Updates to the Sexually Transmitted Infection Guidelines

Adolescents are at high risk for acquisition and transmission of sexually transmitted infections (STI) secondary to both cognitive and biological susceptibility. The prevention, diagnosis, and treatment of STIs are a critical part of adolescent health care. This article discusses the most common bacterial, parasitic, and viral STIs encountered in this age group with an emphasis on new guidelines for screening and management.

Treatment efficacy of azithromycin 1 g single dose versus doxycycline 100 mg twice daily for 7 days for the treatment of rectal chlamydia among men who have sex with men - a double-blind randomised controlled trial protocol

BACKGROUND

Rectal infection with Chlamydia trachomatis is one of the most common bacterial sexually transmissible infections among men who have sex with men (MSM) with diagnosis rates continuing to rise. Current treatment guidelines recommend either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. However, there are increasing concerns about treatment failure with azithromycin. We are conducting the first randomised controlled trial (RCT) to compare treatment efficacy of azithromycin versus doxycycline for the treatment of rectal chlamydia in MSM.

METHODS/DESIGN

The Rectal Treatment Study will recruit 700 MSM attending Australian sexual health clinics for the treatment of rectal chlamydia. Participants will be asked to provide rectal swabs and will be randomised to either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. Participants will be asked to complete questionnaires about adverse drug reactions, sexual behaviour and drug adherence via short message service and online survey. The primary outcome is the treatment efficacy as determined by a negative chlamydia nucleic acid amplification test at 4 weeks post treatment. Secondary outcomes will utilise whole genome sequencing and mRNA assay to differentiate between treatment failure, reinfection or false positive results.

DISCUSSION

Rectal chlamydia is an increasing public health concern as use of pre-exposure prophylaxis against HIV becomes commonplace. Optimal, evidence-based treatment is critical to halting ongoing transmission. This study will provide the first RCT evidence comparing azithromycin and doxycycline for the treatment of rectal chlamydia. The results of this trial will establish which treatment is more efficacious and inform international management guidelines.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12614001125617.

Diagnosis and Management of Uncomplicated Chlamydia trachomatis Infections in Adolescents and Adults: Summary of Evidence Reviewed for the 2015 Centers for Disease Control and Prevention Sexually Transmitted Diseases Treatment Guidelines

In preparation for the 2015 Centers for Disease Control and Prevention (CDC) Sexually Transmitted Diseases (STD) Treatment Guidelines, the CDC convened an advisory group in 2013 to examine recent abstracts and published literature addressing the epidemiology, diagnosis, and management of STDs. This article summarizes the key questions, evidence, and recommendations for the diagnosis and management of uncomplicated Chlamydia trachomatis (CT) infection in adolescents and adults that were considered in development of the 2015 CDC STD Treatment Guidelines. The evidence reviewed primarily focused on CT infection risk factors in women, clinical significance of oropharyngeal CT detection, acceptability and performance of CT testing on self-collected specimens in men, performance of CT point-of-care tests, efficacy of recommended and investigational CT infection treatments, and timing of test of cure following CT infection treatment in pregnant women.

Lymphogranuloma Venereum 2015: Clinical Presentation, Diagnosis, and Treatment

Lymphogranuloma venereum (LGV) has emerged as an important cause of proctitis and proctocolitis in men who have sex with men; classical inguinal presentation is now increasingly uncommon. We report summary findings of an extensive literature review on LGV clinical presentation, diagnosis, and treatment that form the evidence base for the 2015 Centers for Disease Control and Prevention treatment guidelines for sexually transmitted diseases. Proctitis and proctocolitis are now the most commonly reported clinical manifestations of LGV, with symptoms resembling those of inflammatory bowel disease. Newer molecular tests to confirm LGV infection are sensitive and specific, but are generally restricted to research laboratory or public health settings. Doxycycline (100 mg twice daily for 21 days) remains the treatment of choice for LGV. Patients with rectal chlamydial infection and signs or symptoms of proctitis should be tested for LGV, or if confirmatory testing is not available, should be treated empirically with a recommended regimen to cover LGV infection.

