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

Diagnosis and Management of Uncomplicated Chlamydia trachomatis Infections in Adolescents and Adults: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

To prepare for the development of the 2021 Centers for Disease Control and Prevention (CDC) sexually transmitted infections treatment guidelines, the CDC convened a committee of expert consultants in June 2019 to discuss recent abstracts and published literature on the epidemiology, diagnosis, and management of sexually transmitted infections.This paper summarizes the key questions, evidence, and recommendations for the diagnosis and management of uncomplicated Chlamydia trachomatis (CT) infections in adolescents and adults that were reviewed and discussed for consideration in developing the guidelines. The evidence reviewed mostly focused on efficacy of doxycycline and azithromycin for urogenital, rectal, and oropharyngeal CT infection, CT risk factors in women, performance of CT nucleic acid amplification tests on self-collected meatal specimens in men, and performance of newer CT point-of-care tests.

Epidemiology of symptomatic infective anoproctitis in a population of men having sex with men (MSM)

PURPOSE

Anoproctitis due to Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are Sexual Transmitted Infections (STIs) reported in MSM population. This study describes clinical and microbiological epidemiology of infective anoproctitis in MSM population.

METHODS

All patients with symptomatic anoproctitis consulting at the proctology Institute of Saint-Joseph's Hospital, Paris, were included. Detection of CT/NG was performed by PCR GeneXpert^R and other STIs pathogens Mycoplasma sp., HSV, CMV and T. pallidum were detected by multiplex PCR Allplex (mPCR).

RESULTS

Symptoms most frequently reported were pain, rectal bleeding and purulent flow in 66%, 52% and 49% of cases, respectively. On the 311 rectal samples collected, 171 (55.2%) were positive to CT/NG. Among the 194 used for mPCR, 148 were positive to STIs pathogens (76.2%) including 106 samples (71.6%) positive in coinfections. Among NG infections, 22.6% of the strains were resistant to azithromycin and 26.8% to tetracyclines.

CONCLUSIONS

Anorectal infections in this MSM population showed a high prevalence of not only CT/NG but also other pathogens involved in STIs. The high level of coinfections confirms the requirement of accurate PCR tests to improve diagnosis. This study describing increasing antibiotic resistances for NG strains confirms the updating of international guidelines on antibiotic treatments recommendations.

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.

Effective treatment of Lymphogranuloma venereum proctitis with Azithromycin

BACKGROUND

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by Chlamydia trachomatis (CT) serovars L1, L2, and L3 and is endemic among men who have sex with men (MSM) in Europe. We evaluated weekly oral Azithromycin 1 g for 3 weeks as a treatment for LGV proctitis.

METHODS

This is an open clinical trial with convenience allocation according to treating physician preferences. Adults with clinical proctitis received a single dose of 1 g of intramuscular ceftriaxone and were subsequently allocated to receive (i) Doxycycline 100 mg twice daily for 21 days (Doxycycline-group) or, (ii) Azithromycin 1 g orally once weekly for 3 weeks (Azithromycin-group). LGV-cure, (primary endpoint) was defined as resolution of symptoms at week 6 (clinical cure, LGV-CC), with an additional supporting negative rectal PCR at week 4 (microbiological cure; LGV-MC), if available.

FINDINGS

One hundred and twenty-five individuals with LGV clinical proctitis were included. All were MSM and 96% were HIV-positive. Eighty-two were in the Azithromycin-group and 43 in the Doxycycline-group. LGV-cure on a modified intention-to-treat analysis (primary endpoint), occurred in 80 of 82 (98%) in the Azithromycin-group versus 41 of 43 (95%) in Doxycycline-group [treatment difference (95% CI) 2.2% (-3.2; 13.2)]. LGV-MC occurred in 70 of 72 (97%) vs 15 of 15 (100%) in Azithromycin-group and Doxycycline-group, respectively [treatment difference (95% CI) -2.8% (-9.6; 17.7)]. Adverse events were similar in both treatment groups.

INTERPRETATION

Our findings support extended azithromycin dosing as an alternative treatment option for symptomatic LGV proctitis and provides the rationale for future randomized trials.

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.

Treatment Effectiveness of Azithromycin and Doxycycline in Uncomplicated Rectal and Vaginal Chlamydia trachomatis Infections in Women: A Multicenter Observational Study (FemCure)

Background

Rectal infections with Chlamydia trachomatis (CT) are prevalent in women visiting a sexually transmitted infection outpatient clinic, but it remains unclear what the most effective treatment is. We assessed the effectiveness of doxycycline and azithromycin for the treatment of rectal and vaginal chlamydia in women.

Methods

This study is part of a prospective multicenter cohort study (FemCure). Treatment consisted of doxycycline (100 mg twice daily for 7 days) in rectal CT–positive women, and of azithromycin (1 g single dose) in vaginally positive women who were rectally untested or rectally negative. Participants self-collected rectal and vaginal samples at enrollment (treatment time-point) and during 4 weeks of follow-up. The endpoint was microbiological cure by a negative nucleic acid amplification test at 4 weeks. Differences between cure proportions and 95% confidence intervals (CIs) were calculated.

