High-dose oral amoxicillin plus probenecid is highly effective for syphilis in patients with HIV infection

Trends in syphilis treatments and the impact of intramuscular injectable Benzathine penicillin G in Japan: A descriptive study using administrative claims data from April 2016 to September 2023

INTRODUCTION

The incidence of syphilis is increasing in Japan. A new treatment, penicillin intramuscular injection, was launched in January 2022. This study aimed to determine syphilis treatments in Japan and investigate the impact of the new intramuscular penicillin formulation.

MATERIALS AND METHODS

Data from the Japanese Administrative Claims Database from January 2016 to September 2023 were used to identify patients diagnosed with syphilis, and the types and annual trends of antimicrobials prescribed were investigated. Furthermore, the characteristics of patients prescribed an intramuscular injection of benzathine penicillin G were compared with those of patients who were not.

RESULTS

Overall, 7867 patients were included in the analysis (81 %, male; 5.4 % positive for human immunodeficiency virus). Seventy-five percent of patients were diagnosed with syphilis in facilities with 0-19 beds. Annual trends showed oral amoxicillin as the most prescribed drug to 80 % of patients throughout the study period. In 2023, 10.6 % of patients received a prescription for an intramuscular penicillin formulation. Compared with those who did not receive this treatment, those who received it tended to have fewer clinic visits over 1 month (p = 0.0256).

CONCLUSIONS

Oral amoxicillin is the primary treatment for syphilis in Japan; however, the number of patients receiving intramuscular injection of benzathine penicillin G is increasing. Prescribed mainly by clinics, an intramuscular injection of benzathine penicillin G may contribute to a decreased number of office visits.

Congenital Syphilis: A Re-Emerging but Preventable Infection

Congenital syphilis presents a significant global burden, contributing to fetal loss, stillbirth, neonatal mortality, and congenital infection. Despite the target established in 2007 by the World Health Organization (WHO) of fewer than 50 cases per 100,000 live births, the global incidence is on the rise, particularly in low- and middle-income regions. Recent data indicate a rate of 473 cases per 100,000 live births, resulting in 661,000 total cases of congenital syphilis, including 355,000 adverse birth outcomes such as early fetal deaths, stillbirths, neonatal deaths, preterm or low-birth-weight births, and infants with clinical congenital syphilis. Alarmingly, only 6% of these adverse outcomes occurred in mothers who were enrolled, screened, and treated. Unlike many neonatal infections, congenital syphilis is preventable through effective antenatal screening and treatment of infected pregnant women. However, despite available screening tools, affordable treatment options, and the integration of prevention programs into antenatal care in various countries, congenital syphilis remains a pressing public health concern worldwide. This review aims to summarize the current epidemiology, transmission, and treatment of syphilis in pregnancy, as well as to explore global efforts to reduce vertical transmission and address the reasons for falling short of the WHO elimination target.

Resurgence of congenital syphilis: new strategies against an old foe

Congenital syphilis is a major global cause of fetal loss, stillbirth, neonatal death, and congenital infection. In 2020, the global rate of congenital syphilis was 425 cases per 100 000 livebirths-substantially higher than WHO's elimination target of 50 cases per 100 000 livebirths. Case rates are rising in many high-income countries, but remain low compared with those in low-income and middle-income settings. This Review aims to summarise the current epidemiology and knowledge on transmission and treatment of syphilis in pregnancy, and proposes measures to reduce the rising incidence seen worldwide. We also describe emerging diagnostic and treatment tools to prevent vertical transmission and improve management of congenital syphilis. Finally, we outline a programme of public health priorities, which include research, clinical, and preventive strategies.

Antimicrobial susceptibility of Treponema pallidum subspecies pallidum: an in-vitro study

BACKGROUND

The increasing incidence of syphilis and the limitations of first-line treatment with penicillin, particularly in neurosyphilis, neonatal syphilis, and pregnancy, highlight the need to expand the therapeutic repertoire for effective management of this disease. We assessed the in-vitro efficacy of 18 antibiotics from several classes on Treponema pallidum subspecies pallidum (T pallidum), the syphilis bacteria.

METHODS

Using the in-vitro culture system for T pallidum, we exposed the pathogen to a concentration range of each tested antibiotic. After a 7-day incubation, the treponemal burden was evaluated by quantitative PCR targeting the T pallidum tp0574 gene. The primary outcome was the minimum inhibitory concentration (MIC) at which the quantitative PCR values were not significantly higher than the inoculum wells. We also investigated the susceptibility of macrolide-resistant strains to high concentrations of azithromycin, and the possibility of developing resistance to linezolid, a proposed candidate for syphilis treatment.

