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

Clinical Updates in Sexually Transmitted Infections, 2024

Sexually transmitted infections (STIs) continue to increase in the United States with more than 2.5 million cases of gonorrhea, chlamydia, and syphilis reported to the Centers for Disease Control and Prevention in 2022. Untreated STIs in women can lead to adverse outcomes, including pelvic inflammatory disease, infertility, chronic pelvic pain, and pregnancy complications such as ectopic pregnancy, early pregnancy loss, stillbirth, and neonatal transmission. STI-related guidelines can be complex and are frequently updated, making it challenging to stay informed on current guidance. This article provides high-yield updates to support clinicians managing STIs by highlighting changes in screening, diagnosis, and treatment. One important topic includes new guidance on syphilis screening, including a clarified description of high community rates of syphilis based on Healthy People 2030 goals, defined as a case rate of primary or secondary syphilis > 4.6 per 100,000. Reproductive aged persons living in counties above this threshold should be offered syphilis screening. Additionally, American College of Obstetricians & Gynecologists now recommends syphilis screening three times during pregnancy regardless of risk-at the first prenatal visit, during the third trimester, and at delivery. In addition, new guidance to support consideration for extragenital screening for gonorrhea and chlamydia in women at sites such as the anus and pharynx is discussed. Other topics include the most recent chlamydia, gonorrhea, trichomoniasis, and pelvic inflammatory disease treatment recommendations; screening and treatment guidance for Mycoplasma genitalium; genital herpes screening indications and current diagnostic challenges; and the diagnosis and management of mpox in women and during pregnancy.

Doxycycline versus azithromycin for the treatment of anorectal Chlamydia trachomatis infection in women concurrent with vaginal infection (CHLAZIDOXY study): a multicentre, open-label, randomised, controlled, superiority trial

BACKGROUND

Anorectal infections with Chlamydia trachomatis are commonly found in women. Although the efficacy of doxycycline and azithromycin is comparable in the treatment of urogenital infection, their efficacies toward anorectal infection remain unclear. We therefore aimed to compare a single dose of azithromycin with a 7-day course of doxycycline for the treatment of anorectal C trachomatis infection in women with concurrent vaginal infection.

METHODS

We did a multicentre, open-label, randomised, controlled, superiority trial involving four sexually transmitted infection screening centres and three pregnancy termination centres in France. We included sexually active adult women (≥18 years) with a positive C trachomatis vaginal swab who agreed to provide self-collected anorectal swabs for C trachomatis detection. Participants were randomly assigned (1:1), using block sizes of six and eight and stratification by each investigating centre, to orally receive either azithromycin (a single 1-g dose, with or without food) or doxycycline (100 mg in the morning and evening at mealtimes for 7 days [ie, 100 mg of doxycycline twice per day for 7 days]). All laboratory staff who did the bacteriological analyses, but not the participants and the investigators, were masked to the treatment groups. The primary outcome was the microbiological anorectal cure rate defined as a C trachomatis-negative nucleic acid amplification test (NAAT) result in anorectal specimens 6 weeks after treatment initiation among women who had a baseline C trachomatis-positive anorectal NAAT result. The primary analysis was done in the modified intention-to-treat population, with multiple imputation, which included all women who underwent randomisation and had a C trachomatis-positive vaginal and anorectal NAAT result at baseline. Adverse events were reported in all women who underwent randomisation. This study is registered with ClinicalTrials.gov, number NCT03532464.

FINDINGS

Between Oct 19, 2018, and April 17, 2020, we randomly assigned a total of 460 participants to either the doxycycline group (n=230) or the azithromycin group (n=230). Four (1%) of 460 participants were excluded because they refused to take doxycycline or were found to be ineligible after randomisation. Among the 456 participants, 357 (78%) had a concurrent C trachomatis-positive anorectal NAAT result at baseline; 184 (52%) of 357 were in the doxycycline group and 173 (48%) were in the azithromycin group (ie, the modified intention-to-treat population). Microbiological anorectal cure occurred in 147 (94%) of 156 participants in the doxycycline group (28 missing values) versus 120 (85%) of 142 in the azithromycin group (31 missing values; adjusted odds ratio with imputation of missing values 0·43 [95% CI 0·21-0·91]; p=0·0274). Reported adverse events possibly related to treatment were notified in 53 (12%) of 456 women: 24 (11%) of 228 in the doxycycline group and 29 (13%) of 228 in the azithromycin group. Gastrointestinal disorders were the most frequently occurring, in 43 (9%) of 456 women: 17 (8%) of 228 in the doxycycline group and 26 (11%) of 228 in the azithromycin group.

INTERPRETATION

The microbiological anorectal cure rate was significantly lower among women who received a single dose of azithromycin than among those who received a 1-week course of doxycycline. This finding suggests that doxycycline should be the first-line therapy for C trachomatis infection in women.