Design of the FemCure study: prospective multicentre study on the transmission of genital and extra-genital Chlamydia trachomatis infections in women receiving routine care

Background

In women, anorectal infections with Chlamydia trachomatis (CT) are about as common as genital CT, yet the anorectal site remains largely untested in routine care. Anorectal CT frequently co-occurs with genital CT and may thus often be treated co-incidentally. Nevertheless, post-treatment detection of CT at both anatomic sites has been demonstrated. It is unknown whether anorectal CT may play a role in post-treatment transmission. This study, called FemCure, in women who receive routine treatment (either azithromycin or doxycycline) aims to understand the post-treatment transmission of anorectal CT infections, i.e., from their male sexual partner(s) and from and to the genital region of the same woman. The secondary objective is to evaluate other reasons for CT detection by nucleic acid amplification techniques (NAAT) such as treatment failure, in order to inform guidelines to optimize CT control.

Methods

A multicentre prospective cohort study (FemCure) is set up in which genital and/or anorectal CT positive women (n = 400) will be recruited at three large Dutch STI clinics located in South Limburg, Amsterdam and Rotterdam. The women self-collect anorectal and vaginal swabs before treatment, and at the end of weeks 1, 2, 4, 6, 8, 10, and 12. Samples are tested for presence of CT-DNA (by NAAT), load (by quantitative polymerase chain reaction -PCR), viability (by culture and viability PCR) and CT type (by multilocus sequence typing). Sexual exposure is assessed by online self-administered questionnaires and by testing samples for Y chromosomal DNA. Using logistic regression models, the impact of two key factors (i.e., sexual exposure and alternate anatomic site of infection) on detection of anorectal and genital CT will be assessed.

Discussion

The FemCure study will provide insight in the role of anorectal chlamydia infection in maintaining the CT burden in the context of treatment, and it will provide practical recommendations to reduce avoidable transmission. Implications will improve care strategies that take account of anorectal CT.

Trial registration

ClinicalTrials.gov Identifier: NCT02694497.

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.

Asymptomatic Lymphogranuloma Venereum in Men who Have Sex with Men, United Kingdom

We investigated prevalence of lymphogranuloma venereum (LGV) among men who have sex with men who were tested for chlamydia at 12 clinics in the United Kingdom during 10 weeks in 2012. Of 713 men positive for Chlamydia trachomatis, 66 (9%) had LGV serovars; 15 (27%) of 55 for whom data were available were asymptomatic.

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 of and Factors Associated with Rectal-Only Chlamydia and Gonorrhoea in Women and in Men Who Have Sex with Men

BACKGROUND

Both anorectal Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) can occur as a rectal-only infection or concurrently with simultaneous urogenital infection with the same pathogen. Characterising the target groups in which rectal-only infections occur may improve the efficacy of screening practices.

METHODS

We analysed data from two Dutch outpatient sexually transmitted infection (STI) clinics between 2011 and 2012. We included all men who have sex with men (MSM) (n = 9549) and women (n = 11113), ≥18 years, who had been tested for anorectal and urogenital CT and/or NG (either as a result of reporting anal sex/symptoms or via routine universal testing). Factors associated with rectal-only CT and NG infections were assessed using univariable and multivariable logistic regression.