FINDINGS

Amoxicillin, ceftriaxone, several oral cephalosporins, tedizolid, and dalbavancin exhibited anti-treponemal activity at concentrations achievable in human plasma following regular dosing regimens. The experiments revealed a MIC for amoxicillin at 0·02 mg/L, ceftriaxone at 0·0025 mg/L, cephalexin at 0·25 mg/L, cefetamet and cefixime at 0·0313 mg/L, cefuroxime at 0·0156 mg/L, tedizolid at 0·0625 mg/L, spectinomycin at 0·1 mg/L, and dalbavancin at 0·125 mg/L. The MIC for zoliflodacin and balofloxacin was 2 mg/L. Ertapenem, isoniazid, pyrazinamide, and metronidazole had either a poor or no effect. Azithromycin concentrations up to 2 mg/L (64 times the MIC) were ineffective against strains carrying mutations associated to macrolide resistance. Exposure to subtherapeutic doses of linezolid for 10 weeks did not induce phenotypic or genotypic resistance.

INTERPRETATION

Cephalosporins and oxazolidinones are potential candidates for expanding the current therapeutic repertoire for syphilis. Our findings warrant testing efficacy in animal models and, if successful, clinical assessment of efficacy.

FUNDING

European Research Council.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

Changes in rapid plasma reagin titers in patients with syphilis before and after treatment: A retrospective cohort study in an HIV/AIDS referral hospital in Tokyo

INTRODUCTION

Although the rapid plasma reagin (RPR) test is used to determine treatment efficacy for syphilis, animal studies show that it decreases gradually after an initial increase even without treatment. Pre-treatment changes in RPR titer in humans and its relationship with post-treatment changes in RPR titer are not well known.

METHODS

We retrospectively analyzed the clinical records of syphilitic patients who underwent automated RPR (Mediace) testing twice before treatment (i.e., at diagnosis and treatment initiation) within 1-3 months at an HIV/AIDS referral hospital in Japan between 2006 and 2018. The RPR values were expressed as the ratio to the value at treatment initiation. The mean monthly relative change in the RPR after treatment was calculated on the log2 scale for each patient and analyzed by multivariable linear regression.

RESULTS

Sixty-eight patients were identified. The median age was 45 (interquartile range [IQR], 38-50), 98.5% (67/68) were men, and 97.1% (66/68) had HIV. The median RPR titer ratio at treatment initiation/diagnosis was 0.87 (IQR, 0.48-1.30). The RPR titer decreased more than twofold in 26.5% (18/68) and more than fourfold in 10.3% (7/68) before treatment. In the multivariable analysis, higher age (predicted monthly RPR relative change on the log2 scale 0.23/10 years [95% confidence interval [CI], 0.090-0.37]), history of syphilis (0.36 [95% CI, 0.07-0.65]), and a lower ratio of RPR at treatment initiation/diagnosis (-0.52/every 10-fold increase [95% CI, -0.81 to -0.22]) were associated with a slower RPR decrease after treatment.

CONCLUSIONS

In a mostly HIV patient population, RPR titer can show more than four-fold spontaneous increase or decrease within 1-3 months. Pre-treatment spontaneous decrease of RPR titer was associated with a slower decrease in post-treatment RPR titer.

Combination of Amoxicillin 3000 mg and Probenecid Versus 1500 mg Amoxicillin Monotherapy for Treating Syphilis in Patients With Human Immunodeficiency Virus: An Open-Label, Randomized, Controlled, Non-Inferiority Trial

BACKGROUND

Amoxicillin plus probenecid is an alternative to intramuscular benzathine penicillin G for treating syphilis in the United Kingdom. Low-dose amoxicillin is an alternative treatment option used in Japan.

METHODS

We conducted an open-label, randomized, controlled, non-inferiority trial between 31 August 2018, and 3 February 2022, to compare 1500 mg low-dose amoxicillin monotherapy with the combination of 3000 mg amoxicillin and probenecid (non-inferiority margin 10%). Patients with human immunodeficiency virus (HIV) infection and syphilis were eligible. The primary outcome was the cumulative serological cure rate within 12 months post-treatment, measured using the manual rapid plasma reagin card test. Secondary outcomes included safety assessment.

RESULTS

A total of 112 participants were randomized into 2 groups. Serological cure rates within 12 months were 90.6% and 94.4% with the low-dose amoxicillin and combination regimens, respectively. Serological cure rates for early syphilis within 12 months were 93.5% and 97.9% with the low-dose amoxicillin and combination regimens, respectively. Non-inferiority of low-dose amoxicillin compared with amoxicillin plus probenecid overall and for early syphilis was not confirmed. No significant side effects were detected.

CONCLUSIONS

This is the first randomized controlled trial to demonstrate a high efficacy of amoxicillin-based regimens for treating syphilis in patients with HIV infection, and the non-inferiority of low-dose amoxicillin compared with amoxicillin plus probenecid was not seen. Therefore, amoxicillin monotherapy could be a good alternative to intramuscular benzathine penicillin G with fewer side effects. However, further studies comparing with benzathine penicillin G in different populations and with larger sample sizes are needed.

