Treatment Completion With Three-Dose Series of Benzathine Penicillin Among People Diagnosed With Late Latent and Unknown Duration Syphilis, Maricopa County, Arizona

Update on syphilis in pregnancy: marrying basic science advances and clinical perseverance to solve an ancient public health problem

PURPOSE OF REVIEW

While the clinical disease of syphilis, its consequences in pregnancy, and its sensitivity to penicillin treatment have remained relatively unchanged for a century or more, new technologies and basic discoveries in syphilis research have translated into tangible advances in clinical diagnosis, treatment, and prevention. The purpose of this review is to help the reader understand some of the recent relevant scientific publications on syphilis and its causative organism in a clinical obstetric context.

RECENT FINDINGS

Rates of adult and congenital syphilis have risen dramatically in the last decade despite public health efforts. Penicillin shortages and lack of screening or adequate treatment have all contributed to global disease burden. Advances in genomic and microbiological characterization of this spirochete have led to new developments in serologic and molecular diagnosis as well as evaluation of potential vaccine candidates. Until a syphilis vaccine is available, substance use disorders and lack of screening in pregnancy are associated with increased congenital syphilis, and these challenges will require novel solutions to fully address this public health crisis.

SUMMARY

Addressing the burden of congenital syphilis demands that obstetricians stay well informed of new tools and resources for diagnosis, treatment, and prevention of syphilis now and in the future.

Could late-latent syphilis be treated with a single subcutaneous infusion of long-acting penicillin?

Syphilis is an important global health threat and little has changed in its treatment since the mid-20th century. For late-latent or syphilis infection of unknown duration, the standard treatment of multiple intramuscular injections of benzathine penicillin G (BPG) are associated with significant pain and distress to clients and caregivers, negatively impacting on treatment completion. Based on pharmacokinetic modelling from a Phase I study of subcutaneous infusion of high dose BPG (SCIP), we present its feasibility, safety and tolerability for treatment of syphilis in a single infusion. SCIP leads to more sustained penicillin concentrations above the desired target with less reported pain and reduced clinic visits.

Access to Benzathine Penicillin G Treatment for Persons With Syphilis, Maricopa County, Arizona, 2021

BACKGROUND

As the incidence of syphilis continues to increase, examining benzathine penicillin G (BPG) treatment data provides valuable insight for public health strategies. This study analyzed the trends of where BPG is administered relative to the initial clinical site of syphilis diagnosis. Our findings are timely in the context of recent national BPG shortages.

METHODS

The analysis included persons diagnosed with any syphilis stage in Maricopa County, Arizona, from January 1, 2021, to December 31, 2021. The Arizona surveillance database (PRISM) was the source of demographic, testing, and treatment data.

RESULTS

Of a total of 4028 persons with syphilis, 3038 (75.4%) received at least 1 injection of BPG. Among persons who received an initial BPG injection, only 1719 (56.6%) were diagnosed and treated at the same clinical site type. The Maricopa County Sexually Transmitted Disease Clinic administered BPG to 48.8% (n = 1483) of persons with syphilis who received an initial injection.

CONCLUSIONS

Our findings analyze trends in BPG administration that are likely due to treatment referral practices and medication cost. Administration of BPG is not guaranteed at the clinical site of diagnosis, highlighting concerns regarding access to BPG. A burden is placed on patients who are required to leave their diagnosing provider to seek syphilis treatment at other health facilities that administer BPG.

Risk factors for treatment non-completion among patients with syphilis

Background

With recent increases in syphilis, there is growing interest in expanding screening; however, treatment rates have historically been low.

Objectives

This study examines demographic and clinical factors that may contribute to non-completion of syphilis treatment.

Design

This is a retrospective comparative cohort study of all patients with syphilis from January through November 2018 at an urban, tertiary care hospital.

Methods

Demographics and clinical information were extracted from the electronic medical record. Descriptive statistics and odds ratios (ORs) were calculated.

Results

Of 171 patients with syphilis, 89 (52.0%) completed treatment. Patients ages 40-49 were least likely to complete treatment (OR 0.14; 95% CI 0.03-0.72, p = 0.02) compared to those ages 18-24. Non-heterosexual patients were significantly more likely to complete treatment (OR 3.60; 95% CI 1.13-11.49, p = 0.03) compared to heterosexual patients. Patients diagnosed in the emergency department completed treatment at the lowest rate.

Conclusion

A major gap in syphilis treatment still exists, which must be addressed to achieve optimal impact from syphilis screening programs.

Vital Signs: Missed Opportunities for Preventing Congenital Syphilis - United States, 2022

Introduction

Congenital syphilis cases in the United States increased 755% during 2012-2021. Syphilis during pregnancy can lead to stillbirth, miscarriage, infant death, and maternal and infant morbidity; these outcomes can be prevented through appropriate screening and treatment.

Methods

A cascading framework was used to identify and classify missed opportunities to prevent congenital syphilis among cases reported to CDC in 2022 through the National Notifiable Diseases Surveillance System. Data on testing and treatment during pregnancy and clinical manifestations present in the newborn were used to identify missed opportunities to prevent congenital syphilis.

Results

In 2022, a total of 3,761 cases of congenital syphilis in the United States were reported to CDC, including 231 (6%) stillbirths and 51 (1%) infant deaths. Lack of timely testing and adequate treatment during pregnancy contributed to 88% of cases of congenital syphilis. Testing and treatment gaps were present in the majority of cases across all races, ethnicities, and U.S. Census Bureau regions.

Conclusions and implications for public health practice

Addressing missed opportunities for prevention, primarily timely testing and appropriate treatment of syphilis during pregnancy, is important for reversing congenital syphilis trends in the United States. Implementing tailored strategies addressing missed opportunities at the local and national levels could substantially reduce congenital syphilis.