FUNDING

French Ministry of Health.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Controversies and evidence on Chlamydia testing and treatment in asymptomatic women and men who have sex with men: a narrative review

Background

Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection (STI) worldwide. CT is mainly asymptomatic. Test-and-treat strategies are widely implemented to prevent transmission and complications. Strategies are not without controversy in asymptomatic women and men who have sex with men (MSM). Concerns are emerging to test and treat asymptomatic persons for urogenital CT (‘Controversy 1’) and pharyngeal or rectal CT (‘Controversy 2’), whereby testing symptomatic persons is not under debate. Opposed views in CT treatment involve using azithromycin versus doxycycline (‘Controversy 3’). The objective of this review is to provide coverage of these public health and clinical controversies by reviewing the current scientific evidence.

Methods

A literature search was performed using PubMed for relevant publications between 2018 and September 2021, and iterative retrieval of additional relevant publications.

Results

Controversy 1. In women, the majority of asymptomatic CT are at the urogenital site, and detections mostly include viable CT. CT easily transmits to a partner and potentially also between the vaginal and rectal areas; the clinical impact of urogenital CT is established, although risks for adverse outcomes are uncertain. Wide-scale testing in asymptomatic women has not resulted in reduced prevalence. In MSM, evidence for the clinical impact of asymptomatic urogenital CT is lacking. Controversy 2. Rectal CT is common in women diagnosed with urogenital CT, but the clinical impact of asymptomatic rectal CT is uncertain. In MSM, rectal CT is common, and most CT infections are at the rectal site, yet the risk of longer term complications is unknown. In both sexes, pharyngeal CT is uncommon and has no documented clinical impact. Controversy 3. In the treatment of rectal CT, doxycycline has superior effectiveness to azithromycin. Evidence has also accumulated on the harms of test-and-treat strategies.

Conclusions

Current practices vary widely, from widescale test-and-treat approaches to more individual patient- and partner-level case management. Choosing which asymptomatic people to test at what anatomic site, and whether to test or not, requires an urgent (re-)definition of the goals of testing and treating asymptomatic persons. Treatment guidelines are shifting toward universal doxycycline use, and clinical practice now faces the challenge of implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07171-2.

Test-and-treat is a key strategy in the control of Chlamydia trachomatis (CT). We discuss recent controversies and present scientific evidence regarding urogenital, rectal, and pharyngeal CT test-and-treat strategies in women and in men who have sex with men (MSM). This should inform best practices for the prevention and management of the most common bacterial sexually transmitted infection (STI) worldwide.

Incident urogenital and anorectal Chlamydia trachomatis in women: the role of sexual exposure and autoinoculation: a multicentre observational study (FemCure)

BACKGROUND

Anorectal infections with Chlamydia trachomatis (CT) are common in women visiting STI outpatient clinics. We here evaluated the risk posed by sexual exposure and by alternate anatomical site infection for incident anorectal and urogenital CT.

METHODS

Prospective multicentre cohort study, FemCure. Participants were treated for CT, and after 4, 6, 8, 10 and 12 weeks, they self-collected anorectal and urogenital samples (swabs) for CT-DNA testing. We calculated the proportion with incident CT, that is, CT incidence (at weeks 6-12) by 2-week time-periods. Compared with no exposure (A), we estimated the risk of incident CT for (B) sexual exposure, (C) alternate site anatomic site infection and (D) both, adjusted for confounders and expressed as adjusted ORs with 95% CIs.

RESULTS

We analysed data of 385 participants contributing 1540 2-week periods. The anorectal CT incidence was 2.9% (39/1343) (95 CI 1.8 to 3.6); 1.3% (A), 1.3% (B), 27.8% (C) and 36.7% (D). The ORs were: 0.91 (95% CI 0.32 to 2.60) (B), 26.0 (95% CI 7.16 to 94.34) (C), 44.26 (95% CI 14.38 to 136.21) (D).The urogenital CT incidence was 3.3% (47/1428) (95% CI 2.4 to 4.4); 0.7% (A), 1.9% (B), 13.9% (C) and 25.4% (D). The ORs were: 2.73 (95% CI 0.87 to 8.61) (B), 21.77 (95% CI 6.70 to 70 71) (C) and 49.66 (95% CI 15.37 to 160.41) (D).

CONCLUSIONS

After initial treatment, an alternate anatomical site CT infection increased the risk for an incident CT in women, especially when also sex was reported. This may suggest a key role for autoinoculation in the re-establishment or persistence of urogenital and anorectal chlamydia infections.

Chlamydia and Gonorrhea

Gonorrhea and chlamydia rates have risen to record-high levels in the United States over the past decade. Because these infections are often asymptomatic, effective clinical management relies on screening of asymptomatic patients, particularly women younger than 25 years and men who have sex with men. If undetected and untreated, gonorrhea and chlamydia can lead to infertility, ectopic pregnancy, and chronic pelvic pain and can facilitate HIV acquisition and transmission. Primary care providers need to be aware of recent changes in recommended treatments for both infections.