TRIALS REGISTRATION

(UMIN000033986).

Demystifying Ocular Syphilis - A Major Review

Syphilis, caused by the spirochaete, Treponema pallidum, continues to be a public health challenge globally with its rates steadily increasing in the past few years. The disease is transmitted through small breaks in the skin during sexual contact, or via congenital transmission in utero, either across the placenta or by contact with an active genital lesion during delivery. Estimated 5.7-6 million new cases are detected every year worldwide in the 15-49 years age group. An increased incidence has been reported in most populations with particular clusters in special groups like men who have sex with men, female sex workers, and their male clients. Ocular syphilis has a varied presentation and is considered a great mimicker in all cases of uveitis. The laboratory diagnosis of syphilis is predominantly based on serological tests including TPHA and VDRL. Parenteral penicillin is the cornerstone of treatment for all stages of ocular syphilis.

[A case of neurosyphilis presenting as sudden onset of limbic encephalitis]

A 52-year-old male was carried to hospital by ambulance, because of an abrupt abnormal behavior and impaired consciousness. Soon after the arrival, the patient started a generalized seizure. Although the seizure was stopped by Midazolam, amnesia were observed. With meningeal irritation signs, in addition to the clinical course, the patient was thought to develop limbic encephalitis. The cause of the encephalitis was diagnosed as neurosyphilis because of the positive serum and CSF syphilis reactions, and the patient was treated with penicillin G from the first admission day on. Steroid pulse therapy was also conducted, followed by acyclovir since herpes encephalitis could not be ruled out; the brain MRI showed left-side dominant T₂/FLAIR high intensity lesions in the bilateral temporal lobes and left hippocampus. With the treatment progression, the amnestic syndrome improved and the patient returned to work. Although neurosyphilis is a rare cause of acute onset limbic encephalitis, it is important to keep the possibility of this disease in mind in making a treatment plan.

Effect of unintended short-term 3.0 g/day amoxicillin and probenecid treatment for early syphilis on patients with HIV-1 infection

Background

Standard therapy for early syphilis involves intramuscular injections of penicillin G, which frequently faces shortages in several countries. Fourteen-day amoxicillin therapy has been suggested as an alternative to benzathine penicillin G, but the optimal duration of amoxicillin therapy remains unclear and could theoretically be shortened to less than 14 days. The aim of this study was to explore the effectiveness of short-term amoxicillin therapy for early syphilis.

Methods

We retrospectively explored the effectiveness of short-term amoxicillin therapy for early syphilis. The treatment data of patients who had received amoxicillin therapy for less than 14 days for unintended reasons were reviewed. Diagnosis was confirmed based on either the physician's description or clinical presentation. Successful treatment was defined as a fourfold or greater decline in the rapid plasma reagin titer or sero-reversion to negative within 12 months.

Results

Of 295 patients, 8 received short-term amoxicillin treatment. All were men who had sex with men and people living with human immunodeficiency virus. Their median age, CD4 count, and treatment duration were 34 years (range, 26-40), 258/mL (range, 112-930), and 9.5 days (range, 5-11), respectively. One patient had primary syphilis, six had secondary syphilis, and one had early latent syphilis. All patients, except one who showed reinfection, demonstrated a serological response within 4 months. The median time for serological response was 112 days.

Conclusion

The results indicate that early syphilis could potentially be treated with 5-11 days of amoxicillin therapy combined with probenecid. This suggests that short-term amoxicillin therapy might be a sufficient treatment for early syphilis instead of the standard 14-day course.

Combination with a FtsZ inhibitor potentiates the in vivo efficacy of oxacillin against methicillin-resistant Staphylococcus aureus

Oxacillin is a first-line antibiotic for the treatment of methicillin-sensitive Staphylococcus aureus (MSSA) infections but is ineffective against methicillin-resistant S. aureus (MRSA) due to resistance. Here we present results showing that co-administering oxacillin with the FtsZ-targeting prodrug TXA709 renders oxacillin efficacious against MRSA. The combination of oxacillin and the active product of TXA709 (TXA707) is associated with synergistic bactericidal activity against clinical isolates of MRSA that are resistant to current standard-of-care antibiotics. We show that MRSA cells treated with oxacillin in combination with TXA707 exhibit morphological characteristics and PBP2 mislocalization behavior similar to that exhibited by MSSA cells treated with oxacillin alone. Co-administration with TXA709 renders oxacillin efficacious in mouse models of both systemic and tissue infection with MRSA, with this efficacy being observed at human-equivalent doses of oxacillin well below that recommended for daily adult use. Pharmacokinetic evaluations in mice reveal that co-administration with TXA709 also increases total exposure to oxacillin. Viewed as a whole, our results highlight the clinical potential of repurposing oxacillin to treat MRSA infections through combination with a FtsZ inhibitor.