RESULTS

In MSM, anorectal CT prevalence was 9.8% (693/7094), anorectal NG prevalence was 4.2% (397/9534). In women this was 9.5% overall (439/4597) and 0.9% (96/10972) respectively. Anorectal CT prevalence among women who were routinely universally tested was 10.4% (20/192), for selective testing this was 9.5% (419/4405) (p = 0.68). Anorectal NG infections were not detected among women who were routinely universally tested (p = 0.19). Among CT or NG positive MSM, rectal-only CT infections were found in 85.9% (595/693), for NG this was 85.6% (340/397) respectively. In positive women these figures were 22.1% (97/439)for CT and 20.8% (20/96) for NG, respectively. In MSM, independent factors associated with rectal-only CT were: being a sex worker (OR0.4,CI0.2-1.0), exclusively having sex with men (OR3.4,CI1.7-6.8), and absence of urogenital symptoms (OR0.2,CI0.2-0.4). In women, these factors were: older age (OR2.3, CI1.3-4.0) and non-Western nationality (OR1.8, CI1.0-3.5). Factors associated with rectal-only NG in MSM were: having been warned for STIs by an (ex) partner (OR2.9,CI1.1-7.5), oropharyngeal NG infection (OR2.4,CI1.0-5.3), and absence of urogenital symptoms (OR0.02,CI0.01-0.04), while in women no significant factors were identified.

CONCLUSIONS

The prevalence of anorectal CT and NG was substantial in MSM and prevalence of anorectal CT was also substantial in women. Anorectal infections occurred mostly as rectal-only infections in MSM and mostly concurrent with other infections in women. Given the lack of useful indicators for rectal-only infections, selective screening based on a priori patient characteristics will have low discriminatory power both in relation to MSM and women.

Comparison of doxycycline with azithromycin in treatment of pharyngeal chlamydia infection

Recent data suggest that azithromycin may not be as effective as doxycycline in eradication of genital chlamydial infection. The aim of this study was to compare the eradication rate of pharyngeal Chlamydia trachomatis infection after treatment with azithromycin 1 g stat with that of doxycycline 100 mg twice a day for seven days. A prospective open-label observational study was conducted on patients with pharyngeal Chlamydia trachomatis diagnosed at Whittall Street Clinic, University Hospitals Birmingham, Birmingham, UK, between July 2012 and July 2013. We confirmed eradication of pharyngeal Chlamydia trachomatis with a negative test of cure. We treated all our patients with azithromycin 1 g stat until February 2013. At that stage, we offered doxycycline to patients with pharyngeal Chlamydia trachomatis A total of 398 patients (52 men, 346 women) were diagnosed with pharyngeal Chlamydia trachomatis during the study period. Of the 172 patients included in the final analysis, 78 were treated with azithromycin and 64 with doxycycline. Treatment failure was identified among 8/78 (10%) patients treated with azithromycin and 1/64 (2%) treated with doxycycline (absolute difference: 8 percentage points, 95% CI: 0-17%, p = 0.041). In our study, doxycycline 100 mg twice a day for seven days was associated with less treatment failure of oropharyngeal chlamydia compared with azithromycin 1 g stat Future randomised studies should investigate whether patients with pharyngeal Chlamydia trachomatis should be followed up with a test of cure when treated with azithromycin, or be treated with doxycycline.

Treatment challenges for urogenital and anorectal Chlamydia trachomatis

While true antimicrobial resistance to Chlamydia trachomatis is a rare occurrence, repeat chlamydia infections continue to be reported following treatment with a single 1 g dose of azithromycin or week long doxycycline - with considerable more concern about azithromycin treatment failure. While most repeat positive cases are likely to be reinfections, emerging evidence indicates treatment failure may play a role. Current data suggests that there may are differences in the efficacy of the drugs between rectal and non-rectal sites of infection and factors such as immune response, drug pharmacokinetics, organism load, auto-inoculation from rectum to cervix in women and the genital microbiome may play a role in treatment failure. Other possible reasons for repeat infection include the low discriminatory power of NAAT tests to differentiate between viable and nonviable organisms and failure to detect LGV infection. This review will present the current evidence regarding the management challenges for urogenital and anorectal chlamydia infections and provide some suggestions for where future research efforts are needed to address important knowledge gaps in this area and provide stronger evidence for the development of robust treatment guidelines.