High Prevalence of Vaginal and Rectal Mycoplasma genitalium Macrolide Resistance Among Female Sexually Transmitted Disease Clinic Patients in Seattle, Washington

BACKGROUND

Rectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are increasingly recognized as common infections among women. Little is known about the prevalence of rectal Mycoplasma genitalium (MG), rectal MG/CT/GC coinfection, or MG antimicrobial resistance patterns among women.

METHODS

In 2017 to 2018, we recruited women at high risk for CT from Seattle's municipal sexually transmitted disease clinic. Participants self-collected vaginal and rectal specimens for CT/GC nucleic acid amplification testing. We retrospectively tested samples for vaginal and rectal MG using nucleic acid amplification testing and tested MG-positive specimens for macrolide resistance-mediating mutations (MRM) and ParC quinolone resistance-associated mutations (QRAMs).

RESULTS

Of 50 enrolled women, 13 (26%) tested positive for MG, including 10 (20%) with vaginal MG and 11 (22%) with rectal MG; 8 (62%) had concurrent vaginal/rectal MG. Five (38%) were coinfected with CT, none with GC. Only 2 of 11 women with rectal MG reported anal sex in the prior year. Of MG-positive specimens, 100% of rectal and 89% of vaginal specimens had an MRM. There were no vaginal or rectal MG-positive specimens with ParC QRAMs previously associated with quinolone failure. Five MG-infected women received azithromycin for vaginal CT, 4 of whom had a MG MRM detected in their vaginal and/or rectal specimens.

CONCLUSIONS

We observed a high prevalence of macrolide-resistant vaginal and rectal MG among a population of women at high risk for CT. This study highlights how the use of antimicrobials designed to treat an identified infection-in this case, CT-could influence treatment outcomes and antimicrobial susceptibility in other unidentified infections.

Azithromycin in the treatment of rectogenital Chlamydia trachomatis infections: end of an era?

INTRODUCTION

Azithromycin was recommended as the first-line therapeutic regimen for treatment of genital infections in men and women by the Centers for Disease Control in 1998. A series of studies of azithromycin for treatment of rectal chlamydial infection in men who have sex with men (MSM) found that azithromycin was significantly less effective than doxycycline.

AREAS COVERED

Literature on treatment of rectal C. trachomatis from 2000 through May 2020 was searched using PubMed. Retrospective and observational studies were identified documenting the frequency and treatment of rectal chlamydial infection in MSM, heterosexual men and women that reported lower efficacy of single-dose azithromycin compared to doxycycline. Literature on possible reasons for the lower efficacy were also reviewed including studies of antibiotic resistance, impact of organism load, and persistent infection in rectal specimens and pharmacokinetics and pharmacodynamics of azithromycin in rectal tissue.

EXPERT OPINION

The available data suggests that single-dose azithromycin is not as effective as azithromycin for the treatment of rectal infection in MSM and women. Most of these data have been retrospective or from observational studies. Final recommendations will depend on the outcome of prospective, randomized, treatment studies. We may also need to examine other dosage regimens for azithromycin.

Antigen-Specific CD4+ T Cell-Derived Gamma Interferon Is Both Necessary and Sufficient for Clearing Chlamydia from the Small Intestine but Not the Large Intestine

The genital tract pathogen Chlamydia trachomatis is frequently detected in the gastrointestinal tract, but the host immunity that regulates chlamydial colonization in the gut remains unclear. In a Chlamydia muridarum-C57 mouse model, chlamydial organisms are cleared from the genital tract in ∼4 weeks, but the genital organisms can spread to the gastrointestinal tract. We found that the gastrointestinal chlamydial organisms were cleared from the small intestine by day 28, paralleling their infection course in the genital tract, but persisted in the large intestine for long periods. Mice deficient in α/β T cells or CD4+ T cells but not CD8+ T cells showed chlamydial persistence in the small intestine, indicating a critical role for CD4+ T cells in clearing Chlamydia from the small intestine. The CD4+ T cell-dependent clearance is likely mediated by gamma interferon (IFN-γ), since mice deficient in IFN-γ but not interleukin 22 (IL-22) signaling pathways rescued chlamydial colonization in the small intestine. Furthermore, exogenous IFN-γ was sufficient for clearing Chlamydia from the small intestine but not the large intestine. Mice deficient in developing Chlamydia-specific Th1 immunity showed chlamydial persistence in the small intestine. Finally, IFN-γ-producing CD4+ but not CD8+ T cells from immunized donor mice were sufficient for eliminating Chlamydia from the small intestine but not the large intestine of recipient mice. Thus, we have demonstrated a critical role for Th1 immunity in clearing Chlamydia from the small intestine but not the large intestine, indicating that chlamydial colonization in different regions of the gastrointestinal tract is regulated by distinct immune mechanisms.