Management of Adult Syphilis: Key Questions to Inform the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

A panel of experts generated 5 "key questions" in the management of adult syphilis. A systematic literature review was conducted and tables of evidence were constructed to answer these questions. Available data suggest no clinical benefit to >1 dose of benzathine penicillin G for early syphilis in human immunodeficiency virus (HIV)-infected patients. While penicillin remains the drug of choice to treat syphilis, doxycycline to treat early and late latent syphilis is an acceptable alternate option if penicillin cannot be used. There are very limited data regarding the impact of additional antibiotic doses on serologic responses in serofast patients and no data on the impact of additional antibiotic courses on long-term clinical outcomes. In patients with isolated ocular or otic signs and symptoms, reactive syphilis serologic results, and confirmed ocular/otic abnormalities at examination, a diagnostic cerebrospinal fluid (CSF) examination is not necessary, because up to 40% and 90% of patients, respectively, would have no CSF abnormalities. Based on the results of 2 studies, repeated CSF examinations are not necessary for HIV-uninfected patients or HIV-infected patients on antiretroviral therapy who exhibit appropriate serologic and clinical responses after treatment for neurosyphilis. Finally, several important gaps were identified and should be a priority for future research.

Hard bilateral syphilitic testes with vasculitis: a case report and literature review

BACKGROUND

We report the case of a patient with syphilitic testicular gumma and vasculitis with adrenal failure due to chronic steroid use.

CASE PRESENTATION

A 63-year-old male presented with hard right eye swelling and very firm bilateral testes on palpation, which he had for 2 years. Testicular tumor markers were negative; syphilis test was positive. Radiological examination suggested aortitis and bilateral testicular malignancy. The patient received ampicillin for the infection and prednisolone for vasculitis. Left orchidectomy was performed to confirm the presence of testicular tumor; histological examinations revealed granulomatous orchitis. The prednisolone doses were adjusted because of relapses and adverse effects of steroid use. Unfortunately, the patient died in the intensive care unit because of uncontrolled blood pressure and pneumonia.

CONCLUSIONS

This is a rare case of syphilis with testicular involvement and vasculitis. This report shows the importance of broadening the differential diagnoses of testicular firmness.

Ocular syphilis

Multiple studies around the world suggest that syphilis is re-emerging. Ocular syphilis - with a wide range of presentations, most of which are subtypes of uveitis - has become an increasingly common cause of ocular inflammation over the past 20 years. Its rising incidence, diagnostic complexity, and manifestations that have only recently been characterized make ocular syphilis relevant from the public health, clinical, and scientific perspectives. We review the demographics, epidemiology, clinical features, ocular imaging findings, diagnosis, and medical management of this condition.

Novel monocyclic amide-linked phenol derivatives without mitochondrial toxicity have potent uric acid-lowering activity

Although benzbromarone (BBR) is a conventional, highly potent uricosuric drug, it is not a standard medicine because it causes rare but fatal fulminant hepatitis. We transformed the bis-aryl ketone structure of BBR to generate novel monocyclic amide-linked phenol derivatives that should possess uric acid excretion activity without adverse properties associated with BBR. The derivatives were synthesized and tested for uric acid uptake inhibition (UUI) in two assays using either urate transporter 1-expressing cells or primary human renal proximal tubule epithelial cells. We also evaluated their inhibitory activity against mitochondrial respiration as a critical mitochondrial toxicity parameter. Some derivatives with UUI activity had no mitochondrial toxicity, including compound 3f, which effectively lowered the plasma uric acid level in Cebus apella. Thus, 3f is a promising candidate for further development as a uricosuric agent.

Clinical efficacy and tolerability of 1.5 g/day oral amoxicillin therapy without probenecid for the treatment of syphilis

OBJECTIVES

Intramuscular benzathine penicillin G is not available in certain countries. In a previous report, 3 g/day amoxicillin with probenecid was shown to be effective in treating syphilis in patients with HIV; however, 7.3% of patients changed their therapy owing to adverse events. The objective of this study was to assess the clinical efficacy and tolerability of 1.5 g/day amoxicillin without probenecid for the treatment of syphilis.

METHODS

The routine clinical records of patients diagnosed with syphilis and treated with 1.5 g/day amoxicillin at a tertiary care hospital between 2006 and 2018 were retrospectively analysed. Syphilis was diagnosed if serum rapid plasma reagin (RPR) titres were ≥8 RU and the Treponema pallidum latex-agglutination test was positive. Serological cure was defined as a ≥fourfold decrease in the RPR titre within 12 months in symptomatic early syphilis and within 24 months in latent syphilis.

