Congenital Syphilis Evaluation Scenario (CDC 2021)

CDC 2021 congenital syphilis scenario, evaluation, and penicillin dose for a newborn whose mother has reactive syphilis serology.

Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Infant physical exam
Normal
Darkfield or PCR positive
No
Infant nontreponemal titer, the number after 1
4
Maternal nontreponemal titer at delivery, the number after 1
16
Maternal treatment
Penicillin, appropriate for stage, during pregnancy
Date maternal treatment began
2026-08-07
Delivery date
2026-09-01
Maternal evidence of reinfection or relapse
No
Infant weight
3.2

Result: Treatment began 25 days before delivery, under the 30-day cut, so this is Scenario 2: possible congenital syphilis.

The tool opens with these values already filled in. Replace them with your own.

What you enter

  • Infant physical exam
  • Darkfield or PCR positive
  • Infant nontreponemal titer, the number after 1: (0 if nonreactive)
  • Maternal nontreponemal titer at delivery, the number after 1:
  • Maternal treatment
  • Date maternal treatment began (YYYY-MM-DD)
  • Delivery date (YYYY-MM-DD)
  • Maternal evidence of reinfection or relapse
  • Maternal titer low and stable, if treated before pregnancy
  • Infant weight (kg)
How this is calculated

Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021 (CDC), Congenital Syphilis. MMWR Recomm Rep. 2021;70(4):1-187. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.