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

Abstract

Background: Syphilis is a public health concern as cases are rising each year. If untreated, syphilis is associated with significant morbidity and risk of vertical transmission during pregnancy. For people with late latent and unknown duration stages, 3 injections of benzathine penicillin G (BPG) at 1-week intervals are recommended. Our study quantified treatment for people diagnosed with late latent and unknown duration syphilis in Maricopa County, Arizona with a secondary analysis of pregnant women to assess completion of 3 injections of BPG in multiple time intervals.Methods: Maricopa County syphilis case data were extracted from the state-run database (PRISM). Records were reviewed for people with late latent and unknown duration syphilis during January 1, 2016, to December 31, 2021. Treatment types and time intervals between treatments were analyzed.Results: Of a total of 14,924 people with syphilis reported in Maricopa County, 5372 (36.0%) were staged as late latent or unknown duration syphilis. Completion of 3 BPG injections in the time frame of 7 to 9 days was 42.9% (n = 2302). Completion among pregnant women (n = 406) with 3 injections was 68.7% (n = 279). Conclusions:The completion rate of 3 BPG injections for people with late latent or unknown duration syphilis is low. An unmet need exists to identify barriers to treatment including access to BPG and public health follow-up after the first injection. Prioritized effort is needed to identify and classify patients as having earlier stages of syphilis that require only 1 BPG injection.

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

“…[6][7][8] The Maricopa County Department of Public Health qualifies for 340B pricing and operates the only publicly funded sexually transmitted disease (STD) clinic in the county, making it a referral center for STD treatment. 9,10 Few private clinics in Maricopa County stock BPG forcing patients to seek alternative clinics for treatment. Time to BPG administration can vary by diagnosing location, with STD clinics more reliably providing timely treatment.…”

“…Differences in syphilis diagnosis and treatment site likely influence a patient's treatment completion. 9,15 Administration of BPG primarily occurs at fewer sites with the STD clinic, correctional facilities, and hospitals collectively responsible for nearly 80% of initial BPG injections. Aside from the STD clinic, BPG seems concentrated to sites that serve "eligible" patient populations that qualify to receive care at the institutions.…”

“…[17][18][19] The trends in BPG administration among pregnant women reflect public health CDI efforts to bring women to treatment and frequent health care touchpoints during prenatal visits. 9 However, referral to the STD clinic could result in delays in treatment. BPG administration for pregnant patients at their diagnosing provider's office, or potentially at home, could prevent delays or missed treatment in pregnancy and congenital syphilis cases.…”

“…We hypothesize that most patients receiving alternative treatment do not have a penicillin allergy and are instead given a multiday alternative oral regimen of doxycycline because of the lack of BPG access, which raises concerns regarding treatment compliance. Differences in syphilis diagnosis and treatment site likely influence a patient's treatment completion 9,15 …”

“…In contrast, medical institutions that qualify for discounted drug pricing under the Health Resources & Services Administration 340B Drug Pricing Program can obtain BPG for $0.20 per dose 6–8 . The Maricopa County Department of Public Health qualifies for 340B pricing and operates the only publicly funded sexually transmitted disease (STD) clinic in the county, making it a referral center for STD treatment 9,10 . Few private clinics in Maricopa County stock BPG forcing patients to seek alternative clinics for treatment.…”