High prevalence of rectal gonorrhea and Chlamydia infection in women attending a sexually transmitted disease clinic

BACKGROUND

Testing women for urogenital Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) is common in sexually transmitted disease (STD) clinics. However, women may not be routinely tested for rectal GC/CT. This may lead to missed infections in women reporting anal intercourse (AI).

METHODS

This was a retrospective review of all women who underwent rectal GC/CT testing from August 2012 to June 2013 at an STD clinic in Columbus, Ohio. All women who reported AI in the last year had a rectal swab collected for GC/CT nucleic acid amplification testing (n=331). Using log-binomial regression models, we computed unadjusted and adjusted associations for demographic and behavioral factors associated with rectal GC/CT infection.

RESULTS

Participants (n=331) were 47% African-American, with median age of 29 years. Prevalence of rectal GC was 6%, rectal CT was 13%, and either rectal infection was 19%. Prevalence of urogenital GC and CT was 7% and 13% respectively. Among women with rectal GC, 14% tested negative for urogenital GC. Similarly, 14% of women with rectal CT tested negative for urogenital CT. In unadjusted analyses, there was increased rectal GC prevalence among women reporting sex in the last year with an injection drug user, with a person exchanging sex for drugs or money, with anonymous partners, and while intoxicated/high on alcohol or illicit drugs. After multivariable adjustment, no significant associations persisted, but a trend of increased rectal GC prevalence was observed for women <26 years of age (p=0.06) and those reporting sex while intoxicated/high on alcohol or drugs (p=0.05). For rectal CT, only age <26 years was associated with prevalent infection in unadjusted models; this association strengthened after multivariable adjustment (prevalence ratio: 6.03; 95% confidence interval: 2.29-15.90).

CONCLUSION

Nearly one in five women who reported AI in the last year had rectal GC or CT infection. Urogenital testing alone would have missed 14% of rectal infections. Standardized guidelines would increase rectal GC/CT testing in women and help detect missed infections.

The efficacy of azithromycin and doxycycline for the treatment of rectal chlamydia infection: a systematic review and meta-analysis

BACKGROUND

There are increasing concerns about treatment failure following treatment for rectal chlamydia with 1 g of azithromycin. A systematic review and meta-analysis was conducted to investigate the efficacy of 1 g of azithromycin as a single dose or 100 mg of doxycycline twice daily for 7 days for the treatment of rectal chlamydia.

METHODS

Medline, Embase, PubMed, Cochrane Controlled Trials Register, Australia New Zealand Clinical Trial Register and ClinicalTrials.gov were searched to the end of April 2014. Studies using 1 g of azithromycin or 7 days of doxycycline for the treatment of rectal chlamydia were eligible. Gender, diagnostic test, serovar, symptomatic status, other sexually transmitted infections, follow-up time, attrition and microbial cure were extracted. Meta-analysis was used to calculate pooled (i) azithromycin and doxycycline efficacy and (ii) efficacy difference.

RESULTS

All eight included studies were observational. The random-effects pooled efficacy for azithromycin (based on eight studies) was 82.9% (95% CI 76.0%-89.8%; I(2) = 71.0%; P < 0.01) and for doxycycline (based on five studies) was 99.6% (95% CI 98.6%-100%; I(2) = 0%; P = 0.571), resulting in a random-effects pooled efficacy difference (based on five studies) of 19.9% (95% CI 11.4%-28.3%; I(2) = 48.5%; P = 0.101) in favour of doxycycline.

CONCLUSIONS

The efficacy of single-dose azithromycin may be considerably lower than 1 week of doxycycline for treating rectal chlamydia. However, the available evidence is very poor. Robust randomized controlled trials are urgently required.