RESULTS

Overall, 138 patients (112 with HIV) were analysed. The percentages of primary, secondary, early latent, late latent and latent syphilis of unknown duration were 8.0%, 50.0%, 25.4%, 5.8% and 10.9%, respectively. The median treatment duration was 4.5 weeks (IQR 4-8 weeks), which was not related to the stage of syphilis. Two patients (1.5%) changed treatment due to skin rash. The rate of serological cure was 94.9% (131/138; 95% CI 89.8% to 97.9%) overall; 93.8% (105/112; 95% CI 87.5% to 97.5%) in patients with HIV and 100% (26/26; 95% CI 86.8% to 100%) in patients without HIV. Treatment duration was not related to the treatment efficacy.

CONCLUSION

The regimen of 1.5 g/day amoxicillin without probenecid is highly effective with a low switch rate in patients with and without HIV.

2020 European guideline on the management of syphilis

The 2020 edition of the European guideline on the management of syphilis is an update of the 2014 edition. Main modifications and updates include: -The ongoing epidemics of early syphilis in Europe, particularly in men who have sex with men (MSM) -The development of dual treponemal and non-treponemal point-of-care (POC) tests -The progress in non-treponemal test (NTT) automatization -The regular episodic shortage of benzathine penicillin G (BPG) in some European countries -The exclusion of azithromycin as an alternative treatment at any stage of syphilis -The pre-exposure or immediate post-exposure prophylaxis with doxycycline in populations at high risk of acquiring syphilis.

Discovery of Dotinurad (FYU-981), a New Phenol Derivative with Highly Potent Uric Acid Lowering Activity

To derive new uricosuric agents, novel phenol derivatives were synthesized to overcome the disadvantages of benzbromarone (BBR), attributed by its structural features. Herein, we report the discovery of new phenol derivatives with a 1,1-dioxo-1,2-dihydro-3H-1,3-benzothiazole scaffold. The selected compound 11 (dotinurad, FYU-981) demonstrated remarkable inhibitory activity on uric acid uptake by primary human renal proximal tubule epithelial cells (RPTECs) and URAT1-mediated uric acid transport, with weak inhibitory activity against mitochondrial respiration. Dotinurad also displayed favorable pharmacokinetic profiles and higher potency in decreasing uric acid than BBR did in Cebus monkeys. Dotinurad has been approved as a new uricosuric medicine in Japan. Our strategy, which focuses on the structural features resulting in unfavorable effects, could be applied to the future developments of other drugs with disadvantages, particularly those having a bis-aryl ketone structure.

Synthesis and antimicrobial activity of the hybrid molecules between amoxicillin and derivatives of benzoic acid

Due to the increasing problem of bacterial resistance worldwide, the demand for new antibiotics is becoming increasingly urgent. We wished to: (a) prepare hybrid molecules by linking different pharmacophores by chemical bonds; (b) investigate the antib acterial activity of these hybrids using drug-sensitive and drug-resistant pathogens in vitro and vivo. A series of hybrid molecules with a diester structure were designed and synthesized that linked amoxicillin and derivatives of benzoic acid via a methylene bridge. Synthesized compounds were evaluated for activities against Gram-positive bacteria (Staphylococcus aureus American Type Culture Collection [ATCC] 29213, ATCC 11632; methicillin-resistant S. aureus [MRSA] 11; Escherichia coli ATCC 25922) and Gram-negative bacteria (Salmonella LS677, GD836, GD828, GD3625) by microdilution of broth. Synthesized compounds showed good activity against Gram-positive and Gram-negative bacteria in vitro. In particular, amoxicillin-p-nitrobenzoic acid (6d) showed good activity against Salmonella species and had better activity against methicillin-resistant S. aureus (minimum inhibitory concentration [MIC] = 64 μg/ml) than the reference drug, amoxicillin (MIC = 128 μg/ml). Amoxicillin-p-methoxybenzoic acid (6b) had the best antibacterial activity in vivo (ED₅₀ = 13.2496 μg/ml). The hybrid molecules of amoxicillin and derivatives of benzoic acid synthesized based on a diester structure can improve the activity of amoxicillin against Salmonella species and even improve the activity against MRSA.

Recurrent ocular syphilis in a patient living with HIV

A 26-year-old male living with human immunodeficiency virus (HIV) and who had previously been treated for ocular syphilis presented to the Emergency Department with progressive vision loss and uveitis. The efficacy of standard management for neurosyphilis in HIV and recurrence was examined.

Phase II trial evaluating the clinical efficacy of cefixime for treatment of active syphilis in non-pregnant women in Brazil (CeBra)

BACKGROUND

Syphilis is a sexually and vertically transmitted infection caused by the bacteria Treponema pallidum for which there are few proven alternatives to penicillin for treatment. For pregnant women infected with syphilis, penicillin is the only WHO-recommended treatment that will treat the mother and cross the placenta to treat the unborn infant and prevent congenital syphilis. Recent shortages, national level stockouts as well as other barriers to penicillin use call for the urgent identification of alternative therapies to treat pregnant women infected with syphilis.

