Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jun 8;10(6):ofad300.
doi: 10.1093/ofid/ofad300. eCollection 2023 Jun.

Comparing 7-Day Versus 6-8-Day Penicillin Treatment Intervals Among Pregnant People With Syphilis of Late or Unknown Duration: No Difference Found in Incidence of Congenital Syphilis

Affiliations

Comparing 7-Day Versus 6-8-Day Penicillin Treatment Intervals Among Pregnant People With Syphilis of Late or Unknown Duration: No Difference Found in Incidence of Congenital Syphilis

Kelly A Johnson et al. Open Forum Infect Dis. .

Abstract

Background: Guidelines recommend that pregnant patients with syphilis of late/unknown duration be treated with benzathine penicillin G, dosed as 3 weekly intramuscular injections (BPGx3) given ideally at strict 7-day intervals. Given limited pharmacokinetic data, it is unknown whether more flexible BPG treatment intervals might be effective in preventing congenital syphilis (CS).

Methods: We used California surveillance data to identify birthing parent/infant dyads wherein the pregnant parent had syphilis of late/unknown duration between January 1, 2016 - June 30, 2019. We divided the dyads into 3 groups based on prenatal treatment: (1) BPGx3 at strict 7-day intervals, (2) BPGx3 at 6-8 day intervals, and (3) no/inadequate treatment. We then compared CS incidence among infants in each group.

Results: We analyzed 1,092 parent/infant dyads: 607 (55.6%) in the 7-day treatment group, 70 (6.4%) in the 6-8 day treatment group, and 415 (38.0%) in the no/inadequate treatment group. The incidence proportion of infants meeting CS criteria in each group was, respectively, 5.6%, 5.7%, and 36.9%. Compared with BPGx3 at 7-day intervals, the odds of CS were 1.0 [95% CI 0.4-3.0] in the 6-8 day group and 9.8 [95% CI 6.6-14.7] in the no/inadequate treatment group.

Conclusions: Prenatal BPGx3 at 6-8 days was no more likely to lead to CS in infants than 7-days. These findings hint that 6-8-day intervals might be adequate to prevent CS among pregnant people with syphilis of late/unknown duration. Consequently, it is possible that CS evaluation beyond an RPR at delivery may be unnecessary in asymptomatic infants whose parents received BPGx3 at 6-8 days.

Keywords: congenital syphilis; sexually transmitted infections (STIs); syphilis in pregnancy; syphilis prevention; syphilis treatment intervals.

PubMed Disclaimer

Conflict of interest statement

Potential conflicts of interest. All authors: no reported conflicts.

Figures

Graphical Abstract
Graphical Abstract
This graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/comparing-7-vs-6-8-day-penicillin-treatment-intervals-among-pregnant-people-with-syphilis-of-late-or-unknown-duration-no-difference-found-in-incidence-of-congenital-syphilis

Similar articles

References

    1. Centers for Disease Control and Prevention . Sexually transmitted disease surveillance 2020. Available at: https://www.cdc.gov/std/statistics/2020/2020-SR-4-10-2023.pdf. Accessed 27 July 2022.
    1. California Department of Public Health STD Control Branch . 2019 STD surveillance report—executive summary. Available at: https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/2019.... Accessed 27 July 2022.
    1. Centers for Disease Control and Prevention . Congenital syphilis—CDC fact sheet. Available at: https://www.cdc.gov/std/syphilis/stdfact-congenital-syphilis.htm. Accessed 27 July 2022.
    1. Plotzker RE, Murphy RD, Stoltey JE. Congenital syphilis prevention: strategies, evidence, and future directions. Sex Transm Dis 2018; 45:S29–37. - PubMed
    1. Galvis AE, Arrieta A. Congenital syphilis: a U.S. Perspective. Children (Basel) 2020; 7:203. - PMC - PubMed