Antibiotic use before chlamydia and gonorrhea genital and extragenital screening in the sexually transmitted infection clinical setting

Background antibiotic use (i.e., administration of antibiotics not directly related to Chlamydia trachomatis or Neisseria gonorrhoeae infections) has been associated with a lower prevalence of genital C. trachomatis infection in a clinical setting. Associations with specific antibiotic types or with N. gonorrhoeae are lacking. Here, we assessed the prevalence of antibiotic use, the different classes and agents used, and their association with a subsequent sexually transmitted infection (STI) clinic C. trachomatis and N. gonorrhoeae test result. At our STI clinic, we systematically registered whether antibiotics were used in the past month (in 29% of the cases, the specific antibiotic agent was named). Patients were screened for urogenital C. trachomatis and N. gonorrhoeae; a third of them were also screened for anorectal and oropharyngeal C. trachomatis and N. gonorrhoeae. The proportion of antibiotics used and their association with C. trachomatis and N. gonorrhoeae prevalence were assessed for heterosexual men, men who have sex with men (MSM), and women. During 14,775 clinic consultations, antibiotic use was reported by 12.2% (95% confidence interval [CI], 11.7% to 12.7%), i.e., 14.8% of women, 8.6% of heterosexual men, and 11.6% of MSM. The most reported antibiotics were penicillins, tetracyclines, and macrolides, respectively. The prevalence was 11.0% (95% CI, 10.3% to 11.3%) for C. trachomatis and 1.9% (95% CI, 1.7% to 2.1%) for N. gonorrhoeae. Only tetracycline use was associated with a lower C. trachomatis prevalence (3%). Overall antibiotic use was associated with lower anorectal C. trachomatis prevalence in MSM only (odds ratio, 0.4; 95% CI, 0.2 to 0.8). STI clinic visitors commonly report recent antibiotic use. Even in a country with low antibiotic consumption, tetracycline use impacted C. trachomatis prevalence, while there was a notable absence of association with azithromycin.

Comparing azithromycin and doxycycline for the treatment of rectal chlamydial infection: a retrospective cohort study

BACKGROUND

Centers for Disease Control and Prevention guidelines recommend azithromycin or doxycycline for treatment of rectal chlamydial infection.

METHODS

We created a retrospective cohort of male patients diagnosed as having rectal chlamydia between 1993 and 2012 at a sexually transmitted disease clinic in Seattle, Washington. Men were included in the analysis if they were treated with azithromycin (1 g single dose) or doxycycline (100 mg twice a day × 7 days) within 60 days of chlamydia diagnosis and returned for repeat testing 14 to 180 days after treatment. We compared the risk of persistent/recurrent rectal chlamydial infection among recipients of the 2 drug regimens using 4 follow-up testing time intervals (14-30, 60, 90, and 180 days).

RESULTS

Of 1835 cases of rectal chlamydia diagnosed in the study period, 1480 (81%) were treated with azithromycin or doxycycline without a second drug active against Chlamydia trachomatis. Of these, 407 (33%) of 1231 azithromycin-treated men and 95 (38%) of 249 doxycycline-treated men were retested 14 to 180 days after treatment (P = 0.12); 88 (22%) and 8 (8%), respectively, had persistent/recurrent infection (P = 0.002). Persistent/recurrent infection was higher among men treated with azithromycin compared with doxycycline at 14 to 30 days (4/53 [8%] vs. 0/20 [0%]), 14 to 60 days (23/136 [17%] vs. 0/36 [0%]), and 14 to 90 days (50/230 [22%] vs. 2/56 [4%]). In multivariate analysis, azithromycin-treated men had a significantly higher risk of persistent/recurrent infection in the 14 to 90 days (adjusted relative risk, 5.2; 95% confidence interval, 1.3-21.0) and 14 to 180 days (adjusted relative risk, 2.4; 95% confidence interval, 1.2-4.8) after treatment.

CONCLUSIONS

These data suggest that doxycycline may be more effective than azithromycin in the treatment of rectal chlamydial infections.

Should we screen heterosexuals for extra-genital chlamydial and gonococcal infections?

Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) are two of the most prevalent bacterial sexually transmitted infections in the UK. Although the high burden of extra-genital infections with GC and CT in men who have sex with men has been well established, a significant number of extra-genital site infections with CT and GC could similarly be present in heterosexual women. For this reason we started to routinely offer extra-genital site testing for GC and CT in all patients attending our sexual health clinic who reported having had receptive anal sex and/or giving oral sex. This followed a review of current evidence by the clinical team and a change in local testing policy. This study not only confirmed a large reservoir of extra-genital infection amongst men who have sex with men, but also demonstrates that a comparable reservoir of extra-genital infection is present amongst heterosexual women. Our study adds to the mounting evidence that extra-genital site testing in heterosexual women should occur when oral or anal sexual activity is reported.

Analysis of patients with Chlamydia trachomatis genital infection in an STD clinic

INTRODUCTION AND OBJECTIVES

Chlamydia trachomatis genital infection is common in our setting and early treatment can prevent complications. The aim of this study was to report on patients diagnosed with C trachomatis genital infection in a sexually transmitted disease (STD) clinic.

MATERIAL AND METHODS

This was a descriptive, cross-sectional, observational study of patients diagnosed with C. trachomatis infection between 2010 and 2011. We recorded demographic data and information on sexual habits, concomitant sexually transmitted infections (STIs), and various aspects of treatment.

RESULTS

In total, 12.3% of the samples analyzed were positive for C trachomatis genital infection. Sixty-two patients (43 men) with a mean age of 31 years were studied; 75% were heterosexual and 87% had had a sexual partner in the previous 2 months. Condom use was inconsistent in 81%, 79%, and 65% of patients who practiced vaginal, oral, and anal sex, respectively. Thirteen percent of the patients had symptoms and anogenital warts were the most common associated STI. The most widely used treatment was doxycycline.

CONCLUSIONS

A high prevalence of genital C. trachomatis infection was detected in our STD clinic, and the majority of cases were found in young men. We observed a high rate of asymptomatic infection in patients who do not engage in high-risk sexual behavior and who had come to the clinic for another reason. Systematic screening of C. trachomatis infection should be implemented in STD units to enable the early treatment of patients and their recent sexual partners.

High co-occurrence of anorectal chlamydia with urogenital chlamydia in women visiting an STI clinic revealed by routine universal testing in an observational study; a recommendation towards a better anorectal chlamydia control in women

Background

Symptom- and sexual history-based testing i.e., testing on indication, for anorectal sexually transmitted infections (STIs) in women is common. Yet, it is unknown whether this strategy is effective. Moreover, little is known about alternative transmission routes i.e. by fingers/toys. This study assesses anorectal STI prevalence and infections missed by current testing practice, thereby informing the optimal control strategy for anorectal STIs in women.

Methods

Women (n = 663) attending our STI-clinic between May 2012-July 2013 were offered routine testing for anorectal and urogenital Chlamydia trachomatis and Neisseria gonorrhoeae. Data were collected on demographics, sexual behaviour and symptoms. Women were assigned to one of the categories: indication (reported anal sex/symptoms), fingers/toys (only reported use of fingers/toys), or without indication.

Results

Of women, 92% (n = 654) participated. There were 203 reports (31.0%) of anal sex and/or symptoms (indication), 48 reports (7.3%) of only using fingers/toys (fingers/toys), and 403 reports (61.6%) of no anal symptoms, no anal sex and no anal use of fingers/toys (without indication). The overall prevalence was 11.2% (73/654) for urogenital chlamydia and 8.4% (55/654) for anorectal chlamydia. Gonorrhoea infections were not observed. Prevalence of anorectal chlamydia was 7.9% (16/203) for women with indication and 8.6% (39/451) for all other women (P = 0.74). Two-thirds (39/55) of anorectal infections were diagnosed in women without indication. Isolated anorectal chlamydia was rare (n = 3): of all women with an anorectal infection, 94.5% (52/55) also had co-occurrence of urogenital chlamydia. Of all women with urogenital chlamydia, 71.2% (52/73) also had anorectal chlamydia.