METHODS

This prospective, randomized, non-comparative trial will enroll non-pregnant women aged 18 years and older with active syphilis, defined as a positive rapid treponemal and a positive non-treponemal RPR test with titer ≥1:16. Women will be a, domized in a 2:1 ratio to receive the oral third generation cephalosporin cefixime at a dose of 400 mg two times per day for 10 days (n = 140) or benzathine penicillin G 2.4 million units intramuscularly based on the stage of syphilis infection (n = 70). RPR titers will be collected at enrolment, and at three, six, and nine months following treatment. Participants experiencing a 4-fold (2 titer) decline by 6 months will be considered as having an adequate or curative treatment response.

DISCUSSION

Demonstration of efficacy of cefixime in the treatment of active syphilis in this Phase 2 trial among non-pregnant women will inform a proposed randomized controlled trial to evaluate cefixime as an alternative treatment for pregnant women with active syphilis to evaluate prevention of congenital syphilis.

TRIAL REGISTRATION

Trial identifier: www.Clinicaltrials.gov, NCT03752112. Registration Date: November 22, 2018.

Effectiveness and Tolerability of Oral Amoxicillin in Pregnant Women with Active Syphilis, Japan, 2010-2018

We conducted a nationwide retrospective study in Japan to evaluate the effectiveness of oral amoxicillin or ampicillin as alternatives to injectable benzathine penicillin G for treating pregnant women with syphilis and preventing congenital syphilis (CS). We investigated 80 pregnant women with active syphilis treated with amoxicillin or ampicillin during 2010-2018. Overall, 21% (15/71) had pregnancies resulting in CS cases, and 3.8% (3/80) changed therapies because of side effects. Among 26 patients with early syphilis, no CS cases occurred, but among 45 with late syphilis, 15 (33%) CS cases occurred. Among 57 patients who started treatment >60 days before delivery, 8 (14%) had CS pregnancy outcomes. We found oral amoxicillin potentially ineffective for preventing CS cases among pregnant women with late syphilis but potentially effective in those with early syphilis. Prospective studies are needed to definitively evaluate the efficacy of amoxicillin for the treatment of pregnant women with syphilis to prevent CS.

New Developments in Bacterial, Viral, and Fungal Cutaneous Infections

PURPOSE OF REVIEW

This review highlights clinically relevant updates to common and significant bacterial, viral, and fungal cutaneous infection within the past 5 years. Recent developments are presented so that the clinician may provide evidence-based, high-quality patient care.

RECENT FINDINGS

New resistance patterns in cutaneous pathogens have recently emerged as a result of inappropriate antimicrobial use. Several new FDA-approved antimicrobials have been approved to treat such infections, including multi-drug resistant pathogens. Several organizational guidelines for cutaneous infection management have been updated with new recommendations for screening, diagnostic, and treatment strategies.

SUMMARY

Clinicians should be aware of the most recent evidence and guidelines for the management of cutaneous infections in order to reduce the emergence of antimicrobial resistance and most effectively treat their patients.

Usefulness of Automated Latex Turbidimetric Rapid Plasma Reagin Test for Diagnosis and Evaluation of Treatment Response in Syphilis in Comparison with Manual Card Test: a Prospective Cohort Study

The usefulness of an automated latex turbidimetric rapid plasma reagin (RPR) assay, compared to the conventional manual card test (serial 2-fold dilution method), for the diagnosis of syphilis and evaluation of treatment response remains unknown. We conducted (i) a cross-sectional study and (ii) a prospective cohort study to elucidate the correlation between automated and manual tests and whether a 4-fold decrement is a feasible criterion for successful treatment with the automated test, respectively, in HIV-infected patients, from October 2015 to November 2017. Study i included 518 patients. The results showed strong correlation between the two tests (r = 0.931; P < 0.001). With a manual test titer of ≥1:8 plus a positive Treponema pallidum particle agglutination (TPPA) test as the reference standard for diagnosis, the optimal cutoff value for the automated test was 6.0 RPR units (area under the curve [AUC], 0.998), with positive predictive value (PPV) of 92.5% and negative predictive value (NPV) of 99.4%. Study ii enrolled 66 men with syphilis. Their RPR values were followed up until after 12 months of treatment. At 12 months, 77.3% and 78.8% of the patients achieved a 4-fold decrement in RPR titer by the automated and manual test, respectively. The optimal decrement rate in RPR titer by the automated test for a 4-fold decrement by manual card test was 76.54% (AUC, 0.96) (PPV, 96.1%; NPV, 80.0%). The automated RPR test is a good alternative to the manual test for the diagnosis of syphilis and evaluation of treatment response and is more rapid and can handle more specimens than the manual test without interpersonal variation in interpretation.

