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

Multigeographic clinical assessment of a molecular diagnostic assay for detection of key codons to predict decreased susceptibility or resistance to cephalosporins in Neisseria gonorrhoeae

Cephalosporin resistance in Neisseria gonorrhoeae has severely compromised the efficacy of World Health Organization (WHO)-recommended therapies. This study aimed to methodologically evaluate the optimized Six-CodonPlus assay, and additionally conducted a multicenter evaluation to assess its clinical application, especially for predicting antimicrobial resistance (AMR). For methodological evaluation, 397 sequence-known N. gonorrhoeae isolates were evaluated for specificity, 17 nongonococcal isolates were assessed for cross-reactivity, 159 uncultured urogenital swabs and urine samples were evaluated for sensitivity at the clinical level. For multicenter evaluation, 773 isolates with confirmed phenotypic data and 718 clinical urogenital swabs collected from four geographical cities were, respectively, utilized for the evaluation of AMR-prediction strategies and the clinical application of the assay. The assay accurately identified specific single-nucleotide polymorphisms in resistance-associated genes, the detection limits dropped to 10 copies/reaction for individual targets. The specificity reached 100% and no cross-reactivity occurred with double-target confirmation. The assay could be directly applied to clinical samples containing over 20 copies/reaction. Multicenter evaluation formulated two optimal strategies for decreased susceptibility prediction in specific scenarios, and one tactic for prediction of resistance and identification of FC428-like strains. High sensitivity of 86.84% (95% CI, 71.11-95.05) and specificity of 99.59% (95% CI, 98.71-99.89) for resistance prediction were demonstrated for ceftriaxone (CRO). Regarding N. gonorrhoeae identification among multicenter swabs, specificity reached 97.53% (95% CI, 95.49-98.69), and sensitivity reached 93.77% (95% CI, 90.04-96.22). The Six-CodonPlus assay exhibited excellent detection performance and formulated optimal AMR-related prediction strategy with regional adaptability, providing critical information for population screening and clinical treatment.

Neonatal ocular prophylaxis in the United States: is it still necessary?

INTRODUCTION

Much has changed since Credé reported that silver nitrate decreases the incidence of ophthalmia neonatorum. Prenatal screening and treatment of pregnant women for Neisseria gonorrhoeae became standard in the 1950s and for Chlamydia trachomatis in 1993. Neonatal gonococcal and chlamydial conjunctivitis are consequently uncommon today. Currently, only 0.5% erythromycin ophthalmic ointment is available in the United States (U.S.) for neonatal ocular prophylaxis, which is ineffective against C. trachomatis.

AREAS COVERED

This article addresses the altered epidemiology of ophthalmia neonatorum in the U.S. since prophylactic practices began, the lack of data supporting ophthalmic erythromycin for prevention of neonatal gonococcal and chlamydial conjunctivitis, and the impact of prenatal screening and treatment of pregnant women for N. gonorrhoeae and C. trachomatis on conjunctivitis incidence. The authors discuss why erythromycin ophthalmic ointment is likely ineffective against gonococcal ophthalmia, including the development of macrolide resistance. Physiologic limitations and pharmacokinetic properties are considered with respect to ophthalmic erythromycin for the prevention of gonococcal and chlamydial conjunctivitis.

EXPERT OPINION

Administration of erythromycin ophthalmic ointment for the prevention of neonatal conjunctivitis is not literature-supported. Prenatal screening and treatment of pregnant women is the most effective way to prevent ophthalmia neonatorum. National mandates for prophylaxis should be withdrawn.

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.

An Investigation of the Predominant Structure of Antibiotic Azithromycin in Chloroform Solution through NMR and Thermodynamic Analysis

Azithromycin (AZM) is a well-known macrolide-type antibiotic that has been used in the treatment of infections and inflammations. Knowledge of the predominant molecular structure in solution is a prerequisite for...

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.