Conclusions

Current selective testing on indication of symptoms and sexual history is not an appropriate control strategy for anorectal chlamydia in women visiting an STI clinic. Routine universal anorectal testing is feasible and may be a possible control strategy in women. Yet costs may be a problem. When more restricted control measures are preferred, possible alternatives include (1) anorectal testing only in women with urogenital chlamydia (problem: treatment delay or loss to follow up), and (2) direct treatment for urogenital chlamydia that is effective for anorectal chlamydia as well.

Hidden in plain sight: chlamydial gastrointestinal infection and its relevance to persistence in human genital infection

Although the concept of persistence in chlamydial infections has been recognized for about 80 years, there is still very little known about the mechanism by which this occurs. In this review, we revisit an old paradigm, long known to chlamydiologists and veterinarians, that in virtually all hosts of chlamydiae, including mammals and birds, chlamydiae reside in the gastrointestinal tract for long periods of time in the absence of clinical disease. Thus, if gastrointestinal infection occurs in most hosts, then it is very likely that gastrointestinal infection occurs in humans as well. We demonstrate that gastrointestinal infection does indeed occur in humans and propose that this anatomical site is the source of persistent infection in humans. The data in ruminants and animal models demonstrate that the immune system is unable to clear chlamydiae from the gut, so they can remain indefinitely, with continual shedding in feces. Clearly, many women become reinfected from an untreated partner; however, we propose that women, cured of genital infection, remain at risk for autoinoculation from the lower gastrointestinal tract. Moreover, there are substantial data demonstrating treatment failure of chlamydial infections, particularly with azithromycin. New data in the mouse model have shown that azithromycin is far less effective against chlamydial gastrointestinal infection than against genital infections. Therefore, it is possible that women cured of genital infection by antibiotics remain infected in the gastrointestinal tract and can become reinfected by autoinoculation from that site.

2013 European Guideline on the management of proctitis, proctocolitis and enteritis caused by sexually transmissible pathogens

Proctitis is defined as an inflammatory syndrome of the distal 10-12 cm of the anal canal, also called the rectum. Infectious proctitis can be sexually transmitted via genital-anal mucosal contact, but some also via mutual masturbation.N. gonorrhoeae,C. trachomatis(including lymphogranuloma venereum), Herpes Simplex Virus andT. pallidumare the most common sexually transmitted anorectal pathogens. Shigellosis can be transferred via oral-anal contact and may lead to proctocolitis or enteritis. Although most studies on these infections have concentrated on men who have sex with men (MSM), a significant proportion of women have anal intercourse and therefore may also be at risk. A presumptive clinical diagnosis of proctitis can be made when there are symptoms and signs, and a definitive diagnosis when the results of laboratory tests are available. The symptoms of proctitis include anorectal itching, pain, cramps (tenesmus) and discharge in and around the anal canal. Asymptomatic proctitis occurs frequently and can only be detected by laboratory tests. The majority of rectal chlamydia and gonococcal infections are asymptomatic. Therefore when there is a history of receptive anal contact, exclusion of anorectal infections is generally indicated as part of standard screening for sexually transmitted infections (STIs). Condom use does not guarantee protection from bacterial and protozoan STIs, which are often spread without penile penetration.

Rectal Chlamydia in heterosexual women: more questions than answers

The aim of this study was to observe the proportion of concurrent rectal Chlamydia (RCt) infection in women who have cervical Chlamydia (CCt) and to observe whether there was any correlation with receptive anal intercourse (RAI). Untreated CCt-positive women were invited to take part. Women chose either to have a physician-collected or self-taken rectal swab. Treatment was then commenced. 17 samples were physician-collected and 80 were self-collected. 75/97 (77.3%, 95% Confidence Interval [95%CI] 69.0–85.7%) were RCt positive. 25/97 (25.8%, 95%CI 17.1–34.5%) reported RAI. There was no difference in the positivity rate whether RAI was reported (80%) or not (76%) ( P = 0.71); or whether swabs were physician-collected (65%) or self-taken (80%) ( P = 0.17). Only one of those with RCt reported rectal symptoms. One woman had concurrent gonococcal infection. 34/97 (35%) had a history of past sexually transmitted infections. Verified contact attendance was 0.52 and 72% of verified contacts were Chlamydia positive. Reported RAI may not be helpful in guiding RCt testing. RCt infection in women may be more prevalent than previously thought. We do not know whether RCt infections are clinically significant or whether they may act as a reservoir for re-infection. RCt infections in women require further study.