A case of secondary syphilis with pulmonary involvement and review of the literature

Syphilis is a sexually transmitted systemic infection caused by Treponema pallidum. We report a case of a heterosexual, HIV-positive man who presented with secondary syphilis and a lung abscess. A bacterial lung abscess was suspected and a computed tomography-guided percutaneous needle aspiration of the lung abscess was performed. Direct pulmonary involvement by T. pallidum was suggested by a positive PCR result on the aspirated fluid specimen. The clinical signs of secondary syphilis improved, and the lung abscess was resolved after treatment with benzathine penicillin G and amoxicillin-clavulanate. The final diagnosis was secondary pulmonary syphilis. Few reports of secondary syphilis with pulmonary involvement have been reported to date.

Neurosyphilis in patients with HIV

Syphilis is a resurgent sexually transmitted infection in the UK that is disproportionately diagnosed in patients living with HIV, particularly in men who have sex with men. Syphilis appears to present differently in patients with HIV, particularly in those with severe immunosuppression. Progression to neurosyphilis is more common in HIV coinfection and can be asymptomatic, often for several years. The presentations of neurosyphilis vary but can include meningitis, meningovascular disease, general paresis and tabes dorsalis. There is debate about the circumstances in which to perform a lumbar puncture, and the current gold standard diagnostics have inadequate sensitivity. We recommend a pragmatic approach to lumbar punctures, interpreting investigations and deciding when to consider treatment with a neuropenetrative antibiotic regimen.

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.

Prognostic Factors in Syphilitic Uveitis

PURPOSE

To identify predictors of treatment success in syphilitic uveitis (SU).

DESIGN

Retrospective multicentric analysis of patients treated for SU.

PARTICIPANTS

A total of 95 eyes (66 patients, mean [standard deviation] aged 49 [12.5] years, 31 [47%] of whom were human immunodeficiency virus [HIV]+) were analyzed.

METHODS

Activity of SU was assessed at 1 week and 1 month after treatment onset, and at last follow-up. Improvement was defined by a ≥2-step decrease of both anterior chamber and vitreous haze inflammation levels, and by the size reduction in chorioretinal lesions.

MAIN OUTCOME MEASURES

Recovery was defined as the resolution of inflammation in all anatomic structures at 1 month.

RESULTS

Panuveitis and posterior uveitis were the most frequent findings. Inflammatory parameters were higher in HIV+ patients. Recovery was reported in 65% and 85% of eyes at 1 month and at last follow-up, respectively. In multivariate analysis, after adjusting for initial best-corrected visual acuity and the antimicrobial treatment regimen, clinical improvement at 1 week (corrected risk ratios [cRR], 3.5 [2.3-3.8]; P = 0.001) was predictive of recovery at 1 month, whereas the use of periocular dexamethasone injections (cRR, 0.05 [0.02-0.6]; P = 0.01) and methylprednisolone pulses negatively affected the outcomes of eyes.

CONCLUSIONS

Early improvement is the strongest predictor of ophthalmological recovery in SU.

Amoxicillin and Ceftriaxone as Treatment Alternatives to Penicillin for Maternal Syphilis

There is no proven alternative to penicillin for treatment of maternal syphilis. We report 2 case-patients with maternal syphilis who were successfully treated without penicillin. We used amoxicillin and probenecid for the first case-patient and amoxicillin, probenecid, and ceftriaxone for the second case-patient.

Prognosis of ocular syphilis in patients infected with HIV in the antiretroviral therapy era

OBJECTIVE

To describe the clinical course and prognosis of ocular syphilis in patients infected with HIV-1 in the antiretroviral therapy (ART) era.

METHODS

We conducted a single-centre retrospective chart review of ocular syphilis in patients infected with HIV-1 diagnosed between August 1997 and July 2015. The prognosis of best-corrected visual acuity (BCVA) was analysed.

RESULTS

The study subjects were 30 eyes of 20 men who had sex with men (MSM) (median age, 41). Loss of vision and posterior uveitis were the most common ocular clinical features (43%) and location of inflammation at presentation (50%), respectively. The median baseline BCVA was 0.4 (IQR 0.2-1.2), including three eyes with hand motion. BCVA≤0.4 at diagnosis was significantly associated with posterior uveitis or panuveitis (p=0.044). Seventy-five per cent were treated with intravenous benzylpenicillin and 53% were diagnosed with neurosyphilis. After treatment (median follow-up: 21 months), BCVA improved in 89% of the eyes, including all eyes with hand motion, to a median BCVA of 1.2 (IQR 0.8-1.2). Kaplan-Meier analysis showed that >28 days of ocular symptoms before diagnosis was the only factor associated with poor prognosis of BCVA. Three patients (15%) developed recurrence after treatment.