Results

We analyzed 416 patients, of whom 319 had both rectal and vaginal chlamydia at enrollment, 22 had rectal chlamydia only, and 75 had vaginal chlamydia only. In 341 rectal infections, microbiological cure in azithromycin-treated women was 78.5% (95% CI, 72.6%–83.7%; n = 164/209) and 95.5% (95% CI, 91.0%–98.2%; n = 126/132) in doxycycline-treated women (difference, 17.0% [95% CI, 9.6%–24.7%]; P < .001). In 394 vaginal infections, cure was 93.5% (95% CI, 90.1%–96.1%; n = 246/263) in azithromycin-treated women and 95.4% (95% CI, 90.9%–98.2%; n = 125/131) in doxycycline-treated women (difference, 1.9% [95% CI, –3.6% to 6.7%]; P = .504).

Conclusions

The effectiveness of doxycycline is high and exceeds that of azithromycin for the treatment of rectal CT infections in women.

Clinical Trials Registration

NCT02694497.

Azithromycin combined with doxycycline in non-gonococcal urethritis

Non-gonococcal urethritis (NGU) is one of the most common sexually transmitted diseases caused by chlamydia or mycoplasma. The present study aimed to explore the clinical efficacy of azithromycin combined with doxycycline in patients with NGU and its effect on serum levels of inflammatory cytokine interleukin-6 (IL-6). A total of 98 patients with non-gonococcal urethritis were prospectively selected, of which 46 patients were assigned to an azithromycin group (treated with azithromycin alone), while the rest were assigned to a combination group (treated with azithromycin and doxycycline). The conditions of the patients were evaluated and compared between the two groups. The treatment efficacy in patients in the combination group was significantly better than that in the azithromycin group, and the time to symptom relief, period of medication, recurrence rate within 1 year of withdrawal and level of serum IL-6 in the combination group were significantly lower than those in the azithromycin group. The quality of life of patients in the combination group was significantly improved compared to those in the azithromycin group. However, there was no significant difference in the incidence of adverse reactions between the two groups. Azithromycin combined with doxycycline was revealed to be more effective than azithromycin monotherapy for NGU.

Low-dose doxycycline induces Chlamydia trachomatis persistence in HeLa cells

Chlamydia persistence is a viable but non-replicative stage, induced by several sub-lethal stressor agents, including beta-lactam antibiotics. So far, no data about the connection between doxycycline and chlamydial persistence has been described in literature. We investigated the ability of doxycycline to induce C. trachomatis (CT) persistence in an in vitro model of epithelial cell infection (HeLa cells), comparing the results with the well-established model of penicillin-induced persistence. The effect of doxycycline was explored on 10 different CT strains by analysing (i) the presence of aberrant inclusions, (ii) chlamydial recovery, (iii) the expression of different chlamydial genes (omcB, euo, Ct110, Ct604, Ct755, HtrA) and (iv) the effects on epithelial cell viability. For each strain, the presence of foreign genomic islands responsible of tetracycline resistance was excluded. We found that low doses of doxycycline can induce a condition of CT persistence. For concentrations of doxycycline equal to 0.03-0.015 mg/L, CT inclusions are smaller and aberrant and CT cycle is characterized by the presence of viable but non-dividing RBs with the complete abolishment of chlamydial cytotoxic effect. Infectious EBs can be recovered after removal of the drug. During doxycycline-induced persistence, the expression of the late gene omcB is decreased, indicating the blocking of RB-to-EB conversion. Conversely, as for penicillin G, a significant up-regulation of the stress response HtrA gene is found in doxycycline-treated cells. This study provides a novel in vitro cell model to examine the characteristics of doxycycline-induced persistent CT infection.

A review of current guidelines and research on the management of sexually transmitted infections in adolescents and young adults

Adolescents and young adults are at high risk for sexually transmitted infections (STIs). Providers have the responsibility to accurately manage these infections to prevent medical complications and the spread of STIs. This article will review the epidemiology, screening recommendations, diagnostic tests, and treatment guidelines for STIs most commonly encountered in this population: Chlamydia trachomatis, Neisseria gonorrhoeae, Herpes simplex virus, and Trichomonas vaginalis, as well as the sexually associated infection bacterial vaginosis. This review will discuss ongoing research that explores ways to improve the management of STIs in adolescents and young adults.

Sexual safety and HIV prevention in travel medicine: Practical considerations and new approaches

Travellers who engage in sexual contact with a new sexual partner abroad may be at high risk of HIV and other sexually transmitted infections (STIs), but these risks can be reduced through appropriate planning during the pre-travel clinic visit. Here we discuss strategies available to the clinician to maximise travellers' sexual safety during travel. Strategies may include immunizations, condoms, HIV pre-exposure prophylaxis (PrEP), HIV post-exposure prophylaxis (PEP), self-initiated treatment of symptomatic bacterial STIs, post-exposure prophylaxis for bacterial STIs and hormonal contraception. We discuss the role of these different strategies for travellers, and provide resources to assist clinicians in making clinical decisions and in educating travellers about sexual safety.