Detection of anorectal and cervicovaginal Chlamydia trachomatis infections following azithromycin treatment: prospective cohort study with multiple time-sequential measures of rRNA, DNA, quantitative load and symptoms

Background

Determination of Chlamydia trachomatis (Ct) treatment success is hampered by current assessment methods, which involve a single post-treatment measurement only. Therefore, we evaluated Ct detection by applying multiple laboratory measures on time-sequential post-treatment samples.

Methods

A prospective cohort study was established with azithromycin-treated (1000 mg) Ct patients (44 cervicovaginal and 15 anorectal cases). Each patient provided 18 self-taken samples pre-treatment and for 8 weeks post-treatment (response: 96%; 1,016 samples). Samples were tested for 16S rRNA (TMA), bacterial load (quantitative PCR; Chlamydia plasmid DNA) and type (serovar and multilocus sequence typing). Covariates (including behavior, pre-treatment load, anatomic site, symptoms, age, and menstruation) were tested for their potential association with positivity and load at 3–8 weeks using regression analyses controlling for repeated measures.

Findings

By day 9, Ct positivity decreased to 20% and the median load to 0.3 inclusion-forming units (IFU) per ml (pre-treatment: 170 IFU/ml). Of the 35 cases who reported no sex, sex with a treated partner or safe sex with a new partner, 40% had detection, i.e. one or more positive samples from 3–8 weeks (same Ct type over time), indicating possible antimicrobial treatment failure. Cases showed intermittent positive detection and the number of positive samples was higher in anorectal cases than in cervicovaginal cases. The highest observed bacterial load between 3–8 weeks post-treatment was 313 IFU/ml, yet the majority (65%) of positive samples showed a load of ≤2 IFU/ml. Pre-treatment load was found to be associated with later load in anorectal cases.

Conclusions

A single test at 3–8 weeks post-treatment frequently misses Ct. Detection reveals intermittent low loads, with an unknown risk of later complications or transmission. These findings warrant critical re-evaluation of the clinical management of single dose azithromycin-treated Ct patients and fuel the debate on defining treatment failure. Clinicaltrials.gov Identifier: NCT01448876.

Differential susceptibilities to azithromycin treatment of chlamydial infection in the gastrointestinal tract and cervix

Evidence from animal studies suggests that chlamydiae may persist in the gastrointestinal tract (GI) and be a reservoir for reinfection of the genital tract. We hypothesize that there may be a differential susceptibility of organisms in the GI and genital tracts. To determine the effect of azithromycin on persistent chlamydial gut infection, C57BL/6 and BALB/c mice were infected orally and genitally and treated with azithromycin (Az) orally (20, 40, or 80 mg/kg of body weight), and the numbers of chlamydiae were determined from cervix and cecal tissues. The Az concentration in the cecum and cervix was measured by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). Az treatment cleared genital infection in both C57BL/6 and BALB/c mice; however, GI infection was not cleared with the same doses. HPLC data showed the presence of Az at both sites of infection, and significant amounts of Az were measured in treatment groups. However, no significant difference in Az levels between the cecum and the cervix was observed, indicating similar levels of Az reaching both sites of infection. These data indicate that antibiotic levels that are sufficient to cure genital infection are ineffectual against GI infection. The results suggest a reevaluation of antibiotic therapy for chlamydial infection.