CONCLUSIONS

The prognosis of BCVA in HIV-infected patients with ocular syphilis in the ART era was favourable after proper treatment. Having >28 days of ocular symptoms before diagnosis was associated with poor prognosis. Changes in visual acuity in HIV-infected MSM should prompt an immediate assessment for ocular syphilis as delays in diagnosis and therapy can lead to irreversible visual loss.

A new enhanced antibiotic treatment for early and late syphilis

The objective of this study was to evaluate the efficacy of an enhanced treatment regimen for syphilis with the addition of doxycycline and ceftriaxone to the conventional benzathine penicillin G (BPG) treatment. Sixty-nine syphilis patients were recruited and were randomly assigned to two groups: group 1 (38 patients) received standard therapy and group 2 (31 patients) received the enhanced therapy. All patients were followed-up for at least 12 months. Patients underwent physical examination and serology every 6 months as well as echocardiography and neurological examination every year. A three- to four-fold decline in the initial Venereal Disease Research Laboratory (VDRL) titre within 6 months after therapy was considered as serological cure. At 12 months, 68% of patients in group 1 and 100% in group 2 were serologically cured (P=0.002). During follow-up, no patients in group 2 experienced complications related to syphilis. In contrast, one patient in group 1 developed neurosyphilis. In conclusion, the enhanced treatment is more effective than standard treatment and results in a higher and faster cure rate. Moreover, it provides treponemicidal antibiotic levels in the cerebrospinal fluid, thereby preventing possible late complications.

What Triggers a Diagnosis of HIV Infection in the Tokyo Metropolitan Area? Implications for Preventing the Spread of HIV Infection in Japan

BACKGROUND

Japan has not succeeded in reducing the annual number of new HIV-infected patients, although the prevalence of HIV infection is low (0.02%).

METHODS

A single-center observational study was conducted at the largest HIV clinic in Tokyo, which treats 15% of the total patients in Japan, to determine the reasons for having diagnostic tests in newly infected individuals. HIV-infected patients who visited our clinic for the first time between 2011 and 2014 were analyzed.

RESULTS

The 598 study patients comprised one-third of the total reported number of new patients in Tokyo during the study period. 76% were Japanese MSM. The reasons for being tested which led to the diagnosis was voluntary testing in 32%, existing diseases in 53% (AIDS-defining diseases in 22%, sexually transmitted infections (STI) in 8%, diseases other than AIDS or STIs in 23%) and routine pre-surgery or on admission screening in 15%. 52% and 74% of the study patients and patients presented with AIDS, respectively, had never been tested. The median CD4 count in patients with history of previous testing (315/μL) was significantly higher than that of patients who had never been tested (203/μL, p<0.001).

CONCLUSIONS

Only 32% of the newly HIV diagnosed patients were diagnosed because of voluntary testing, and 53% were diagnosed due to presence of other diseases. These results remain unchanged from our previous report 10 years earlier (2000-2004) on newly diagnosed patients at the same clinic. HIV testing has not been widely used by newly diagnosed patients in the Tokyo metropolitan area.

Comparison of serological responses to single-dose azithromycin (2 g) versus benzathine penicillin G in the treatment of early syphilis in HIV-infected patients in an area of low prevalence of macrolide-resistant Treponema pallidum infection

OBJECTIVES

Effectiveness of single-dose azithromycin (2 g) in the treatment of early syphilis among HIV-infected patients has rarely been evaluated in the era of combination ART.

METHODS

Consecutive HIV-infected patients with early syphilis, who received 2 g single-dose azithromycin or 2.4 MU benzathine penicillin G, between 2007 and 2014, were prospectively observed. Genotypic resistance to macrolides was determined in Treponema pallidum isolates identified from clinical specimens using PCR assays. Rapid plasma reagin (RPR) titres were determined at baseline and every 3 months after treatment. Primary outcome was a decline of RPR titre by ≥4-fold at 12 months after treatment.

RESULTS

During the study period, 162 HIV-infected patients with early syphilis received benzathine penicillin G and 237 patients received azithromycin. At 12 months follow-up, the serological response rate for penicillin and azithromycin groups was 61.1% and 56.5% (P = 0.41), respectively; respective response rate was 61.1% and 65.9% (P = 0.49) if we only included patients infected with T. pallidum not harbouring macrolide resistance in the azithromycin group. In multivariate analysis, RPR titres ≥1:32 (OR 2.56; 95% CI 1.55-4.21) and prior syphilis (OR 0.54; 95% CI 0.35-0.81) were predictors of serological response. Most common adverse effects of azithromycin included diarrhoea (52.7%), nausea (22.4%), abdominal pain (18.6%), bloating (17.7%) and lassitude/somnolence (27.4%).

CONCLUSIONS

In the setting of a low prevalence of macrolide-resistant T. pallidum, 2 g single-dose azithromycin achieved a similar serological response to benzathine penicillin G in HIV-infected patients with early syphilis. Major adverse effects of azithromycin were gastrointestinal symptoms and lassitude/somnolence.